204 MSK - Anatomy Flashcards
What does the superior gluteal nerve innervate?
Motor:
Gluteus medius
Gluteus minimus
Tensor fascia latae
Origin of superior gluteal nerve
Lumbo-sacro plexus - nerve roots L4-S1
Course of superior gluteal nerve
Leaves pelvis through the greater sciatic notch → runs over the piriformis between the gluteus medius & minimus
- branches to the gluteus minimus and medius muscles and terminates by innervating the tensor fasciae latae muscle.
What happens if superior gluteal nerve is injured?
Positive Trendelenburg test
- gluteus medius & gluteus minimus keeps pelvis level when contralateral limb is elevated
- When superior gluteal nerve injured – pelvis drops on unaffected side, bc contralateral muscles are paralyzed
Which anatomical landmark marks the transition from the femoral vein to the external iliac vein?
Inguinal ligament
- The femoral vein leaves the thigh by running underneath the inguinal ligament, at which point it is known as the external iliac vein.
Which vessel do the superior and inferior gluteal veins empty into?
Internal iliac
- The gluteal region is drained by inferior and superior gluteal veins. These empty into the internal iliac vein.
The small saphenous vein drains into the deep vasculature at which level?
Popliteal vein
- The small saphenous vein moves between the two heads of the gastrocnemius muscle and empties into the popliteal vein in the popliteal fossa.
A vascular surgeon is preparing to harvest the longest vein in the body to use as a conduit for peripheral arterial bypass procedure. Where will she find and harvest this vein?
Medial side of the thigh
- The great saphenous vein is the longest vein in the body and runs along the length of the leg. It can be found traveling up the medial side of the thigh.
The great saphenous vein originates at the medial aspect of the foot, courses anterior to the medial maleolus and travels up the medial side of the leg and thigh to just inferior to the pubic tubercle. There it joins with the femoral vein in the region of the femoral triangle.
Deep veins of lower limbs
Located underneath the deep fascia of the lower limb, accompanying the major arteries
Superficial veins of lower limbs
Found in the subcutaneous tissue. They eventually drain into the deep veins.
Great saphenous vein
Small saphenous vein
Deep vein course
- (foot) Deep perforating veins from dorsal venous arch form anterior tibial vein
- (plantar foot) Medial & lateral plantar veins arise → combine to form posterior tibial & fibular veins
- (posterior surface of the knee) Anterior tibial, posterior tibial & fibular veins → combine to form popliteal vein
- (enters thigh via adductor canal) Popliteal vein is now known as femoral vein
- (terminal section of femoral vein) Deep vein of thigh joins femoral vein
- (Leaves thigh by running underneath inguinal ligament) Femoral vein known as external iliac vein
Great saphenous vein (course)
Dorsal venous arch gives rise to great saphenous vein on medial side of foot → ascends up medial side of leg, passes anteriorly to medial malleolus at ankle & posteriorly to medial condyle at knee
→ drains into femoral vein distal to inguinal ligament
Course of small saphenous vein
Dorsal venous arch gives rise to small saphenous vein on lateral side of foot → ascends on posterior side of leg, passes posterior to lateral malleolus along lateral border of calcaneal tendon
→ moves between 2 heads of gastrocnemius muscle
→ drains into popliteal vein in politeal fossa
Varicose veins
Valves of superficial veins become incompetent, resulting in dilation of superficial veins
Origin of obturator nerve
Lumbar plexus - L2 - L4
Sensory innervation of the obturator nerve
Medial aspect of thigh
Articular branches to hip & knee joints
Motor innervation of the obturator nerve
Muscles of the medial compartment of the thigh:
Anterior:
- Adductor longus
- Adductor brevis
- Gracilis
Posterior:
- Obturator externus
- Adductor magnus
Course of obturator nerve
Formed in lumbar plexus – L2-L4 → descends through psoas major → posterior to common iliac arteries → laterally along pelvic wall → enter obturator foramen of pelvis → enters medial thigh through obturator canal
A patient visits her GP with difficulty walking. After clinical examination, obturator nerve palsy is suspected. Which movement is most likely to be impaired?
Hip adduction
- The obturator nerve innervates the muscles of the medial thigh. Their collective action is hip adduction.
Which muscle is the exception in the medial compartment of the thigh (not innervated by obturator nerve)?
The hamstring part of the adductor magnus (innervated by the tibial nerve).
What are the spinal roots of the deep fibular nerve?
L4-S1
Which artery does the deep fibular nerve follow as it descends inferomedially along the leg?
Anterior tibial
Which structure does the deep fibular nerve pass under at the ankle joint?
Extensor Retinaculum
Motor innervation of deep peroneal nerve
Muscles on anterior compartment of the leg
- tibialis anterior
- extensor digitorum longus
- peroneus tertius
- extensor hallucis longus
Intrinsic muscles of the foot.
- extensor digitorum brevis - extensor hallucis brevis
Sensory innervation of deep peroneal nerve
The triangular region of skin between the 1st and 2nd toes.
Footdrop
Paralysis of the muscles in the anterior compartment of the leg - due to deep peroneal nerve injury
- so a patient loses the ability to dorsiflex the foot.
Course of deep peroneal nerve
Bifurcation of the common peroneal nerve → interosseous membrane → crosses anterior tibial artery → anterior tarsal tunnel → lateral & medial terminal branches
Action of flexor digitorum profundus
Flexion of the fingers at the MCP and IP joints.
Assists with flexion of the hand
Innervation of flexor digitorum profundus
Digits 2-3: Median nerve (anterior interosseous nerve);
Digits 4-5: Ulnar nerve (C8, T1)
Action of supraspinatus
Initiates and assists deltoid in abduction of arm and acts with other rotator cuff muscles
Innervation of supraspinatus
Suprascapular nerve (C5, C6)
What does the long thoracic nerve innervate?
Serratus anterior
Origin of the long thoracic nerve
Arises from ventral rami of C5, C6, C7 roots of brachial plexus
2 types of winging of scapula
Medial winging of scapula - serratus anterior problem
Lateral winging of scapula - trapezius problem
Medial winging of scapula
Dysfunction of the serratus anterior (long thoracic nerve)
Lateral winging of scapula
Dysfunction of the trapezius (cranial nerve XI - spinal accessory nerve)
Sign of axillary nerve injury
Flattened deltoid
Sign of radial nerve injury
Wrist drop
Sign of median nerve injury
- distal
- proximal
Distal - median claw hand (when asked to extend figers) - bc loss of lateral lumbricals
Proximal - ulnar claw hand (when asked to flex fingers) - bc loss of long forearm flexors
Sign of ulnar nerve injury
- distal
- proximal
Distal - ulnar claw hand (when asked to flex fingers) - bc loss of long forearm flexors
Proximal - median claw hand (when asked to extend figers) - bc loss of lateral lumbricals
What are the 4 rotator cuff muscles & their functions ?
Supraspinatus - initial abduction
Infraspinatus - lateral rotation of arm
Teres minor - adduction & lateral rotation of arm
Subscapularis - adduction & medial rotation of arm
Rotator Cuff Tendonitis
Inflammation of the tendons of the rotator cuff muscles – most commonly supraspinatus
What are the 3 thenar muscles & their innervation?
Opponens Pollicis
Abductor Pollicis Brevis
Flexor Pollicis Brevis
Innervated by median nerve
What are the 3 hypothenar muscles & their innervation?
Opponens Digiti Minimi
Abductor Digiti Minimi
Flexor Digiti Minimi Brevis
Innervated by ulnar nerve
What are the actions of the 3 thenar muscles?
Opponens Pollicis - opposes thumb
Abductor Pollicis Brevis - abducts thumb
Flexor Pollicis Brevis - Flexes thumb at MCP
What are the actions of the 3 hypothenar muscles?
Opponens Digiti Minimi - opposes little finger
Abductor Digiti Minimi - abducts little finger
Flexor Digiti Minimi Brevis - Flex MCP of little finger
What are the lumbricals?
4 lumbricals each associated with a finger
Act to flex the fingers at MCP & extend at IP
Innervation of lumbricals
Lateral 2 (index & middle) – median nerve Medial 2 (little & ring) – ulnar nerve
PAd Dab
P: palmar interossei
Ad: adduction
D: dorsal interossei
Ab: abduction
Which nerve innervates the opponens digiti minimi muscle of the hand?
Ulnar nerve
- The ulnar nerve innervates the muscles of the hypothenar eminence, including the opponens digiti minimi.
What is the action of the lumbricals on the interphalangeal joints?
Extension
- The lumbricals extend at the IP joints and flex at the MCP joints.
Hand muscles supplied by ulnar nerve
All except 3 thenar muscles & 2 lateral lumbricals
3 hypothenar muscles
- opponens digiti minimi
- abductor digiti minimi brevis
- flexor digiti minimi brevis
2 medial lumbricals
- little & ring
Interosseous
- Dorsal & Palmar
Palmaris Brevis
Adductor Pollicis
Hand muscles supplied by median nerve
3 thenar muscles
- opponens pollicis
- abductor pollicis brevis
- flexor pollicis brevis
2 lateral lumbricals
- index & middle
Which nerve innervates the interosseous?
Ulnar nerve
How many dorsal & palmar interosseous?
Dorsal: 4
Palmar: 3
Action of palmaris brevis
Wrinkles skin of hypothenar eminence & deepens curvature of hand, improving grip
Action of adductor pollicis
Adductor of thumb
Ulnar paradox
Higher the lesion, less the deformity
4 normal curves of the vertebral column
Cervical lordosis
Thoracic kyphosis
Lumbar lordosis
Sacral kyphosis
Regions of vertebral column and their number of vertebrae
Cervical - 7 Thoracic - 12 Lumbar - 5 Sacrum - 5 Coccyx - 4
3 types of prolapsed intervertebral disc (PID)
Central - compress on spinal cord
Posterolateral - compress nerve on its way to next intervertebral level
Far lateral - compress spinal nerve leaving the level
Femoral nerve palsy
Loss of knee extension & weak hip flexion
Tibial nerve palsy
Loss of plantar flexion, weak inversion
Common peroneal nerve palsy
Loss of ankle dorsiflexion (foot drop) & foot eversion
Numbness on dorsum of foot & lateral leg
Superficial peroneal nerve palsy
No foot drop, loss of foot eversion, numbness on foot dorsum (except 1st web)
Deep peroneal nerve palsy
Loss of dorsiflexion (foot drop), numbness in 1st web
Valgus stress test for elbow
Test medial collateral ligament
Distal part push to lateral side
Varus stress test for elbow
Test lateral collateral ligament
Distal part push to medial side
Test for anterior cruciate ligament (ACL)
Anterior drawer test
Test for posterior cruciate ligament (PCL)
Posterior drawer test
Posterior sag test
ACL enters the ______ anteriorly
knee
tibia
PCL enters the tibia ______
knee
posteriorly
ACL function (knee)
Prevents knee from sliding forward
PCL function (knee)
Prevents knee from sliding backward
McMurray’s test
For meniscal tear
Apley’s test
For meniscal tear
Varus stress test for knee
Test lateral cruciate ligament
Distal part push to medial side
Valgus stess test for knee
Test medial cruciate ligament
Distal part push to lateral side
Varus stress test for elbow/knee tests ______;
Valgus stress test for elbow/knee tests ______
lateral; medial
Carpal tunnel syndrome
Compression of the median nerve as it runs deep to the transverse carpal ligament (TCL) causes:
- atrophy of the thenar eminence
- weakness of the flexor pollicis brevis, opponens pollicis, abductor pollicis brevis
- sensory loss in the digits supplied by the median nerve.
