Anatomical Areas Flashcards
Clinical link: Carpal tunnel syndrome
Mechanism and symptoms
Mechanism: Caused by entrapment or irritation of the median nerve within the carpal tunnel. Such as through thickening of the flexor retinaculum
Symptoms: Paresthesia in the median nerve distribution, wasting of the thenar muscles, reduced strength of grip, reduced thumb abduction; numbness in the thumb, middle and index fingers (not palm due to cutaneous branch).
Clinical link: Blood supply of the hand - Allen’s Test
- Used to test the perfusion capability of the ulnar artery to the hand
- The both arteries and occluded. Pallour seen
- The ulnar artery is released.
- If perfusion is adequate then the hand will return to normal colour (flushing) in 5-15 seconds - positive
- If negative the radial artery should not be punctured for an arterial blood sample
Palmar spaces and synoival sheaths: Describe the palmar spaces and synovial flexor sheaths of the hand.
Clinical relevance?
Infections may ‘jump’ between these spaces. Particularly important is the midpalmar space
☆Tenosynovial lining of flexor sheaths
Elbow joint: Dislocation and annular joint subluxation
Dislocation: Commonly occurs in the posterior direction
Annular ligament: Surrounds the radius
- Function: Allows sliding of the ulnar on the radius and pivoting of the radius bone during supination and pronation
- Can be subluxed due to excessive force
Fractures of the forearm: Describe Colle’s, Smith’s and Bennett’s fractures
Colle’s: Sees dorsal displacement of the distal fragment of the radius. Shortening and dorsal angulation seen
- FOOSH
Smith’s: Palmar displacement of the distal fragment of the radius. Shortening and volar angulation.
- Fall onto flexed wrist, direct blow to dorsal forearm
Bennett’s: Fracture of the carpometacarpal joint
- Forced abduction of the thumb
Lower limb: Lateral compartment of the leg
Innervation: Superficial fibular nerve (L4-S3)
Muscles: Fibularis longus and brevis
Action: Eversion of the foot
Clinical relevance: Nerve injury may occur in neck of fibular fracture, sciatic nerve compression will also affect the compartment.
Inversion injuries can damage the muscle tendons and cause an avulsion injury of the 5th metatarsal
☆ The superficial fibular nerve and small saphenous vein pass posteriorly to the lateral malleolus
- Great saphenous vein passes anteriorly to the medial malleolus
Scaphoid: Consequence of fractures and region for palpation
Fracture: Avascular necrosis may result as blood supply is provided in a distal to proximal fashion. A fracture in the middle of the scaphoid may disrupt this and avascularise the proximal portion
Palpation: The scaphoid bone can be palpated within the anatomical snuffbox
Lower limb: Posterior compartment of the thigh
Innervation: Sciatic nerve (L4 - S3)
Muscles: Hamstring muscles (semimembranous, semitendinous and biceps femoris)
Action: Hip extension, knee flexion
Clinical relevance: The sciatic nerve may be impinged through vertebral disc herniation, at the sciatic notch, by piriformis
Ischial tuberosity avulsion fracture
Upper limb: Dorsal scapular spaces
Quadrangular space: Axillary nerve
Triangular interval: Profunda brachii artery and radial nerve
Pectoral girdle: Deltoid and pectoral muscles
Pectoralis major: Medial and lateral pectoral nerve
- Adducts, flexes and medially rotates the arm
Pectoralis minor: Medial pectoral nerve
Deltoid: Axillary nerve
- Abducts the arm (beyond the first 15 degrees of supraspinatus)
Lower limb: Outline the landmarks of the pelvis
☆ The greater sciatic foramen is formed by the sacrospinous and sacrotuberous ligaments
☆ Piriformis muscle divides the greater sciatic foramen into an upper and lower region.
Upper sciatic foramen: Superior gluteal nerve, artery and vein
Lower sciatic foramen: All other vessels pass through this foramen
Intervertebral foramen: Formation, patholgy
Formation: From the inferior vertebral notch of the superior vertebrae and the superior notch of the inferior vertebrae (of the pedicles)
Pathology: Narrowing of the intervertebral foramen
- Arthritis
- Spondylolisthesis
- Osteophyte growth (OA)
Clinical link: Medial humeral epicondyle fracture and tunnel through which the associated nerve runs
- Can damage the ulnar nerve
- Cubital tunnel of the elbow
- Runs through Guyons Canal at the wrist
Gluteal muscles
Gluteus maximus
Innervation: Inferior gluteal nerve (sacral plexus)
Action: Extends the thigh and lateral rotation
☆ Only active when force is required
Gluteus minimus and medius
Innervation: Superior gluteal nerve (sacral plexus)
Action: Abducts and medially rotates the thigh
Lower limb: Sensory innervation
- Consider that the sensory innervation of the leg is suppled mostly by branches of the sciatic nerve
Stability of the hip joint: Name the ligaments which contribute to the stabilty of the hip joint
- Iliofemoral
- Pubofermoral
- Ischiofemoral
-
Ligamentum teres
- Of the femoral head. Inserts into the fovea capitus. Important hip stabiliser.
- Transmits a nutrient artery to the femoral head in infants
Elbow joint: Name the ligaments of the elbow joint
- Radial collateral ligament
- Ulnar collaterol ligament
- Annular ligament
Clinical link: Lumbar puncture - positon and surface marking
Position: Patient to lay on their side with their knees raised to their chect
Surface marking: The posterior iliac crest. Intersects the L4 spinous process
Structures passed through: Skin, superficial fascia, supraspinous ligament, intraspinous ligament, ligamentum flavum, epidural space, dura mater, arachnoid mater, subarachnoid space
Pectoral girdle: Muscles of the anterior aspect
Suprascapular foramen: The suprascpaular nerve passes through this space
Subscapularis: Upper and lower subscapular nerves
Latissimus dorsi: Thoracodorsal nerve
Long and short heads of biceps brachi: Musculocutanous nerve
Bicipital aponeurosis: Seen at the sharp medial margin. Covers the brachial artery and the median nerve
Upper limb: Posterior compartment of the arm
Innervation: Radial nerve
Muscles: Triceps brachii
Actions: Extension at the elbow joint
Clinical relevance: Radial nerve may be injured at the lateral epicondyle, tight watch/handcuffs, mid-shaft humeral fractures (radial groove), falling asleep with hand over the back of the chair, upper limb dislocation - becomes stretched (commonly anterior)
The radiocarpal joint: Label the carpal bones
Scaphoid, lunate, triquestrum, pisiform (sesamoid bone), hamate, capitate, trapezoid, trapezium
Outline the blood supply to the upper limb
- include areas of ‘transition’
Lower limb: Medial compartment of the thigh
Innervation: Obturator nerve
Muscles: Adductor longus and brevis
Actions: Adducts the thigh
Clinical relevance: The obturator nerve may be damaged in birthing mothers and in sports (e.g. fencing)
Quadratus lumborum: Action and innervation
Action: Extension and lateral flexion of the vertebral column
Innervation: Anterior rami of spinal nerves T12-L4
Erector Spinae Muscles: Action and innervation
Action:
Unilateral contraction: Lateral flexion
Bilateral contraction: Supports the vertebral column and increases intra-abdominal pressure
Innervation: Dorsal rami of spinal nerves
Clinical link: Surgical neck and mid-shaft humerus fracture.
Surgical neck:
- Can damage the axillary nerve.
- Leads to loss of innervation to the deltoid muscle and teres minor
- Weakened abduction and lateral rotation
Mid-shaft humerus fracture:
- Can damage the radial nerve
- Leads to loss of innervation of the triceps branchii
- Loss of extension of the elbow joint
- Loss of innervation of the dorsal forearm
- Sensory loss to dorsal forearm and hand
Spinal nerves: Outline the 2 branches derived from spinal nerves
Spinal nerves (emerging from ventral rami) →
Large anterior rami: Innervates most skeletal muscles and skin
Small posterior rami: Innervates the intrinsic muscles of the back and narrow strip of associated skin
Intervertbral disc herniation: Most common ‘direction’ and region
Posterior: Most common due to tapering of the posterior longitudinal ligament of the spine, weaker/less organised, flexion is much more common, nucleus becomes more posterior moving down the spine
Region: Most commonly occurs in the lumbar region of the spine. This is due to the curvature of the spine and the large amount of pressure placed upon this region
Muscles of the forearm: Outline the functions of the FDPs and FPS
Flex the digits at the IPJs, can flex the MCPJs
Upper limb: anterior compartment of the forearm
Innervation: Median nerve (C5-T1)
- Except medial half of FDP and FCU which are innervated by the ulnar nerve
Muscles: FDS, FPL, pronator teres
Actions: Flexion of the wrist and digits, pronation
Clinical relevance: The median nerve may be damaged at the cubital fossa, brachial plexus lesions (upper or lower), supracondylar fracture of the humerus, damage at the wrist (e.g. self-harm)
Intervertebral discs: Anatomy
IV disc bodies: Increase in size from rostral to caudal. Flexibility is sacrificed to allow stabilty. The amount of force apparent on the dics increases caudally. (shapes)
Central nucleus pulposus: Derived from the notochord. Keeps the annulus fibrosus under constant tension. Contains proteoglycans with GAG side chains, type II collagen. Compression resistant.
Annulus fibrosus: Layers of oliquely organised fibrocartilage. Less well organised posteriorly.
Venous drainage of the upper limb: Name the deep and superficial vessels
Superficial: Basilic and cephalic veins
Deep: Radial, ulnar and branchial veins
Hip joint: Outline the relation of the hip joint to our centre of gravity when standing
The hip joint lies anterior to the centre of gravity.
The knee joint is posterior to the centre of gravity.
Allows us to ‘lock’ joints, reducing the muscular energy required for standing.
The axilla: Describe the boundaries of the axilla
Inlet: Lateral margin of rib I
Anterior wall: Pectoralis major and minor muscles
Medial wall: Upper thoracic wall, serratus anterior muscle
Posterior wall: Subscapularis, teres major and latissimus dorsi
Lateral wall: Intertubecular sulcus
Floor: Skin of the armpit
Outline the blood supply to the lower limb
Common iliac → Internal and external iliac
Internal iliac → Superior and inferior gluteal, obturator
External iliac → Femoral artery → *Branch: Profunda Femoris→ medial and lateral circumflex *→ Popliteal artery → anterior and posterior tibial
Anterior tibial → dorsalis pedis
Posterior tibial → Fibular, medial and lateral plantar
Hip joint: Label the hip joint and describe the stabilty of the joint
The pelvis is formed by the ilium, ischium and pubic bones.
The acetabulum of the pelvis and the head of the femur form the hip joint.
Acetabulum: Fossa, notch and labrum
- Large and cup shaped
- Allows weight to be transferred to the femur
The joint is very stable, to accomodate the large amount of force placed upon it. However, this is at the expense of movement.
The acetabulum is large whilst the head of the femur is small.
Forearm: Label the key anatomical regions of the forearm
Nerve: Radial
- Loss leads to wrist drop
- Can be injured at the lateral epicondyle and also by tight wrist watches/handcuffs
The interosseus membrane
- Provides attachment for muscles
- Fibres orientated such that forces are transmitted from the hand to the humerous
- Allow attachment of the radius and ulnar without restriction pro- and supination
Gleno-humeral joint: Decribe the anatomy of the gleno-humeral joint
- A synovial ball and socket joint
- Formed from the head of the humerus inserting into the glenoid cavity, which has a surrounding glenoid labrum
- The large head and small cavity cause the joint to be relatively unstable and therefore requires stabilisation by surrounding ligaments and muscles
- The tendon of the long head of biceps is found near the joint
- Blood supply: Medial and lateral circumflex arteries of the profunda brachii artery
Vertebral bodies: Name the features of the vertebral bodies
Transverse processes
Spinous process
Pedicle
Lamina
Neural arch
Body
Dermatomes: Label the dermatomes of the upper limb
Pectoral girdle: Muscles of the back
Trapezius: Accessory nerve
- Movement of the scapula
Latissimus dorsi: Thoracodorsal nerve
- Extends, adducts and medially rotates the humerus
Levator scapulae: Dorsal scapular nerve
- Elevates scapula
Rhomboid minor and major: Dorsal scapular nerve
- Adducts and elevates the scapula
Clinical link: Outline the boundaries for IM injection of the gluteal muscles
- Vertical line from the posterior iliac crest to the ischial tuberosity
- Horizontal line from the midpoint of this line
- The left upper quadrant is the ‘safe’ area
Clinical relevance: Failure to correctly recognise this site may lead to injury to the sciatic nerve
☆ REMEMBER ☆ The sciatic nerve ultimately innervates the leg and provides sensory innervation to the majority of the area
Pectoral girdle: Muscles of the posterior aspect
Supraspinatus: Suprascapular nerve
Infraspinatus: Suprascapular nerve
Teres minor: Axillary nerve
Teres major: Inferior subscapular nerve
Long head of triceps brachii
Triangular space: Circumflex scapular artery
Quadrangular space: Axillary nerve, posterior circumflex arterty and vein
Triangular interval: Radial nerveand profunda branchii artery
Outline the borders and contents of the tarsal tunnel
Borders: Passes posteriorly to the medial malleolus, held in place by fibrous band (flexor retinaculum)
Contents: Tibialis anterior, flexor digitorum longus, flexor digitorum brevis, posterior tibial artery, tibial nerve, posterior tibial vein
Spinal ligaments: Name the ligaments of the spinal column
Anterior and posterior longitudinal ligaments: Support the vertebrae
Ligamentum flavum: Resists separation of laminae
Inter- and supraspinatous ligaments: Limit flexion
Ligamentum nuchae: Supports the head, resists flexion, returns the head to anatomical postion
- Attaches to the skull, extending down to the spinous process of cervical vertebrae VII
Elbow joint: Decribe the basic anatomy of the elbow joint
- A synovial hinge joint
- Formed by articulation of the radial head on the capitulum of the humerus and articular of the ulnar head on the trochlea of the trochlea
Osteology: Identify the key features of the humerus
Anatomical and surgical necks
Greater and less tubercles
Bicipital groove: The tendon of the long head of biceps passes through this groove. The tenosynovium enclosing the tendon may become inflammed - tenosynovitis.
Medial and lateral epicondyles
Olecranon fossa
Lateral epicondyle
Outline the borders and contents of the cubital fossa
Borders: Pronator teres medially, brachioradialis laterally and between the lateral and medial epicondyles superiorly
Contents: Median nerve, Brachial artery, Tendon of biceps brachii, Radial nerve
Hip joint: Proximal femur
- Fovea
- Head of the femur
- Neck of femur
- Greater trochanter
- Lesser trochanter
- Gluteal tuberosity
Lower limb: Ankle joints
- Movements and ligaments
Movement: Plantar and dorsiflexion
- Myotomes: Plantarflexion (S1-S2)
- Plantarflexion is unstable due to the narrow area of talus in contact with the distal tibular. Mortise when more stable
Ligaments:
Medially: Anterior and posterior tibiotalar, tibionavicular and tibiocalcaneal, plantar calcaneonavicular ligament (spring)
Laterally: Anterior and posterior talofibular, calcaneofibular ligaments
Outline the borders and contents of the femoral triangle
Borders: Adductor longus medially, sartorius laterally, inguinal ligament superiorly, fasica lata roof
Contents: Femoral nerve, femoral artery, femoral vein, empty space and lymph nodes
☆ Femoral artery and femoral vein are in the femoral sheath
☆Femoral artery travels down the femoral canal, gives off its profunda femoris branch and passes through the adductor hiatus to enter the posterior compartment of the thigh
Clinical link: Locating the femoral pulse. Found half way between ASIS and the pubic symphysis
Outline the borders and contents of the anatomical snuffbox
Borders: EPL laterally, APL and APB medially
Contents: Cephalic vein, radial artery and cutanous branch of radial artery, scaphoid, trapezium
