Regional anatomy

Two regions:

1. Pre-axial region = Radial side of the limb (lateral)

2. Post-axial region = ulna side (medial)

3. Ventral axial line - separates tissues of arm and forarm into embryological regions of limb

Shoulder > arm > forarm > wrist > hand

Joints - Sternoclavicular joint (Girdle), Gleno-humeral Joint (Girdle), Elbow joint, Wrist Joints, Joints of the hand

Two musculo-fascial compartments

• each has its own muscles, blood supply, venous drain, nerve innervation and lymphatics

The groove is between anterior and middle scalene muscle

• the roots of brachial plexus lie in relation to the scalene muscles

• Nerve root value of brachial plexus are C5 to T1

• Clinical significance is to be able to temporarily block all sensation arising from the upper limb by anaesthetising roots of brachial plexus.

  • Needle inserted halfway between lateral border of sternocleidomastoid muscle and anterior border of trapezius muscle.

Sternoclavicular joint

• Formed by articulation of medial aspect of clavicle with manubrium of sternum

• Classified as plane style synovial joint and has fibrocartilage joint disc

• One of the 4 joints that compose the shoulder complex (pectoral girdle)

Clavicle extends from manubrium of the sternum to acromion

• Its sternal (or medial) end is triangular & articulates with the Sternum at the Sternoclavicular joint

• Its acromial (or lateral) end is flattened & articulates with the Acromion of the Scapula at the acromioclavicular joint

Sternocleidomastoid muscle pulls the medial 2/3 of the clavicle upwards (convex anteriorly) while the trapezius muslce pulls the lateral piece medially (concave anteriorly) .

Axilla is the anatomical space of the armpit (under where arm connects shoulder). It is a pyramid shape, has 4 sides, apex and base.

Axillary sheath - Brachial plexus, axillary artery, axillary vein

Axillary lymph nodes

• Part of axial skeleton

• Acts as a site of attachment of lower limbs > enables locomotion

• Supports vertebral column, spinal cord and attendant CSF

• Suppors upright posture when standing

• In upright position, supports carrying of weight of head, neck, thorax, upper limbs and trunk

• Site for pregnancy

• Houses important viscera - pelvic viscera proper, viscera of abdomen.

PID, UTI, pregnancy, urinary / faecal incontinence, childbirth

• shared - bones

• Female has wider (rounder) pelvic brim, male ha heart shaped.

• Male has acute (triangular) pubic arch, female is slightly rounded (pic)

Urinary system

Lower GI tract

Reproductive system

Parturition (female)

Pelvic floor (pelvic diaphragm)

Musculature of proximal lower limb

• Greater Pelvis (or False Pelvis)

• Pelvic Brim

  • Also known as the Pelvic Inlet

  • True Pelvis (vs Lesser Pelvis)

• Outlet

  • Pelvic Floor

  • Interaction between the Pelvic Floor & Viscera of

    the Urinary Tract & Reproductive Tract

Formed of 3 main bones;

• 2 pelvic bones - left and right, joined anteriorly by pubic symphysis

• 1 sacrum & coccyx - form middle of the posterior border

Direct landmarks

• Supracristal plan (top black line) - L4/L5, safe site for LP

• Anterior superior iliac spine - site for inguinal ligament attachment, used in measurement of limb length

• Anterior inferior iliac spine (top dot)

• posterior superior iliac spine (bottom dot)

• pubic crest (bottom line) - site for suprapubic puncture of urinary bladder

Indirect landmarks

• Greater trochanter - hip joint

Composed of union of 3 bones - the bones unite to form the acetabulum.

They unite by ossification of tri-radiate cartilage of acetabulum.

• Ilium (forms most of the superior part)

• Ischium (forms most of the Posterior portion)

• Pubis (forms most of the anterior portion)

• forms the lowermost aspect of vertebral column

• Fomed from fusion of 5 sacral bones (S1 to S5)

• Form the sacral curvatures of the vertebral column

• Articulates with hip bones via 2 articular surfaces

• The holes are sacral foramen where spinal nerves comes through

• Forms the final segment of the vertebral column

• Formed by process of secondary neurilation

• Composed from the union of 4 coccygeal bones

• Greater (false) pelvis

• Lesse (true) pelvis

• anterior wall

• posterior wall

• 2 lateral walls (L + R)

• Inferior wall (pelvic floor)

• its the continuation of the pelvic body wall

• Major site of attachments of pelvic organs - uterus

• Site of attachments of muscles that move the lower limb - esp thigh

• important anatomical features includes - pelvic bone, ligaments of pelvis, msucles, peritoneum, fascia, anatomical spaces

• Hip bone

• Ligaments - Sacrospinous and sacrotuberous

• Obturator membrane

• anatomical spaces - obtrurator foramen (anteriorly), greater sciatic foramen, lesser sciatic foraemen (posteriorly)

There are a number of palpable bony landmarks of significance

• Iliac crest

• Anterior superior iliac spine (ASIS)

• Pubic tubercle

• Greater Trochanter

• Medial / inferior edge of the patella

• Tibial tuberosity

• Medial malleolus (tibia)

• Lateral malleolus (fibula)

• Navicular

Iliac crest left and right

• they mark the highest anatomical points of LL

• Imaginary line between the two iliac crest > anatomical plan known as supracristal plane (Tuffier’s line)

• Horizonal plan between R and L iliac crest

• Occurs around level of L4 (L3/4 intervertebral disc)

• landmark for:

  • Bifurcation of descending aorta into left and right common iliac arteries

  • safe area for LP, epidural anaesthesia and determining site for aspiration of bone marrow.

-> Neck connets the head of femur to shaft. Usually 120-135C

-> Angle <120c = coxa vara > knock knees

-> Angle >135c = coxa valga > bow legs

• Intracapsular – fracture occurs proximally to the site of attachment of the joint capsule to the femur = within the joint capsule.

• Extracapsular – fracture occurs distal to the attachment of the joint capsule. A fracture below the lesser trochanter is known as subtrochanteric. If it is superior to the lesser trochanter, but extracapsular, the fracture is trochanteric.

Anterior superior iliac spine (ASIS)

• prominence of the ilium - located onthe superior, anterior margin of the pelvis.

McBurney’s point

• On the right side of the abdomen, 1/3 of the distance from ASIS to the umbilicus - corresponds to the location of appendix.

• Used to assess palpation in suspected appendicitis and used for surgery such as appendicetomy

Inguinal ligament is a fibrous inferior border of the anterior abdominal wall. It attach to ASIS (supero-laterally) and pubic tubercle (infero-medially).

• Defines the border between abdomen and lower limb

• anatomical structures that pass (deep):

  • Femoral canal containing lymphatics

  • femoral sheath - fascia which encloses femoral artery and veins

  • femoral nerve/artery /vein (lateral to medial)

  • lateral cutaneous nerve of the thigh

  • psoas major/ iliacus / pectineus muscles (floor of the femoral triangle)

Inguinal canal

• runs directly superior and parallel to the inguinal ligament = runs inferior and medial through inferior part of abdominal wall.

• Canal starts at the deep inguinal ring and ends at the superficial inguinal ring.

• Structures that pass through:

  • Male - spermatic cord and testicular artery

  • female - round ligament of the uterus

  • both - ilio-inguinal nerve and genital branch of genitofemoral nerve

-> Lateral cutaneous nerve of the thigh pass deep into the inguinal ligament.

-> It can be compressed by inguinal ligament > painful numbness of the upper part of the thigh

Femoral hernia

• herinated peritonieal sac protrude through fermoral ring > femoral canal

• This is because the femoral sheath is only closed by extraperitoneal tissue > site of weakness

Inguinal hernia - can be direct or indirect

• Direct - protrude through posterior wall of the inguinal canal

• Indirect - protrude through deep inguinal ring

• It is a lateral bony prominence of LL

• Detects ant changes in direction of the neck of femur relative to the shaft

• indirect landmark for position of the hip joint, capsule and extracapsular ligaments of hip joint.

Most hip dislocations are posterior (90%). This is due to the posterior (ischiofemoral) ligament being the weakest of the 3 ligaments of the joint.

The clinical presentation of a posterior hip dislocation includes:

• Shortened appearance of the affected lower limb

• Flexed position and Internal rotation of limb

Can occur as a result of motor vehicle collision where the hip joint is flexed

Medial malleolus of tibia

lateral malleolus of fibula

• The greater saphenous vein ascends anterior to medial malleoulus

• posterior tibial pulse of posterior tibial artery palpable in tarsal tunnel. it runs posteriorly and inferiorly to medial malleolus.

-> Pott’s # = # of leteral or medial malleolus, as a result of severe angle sprain > tenderness on palpation

Tibial tuberosity - inferior border of the patella

• between these bony landmark is where patella tendon is located.

• strike of the tendon > knee jerk reflex

‘Apparent’ = one limb appears shorter than other, not necessarily short. Distance from umiblicus to medial malleolus

• Posterior dislocation of hip joint in ‘shorter’ limb.

• Congenital cause of hip dislocation in ‘shorter’ limb.

• Hip tilting, for example due to scoliosis.

‘True’ = The limb is actually shorter in distance between ASIS (hip) and medial malleolus (tibia)

• Congenitally shorter LL compared to the other limb.

• Fracture of one or more of the long bones of the shorter limb, leading to overlap in the bone fragments.

• Skeletal growth disorders.

• Scoliosis.

True limb length

• Measure the distance of the right and left limbs between anterior superior iliac spine (proximally) and medial malleolus of tibia (distally)

• If the length between R + L not same = true limb length discrepancy

Apparent limb length

• Measures the distance of R and L between umbilicus (proximally) and medial malleolus (distally)

• If the length between R+L not same = aparent limb length discrepancy

Examination:

• Patient lie down supine on their back then elevate the leg straight individually.

• Aims to stretch the sciatic nerve directly - if the nerve is pinched by slipped IV dic > stress > pain

• if stretched within CNS > pull and irritation of spinal meninges in neck > Meningism = Sign of Kernig

Indication:

• Sciatica (lumbar rediculopathy) - spinal roots of sciatic nerve are damaged or injured

• Lumbar slipped disc or herniation

• Inflammed meninges of the spinal cord (meningism)

-> Stiffness of the neck knowns as nuchal rigidity is tested by stretching or raising the neck of a patient in supine position

-> If this stretch result in flexion of the hip and knee = +ve sign for meningism

• Superior = inferior border of diaphragm

• Anterior = abdminal muscles and anterior bony pelvis

• posterior = Ribs, vertebral column, sacrum

• Inferior = pelvic floor & perineum

• Lateral = Ribs (superolateral), thigh (infero-lateral)

They all are built from set of specialised standard tissues:

• Skin, superficial and deep connective tissue, membranes that cover and seperate the organs, skeletal muscles, arteries, veins, lymphatics, LN, nerves and blood cells.

Some regions will contain specialised tissues and organs:

e.g abdominal region - liver, kidney, pancreas, heart, lung, muscles, bones, joints, special sense organs

The Upper Limb (neural level)

• Supplied by the brachial plexus of nerves.

• The Spinal Neural Root values of the brachial plexus are C5 to Tl - (not be confused with vertebral levels)

The Lower Limb (neural level)

• Supplied by a combination of 2 nerve plexuses —> Lumbar Plexus and Sacral Plexus

• Neural Root values of the Lumbar plexus L2 to L4 (half)

• Neural Root values of the Sacral Plexus L4 (half) to S4

Defined as ‘Continuous area or expanse which is free, available, or unoccupied’ e.g oral cavity, nasal cavity.

There are 2 classes of anatomical spaces:

• True anatomical space - Occurs normally, demostrable

• Potential space - Do not exist normally, created as a result of pathological development e.g blister, hepato-renal or Pouch of Morrison.

• AS are site of normal / abdnormal collections:

  • gases, blood, pus, oedema, fat, liquids, calcified LN

• Varients of AS - Rectouterine pouch / puch of Douglas

Cavity

• Defined as empty space within a solid object e.g Thoracic, abdominal, pelvic cavities

• Space with defined boundaries, shape, contents, point of entry and exit

Compartment

• separate section / sub-section within a cavity

• Have defined boundaries with connective tissues, independnet, self-sufficient units.

-> Skin

-> Superficial fascia - binds skin to the tissues of the body

-> Deep fascia - Encloses organs, divides muscles into compartments (investing and intermediate layer)

-> Muscles

-> Deepest layer of deep fascia

After the deep fascia, there are 3 layers of muscles lining body wall:

> Abdominal wall: external oblique -> internal oblique -> transversus abdominis

> Thoracic wall: external intercostal -> internal intercostal -> innermost intercostal

> Ribcage: External intercostal -> internal intercostal -> innermost intercostal

> Heart: fibrous pericardium -> parietal serous pericardium -> visceral serous pericardium (aka. epicardium) -> myocardium -> endocardium

Nerves (out-in)

• Epineurium - ensheathes entire nerve

• Perineurium - ensheathes nerve fascicle (collection of axons)

• Endoneurium - ensheathes single axon

Muscles (out - in)

• Individual muscles (multiple fascicles) are enclosed by the epimysium.

• Bundles (fascicles) enclosed by perimysium

• Individual fibres enclosed by endomysium

• Largest sensory organ, part of integumentary system

• Consits of connective and epithelial tissues

Functions:

• Protection e.g. from water loss, Insulation, Temperature regulation, UV, 1st line immune defence

• Metabolic - synthesis of vitamin D, protects Vit B and folate

• Sensation, Signalling

Lack of skin > infection, abrasion, radiation, dehydration and loss of nutrients

Macroscopic

• 2 types - hairy and glaborous (palms / sole)

Microscopic

• Epidermis - Epithelial layer of skin

• Dermis (skin proper) - Superficial connective tissue layer

• Hypodermis/subcutis - Deep connective tissue layer

• Stratum Corneum – top most layer, doesn’t have nucleus / nutrient supply, made of corneocytes (dead keratin)

• Stratum Lucidum - only in thick skin

• Stratum Granulosum - Here keratinocytes produce granules containing enzymes that dissolve phospholipid bilayer

• Stratum Spinosum – has keratinocytes > synthesis keratins > strength of epidermis

• Stratum Basale - Cells here divide and multiply to give rise to more skin cells, where the keratinocyte mitotic activity occurs.

Melanocytes

• found in basal layer, produce melanin > skin pigmentation

Langerhans cells

• Found in S. spinosum, mediates immune reaction (e.g allergic contact dermatitis), present Ag to WBC

Merkel cells

• Oval shaped mechanoreceptor for light touch sensation (e.g in finger tips)

-> Have papillary and reticular layers

-> Tough, fibrous and vascular connective tissue

-> Mostly made of ECM - colagen (T1), elastin

-> Spindle shaped fibroblasts are scattered throughout - produce matrix and fibres

-> Has blood vessels, lymphatics, mast cells and nerves

-> Body consists of 4 basic tissues arranged into layers:

• Skin > superficial fascia > deep fascia > muscles > neurovasculature > visceral organs

-> Fascia = Part of CT that holds substances of body together.

e.g Skin is tethered to body by superficial fascia (contains CT, fat + blood vessels) > fluidity of movements.

Note: superficial fascial plane of thorax is unusual and has additional contents not seen elsewhere - platysma muscle and mammary gland of male and female.

-> Retro-mammary space or sub-mammary space - lymphatics of mammary runs here

-> Mammary gland is invested with loose CT > allows breast tissue development and movement.

-> the gland is NOT attached to deep fascia of the anterior chest wall

-> Lines of cleavages in the skin - its tethered to the body through pre-determined lines of tension.

-> Incisions along this lines > optimal healing with less scarring.

-> If not followed this line > keloid scars

1. Hair follicles

2. Sebaceous glands (secretes fat into hair shaft)

3. Sweat glands (eccrine, apocrine)

4. Nails

1 & 2 forms Pilosebaceous unit

-> Large sweat gland, most abdundant in axillae, genital and submammary areas

-> ducts open into hair follicles, produce odourless, protein-rich secretions which get digested by cutanous microbes > body odour.

• Psoriasis: abnormal epidermal growth and differentiation > hyperproliferation of basal layer > gross thickening > excess S. cornum cells

• Allergic contact dermatitis: mediated by Langerhans cells & T lymphocytes

• Malignant melanoma: malignant growth of melanocytes

• Vitiligo: Autoimmune destruction of melanocytes > symmetrical localised skin depigmentation.

‘Port wine stain’ (dermis) - congenital malformation of dermal blood vessels.

• Mast cells are cytoplasmic granules containing histamines, they are distributed around dermal blood vessels

• Activated in T1 immediate hypersensitive allergic reaction > histamine release > increased vascular permeability > leakage of plasma > urticaria and angioedema

• Attachement site for muscles

• Has joints which allows muscles to produce movements

• Protects internal organs

• Reservoir of minerals (Ca2+, PO4+)

• Harbours bone marrow - Red marrow contains haematopoietic SC (abdundant in children), yellow marrow contains adipose tissue & SC (replaces red BM in adult)

Bone

• Hard, not flexible, highly vascularised (bleeds when #)

• Forms body framework > shape e.g. height, facial features

Ligaments

• Dese regular CT, less vascularised = slow to heal

• Provides joint stability

Cartilages

• Soft, elastic, avascular = longest to heal

• Roles: shock absorption, reduce friction by lining joint surfaces

Axial

• Skull, sternum, ribs, vertebral column, sacrum

Appendicular

• Upper limb (pectoral girdle), lower limb (pelvic girdle)

• Consists of 33 vertebrae > subdivided 7 cervical, 12 thoracic, 5 lumbar, 5 fused sacrum, 3-4 fused coccygeal verterbrae.

  • Joints between vertebrae occupied by intervertebral discs

• Function - Encloses & protects spinal cord, carries body weight above pelvis, permits extension / flexion / rotation.

12 ribs - attach to the thoracic vertebral column posteriorly and to sternum anteriorly by via costal cartilage

• Ribs 1-7 = true ribs - directly attach to sternum via costal cartilage

• Ribs 8-10 = false ribs, indirectly attach to sternum

• Ribs 11 and 12 = floating ribs, don’t attach to sternum

• Creates boundaries of the thoracic cavity with vertebral column and sternum

Consits of 3 bones

1. Manubrium - provides attachement for clavicles and costal cartilages 1-2

2. Sternal body - attachement for costal cartilages 2-7

3. Xiphoid process - attachment of muscles

1. Intramembranous ossification - direct bone formation from precursor cells, forms skull cap and clavicle

2. Endochondral ossification - cartilages formed during embryogenesis serves as template which later convert to bone, forms rest of the human skeleton

Some bones are fully formed in embryo, develops / fuse as human ages. New borns have lots of cartilages & gaps in bones

• Bone is capable of repair - - # > haematoma > soft callus > bony callus > healed #.

• #must be stabilised using reduction / cast - without proper reduction, displaced ends of bone may misalign > malunion

  • Lead to reduced mobility, pain, nerve/tendon issues

• Fibrocartilage - shock absorption e.g. intervertebral discs

• Elastic cartilage - e.g. ear

• Hyaline cartilage - growth plates, found in joints, stopping friction, permits movement

  • wear & tear > break down of cartilage > OA

Tendons attach bone to muscles, ligaments attach bone-bone

Stability vs mobility - shoulder joint is more mobile than hip joint but is less stable = more likley to dislocate

2 largest anatomical spaces are created from embryonic fluid-filled cavity lined with thin membranous lining

• Coelomic cavity

Visceral organs form wihtin the coelom are able to move, grow and develop independently of body wall.

-> Bone is a living tissue that forms the skeleton of the body. Constitues from CT and made from cells, fibres and matrix.

Occurs in 2 forms:

• Compact bone - solid mass of compacted dense CT

• Cancellous bone - branching network of trabeculated dense CT.

-> Classifications

• Fat - strongest, protective, trilaminar (compact-trabecular-compact) e.g skull, sternum

• Short

• Long - longer than wider, 2 surfaces (outer & inner lines the marrow cavity) lined by periosteum & endosteum.

• Sesamoid

• Irregular

• Periosteum (peri=long, osteum = bone) - lines the outer surface

  • Has 2 layers - fibrous outer & cellular inner layers

  • Importance - have stem cells that generate bone cells (osteoblasts) which interacts with osteocytes & osteoclasts for homeostasis of the bone, mineral & Ca2+ storage.

  • Rich in blood supply that nourishes & maintain bone health, repairs #. Also has rich sensory nerve supply

• Endosteum - inner surface lining / marrow cavity

• Cartilage also covered by soft tissue like that of bone

• Called Perichondrium - it supports cartilages like periosteum supports bones.

• Has 2 layers - fibrous outer (maintained by fibroblats) and cellular inner (chondrogenic layer).

• They are surfaces of bones onto which muscles, tendons, ligaments and soft tissues attach. They can be sites for pathologies

-> Sinuses are cavities within bones of the head - open into nasal cavity.

-> Helps to drain mucus & keep pathogens away

-> lined by 2 layers of soft tissues:

• Periosteum

• Secretory epithelium -> Ciliated pseudostratified columnar epithelium with goblet cells! - Its a continuous thin membrane > route to infection from one to another sinus

• Somatic sensory (afferent) innervation – general sensation

  • From sensory division of the trigeminal nerve

  • Pain, temperature, irritation

• Autonomic parasympathetic innervation – for secretion

  • From efferent division of autonomic nervous system

  • Increases secretions from nasal cavity & paranasal sinuses

  • Derived from autonomic division of cranial nerve VII

• Meninges divides the intracranial compartment into sub-compartments

  • The two main ones are: Supra tentorial compartment and Infra-tentorial compartment

• Hepato-renal pouch of Rutherford Morrison

• Recto-uterine pouch of Douglas (in female pelvis)

  • Pouch between rectum and uterus

• Recto-vesical pouch (only in male pelvis)

• Coronary ligament

• Greater omentum

• Lesser omentum

• Houses lungs, heart, great vessels

• Musculatures inflate & deflate the lungs

• Site for passage of major viscera between pharyx & abdo

• Site for attachment of upper limb to axial skeleton

• Important clinical procedures - chest compression, HS, percussion of lungs, BS, CXR

-> Part of the trunk that extends from root of the neck to abdo

Boundaries are:

-> Superior - thoracic inlet (superior thoracic aperture)

-> Inferior - Thoracic diaphragm

-> Antero-latero-posterior - ribs & costal cartilages

-> anterior - Manubrium, sternum, xiphoid process

-> Posterior - thoracic vertebrae & scapula

Margins:

- Body of first thoracic vertebra (T1)

– 1st ribs and their cartilages

– Manubrium of the sternum

– Suprasternal Notch

Contents:

- Apices of R & L lung

- brachiocephalic, subclavian arteries & veins

- trachea, oesophagus

- Vagus nerve, sympathetic trunk, phrenic nerve

The chest wall has 10 layers of tissues, namely (superficial to deep):

– Skin

– Superficial Fascia

- Mammary gland

– Pectoral Fascia (superficial)

– Pectoralis Major Muscle (or latissimus dorsi or serratus ant)

– Clavipectoral Fascia

– Pectoralis Minor Muscle

– External Intercostal Muscle

– Internal Intercostal Muscle & Ribs

– Innermost Muscle (Limited coverage)

- Endothoracic fascia (deep)

3 layers - all are part of deep fascia of the thorax

• Superficial pectoral fascia (= fascia pectoralis)

  • covers outer surface of pectoralis major muscle

  • seperates thoracic piece of this muscle from breast

• Deep pectoral fascia (clavipectoral fascia)

  • Seprates pec major from pectoralis minor muscle

  • At the top fuses with clavicle & coracoid process, goes onto form fascia of axilla.

• Endothoracic fascia

  • Loose CT deep to intercostal spaces & rubs

  • Separates the internal thoracic wall from the pleura

  • Forms outermost membrane of the thoracic cavity

Typical rib (3-9)

• Have a head with 2 facets, neck, tubercle (facet), angle, costal groove and proximal end (costal cartilage)

Atypical ribs

• 1st rib - broad, flat, shortest & groove for subclavian vessel

• 2nd rib - bifid anteriorly

• 10th-12th rib - shorter, no tubercle or angle or neck (11,12)

• 1st Rib > sternum (manubrium) - fibrous joint, no movement

• Ribs 2-7 (true ribs) - synovial gliding joint

• Ribs 8-10 (false ) - articulates with costal cartilage of rib 7

• 11-12th ribs - floating

Posterior joints:

Musclces of the thoracic regions are divided into 2:

• Muscles that attach the upper limb to axial skeleton

  • e.g Pec major, pec minor, serratus ant

• Muscles of inspiration

  • External, internal, innermost IC

• Neurovascular bundle of intercostal muscles runs on the inferior aspect of the ribs, under the cover of sub-costal groove.

• Procedure e.g aspiration must be carried out on upper surface of the rib to avoid damage.

• Rigid yet mobile, movement comes largely from contraction of the intercostal muscles and diaphragm.

• Midline bony structures -> Manubrium, Sternal body, Xiphoid process, Vertebral column

• And the bilateral bony assemblies - Ribs, Costal cartilages 

• Boundaries: Superior (thoracic inlet, 1st rib, clavicle), anterior (manubrium, sternum, xiphoid), posterior (T1-T12 verterbral column), antero-lateral (ribs & cartilages), inferior (diaphragm)

The major viscera of this region are 2 lungs & heart

3 compartments:

1. Left pulmonary cavity (L to mediastinum) - L lung

2. Mediastinum (centre of the thoracic cavity) - fibrous pericardium (defines the boundaries of mediastinum)

3. Right pulmonary cavity (R to mediastinum) - R lung

-> Thorax has 2 pulmonary cavities, seperated by mediastinum (fibrous pericardium) - are true anatomical spaces

-> Each cavities are occupied by their respective lungs with opening on its medial surface (hilum) - attached to trachea by respective bronchus and connect to heart by pulmonary vessels

-> Each lung is divided into lobules by fissures:

• The right lung is divided into upper, middle and lower lobules (3 in total), by the oblique and horizontal fissures

• The left lung is divided into upper and lower lobules (2 in total), by an oblique fissure

-> They are further divided into segments - each lungs have 10 bronchopulmonary segments.

-> Gross boundaries - Medial (fibrous pericardium), lateral (parietal pleura)

The internal walls of the cavities are lined by a single continuous epithelium that covers the body wall and then lines the outer surfaces of the lung = parietal pleura change direction to become visceral pleura > creating potential anatomical space.

• Epithelial lining of the body wall = parietal pleura (outside)

• Epithelial lining of the lung (or viscera) = visceral pleura (inside)

• Continuations of the same epithelium – classified as simple squamous epithelium

• They have different innervations from the nervous system

• These two layers 'double up' on one another and form a potential anatomical space, the pleural cavity

• Endothoracic fascia (part of body wall)

• Parietal pleura

• Pleural cavity (filled with pleural fluid)

• Visceral pleura

• Outer surface of the lung

• Parenchyma of the lung (alveoli)

Note: due to surface tension, the pleural fluid makes the pleural cavity a space of -ve pressure > keep lungs open. Infections that compress the pleural cavity > lung collapse, those that can dry the fluid > friction when lung moves.

-> Mediastinum is the central compartment of the chest

-> Further divided by imaginary oblique line joining manubriosternal joint and T4/5 intervertebral disc (sternal angle of louis) into:

• Superior and Inferior mediastinum

-> The inferior mediastinum is divided further by pericardial sac:

• Anterior inferior mediastinum – contains thymus in children

• Middle inferior mediastinum – contains heart &great vessels

• The posterior inferior mediastinum – descending aorta, IVC

• Fibrous pericardium

• Parietal layers of serous pericardium

• Pericardial cavity – filled with serous fluid

• Visceral layer of serous pericardium –known as epicardium

• Myocardium – variable thickness depending on chambers of the heart

• Endocardium

-> Pericardial sac is double walled, contains heart & vessels

-> The outermost layer is the fibrous pericardium

-> The innermost layer is the serous pericardium

• Further divided into the parietal pericardium and visceral pericardium, between these is the pericardial cavity.

-> Pericardial cavity is derived along the same line as pleural cavity

-> Space between fibrous & parietal layer is site for potential space where cardiac tamponade can occur

-> Lines of reflection (where pleura changes direction) between visceral & parietal layers of serous pericardium forms 2 sinuses:

1. Transverse pericardial sinus - Lies anterior to SVC, posterior to ascending aorta & pulmonary trunk

2. Oblique pericardial sinus - is a cul-de-sac reflection of serous pericardium lining the venous structures, lies posterior to heart in pericardial sac.

There are 3 natural perforations of diaphragm:

• Caval hiatus (T8) = IVC & R phrenic nerve pass through

• Oesophageal hiatus (T10) = oesophagus, branch of L gastric vessel & vagus nerve

• Aortic hiatus (T12) = aorta, azygous vein & thoracic duct

-> A shallow depression found between deltoid and pectoralis major muscle on the front of the shoulder

-> Runs vertically from just below clavicle towards upper arm, ends superiorly in a triangular notch > deltopectoral triangle

• Landmark where cephalic vein passess and coracoid process can be palpable

• Deltopectoral triangle -> Surgical access for humerus & shoulder procedures or PPM insertion

-> Axillary vein

• Its the segment between subclavian & brachial vein

• An extra thoracic structure, lies anterior wall of axilla and deep to pectoralis major muscle

-> Subclavian vein

• Found medial to 1st rib, intrathoracic structure

• Upper limb drain into axillary vein > subclavian vein > thoracic inlet

-> Cephalic vein

• Drains superficial lateral UL, lies within lateral deltopectoral triangle > axillary vein

Sensory supply is by group of 3 cutaneous nerves:

• Supra-clavicular nerve of cervical plexus

• Lateral cutaneous nerve from intercostal nerves

• Anterior cutaneous nerve from intercostal nerves

-> It is a potential SC space created surgically below clavicle

• Parallel incision 2 finger breadths below mid clavicle or curved incision over the deltopectoral groove along Langer’s line

-> Often created within pectoral region

-> Boundaries:

• Roof -> Skin, superficial fascia & superficial layers of deep fascia, cephalic vein

• Floor -> Pectoral fascia (covers pec major muscle)

-> Can be prepectoral (superficial to pec major muscle) or subpectoral (deep to pec Major) or dual plane (combination of both).

-> Its a collection of air in the pleural space

-> Managed by chest drain inserted in the safe triangle. The boundaries are:

• Laterally – latissimus dorsi muscles

• Medially - Pectoralis major

• Superiorly – base of axilla

• Inferiorly – Horizontal plane of nipple (5th IC space mid-axillary line)

• 5th IC space, mid axillary line

• Needle over the rib to avoid damage to IC nerve/vessel

• Safety triangle landmark, which includes the lateral edge of the latissimus dorsi muscle, the lateral border of the pectoralis major muscle, and the horizontal level of the fifth intercostal space.

-> Abdominal wall boundaries

• Superiorly - Diaphragm, costal margin

• inferior - pelvic brim

• Posteriorly - gluteal fold

• Anterior - Inguinal folds

• Laterally - axillary folds

-> Importance

• Largest anatmical space, continues as pelvic cavity

• Houses digestive organs, urinary system, large no of LN, foreign DNA from gut bacteria, pregnancy

• Site for passage of blood vessels between thorax & LL

• Clinical procedures & imaging

Transpyloric plane, trans-tubercular plane, mid-clavicular line

-> Transpyloric plane: L1 vertebral level

• passes through pylorus of the stomach.

• Also known as Addison’s plane.

• It is midway between jugular notch of sternum & pubic symphysis or between xiphoid process & umbilicus

-> Important surgical landmak

-> Midpoint of imaginary line between anterior superior iliac spine and pubic symphysis

-> Position where external iliac artery leaves the abdomen > femoral artery

-> Where femoral pulse is palpable

-> Deep inguinal ring is lateral to it

Note: It is NOT the midpoint of inguinal ligament

McBurney’s point

• On the right side of abdomen - 1/3 of the distance from ASIS to umbilicus (spino-umbilical line)

• Tenderness ++ during examination = appedicitis

• Skin

• Superficial fascia (camper fascia)

• Deep fascia (scarpa fascia)

• Abdominal muscles (external oblique, internal oblique, transverse abdominis) with their corresponding investing (deep) fascia (superficial, intermediate & deep)

• Transversalis fascia

• Extraperitoneal fat

• Parietal peritoneum

-> 2 sets of muscles come together

-> Lateral group (flat muscles) - continuation of muscles of thoracic wall

• External oblique, internal oblique & transverse abdominis

• They lie on the side of the abdomen, form aponeurosis & join at the linea alba (fibrous structure that extends from xiphoid process to pubic symphysis)

-> Anterior group (vertical group)

• ectus abdominis & pyramidalis

• Enclosed within the rectus sheath, an aponeurosis formed by flat muscles

-> Also known as semicircular line of Douglas

-> curved line found posteriorly to rectus abdominis muscle B/L

-> It determines the order of layering tissues of rectus sheath (the tissues above arcuate line is different from the ones below the line)

-> Occurs around half the distance from the umbilicus to pubic crest

-> Clinical site where anterior abdo wall could herniate

Tissue layers superior to Arcuate line

• External oblique aponeurosis pass anterior to rectus abdo

• Internal oblique anterior slip pass anterior and posterior slip aponeurosis pass posterior to rectus abdominis

• Transversus abdominus aponeurosis pass posterior to RA

• All the aponeurosis wraps around rectus abdominis to form rectus sheath - the R & L meet at linea alba

Tissue layers inferior to Arcuate line

• Internal oblique & transverse abdominis aponeurosis pass anterior to rectus abdominis

• Therefore, only transversalis fascia is the only structure located posterior to rectus abdominis muscle

Note:

aponeurosis is a flat tendon sheet derived from lateral wall muscles.

Linea alba is midline entwined aponeurosis

Rectus sheath is made of aponeurotic tendon, encloses rectus abdominus muscle (upper 3/4 is completely covered, lowe 1/4 is covered anteriorly only)

• Clinically a anatomical weakness of abdominal wall

• An oblique intermuscular slit of anterolateral abdo wall

• Starts at deep inguinal ring and ends at superficial ring

• Transmits sparmatic cord in male, round uterus ligament in female

Fascia transversalis

• A layer of deep fascia between transversus abdominus & extra peritoneal fascia

• Lines the abdominal cavity & continues to pelvic cavity

  
  

• A lining that forms the deepest tissue envelop lining viscera & walls of the abdomen & pelvis

• Known as the ‘pavement epithelium’ - one cell thick

• Classified as simple squamous epithelium

• Covers the inner surface of all abdominal & pelvic wall (except area of coronary ligament - area between liver & diaphragm called ‘Bare area of the liver’) and the inferior surface of the diaphragm = parietal peritoneum

• Also lines the surface of all visceral organs in the abdomen (except bare area of liver) = visceral peritoneum

Parietal peritoneum

• lines inner wall of abdomen, pelvis & inferior surface of diaphragm

• Innervated by sensory division of somatic nervous system > sharp, localised pain

Visceral peritoneum

• Lines visceral organs of the abdomen

• Innervated by sensory division of autonomic nervous system. - the pain is not localised & perceived as referred pain

• Only part of the liver that is not covered by peritoneum

• Fibrous capsule of the liver is in direct contact with diaphragm

• Site for portocaval anastamosis

• Potential pathway for infection such as suphrenic abscess, to spread between thoracic and abdominal cavities without peritoneal barrier

• Peritoneal compartment – potential space which only contains tiny serous fluid, no organs found

• Intraperitoneal compartment

• Extraperitoneal compartment (retroperitoneal compartment or space) – organs that lie outside the parietal peritoneum e.g kidney

• During organogenesis in the embryo, the organs develop into the abdominal cavity in a ‘fist & balloon model’

• Developing organs invade the abdo cavity by pushing against one side of the balloon (visceral peritoneum) whilst not having any contact with other wall of the balloon (parietal peritoneum)

• The space occupied the organ = intraperitoneal cavity

  • Organs here are completely covered by visceral peritoneum

• Potential space between 2 peritoneal membrane = peritoneal cavity

  • It contains thin film of serous fluid which reduce friction when serous membranes rub against each other

Any space that is outside the peritoneal cavity - posterior to intraperitoneal cavity. Further divided into:

• Retro-peritoneal space:

  • This is the space posterior to the intraperitoneal cavity, it contains retro-peritoneal structures (posterior to the intraperitoneal cavity)

  Pre-peritoneal space:

  • Space anterior to the intraperitoneal cavity - no structure is found in this area

  • It is a potential anatomical space - can be invaded pathologically at the level of the pelvis

-> Intraperitoneal cavity is divided into greater & lesser sac

-> Visceral peritoneum forms double layers of peritoneum around the organ - these double folds can be referred to as:

• Abdominal Ligament - Double fold visceral peritoneum that joins 2 abdominal organs or attach visceral organ to posterior abdominal wall

• Omentum - double fold of peritoneum that starts on the curvature of the stomach & connects it to other abdominal viscera. -> greater & lesser omentum

  • Between the 2 layers of the visceral peritoneum here, fat / peritoneal fluid & WBC are found

• Mesentery - double fold of peritoneum starting on the intestines & ends bacl on the intestines.

  • Contains neurovascular structure between the 2 layers of the peritoneum

The greater omentum

• double fold of visceral peritoneum that starts on the greater curvature of the stomach & connects it to the transverse colon.

• also known as the abdominal apron / policeman of abdomen. It is chemotactic (kills infection) & can move.

The less omentum

• double fold of the peritoneum that starts on the lesser curvatures of the stomach and connects it to the liver

• Greater omentum - Gastrophrenic, gastrosplenic and gastrocolic ligaments

• Lesser omentum - Hepatoduodenal and hepatogastric ligament

-> Protrusion of soft tissues of one anatomical compartment to an adjacent compartment or adjacent potential space due to weakness in the boundary wall between the spaces.

• Protrusion = forward movement of a body part in sagital plane

• Retrusion = the oppsite > moving backwards & medially

-> Can cause discomfort, be life threatening

-> classes - congenital, physiological, pathological & acquired

1. Arterial dissection - partial weakness through the thickness of tissue layers of artery > leakage & accumulation of blood within the walls of the vessel

2. Aneurysm - weakness in the vessel wall involving all layers > blood from lumen burrows through all layers

• Anatomical compartment with content

• Neighbouring compartment or potential space

• weakness in the boundary between the compartments

• Pressure gradient between the compartments

• Mobile or moveable contents of one of the compartment

Diaphragm

Umbilicus

Inguinal ligament / femoral canal

Inguinal canal

• Congenital defect (hole) in the diaphragm that allows abdominal contents to protrude into thorax

• Potential vertebral levels of the hernia - T8 (caval hiatus), T10 (oesophageal hiatus), T12 (aortic hiatus)

• 2 types based on the location of the hole in the diaphragm

• Cause - nil known

• Rx - surgical intervention

• Bulge of intestinal tissue on or near the umbilicus.

• Painless, common in infants, often closes spontaneously before age 5. May require surgery.

• In adults, doesn’t close on their own, often leads to strangulation of herniating tissue.

• Can be more prominent if raised intra-abdominal pressure e.g. crying, coughing, laughing and abdominal strain.

-> A paraumbilical hernia is a protrusion through the superior aspect between the umbilical vein and the upper margin of the umbilical ring. This is the weakest area of the umbilical scar

• Femoral hernia result from abdominal tissue or part of intestine pushing through weak spot in abdominal wall

• Herniating tissue pass into the femoral canal (passageway in upper thigh near the groin

• common in female, caused by straining activity e.g. lifting

• Sx - bulge in groin, pain, nausea

• Risk of strangulation - need surgical evaluation

Result of abdominal tissue / fat / loop of intestine bulges through opening in the lower abdominal wall.

-> 20x more common in men

-> Direct inguinal hernia

• Bulges through posterior wall of the inguinal canal medial to inferior epigastric artery

• The peritoneal sac enters directly through weak posterior wall

-> Indirect inguinal hernia

• Passes through inguinal canal lateral to inferior epigastric artery. Most common type, often reducible

-> Arcuate line of abdominal wall - occurs halfway between umbilicus & pubic crest

• above the line, posterior sheath is formed by internal oblique & transversus abdominis muscles. Below the line, posterior rectus sheath is absent & only has transversalis fascia

• It is where the epigastric artery enters the rectus sheath - common site for spigelian hernias

-> Its a rare type of ventral hernia where part of bowel or abdo contents pokes through weaness in spigelian fascia (aponeurotiv layer between rectus abdominis muscle medially

• Its a hernia through linea semilunaris - line between the edge of the rectus muscle & oblique muscles

Xray

• Xray beam (ionising radiation)

• Radiolucent structures allow xray to penerate > appears black e.g. Air. Radiopaque structures absorb Xray > appears white e.g. bone.

• 2D images - AP, PA, lateral oblique

CT

• Xray tube & detector rotates > 3D images in coronal, saggital & axial view

• Uses high radiation

USS

• uses high frequency sound waves

• Solid particles are dense so waves are reflected > white

• fluid transmit sound waves > black. Air is even stronger reflector so cant see behind it

MRI

• Great for soft tissue Ix, might use gadolinium contrast

• Uses magnetic field which is emitted by machine > into patient & reacts with water molecules

• Contrast (iodine) for luminal structures e.g. blood vessel

• Barium sulphate for GI e.g. oesophagus, given PO

-> Burn is a coagulative injury to the skin

-> Types of burn - scald, flame, flash, contact, chemical, electrical & friction

-> Body’s response:

-> 5 principles - Rescue, Resuscitate, Resurface, Reconstruct & Rehabilitate

-> 1st aid - stop the burn, ABCDE (O2, fluids)

-> consider escharotomy for tight burned black skin

-> Assess size & depth of burn using ‘total body surface area’ (TBSA) value + age = % mortality (higher with age)

• Superficial - only epidermis has damage

  • Erythema due to sun burn, appears pink, blanching, very painful, heals rapidly without scar

• Superficial dermal - epidermis & papillary dermis is damage

  • superficial partial thickness, skin is lost, blistered,wet, red, painful & blanches

• Deep dermal - epidermis, papillary dermis and reticular dermis are damaged

  • Deep partial thickness, dry, pale, cherry red, does not blanch & reduced sensation

• Full thickness - destroys all layers of epidermis and dermis, subcutaneous tissue is damaged.

  • dry, leathery, painless due to nerve damage, no CRT

In major burns, fluid & electrolytes are lost & must be replaced if:

• The burn is >10% TBSA in children

• The burn is >15% TBSA in adults

Parkland formula:

• Fluid (over 24 hours) = 4x Weight (kg) x TBSA (%)

• e.g 70kg male with 45% TBSA > 4x70x45 = 12600ml

• Give half (6300ml) in 1st 8hrs then rest over 16hrs

• Monitor urine output

This model splits site of burn into 3 zones:

• Zone of hyperaemia - suffered reversible damage

• Zone of stasis - can be recovered or lost, depending on medical intervention. With adequate resuscitation this zone is preserved, otherwise its lost.

• Zone of coagulation - tissue in this zone is irreversibly damaged, undergoes necrosis

• Larger, deeper burns may need excision - removes scarred tissue

• Benefits - burnt tissue is source of infection & inflammation. Early excision > better scar when healing

• Risks - blood loss, hypothermia, may need graft > wound elsewhere in the body

-> Abdominal cavity (peritoneal cavity) - largest anatomical space. Divided into:

Greater sac

• Largest portion of the abdomical cavity, divided into 2 compartments by mesentry of transverse colon (transverse mesocolon).

Lesser sac

• Also known as omental bursa, a potential space that lies behind the stomach & enables stomach to move freely

• Obliterated (get smaller) in full stomach

• Boundaries - anterior (stomach, pancreas, diaphragm), postero-inferior (kidney)

• Cliical importance - site of abdomen into which posterior peptic ulcers drain their secretions into

• Through omental foramen = epiploic foramen of Winslow

• Crucial for drainage & fluid movement

-> Greater sac is divided into 2 compartments by transverse mesocolon into:

• Supracolic ompartment (above transverse mesocolon) - contains liver, GB, stomach

• Infracolic compartment (below transverse mesocolon) - contains most intestine.

  • Can be further divided into R & L infracolic

-> These compartments are connected by paracolic gutters which is located between postero-lateral abdominal wall and lateral to asceding & descending colon.

• bleeding in supracolic can move into infracolic via the gutter. If pt spine, fluid from infra can move to supracolic compartment

• On the R, the flow between the compartment is free but on L side the phrenicocolic ligament blocks the flow between the compartments

-> Abdo cavity is divided into greater & lesser sac

-> The greater sac is divided into supracolic and infracolic compartment by mesentry of transverse colon

-> Supra-colic compartment is the space below the diaphragm & above transverse colon. Has 4 entities:

• Subdiaphragmatic space

• Sub-hepatic space

• Coronary ligament of liver

• Bare area of the liver

->There are no of ligaments that attaches liver to the nearby structures, formed by double layer of peritoneum.

-> This includes falciform, coronary & triangular ligaments

• Coronary ligament attaches the superior surface of the liver to the inferior surface of the diaphragm and demarcates the bare area of the liver:

  • Its the part of the liver surface which is not covered by visceral peritoneum

  • Has no sensory or nervous innervation

• The anterior and posterior folds unite to form the triangular ligaments on the right and left lobes of the liver.

Hepatic recesses are anatomical spaces between liver & surrounding structures. Infection may collect in these areas, forming an abscess.

• Subphrenic spaces – located between the diaphragm and the anterior/superior aspects of the liver. Divided into a right and left by the falciform ligament.

• Subhepatic space – a subdivision of the supracolic compartment (above the transverse mesocolon), located below the liver & above the transverse colon.

• Morison’s pouch (hepatorenal recess) – a potential space between liver & right kidney. This is the deepest part of the peritoneal cavity when supine = pathological abdominal fluid such as blood or ascites is most likely to collect in this region in a bedridden patient.

-> Abdo cavity is divided into greater & lesser sac

-> The greater sac is divided into supracolic and infracolic compartment by mesentry of transverse colon

-> Infracolic compartment is inferior to transverse mesocolon & superior to pelvic inlet. Anatomical spaces of important are:

• Recto-uterine Pouch (female) - aka pouch of Doughlas is between rectum & uterus

• Recto-vesical pouch (male) - peritoneal recess between rectum & bladder.

These both are the lowest point of the peritoneal cavity in male & female - fluid such as blood / puss can accumulate here

-> Defined as change in the angle at any joint.

• Isometric - the muscle contracts but does not shorten. It generates force without changing its length. e.g. holding a weight in place.

• Concentric – a type of muscle contraction where muscles shorten whilst generating force to overcome resistance e.g. bicep curl.

• Eccentric – a type of muscle contraction where a muscle lengthens as it generates force to overcome resistance e.g. the downward phase of a bicep curl.

-> Intermedial mesoderm

-> Lateral plate mesoderm

-> Paraxial mesoderm

• Mesoderm forms nearly all of the CT of the MSK system

• Cartilage, bone, muscles differentiates from mesoderm

• Stylopod - The proximal region > gives rise to the humerus in the UL and the femur in the LL

• Zeugopod - the intermediate region > give rise to the radius and ulna in the UL & the tibia and fibula in the LL, has 2 parallel elements.

• Autopod  - The distal region > gives rise to the wrist and fingers in the UL and the ankle and toes in the LL.

Skeleton is divided into Axial and appendicular system and is made up of cartilages and bones.

- Axial skeleton forms – head, vertebral column & thoracic cage

- Appendicular forms – 2 upper and 2 lower limbs

The root of limb is the point at which the axial skeleton meets the appendicular skeleton

• The upper limb root of limb is the pectoral/shoulder girdle

• The lower limb root of limb is the pelvic girdle

Both upper and lower limbs are connected to the axial skeleton by ball and socket synovial joints, giving them lots of mobility.

Upper limb can be divided into 6:

-> Pectoral girdle (shoulder) - clavicle & scapula

-> Brachium (arm) - humerus

-> Antebrachium (forearm) - radius & ulna

-> Wrist

-> Manus (hand) - carpals, metacarpals & phalanges

Lower limb is made of 4 divisions:

-> Hip - between iliac crest & femur

-> Thigh - femur

-> knee joint - femur meets tibia & patella

-> leg - below knee & above foot (tibia & fibula)

-> Foot - tarsals, metatarsals, phalanges

Each compartments have own muscles, nerves and blood supply

• The Upper Limb - divided into anterior and posterior compartments.

• The Thigh - divided into anterior, medial and posterior compartments.

• The Leg can be divided into anterior, lateral and posterior compartments

The fascia lata is the deep fascia of the thigh, which is the investing layer of the deep fascia in the limbs.

• Begins proximally around the iliac crest & inguinal ligament and ends distal to the bony prominences of the tibia.

• Thickness varies across the LL

• The deepest aspect gives rise to three intermuscular septa that attach centrally to the femur:

  • Medial – separates the anterior thigh compartment from the medial compartment.

  • Lateral (thickest)– separates the anterior thigh compartment from the posterior compartment.

  • Posterior – separates the medial thigh compartment from the posterior compartment.

-> The fascial compartments area sealed tissue compartments whose walls are formed by thick, inexpansible, impenetrable layers of fascia

-> Pressue due to fluid build up in one compartment can not be relieved by passing it to another > arterial perfusion pressure falls below tissue pressure > compartment syndrome > avascular necrosis

• Fascia lata (deep fascia) - forms the boundary of muscles and is thickened at the lateral part of the thigh forming iliotibial tract

• Iliotibial tract is also formed by 2/3 of the fascia of the gluteus maximus - when tensed, the tract maintains knee extension (helps standing up)

• Fascia lata can be tightened by muscle known as ‘Tensor of fascia lata’

• 
  

-> Skin

-> superficial fascia

-> Deep fascia (fascia lata)

-> muscles with medial, lateral & posterior intermuscular septa)

-> periosteum

-> Bone (femur)

-> Neurovascular bundle & lymph nodes

-> medullary cavity

-> Endosteum

1. Sterno-clavicular joint

   - Articulation of clavicle + manubrium of the sternum

   - A modified (plane) synovial joint - has fibrocartilage joint disk

2. Acromioclavicular joint

   - Lateral clavicle + acromion of scapula

3. Glenohumeral joint

   - Head of humerus (ball) + glenoid fossa of scapula (socket)

4. Scapulothoracic joint (not a true joint)

   - Anterior surface of scapula + posterior thoracic cage

• When clavicle # > medial part will protrude up and lateral part points down (due to gravity pulling the limb down)

• Sternocleidomastoid (pulls the medial part up) and pectoralis major muscles goes into spasm

• Pt would support the elbow to prevent gravity pull

• Clavicle shortens as pec major pulls the UL close to the body > overlap

• Sx: pain, swelling, bruising.

The pelvis is formed from the union of the sacrum and the left & right innominate bones of the hip. It is also made up of 3 joints

• Sacroiliac joints (x2): fibrous joints posteriorly and synovial plane joints anteriorly.

• Pubic symphysis: secondary cartilaginous joint. ie it does not ossify through the human lifespan and maintains its cartilaginous structure.

  • functionally important as it allows pelvic movement and mobility as well as flexibility during childbirth.

Innominate bones = ilium, ischium & pubis

• They unite to form cup shaped depression = acetabulum

• Acetabulum is made up of weight-bearing part which articulates with head of femur and the non-weight bearing part called the acetabular fossa.

• Fascia is a form of fibrous connective tissue, containing various amount of fat

• Provides framework that organises, support and protects muscle groups, organs & tissue units of the body.

• Generic tissue layer: Skin > superficial fascia (binds skin to the rest of the body tissues) > deep fascia (encloses organs, divides muscles into compartments) > muscles > deepest layer of deep fascia

  • The neck has superficial cervical fascia (1 layer) and deep cervical fascia.

• ‘Flesh eating bacteria’ that feeds on fascia and spreads along the fascial plane

• Commonly caused by Group A strep

-> Each compartment has its own muscles, nerve supply & motor function - seperated by deep fascial septa.

-> They have common blood supply from profunda femoris

• Anterior - has Quadriceps > extension of the knee.

  • Innervated by the Femoral Nerve (L2-L4) and supplied by the Femoral Artery.

• Medial  -  has Adductors > Hip Adduction.

  • Innervated by the Obturator Nerve (L2-L4) and supplied primarily by the Obturator artery.

• Posterior- has Hamstrings > flexion of the knee and extension of the hip.

  • Innervated by the Sciatic Nerve (L4-S3) and supplied by the Perforating branches of Profunda Femoris.

-> Deep fascia of the leg is continuous with that of the thigh and is called Crural fascia

-> Crural fascia + tibia + fibula & interosseus membrane together divides the leg into 3 muscular comparments

• Anterior - Has Tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius muscles.

  • innervated by the Deep Peroneal/fibular nerve (L4-S2) and supplied by the Anterior Tibial artery

• Lateral - fibularis longus and fibularis brevis.

  • innervated by the Superficial Peroneal/fibular nerve. Supplied by the Anterior Tibial and Fibular arteries

• Posterior - Has Calf Muscles - flexors (grouped superficial, intermediate and deep) such as the Soleus, Gastrocnemius, and plantaris superficially and the popliteus, flexor hallucis longus, flexor digitorum longus, and tibialis posterior muscles deep

  • innervated by the Tibial nerve and supplied by the Posterior Tibial artery

• Arm - Contains the Humerus, located between the glenohumeral and elbow joints

• Forearm - Contains the Radius + Ulna, located between the elbow and radiocarpal joints. They join at the proximal & distal radioulnar joints

• Wrist - Contains the carpal bones between the radiocarpal and carpometacarpal joints. There are also intercarpal joints between carpal bones

• Hand - Contains the metacarpals between carpometacarpal and metacarpophalangeal joints. As well as the phalanges between proximal and distal interphalangeal joints (PIPs and DIPs)

-> The investing layer of the deep fascia of the arm is known as brachial fascia - extends to form medial & lateral intermuscular septa. The septa divides the muscles into:

• Anterior (flexion) - innervated by musculocutaneous (C5-7) nerve, supplied by muscular branch of brachial artery

• Posterior (extension) - Innervated by radial nerve (C5-T1), supplied by profunda (deep) brachii artery

-> Investing layer of the deep fascia is called Antebrachial fascia (continuous with brachial fascia) and > interosseous membrane between ulna & radius and lateral intermuscular septum. This divides the forearm into:

• Anterior (flexion) - innervated by median nerve (C6-T1) and supplied by ulnar & radial artery

• Posterior (Extension) - innervated by Radial nerve (C5-T1) and supplied by proximal ulnar artery

-> Investing layer of deep fascia is called palmar aponeurosis > lateral, medial and intermediate palmar septa.

-> These divides the hand into 11 compartments:

• Dorsal interossei x4 (abduction) and Palmar interossei x3 (adduction) - both innervated by the ulnar nerve

• Thenar (fine movements of the thumb) - innervated by the median nerve

• Hypothenar (fine movements of the 5th digit) - innervated by the ulnar nerve

• Midpalm - Contains the Lumbricals (movements of fingers) - The two lateral lumbricals are innervated by the median nerve, two medial lumbricals are innervated by the ulnar nerve

• Adductor - Contains the adductor pollicis muscles (adducting the thumb) - innervated by the ulnar nerve

-> Occurs when arterial pressure falls below tissue pressure in closed anatomical comparment > damage to nerves & vessels necrosis

-> Occurs due to pressure in a compartment is too high either due to decreased compartment size or increased fluid content > decreased oxygen perfusion > impacts cellular metabolism

-> Causes:

• Fractures/blunt trauma/crush/burns

• Restoration of perfusion after an ischaemic limb

• Infiltrated infusion - catheter fails to remain within vein so IV fluid enters surrounding tissue

• Haemorrhage

• Intra-arterial injection

• Envenomation (exposure to a poison or toxin resulting from a bite or sting from an animal).

-> Sx - severe pain on passive extension of the muscle, not relieved by simple analgesia, paraesthesia (tingling), paralysis, pulselessness.

-> Late decompression > Increased infection risk and leakage of myogobin > renal failure

-> Rx - Fasciotomy = incision in the affected compartment to relieve pressure

Fat filled depression in the anterior elbow, point of transition fom arm > forarm. Its borders are:

• Superior - imaginary line between medial and lateral epicondyles of humerus

• Lateral - brachioradialis muscle

• Medial - pronator teres

• Floor - brachialis proximally and supinator muscle distally

• Roof (superficial) - deep fascia by bicipital aponeurosis

Contents:

• Tendon of biceps brachii

• Brachial artery

• Median nerve, lateral cutaneous nerve of forearm, and the deep branch of radial nerve

Clinical relevance:

• Site of venepuncture & cannulation (median cubital vein communicates with basilic & cephalic vein > blood to heart

• Brachial pulse palpable and brachial artery bifurcates into radial & ulna arteries here

-> The groove is between anterior & middle scalene muscle

-> Roots of the brachial plexus lie in relation to scalene muscles

-> Clinical significance: to temporarily block all sensation arising from the UL by anaestehetising the C5-7 roots of brachial plexus

• By inserting needle halfway between lateral border of sternocleidomastoid muscle & anterior border of the trapezius muscle - at the level of cricothyroid membrane

• Used for surgeries involving shulder, proximal humerus & lateral 2/3 of clavicle

-> Its the anatomical space of armpit, area under shoulder joint

• Anterior = Pectoralis major/minor, pectoralis fascia & clavipectoral fascia

• Posterior = scapula, teres major, subscapularis muscle

• Medial = serratus anterior & fascia

• Lateral = Tendons of anterior & posterior axillary folds

• Apex = convergence of clavicle, scapula & 1st rib

-> Conents - Brachial plexus, axillary artery & vein & LN

-> Elbow is formed between humerus, ulna & radius

-> Ulnar nerve runs behind the medial epicondyle & can get pinched during injury to elbow

-> Also known as transverse carpal or anterior annular ligament

-> It isa fibrous band on the palmar side of the hand near wrist

-> Arches anteriorly over the carpal bones, forming the carpal tunnel

-> Main function - holds down tendons of forearm muscles as the pass the wrist into the hand.

-> Narrow passageway in the anterior wrist

-> Bound by carpal arch (carpal bones) posteriorly and flexor retinaculum anteriorly

-> Contains - medial nerve & 9 tendons (flexor pollicis longus, 4x flexor digitorum superficial tendons, 4x flexor digitorum profundus tendons)

-> Carpal tunnel syndrome -> compression of medial nerve

-> Causes - repetitive hand movements, overweight, wrist trauma. vibrating tools, pregnancy

-> Symptoms:

• Pain or paraesthesia over median nerve sensory territory

• Wasting of abductor pollicis > weakness of thumb abduction and a reduced thenar eminence

• Phalen test, flex wrist to compress nerve > symptoms

• Tinel test, tap on nerve to compress, will cause symptoms

-> Humerus is related to 5 terminal brachnes of brachial plexus

-> Nerve damage in # > loss of sensation or parasthesia

• Axillary nerve - loss of deltoid muscle strength

• Radial nerve - wrist drop

• Median nerve - loss of thumb opposition and pinch

• Ulnar nerve - clawed hand

-> # surgical neck > axillary nerve damage + posterior Cx humeral artery

-> Mid shaft # > radial nerve damage + profunda brachii artery

-> Supracondylar # > median nerve + brachial artery damage

-> Medial epicondyl # > ulnar nerve damage + collateral ulnar artery

C3, C4, C5 - ‘keep the diaphragm alive’

The intervertebral disc contributes to 25% of the vertebral height

A central region

-> Has nucleus pulposus (remenant of notchord), has high osmotic power (attracts water).

-> Responsible for water retention and size of IVD (this changes within 24 hr cycle > varying height)

A Peripheral region

-> The annulus fibrosis (CT bands arranged in different directions), very resilient

-> Responsible for retention of nucleus pulposus and confers strength to IVD.

• Inferior boundaries make up the pelvic outlet - act as sites of attachement of soft tissue that constitute the pelvic floor.

• Pelvic floor lacks bony or cartilaginous reinforcements

• When the pelvic outlet is covered with soft tissues, muscles and skin, it is known as perineum

• Pelvic floor is largely a soft tissue complex that closes-off inferior pelvic aperture (shape of hammock)

• Pelvic floor is diamond shape, Composed of: muscles, pelvic fascia, superficial fascia & skin

• It seals the pelvic outlet

• Anterior triangle - aka urogenital triangle

• Posterior triangle - aka ischio-anal fossa or anal triangle

Transverse perineal muscles spans across their boundaries

Pelvic diaphragm refers to - sheet of muscle covered on both surfaces by fasciae. Occupies the urogenital triangle.

• It assists in support of abdomino-pelvic viscera

• Stretched like hammock between pubis (front) and coccyx (back). Attached along the alteral pelvic wall to thickened band of obturator fascia

• Consits of —> superior layer of pelvic fascia, levator ani & coccyegus muscles and inferior layer or pelvic fascia.

Composed of 2 sets of muscles on either sides of midline

• 2 Levator Anni (anterior)

• 2 coccygeus muscles (posterior)

• Its a complex funnel-shaped structure composed of striated muscle.

• It supports & raises pelvic floor

• Allows various pelvic structures to pass through

• Formed by 3 muscles: Puborectalis, pubococcygeus & iliococcygeus

• Supplied by: somatic nerves from sacral plexus (pudendal nerve, nerve of levator ani) and autonomic nerves (from inferior hypogastric plexus)

The deep perineal pouch (space)

• Region between the perineal membrane & pelvic diaphragm

• Inferior border (perineal membrane), superior border (external layer of fascia of the pelvic diaphragm)

Bones & ligaments create a basket in which viscera contained:

• Lower digestive & urinary tract

• Apparatus for reproduction function and pregnancy

Rectouterine pouch (Pouch of Douglas) - in the female

Other pouches:

• Vesicouterine Pouch (female) and rectovesical pouch (male)

• Dropped or prolapsed bladder bulging into vaginal space

• Often due to muscles and tissues that supports the bladder give way