Muscular System - Antatomy

Frontalis function

raises eyebrows (upward)

Temporalis function

elevates mandible (upward)

Occipitalis function

tenses and retracts scalp (downward)

Platysma function

depresses mandible

Trapezius function

extension at the neck

Splenius Capitis function

extension at the neck

Sternocleidomastoid function

both contract = flexion at the neck

one contract = rotation at the neck

Orbicularis oculi function

open/close eye

orbicularis Oris function

purses lips

Buccinator function

compresses cheek

Zygomaticus function

smile

Functions of the muscular system (5)

Movement

Generating Heat

Posture/Support

Guards entrances/exits

supports soft tissue

Properties of Muscle Tissue (4)

contractility (get shorter)

extensibility (get longer)

elasticity (bounce back)

excitability (respond to stimuli)

Masseter

Elevates mandible

What thoracic muscles can you see both anterior and posterior (3)

Deltoid

Trapezius

Serratus Anterior

What thoracic muscles are only seen from the posterior (8)

Latissimus Dorsi

Infraspinatus

Supraspinatus

Teres major

Teres minor

Rhomboid

Splenius Capitis

Levator Scapulae

What thoracic muscles can only be seen from the anterior (4)

Pectoralis major

Pectoralis minor

External/Internal oblique and transverse abs

Rectus abdominis

List the ab muscles from deep to superficial

transverse →internal oblique →external oblique

Gracilis (most medial) function (2)

adduction at hip

flexion at knee

Tensor fascia late function

hip abduction

Sartorious function

flexion at hip and knee

Rectus femoris function (2)

flexion at the hip

extension at knee

4 muscles that make up the quads

vastus lateralis

vastus medialis

vastus intermedias

rectus femoris

vastus lateralis function

extension at knee

vastus medialis

extension at knee

vastus intermedialis

extension at knee

Iliopsoas function

flexion at hip

Tibialis anterior function

dorsiflexion (flexion at foot)

Gluteus maximus function

extension at hip

Gluteus medius function

abduction at hip

Biceps femoris (most lateral) function

flexion at the knee

extension at the hip

Semitendionosus

flexion at the knee

extension at the hip

Semimembranosus function

flexion at the knee

extension at the hip

What make up your hamstrings (3)

Biceps femoris

semimembranosus

semitendinosus

Gastrocnemius function

plantar flexion

flexion at the knee

soleus function

plantar flexion

The anterior arm muscles do what

flexion

The muscles that make up the anterior of the arm (7)

brachialis

brachioradialis

biceps brachii

pronator teres

flexor Carpi ulnaris

palmaris longus

flexor Carpi radialis

pronator function

rotate medially (inward)

Supinator function

rotate laterally (outward)

what one flexor muscle can you see posteriorly on the arm

flexor carpi ulnaris

What function do the posterior arm muscle do

extend

epimysium

outermost layer - surrounds entire muscle

fascicle

bundles of muscle fibers

perimysium

separates and surrounds fascicles

muscle fiber

cells

endomysium

surrounds each individual muscle fiber

sarcolemma

muscle fiber membrane

sarcoplasm

muscle cell cytoplasm

sarcoplasmic reticulum

specialized endoplasmic reticulum

myofibrils

within the sarcoplasm are parallel fibers - multinucleated

steps in the sliding filament theory (5)

sarcoplasmic reticulum releases calcium

Calcium bind to troponin →moves tropomyosin out of the way

myosin head bind to actin →crossbridge

“power stroke”→myosin release energy (ratcheting)

ATP →resets"

process of neuromuscular junction (5)

electrical signal travels down the axon

synaptic vesicles release ACh in synaptic cleft

ACh binds to receptors

ACh receptors initiate contraction of fibers (T tubules)

ACh is removed from cleft by AChE