Part 3: Appendicular musculature Flashcards
Major characteristics of the appendicular musculature
1) Innervation by spinal nerves forming plexuses (with exception of trapezius - CN XI spinal accessory nerve)
2) Attachments on axial & appendicular skeleton
3) Movements: muscle contractions cause a limb segment to move in a specific plane at a given joint
Limb muscles are organized into ______(each is innervated by ______)
compartments
a specific nerve branch of a plexus
Upper limbs are innervated by _____ except ____
by branches of the brachial plexus (levels C5 to T1 of spinal cord) except trapezius (CN XI – spinal accessory n.)
Fur major muscle groups crossing upper limb joints
Shoulder (pectoral girdle)
Arm
Forearm
Hand
Upper limb joints are designed for ____(rather than ____).
mobility
stability
Major functions of the upper limb musculature
1) Muscles positioning the pectoral girdle
2) Muscles moving the arm
3) Muscles moving the forearm & hand
4) Muscles moving the hand & digits
Label Muscles moving the pectoral girdle (shoulder)
1) Trapezius: Occipital & spinous processes to clavicle & scapular spine; elevator, retractor, & depressor of scapula
2) Levator scapulae: Transverse processes to superior vertebral border of scapula; Elevator of scapula
3) Rhomboids (major & minor): Spinous processes to vertebral border of scapula; Retractors of scapula
4) Serratus anterior: Ribs to vertebral border of scapula (anterior surface); Protractor of scapula
To move arm up, these muscles contract
Trapezius (lower) + Trapezius (upper)
Serratus anterior
Pectoralis minor attaches where? does what?
anteriorly to girdle
Depresses & protracts scapula; elevates ribs
To move arm down, these muscles contract
pectoralis minor (brings hand down)
levator scapulae (contract up)
rhomboids (contract up)
label muscles moving the arm
Pectoralis major: Ribs/sternum, clavicle to lateral side of intertubercular sulcus; Arm adductor, flexor & medial rotator
Deltoideus: Clavicle & scapular spine to deltoid tuberosity; Major arm abductor; arm flexor & medial
rotator (anterior part)
Subscapularis: Subscapular fossa to lesser tubercle; Medial arm rotator
label muscles moving the arm
Deltoideus: Clavicle & scapular spine to deltoid tuberosity; Major arm abductor; arm extensor & lateral rotator (posterior part)
Latissimus dorsi: Spinous processes, ribs, iliac crest to the intertubercular sulcus (middle); Powerful arm retractor; arm extensor, adductor & medial rotator
Teres major: Inferior angle of scapula to medial side of intertubercular sulcus; Arm extensor & medial rotator (assists latissimus dorsi)
label muscles moving the arm
Supraspinatus: Supraspinous fossa to greater tubercle;Arm abductor (assists deltoid)
Infraspinatus: Infraspinous fossa to greater tubercle;Lateral arm rotator
Teres minor: Axillary border to greater tubercle; Lateral arm rotator
Rotator cuff muscles
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Tendons of SITS muscles reinforce _____& hold the humeral head against _____
shoulder joint capsule
glenoid fossa (preventing dislocation of shoulder joint)
The only muscle NOT on the greater tubercle is the ______
anterior muscle (subscapularis muscle = lesser tubercle)
label muscles- the forearm at the elbow joint: flexors
Brachialis (deeper): Humeral shaft to coronoid process of ulna; Powerful forearm flexor (especially when pronated)
Brachioradialis: Above lateral epicondyle to styloid process of radius; Forearm flexor when half pronated
Biceps brachii (long & short heads): Scapula (above glenoid cavity & coracoid process) to radial tuberosity; Powerful forearm supinator; forearm flexor (especially strong when supinated); assists arm flexing
label muscles- the forearm at the elbow joint: extensor
Triceps brachi (long, lateral, medial heads): under glenoid cavity, superior shaft of humerus, inferior shaft of humerus (deepest head) to olecranon process; Forearm extensor (assists in arm extension), antagonist of all 3 flexors
Abduction of the wrist = ____
Adduction of the wrist = _____
All muscles attach at ____ for wrist joint
radial deviation
ulnar deviation
the carpals
anterior muscles at wrist joint
Flexor carpi radialis: Hand flexor & abductor
Palmaris longus: Weak hand flexor (not always present)
Flexor carpi ulnaris: Hand flexor & adductor
Flexor retinaculum: Strong fibrous band forming roof of carpal tunnel
anterior muscles at digits -intermediate layer
Flexor digitorum superficialis (FDS): Finger flexor (insert on middle phalanges of digits 2,3,4,5)
anterior muscles at digits -deep layer
Flexor pollicis longus (FPL): Radial shaft to distal phalanx of digit 1; Thumb (pollex) flexor
Flexor digitorum profundus (FDP): Ulnar shaft to distal phalanges of digits 2-5
Finger flexor
Carpal tunnel syndrome
Repetitive motion of flexor tendons can irritate their sheath coverings, leading to swelling & compression of median nerve in carpal tunnel
9 flexor muscle tendons_______ travelling through carpal tunnel (_____)
(FDS, FDP, FPL) & median nerve
Flexor retinaculum - anterior roof
Label Posterior muscles moving the hand at the wrist joint
Extensor carpi radialis longus & brevis: Hand extensor & abductor
Extensor carpi ulnaris: Hand extensor & adductor
All muscles attach at the carpals
Label Posterior muscles moving the digits
Extensor digitorum & extensor digiti minimi (5th digit) : Finger extensors (digits 2,3,4,5)
Extensors (longus & brevis) & abductor pollicis (for thumb) : Thumb extensor & abductor
All muscles attach at the distal phalanges (via extensor hood)
Muscles involved in supination of the wrist
supinator
biceps branchii
Muscles involved in pronation of the wrist
pronator teres
pronator quadratus
pronator teres
Both pronator teres and quadratus go from ____ (pronator teres has an additional head on the ___)
ulna to radius
medial epicondyle
Hypothenar muscles are ____ and control ____
Flexor digiti minimi, Opponens digiti minimi, Abductor digiti minimi
pinky finger
Thenar muscles are ____ and control ____
Flexor pollicis brevis, Opponens pollicis, Abductor pollicis brevis
thumb
Thenar & hypothenar muscles (important role for _______)
opposition of thumb & pinky finger
anterior muscles moving the digits
orange: 3 palmar interossei - finger adductors (digits 2,4,5)
yellow: 4 lumbricals: Flexor of metacarpophalangeal joints but extensors for interphalangeal joints (Digits 2,3,4,5) since they attach on the extensor hood
green: adductor pollicis: thumb pollicis
purple: felxor pollicis brevis
blue: opponens pollicis
pink: abductor pollicis brevis
posterior muscles moving the digits
4 Dorsal interossei: Finger abductors (digits 2,3,4); Middle finger gets 2 dorsal interossei; little finger & thumb have their own abductors
power grip muscle activated
Active contraction of digital flexors muscles found in the forearm (ex. flexor digitorum profundus)
precision grip muscle activated
Active contraction of some short muscles found in the hand (ex. thenar & hypothenar muscles)
lower limb innervated by _____
branches of the lumbosacral plexus (levels L2 to S3 of spinal cord)
Four major muscle groups crossing lower limb joints:
Hip (pelvic girdle)
Thigh
Leg
Foot
Lower limb joints are designed for _____(with various degrees of _____depending on joint).
stability
mobility
________ are all important functional roles of the lower limb.
Locomotion, posture, & balance
Major functions of the lower limb musculature
Muscles moving the thigh
Muscles moving the leg
Muscles moving the foot & toes (digits)
label muscle moving the thigh at hip joint
Gluteus minimus : Ilium to greater trochanter; Thigh abductor & medial rotator
Gluteus medius: Iliac crest to greater trochanter ; Thigh abductor & medial rotator
Gluteus maximus: Iliac crest & sacrum to gluteal tuberosity ; Thigh (hyper) extensor & lateral rotator (good for running & climbing)
The lesser gluteal muscles (gluteus medius & minimus muscles keep _____
the pelvis from tilting down on unsupported side (side of swinging leg) during walking
label muscles at thigh (hip joint)
Iliopsoas (iliacus + psoas major): Iliac fossa & transverse processes to lesser trochanter; Thigh flexor
Adductor muscle group:(magnus, longus, brevis):
Pubis to linea aspera; Thigh adductor, flexor, & medial rotator
label anterior thigh muscles
Quadriceps femoris (rectus femoris & vastus lateralis, intermedius, medialis): ASIS & femoral shaft to tibial tuberosity via patella; Leg extensor; Thigh flexor (rectus femoris only)
Sartorius: ASIS to medial side of tibial tuberosity; Thigh & leg flexor; abduction & lateral rotation
label posterior muscles moving leg at the knee point
Semitendinosus: Medial condyle of tibia
Semimembranosus :Medial condyle of tibia
Biceps femoris (long & short heads): Lateral condyle of tibia & head of fibula
All are leg flexors & thigh extensors at hip joint
label posterior muscles moving the foot at the ankle joint
Gastrocnemius (superficial): Medial & lateral femoral condyles; flexor at the knee
Soleus (deeper): shafts of both the tibia & fibula
*Both muscles (also known as triceps surae) are powerful foot plantarflexors
Calcaneal (Achilles) tendon (attach to the calcaneal tuberosity of the calcaneus)
flexor digitorium longus
Tibia to distal phalanges (digits 2,3,4,5); Foot plantarflexors & digit flexors
tibialis posterior
Tibia & fibula to tarsals; Foot plantarflexors
& digit flexors
flexor hallucis longus
Fibula to distal phalanx of 1st digit (big toe); Foot plantarflexors & digit flexors
label posterior muscles moving the foot at the ankle joint
red: flexor digitorium longus
yellow: flexor hallucis longus
blue: tibialis posterior
label Muscles moving the digits of the foot
Extensor digitorum longus: Tibia to distal phalanges (digits 2,3,4,5); Toe extensor (digits 2,3,4,5)
Extensor hallucis longus: Fibula to distal phalanx of 1st digit; Big toe (hallux) extensor
Tibialis anterior: Tibia to 1st metatarsal superiorly; Foot dorsiflexor & inverter
label anterior muscles moving the foot at the ankle joint
2 fibularis (peroneus) muscles (longus & brevis): Fibula to metatarsals inferiorly; Foot everters & plantarflexors
Fibularis longus – support arches of foot
