MSK anatomy Flashcards
Which muscles are involved in upper limb extension?
posterior deltoid, latissimus dorsi and teres major.
Which muscles are involved in upper limb flexion?
pectoralis major, anterior deltoid and coracobrachialis.
Biceps brachii weakly assists in forward flexion.
Which muscles are involved in upper limb abduction?
0-15 degrees of abduction is supraspinatus.
15-90 degrees middle fibres of the deltoid
Past 90 degrees, the scapula needs to be rotated to achieve abduction – trapezius and serratus anterior.
Which muscles are involved in upper limb adduction?
pectoralis major, latissimus dorsi and teres major.
Which muscles are involved in upper limb external rotation?
infraspinatus and teres minor.
Which muscles are involved in upper limb internal rotation?
subscapularis, pectoralis major, latissimus dorsi, teres major and anterior deltoid.
Where do the shoulder extrinsic muscles originate and attach?
originate from the torso, and attach to the bones of the shoulder
Where do the shoulder intrinsic muscles originate and attach?
originate from the scapula and/or clavicle, and attach to the humerus
What are the two superficial extrinsic muscles in the shoulder?
the trapezius and latissimus dorsi
What are the 3 deep muscles involved in upper limb/shoulder movement?
Rhomboid major and minor
Levator scapulae
Which 4 muscles make up the rotator cuff?
supraspinatus
infraspinatus
subscapularis
teres minor
What is the innervation of the deltoid?
Axillary nerve
What are the actions of the different deltoid fibres?
Anterior fibres – flexion and medial rotation.
Posterior fibres – extension and lateral rotation.
Middle fibres – the major abductor of the arm
What are the 6 muscles that attach scapula to humerus?
Deltoid
supraspinatus
infraspinatus
subscapularis
teres minor
teres major
What are the actions of teres major?
Medial rotator and adductor
Where do supraspinatus, infraspinatus, teres minor originate from and insert?
Posterior surface of scapula and attach to greater tubercle
What space between the teres does the axillary nerve travel through?
Quadrilateral space
Where does subscapularis originate from and attach to?
Originates from anterior surface and inserts onto lesser tubercle of humerus
How does rotator cuff provide stability?
Contraction of RC muscles holds head of humerus in glenoid
RC tendons fuse with capsule of shoulder joint
How do the radius and ulna articulate with humerus?
Trochlea notch of ulna articulates with trochlea of humerus
Radial head articulates with capitellum of humerus
Which movements occur at elbow?
Flexion and extension
Where do radius and ulna articulate with each other?
Radioulnar joints (proximal and distal)
What movements do the radioulnar joints allow?
Pronation and supination
What is the joint called where radius articulates with carpus?
Radiocarpal joint (wrist)
What movements can occur at wrist?
Flexion
Extension
Abduction
Adduction
Which bones form the radiocarpal joint?
Radius
Scaphoid and lunate
Where are the metacarpal bones?
Distal to carpus
Where are the phalanges?
Bones of the digits
3 in fingers
2 in thumb
What bounds the cubital fossa medially?
Pronator teres
What bounds the cubital fossa laterally?
Brachioradialis
What are the 4 superficial muscles of the anterior forearm?
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Which 3 superficial anterior forearm muscles are innervated by median nerve?
Pronator teres
Flexor carpi radialis
Palmaris longus
Which nerve innervates FCU?
Ulnar
How many muscles are in anterior compartment of forearm?
8
Where do the superficial anterior forearm muscles attach proximally?
Medial epicondyle
What movements does pronator teres do?
Pronation of forearm
What movements does FCR do?
Flexion and abduction of wrist
What movements does palmaris longus do?
Flexion of wrist
What movements does FCU do?
Flexion and adduction of wrist
Which muscle is in the middle layer of the anterior forearm?
Flexor digitorum superficialis
What does FDS give rise to?
4 tendons
Which muscles are in the deep layer of the anterior forearm?
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
What is the innervation of flexor digitorum profundus?
Lateral half which gives rise to tendons in index and middle fingers = median
Medial half for tendons in ring and little fingers = ulnar
What forms the floor and roof of carpal tunnel?
Floor = carpal bones
Roof = flexor retinaculum
How many tendons pass through carpal tunnel?
9
Which give rise to tendons that pass through carpal tunnel?
Flexor digitorum superficialis
Flexor digitorum profundus
Flexor pollicis longus
Which nerve travels through carpal tunnel?
Median
Where does the brachial artery bifurcate?
Cubital fossa into radial and ulnar
Which are the two main superficial veins in the upper limb?
Cephalic (laterally) and basilic (medially)
What connects the cephalic and basilic arteries?
Medial cubital vein in cubital fossa
What do the deep veins drain into?
Axillary vein
What does the basilic vein form proximally?
Axillary vein when received input from deep veins
What does the cephalic vein drain into?
Axillary
What forms the radiocarpal joint?
Distal radius articulates with scaphoid and lunate
What is the 1st metacarpal?
Lateral, the thumb
How many phalanges are in each finger?
3
2 in the thumb
What are the 3 phalanges if each finger called?
Proximal, middle, distal
Where are the carpometacarpal joints?
Between distal carpals and proximal base of metacarpala
Where are the metacarpophalangeal joints?
Between distal metacarpals and proximal phalanges
Where are the interphalangeal joints? And how many are there?
Lie between the phalanges
Thumb has 1, fingers have 2 (proximal and distal)
What is the power grip of the hand used for?
Hold or squeeze objects tightly
What is the hook grip of the hand used for?
Carrying objects with handles
What is the precision grip used for?
Hold objects between thumb and index finger
What are the movements of fingers (digits 2-5)?
Flexion
Extension
Abduction
Adduction
What are the movements of the thumb?
Flexion
Extension
Abduction
Adduction
Oppositiion
Where are the extrinsic muscles of the hand?
Anterior and posterior forearm
Where are the intrinsic muscles of the hand?
Within hand
What muscles from the anterior forearm are prime flexors of the wrist?
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Where do flexor carpi radialis and ulnaris attach in the hand?
FCR inserts onto 2nd metacarpal
FCU inserts onto 5th metacarpal
Where does palmaris longus insert if present?
Palmar fascia
Which anterior compartment muscles flex the digits?
Flexor digitorum superficialis
Flexor digitorum profundus
Flexor pollicis longus
Also cross the wrist so contribute to wrist flexion
What does the tendon of fds flex?
metacarpophalangeal joints and proximal interphalangeal joints of digits 2-5
What does the tendon of fdp flex?
The only muscle capable of flexing distal interphalangeal joints
Also flexes proximal IP and metacarpophalangeals of 2-5
What does the tendon of flexor pollicis longus do?
Inserts onto distal phalanx of thumb and flexes interphalangeal joint
Where does the tendon of fds insert?
Splits into two and inserts either side of the middle phalanx on digits 2-5
Where does the tendon of fdp insert?
Through the slit in fds into palmar aspect of distal phalanx on digits 2-5
Where does the tendon of FPL insert?
Distal phalanx of thumb
What are flexor tendon sheaths?
Fibrous sheaths that enclose long flexor tendons
Maintain position of flexor tendons in the midline of each finger
What does the synovial sheath do in finger tendons?
Within fibrous sheath
Reduces friction
Allows tendons to slide freely within fibrous sheath
What is tenosynovitis
Inflammation of tendon and synovial sheath
What are the four groups of intrinsic muscles in the hand?
Thenar eminence
Hypothenar eminence
Lumbricals
Interossei
Where is the thenar eminence?
Fleshy mass at base of thumb on palm side
What are the three muscles of the thenar eminence and what do they do?
Flexor pollicis brevis- flexes the thumb
Abductor pollicis brevis- abducts the thumb
Opponens pollicis, deep to other two- opposes the thumb
What innervates the muscles of the thenar eminence?
Recurrent branch of median nerve
Where do the 3 muscles of thenar eminence insert?
FPB- proximal phalanx
APB- lateral proximal phalanx
OP- 1st metacarpal
What does adductor pollicis do?
Contraction adducts the thumb
Where does adductor pollicis lie and what is its innervation?
Deep in palm
Attached to 3rd metacarpal an proximal phalanx of thumb
Ulnar nerve
What is the hypothenar eminence?
Fleshy mass on the medial side of the palm of the hand, proximal to little finger
Contains 3 small muscles that act on little finger
What are the 3 muscles in the hypothenar eminence?
Flexor digiti minimi- flexes little finger
Abductor digiti minimi- abducts little finger
Opponens digiti minimi- opposes little finger
Where do the muscles of the hypothenar eminence insert and what is their innervation?
FDM and ADM- insert onto proximal phalanx
ODM- 5th metacarpal
Ulnar nerve
What are the lumbrical muscles?
Arise from the tendons of FDP
Travel along the lateral aspects of digits 2-5 and insert onto dorsal
Flex the metacarpophalangeal joints and extend interphalangeal simultaneously
How many lumbrical muscles are there?
4 one for each finger
What is the innervation of the lumbrical muscles?
Digits 2-3 (lateral) median
Digits 4-5 (medial) ulnar
What are the 2 groups of interossei muscles and where do they lie?
Between metacarpals and insert onto dorsal aspects of digits 2-5
Palmar and dorsal group
What do the palmar interossei do?
Contract to adduct the fingers
What do the dorsal interossei do?
Contract to abduct the fingers (away from middle finger)
Locations of the palmar interossei
1st: arises from medial side of 2nd metacarpal, inserts onto medial aspect of 2nd proximal phalanx
2nd: arises from lateral side of 4th metacarpal, inserts onto lateral 4th proximal phalanx
3rd: arises from lateral 5th metacarpal, inserts onto lateral 5th proximal phalanx
Locations of the 1st and 2nd dorsal interossei
1st: arises from medial side of 1st metacarpal and lateral of 2nd, inserts onto lateral 2nd proximal phalanx
2nd: medial side of 2nd metacarpal and inserts onto lateral 3rd proximal phalanx
Locations of 3rd and 4th dorsal interossei
3rd: medial side of 3rd metacarpal and lateral of 4th to insert onto medial aspect of 3rd proximal phalanx
4th: arises from medial side of 4th metacarpal and lateral side of 5th, inserts onto medial aspect of 4th proximal phalanx
What makes up the carpal tunnel?
Carpal bones and flexor retinaculum
What tendons travel through the carpal tunnel?
Long flexor tendons of FDS, FDP and FPL
What travels over the carpal tunner?
Tendons of flexor carpi radialis and ulnaris and palmaris longus
Radial and ulnar artery
Ulnar nerve
Where in the skin of the hand does the median nerve innervate?
Palmar surface of lateral side and lateral 3 1/2 digits (skin over dorsum of distal phalanges of these digits)
Where in the skin of hand does the ulnar nerve innervate?
Palmar and dorsal surfaces of the medial side of the hand and medial 1.5 digits
Where does the radial nerve innervate in the hand?
Dorsal surface of lateral side of hand
Skin over the dorsum of lateral 3.5 digits as far as the distal IP joint
Why would an injury to the median or ulnar nerves at the wrist not impair sensation to the palm of the hand but would to the fingers?
Cutaneous branches that supply the palm arise in the forearm
The branches that supply the palmar aspect of the corresponding fingers would be impaired as these branches come from distal to wrist
Where are the dermatomes from C4-6?
C4- Upper shoulder
C5- lateral side of anterior and posterior arm
C6- lateral side of anterior and posterior of forearm and palm, both sides of thumb and index
Where are the dermatomes for C7-T1?
C7- anterior and posterior surfaces of the middle finger and middle palm
C8- medial side of anterior and posterior forearm and palm, both sides of digits 4-5
T1- medial side of the arm
Where would you test sensation for C5-T1?
C5: Upper lateral arm
C6: Thumb
C7: Middle finger
C8: Medial border of hand
T1: Medial border of arm
What are the terminal branches of the brachial artery?
Radial and ulnar
What are the 2 palmar arterial arches?
Superficial formed mostly by ulnar
Deep palmar arch formed mostly by radial
What are the 6 superficial muscles of the posterior compartment?
Brachioradialis
Extensor carpi radialis longus and brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
Where does brachioradialis begin and insert?
Originates on humerus proximal to lateral epicondyle
Inserts on the distal radius
Which nerve innervates the muscles in the posterior compartment of the forearm?
Radial
Actions of brachioradialis and extensor carpi radialis/brevis
Brachioradialis is a weak flexor of the elbow joint
ECRL/B extend and abduct the wrist
What do extensor digitorum, digiti minimi and carpi ulnaris do?
ED: extends digits via 4 long tendons that insert onto dorsal aspects of fingers
EDM: extends little finger
ECU: extends and adducts the wrist by inserting onto 5th metacarpal
What are the deep muscles of the posterior compartment? (upper limb)
Supinator
Abductor pollicis longus
Extensor pollicis brevis and longus
Extensor indicis
Which 3 bones make up the hip bone?
pubic bone, the ilium and ischium, which fuse at the acetabulum
Where do the hip bones articulate?
anteriorly with each other at the pubic symphysis
posteriorly with the sacrum at the sacroiliac joints.
What is the obturator canal?
A small gap in the obturator membrane for vessels and nerves to pass between pelvis and thigh
Describe the femur
The long bone of the thigh
Has a head, neck and shaft
It’s distal end is expanded
What does the head of the femur articulate with?
the acetabulum of the pelvis to form the
hip joint
What are the greater and lesser trochanters of the femur?
2 bony processes distal to the neck
Sites of muscle attachment
Greater is lateral and anterior
Lesser is posteromedial, iliopsoas attachment
Where is the intertrochanteric line?
Between the greater and lesser trochanters on anterior femur
What is the trochanteric fossa?
A small hollow on the medial aspect of the greater trochanter
What is the linea aspera?
A bony vertical ridge on the posterior aspect of the shaft of the femur
Site of muscle attachment
What does the distal end of the femur expand to form?
medial and lateral femoral condyles
What surrounds the thigh?
Fascia lata
What is the iliotibial band?
A thickening of the lateral part of the fascia lata
Attaches to the lateral aspect of the proximal tibia
Important for stabilising the knee joint
What are the muscles of the anterior compartment of the thigh?
Quadriceps femoris (4)
Sartorius
Iliopsoas
Pectineus
What makes up the quadriceps femoris and what does it do?
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Extend the knee
Where do quad femoris run?
converge onto the quadriceps tendon which runs over the patella to insert onto the tibial tuberosity via the patellar ligament
What innervates the muscles of the anterior compartment of the thigh?
Femoral nerve (L2-4)
Where does rectus femoris lie?
Attached to anterior inferior iliac spine proximally
Lies in midline of thigh
Crosses the hip
What actions does rectus femoris help with?
Extension of knee
Flexion of hip
Where does vastus lateralis attach and run?
Lies lateral to RF and attaches to linea aspera on posterior aspect of femoral shaft
Where does vastus medialis lie?
Medial to RF
Attaches to linea aspera
Where does vastus intermedius lie?
Deep to rectus femoris
Attaches to anterior aspect of the femoral shaft
Where does sartorius lie and attach?
Superficially in anterior thigh
Attaches proximally to anterior superior iliac spine
Inserts onto medial proximal tibia
Crosses hip and knee joints
What movements does sartorius do?
Not a prime mover
Contributes to flexing hip and knee, and laterally rotating hip
Which muscles make up iliopsoas?
Psoas major and iliacus
Converge onto lesser trochanter
Where do iliopsoas originate from?
Psoas major- lumber vertebrae
Iliacus- iliac fossa of pelvis
What movement does iliopsoas do?
Flexion of hip joint
Where does pectineus lie?
Originates from the pectineal line of the pubis bone.
Inserts onto the pectineal line on the posterior aspect of the femur, immediately inferior to the lesser trochanter
Innervation of sartorius and pectineus?
Femoral nerve
Innervation of iliopsoas
psoas major is innervated by anterior rami of L1-3
iliacus is innervated by the femoral nerve
What are the muscles of the medial thigh (5)?
Adductor brevis, longus and magnus
Gracilis
Obturator externus
What innervates the muscles in the medial thig?
Obturator (L2-4)
What is the primary movement of the medial thigh muscles?
Adductors of hip
What are the 2 components of adductor magnus?
adductor component and a hamstring component
Attachments of adductor part of AM
Attaches to inferior pubic ramus and linea aspera
Attachments of hamstring part of AM
Attaches to ischial tuberosity and adductor tubercle
Attachments of adductor brevis and longus
AB deep to AL
Attach to pubic bone and linea aspera
Obturator nerve lies inbetween
What is the adductor hiatus?
a gap between the adductor and hamstring attachments of the adductor magnus muscle
femoral artery and veins travel through to enter posterior thigh
Where does gracilis attach?
Most medial
Attaches to pubic bone and medial aspect of tibia
Movements of gracilis?
Weak adductor of hip and flexor of hip and knee