Maddie Robinson Chpater 6- Myology

number of muscles in the body

650

general characteristics of muscles

excitability and contractility

excitability

capacity to generate electrical impulses (AP)

contractility

capacity to shorten length

only 2 cells that exhibit excitability

muscle and nerve

3 functions of muscles

voluntary movement, maintenance of posture, heat

tendon of origin

head/cep

tendon of origin connects to

less moveable structure

tendon of insertion

tail

tendon of insertion connects to

more moveable structure

3 layers of fascia

epimysium, perimysium, endomysium

somatic motor unit consists of

somatic motor neurons + all muscle fibers it stimulates

proprioceptors

nerve receptors we feel

agonist

prime mover

synergist

helps movement

antagonist

causes opposite action to agonist

fixator

stabilizes + decreases unnecessary movement

characteristics of maximal training

anaerobic, low myoglobin = white

characteristics of sub-maximal training

aerobic, high myoglobin = dark

frontalis

raises eyebrows/wrinkles forehead

orbicularis oculi

closes eyelid

orbicularis oris

puckers lips

buccinator

compresses cheek

platysma

pulls lower lip + jaw downwards

zygomaticus

smiling

superior rectus

looking up

inferior rectus

looking down

medial rectus

looking towards middle

lateral rectus

looking towards sides

temporalis

closes jaw/elevates jaw

masseter

synergist for temporalis; elevates jaw

genioglossus

stick out tongue

styloglossus

pull tongue in

characteristics of facial muscles

superficial muscles, insert into overlaying skin, innervated by facial nerve

action of frontalis

raises eyebrow; wrinkle forehead

closes eyelids

orbicularis oculi

squinting, winking, blinking

orbicularis oculi

puckers lips

orbicularis oris

compresses the cheeks

buccinator

pulls lower lip down

platysma

bell’s palsy

unilateral paralysis of facial nerve

how many muscles move the eye

6

muscles elevates the mandible

temporalis

nerve innervates tongue

trigeminal nerve

2 characteristics of muscles of vertebral column

allow movement, stabilize spine when moving limbs

prevertebral muscles role

flex the spine

sternocleidomastoid

flex the neck

external oblique

flex waist; angle

internal oblique

flex waist; angle

transversus abdominus

flex waist; across/horizontal

rectus abdominus

flex waist; upright/vertical

quadratus lumborum

flex waist; 4 parts

iliopsoas

2 parts; psoas major/iliacus

why is iliopsoas switch hitter

allow flexion and extension of waist

postverbal muscle role

extension of spine

splenius

extend the neck; antagonist of sternocleidomastoid

3 muscles of erector spinae

spinalis, longissimus, iliocostalis

trapezius

pulls shoulders to midline

3 parts of trapezius

clavotrapezius, spinotrapezius, acromiotrape

rhomboideus

pulls shoulders to midline (synergist with trapezius)

serratus anterior

pulls shoulders down towards ribs

abduct

take away from midline

deltoid

abducts the arm

supraspinatus

abducts arm (synergist with deltoid)

supinate

cupping from under

biceps brachii

flexes forearm + supinates hand

brachialis

flexes forearm (synergist with biceps brachii)

brachioradialis

flexes forearm (synergist with biceps brachii)

triceps brachii

extends forearm

flexor carpi radialis

flex thumbs

palmaris longus

flex center fingers

flexor carpi ulnaris

flex pinky

pronator teres

pronates hand

extensor carpi radialis

extend thumb

extensor carpi ulnaris

extend pinky

thennar eminence

muscle for opposable thumb

levator ani

bulbocavernosus

tensor fascia lata

gluteus maximus

quadriceps femoris

rectus femoris

vastus lateralis

vastus medialis

vastus intermedius

sartorius

gracilis

biceps femoris

semitendinosus

semimembranosus

plantar flexion

dorsiflexion

tibialis anterior

extensor digitorum longus

gastrocnemius

soleus

flexor digitorum longus

peroneus longus

sternocleidomastoid

flex the neck