BIOL 2401 Ex 8A Set 1

frontalis

Raises eyebrows

occipitalis

Draws scalp backwards

orbicularis oculi

Closes, blinks, squints eye

orbicularis oris

closes, purses lips

zygomaticus major

pulls mouth into smile

temporalis

muscle on the cranium that elevates the mandible

masseter

muscle on the mandible that elevates mandible

sternocleidomastoid (both sides)

flex head and neck

sternocleidomastoid (single side)

rotate head and neck

trapezius (superior region)

extends head

trapezius (upper/middle region)

elevates scapula

trapezius (lower region)

depresses scapula

deltoid

abducts arm (humerus)

pectoralis major

flexes and adducts arm

latissimus dorsi

extends and adducts arm

pectoralis major and latissimus dorsi

2 muscles that both rotate arm medially

serratus anterior

scapula fixator (holds against chest wall) - protracts scapua

external intercostals

elevate ribs during inspiration

internal intercostals

depress ribs during forced expiration

diaphragm

enlarges thoracic cavity (vertically) during inspiration

external obliques

lateral abdominal muscles compress abdomen

rectus abdominis

midline muscle pair compresses abdomen and flexes vertebral column

biceps brachii

flexes arm (at shoulder) and forearm (at elbow); supinates hand

triceps brachii

extends forearm

iliopsoas

This group flexes at the hip

adductor group

This group brings the thigh in medially, as in jumping jacks.

gluteus medius

abducts and medially rotates thigh

gluteus maximus

extends and laterally rotates thigh

sartorius

crosses legs by flexing leg and thigh, and laterally rotating thigh

quadriceps femoris

this group extends the leg (at the knee)

rectus femoris

flexes thigh and extends leg

hamstrings

this group extends the thigh and flexes the leg

gastrocnemius

Main muscle that plantar flexes foot

tibialis anterior

dorsiflexes and inverts foot

peroneus (fibularis) longus

plantar flexes and everts foot