Head and Chest Muscles and Skeletal Muscle Structure Quiz

muscle fibers

skeletal muscle cells

fascicles

bundles of muscle fibers

myocytes

muscle cells, make up muscles

fascia

thin connective tissue around each individual muscle

epimysium

outermost layer of tissue that surrounds the entire muscle

perimysium

separates and surrounds the fascicles (muscle fiber bundles)

endomysium

surrounds each individual muscle fiber

sarcolemma

muscle fiber membrane

sarcoplasm

inner cytoplasmic material surrounding fibers

sarcoplasmic reticulum

transports and releases calcium

myofibril

individual parallel muscle fibers within sarcoplasm

1. divided into sarcomeres

myofilament

proteins actin (thin filaments) and myosin (thick filaments), located into myofibrils

frontalis

raises eyebrows

• forehead

occipitalis

assists frontalis

• lower back of head

temporalis

closes jaw

• side of head, above ear

orbicularis oculi

closes eyelid (blink)

• surrounding eye

zygomaticus

pulls up corners of lips (smile)

• across cheek, connecting orbicularis oris and temporalis

masseter

clenches jaw (Channing Tatum)

• across cheek, going down into point of jawline

orbicularis oris

purses lips (kissy face)

• surrounding lips

buccinator

pulls in cheeks (fishy face)

• across cheek, parallel to jawline

mentalis

protrudes + pulls down lower lip (frown/pouty face)

• point of chin

platysma

depresses mandible (double chin)

• complete side of neck

sternocleidomastoid

rotation of head + flexion of neck (chin to chest)

• crosses across neck from jawline to sternum

pectoralis major

flexes (arm down) + adducts whole arm (arms in front like macarena)

• pecs

pectoralis minor

depresses scapula

• inside of pecs, towards shoulder/armpit

rectus abdominis

flexes trunk + tightens abdomen

• middle of torso, abs

serratus anterior

draws scapula forward + rotates scapula (boxer’s muscle [throwing a punch])

• side under biceps, ribs area

external obliques

lateral flexion + rotation of trunk

• sides of torso, sides of abs