Anatomy Muscular System Test

Produce movement, maintain posture, joint stability, generate heat

4 important functions of the muscular system

Excitability, contractility, extensibility, elasticity

4 Functional characteristics of muscles

Excitability

Muscles retain the ability to receive and respond to stimuli from the nervous system

Contractility

Muscles shorten upon stimulation

Extensibility

When relaxed, muscles may be stretched

Elasticity

After shortening or stretching, muscles return to original length

Origin and insertion

sites where muscle originates and inserts

Flexion

Decreasing angle between 2 bones

Dorsiflexion

Decreasing angle between foot/shin

Plantar flexion

Pointing toes

Extension

Increasing angle between 2 bones

Abduction

Body parts away from midline

Adduction

Body part toward midline

Circumduction

Movement in circular motion

Rotation

Turning movement of bone about its long axis

Supination

Palm up

Pronation

Palm down

Inversion

Soles of feet in

Eversion

Soles of feet down

Elevation

Lifted up

Depression

Lowered back to normal state

Prime mover

Muscle with the major responsibility for a certain movement (ex. biceps brachii)

Antagonist

The muscle in opposition to the action of the prime mover; relaxes (stretches) during the prime movement (ex. triceps brachii)

Synergist

Muscle that aids a prime mover in a movement; helps prevent rotation (ex. brachialis)

Fixator

Muscle that stabilizes the origin of the prime mover (holds in place) so that the prime mover can act more efficiently (ex. serratus anterior, pectoralis major)

Rectus, transverse, oblique

direction of fascicles relative to midline... directional term examples

Rectus

Straight up/down

Transverse

Side to side

Oblique

45 degree angle

Frontal bone, tibia

Terms for the muscle classification: location

Maximus, longus, brevis

Terms for the muscle classification: relative size

Maximus

Largest

Longus

Longest

Brevis

Shortest

Biceps (2), triceps (3)

Terms for the muscle classification: # of origins (heads)

Deltoid, trapezius, serratus, orbicularis

Terms for the muscle classification: shape

Deltoid

Triangle

Trapezius

Trapezoid

Serratus

Saw-toothed

Orbicularis

Circular

Flexion, extension, abduction

Terms for the muscle classification: action

Epicranius

Muscle of facial expression; covers cranium; elevates eyebrow

Frontalis

Muscle of facial expression; over forehead; elevates eyebrow

Occipitalis

Muscle of facial expression; over occipital; elevates eyebrow

Orbicularis oris

Muscle of facial expression; circular muscle around the mouth; closes/purses lips; "kissing muscle"

Zygomaticus

Muscle of facial expression; muscle that connects zygomatic arch to corner of mouth; elevates corners of mouth; "smiling muscle"; O: zygomatic arch; I: corners of orbicularis oris

Buccinator

Muscle of facial expression; hollow of cheek; compresses cheek; "trumpeter's muscle"

Platysma

Muscle of facial expression; over lower jaw to neck; depresses mandible; "jaw-dropping" muscle

Orbicularis oculi

Muscle of facial expression; circular muscle around eye; closes eye

Massater

Muscles of mastication/head movements; over lateral mandible; elevates mandible/aids in chewing; O: zygomatic arch; I: lateral mandible

Temporalis

Muscles of mastication/head movements; convergent muscle over temporal bone; elevates mandible

Sternocleidomastoid

Muscles of mastication/head movements; major neck muscle; flexion of head toward chest; "head-turning" muscle; O: sternoclavicular region; I: mastoid process of temporal bone

Trapezius

Muscles moving pectoral girdle; trapezoid-shaped muscle in posterior neck/upper back; elevates pectoral girdle; "shoulder shrug" muscle; O: occipital bones/spine C7-T12; I: Clavicle/acromion process of scapula

Pectoralis minor

Muscles moving pectoral girdle; muscle deep to pectoralis major; scapula fixator;

Serratus anterior

Muscles moving pectoral girdle; saw-toothed lateral thoracic muscle; scapula fixator

Pectoralis major

Muscles that move the arm; large, convergent chest muscle; flexes arm medially (pull arms forward/together); O: Clavicle, sternum, and costal cartilage of ribs 1-6; I: greater tubercle of humerus

Latissimus dorsi

Muscles that move the arm; large, back muscle; adduction of humerus

Deltoid

Muscles that move the arm; triangle-shaped shoulder muscle; abduction of humerus

Biceps brachii

Muscles that move the forearm; fusiform (2 branches), parallel, anterior upper arm (2 origins); flexion of arm at elbow; prime mover; O: coracoid process; I: radial tuberosity

Brachialis

Muscles that move the forearm; muscle beneath bicep brachii; flexion of arm at elbow; synergist

Brachioradialis

Muscles that move the forearm; lateral muscle between upper arm;forearm; flexion of arms at elbow; synergist

Triceps brachii

Muscles that move the forearm; posterior upper arm muscle; 3 heads; extension of arm at elbow

Flexors

Anterior muscles of the forearm are mostly _______ of wrist/fingers.

Extensors

Posterior muscles of the forearm are mostly ________.

Flexor carpi, radialis

Muscles that move the forearm; (2 answers); anterior, lateral forearm muscle; flexion of wrist

Flexor carpi, ulnaris

Muscles that move the forearm; anterior, medial forearm muscle; flexion of wrist

Extensor digitorum

Muscles that move the forearm; posterior forearm muscle; extension of wrist/fingers

Subscapularis

Muscles of the shoulder-rotator cuff; anterior surface of scapula; internal rotation/stabilization

Supraspinatus

Muscles of the shoulder-rotator cuff; posterior side of scapula above spine; abduction/stabilization

Infraspinatus

Muscles of the shoulder-rotator cuff; below scapular spine; lateral rotation/stabililzation

Terers minor

Muscles of the shoulder-rotator cuff; lateral border of scapula; lateral rotation/stabilization

Rectus abdominus

Muscles that tense the abdominal wall; Strap-like muscle from costal cartilage to ilium; parallel to midline (6 pack); tenses abdominal wall/flexion of torso; O: pubic crest/symphysis, I: xiphoid process/costal cartilages of ribs 5-7

External oblique

Muscles that tense the abdominal wall; superficial/lateral oblique abdominal muscles; tenses abdominal wall/twist

Internal oblique

Muscles that tense the abdominal wall; deep oblique abdominal muscle; tenses abdominal wall/twist

Transversus abdominis

Muscles that tense the abdominal wall; deep abdominal muscle that runs perpendicular to rectus abdominis; tenses abdominal wall

Gluteus maximus

Muscles that move the thigh; buttocks, largest muscle in body; extension of hip at though; walking/climbing stairs; O: dorsal ilium, sacrum, coccyx; I: posterior femus

Gluteus medius

Muscles that move the thigh; lateral hip muscle; abduction of femur

Adductor longus

Muscles that move the thigh; medial thigh muscle; adduction of femur

Rectus femoris

Muscles that move the leg; ANTERIOR; anterior thigh, quadricep; extension of leg at the knee

Vastus lateralis

Muscles that move the leg; ANTERIOR; lateral anterior thigh, quadricep; extension of leg at the knee

Vastus medialis

Muscles that move the leg; ANTERIOR; medial anterior though, quadricep; extension of leg at the knee

Vastus intermedius

Muscles that move the leg; ANTERIOR; deep anterior thigh, quadricep; extension of leg at the knee

Sartorius

Muscles that move the leg; ANTERIOR; parallel straplike muscle that crosses the thigh; flexion of knee forward (hip); crossing leg motion; O: Iliac spine; I: medial tibia

Biceps femoris, semitendinosus, semimembranosus

Muscles that move the leg (3); POSTERIOR; posterior thigh, manstring; flexion of leg at the knee

Quadriceps

Collective name for all 4 anterior leg muscles; most powerful muscle group in body

Hamstrings

Collective name for all 3 posterior leg muscles

Tibialis anterior

Muscles that move the foot/toes; anterior to tibia; dorsiflexion

Fibularis longus

Muscles that move the foot/toes; Lateral to fibula; eversion

Gasterocnemius

Muscles that move the foot/toes; posterior lower leg (calf muscle), 2 origins; plantar flexion; prime mover; O: condyles of femur; I: Calcaneus

Soleus

Muscles that move the foot/toes; behind (deep to) gastrocnemius; plantar flexion; synergist