ZOOL 2403 Exam 2

frontalis

raises eyebrows

orbicularis oris

puckers lips

orbicularis oculi

closes eye

levator labii

raises lips

zygomaticus

smile

buccinator

tightens cheeks

depressor labii

lowers lips, frown

muscles of mastication

masseter and temporalis

suprahyoid muscles

elevate hyoid bone and depress mandible

infrahyoid muscles

depress hyoid bone and elevate larynx and pharynx

sternocleidomastoid

head/neck rotator

Head/neck extensors

function of posterior neck muscles

Erector spinae muscles

extend the trunk/keep it erect

2 intercostals

maintain distance between ribs

2 obliques

rotate the trunk

transverse abdominis

flattens abdomen

rectus abdominis

flexes trunk

diaphragm

primary muscle of respiration

urethral/anal sphincter

control urination and defecation

serratus anterior

shoulder protractor

levator scapulae

elevate scapula

rhomboid group

retract/adduct scapula

trapezius

shoulder elevator

deltoid

arm abductor

pectoralis major

arm medial rotation

latissimus dorsi

arm extensor and adductor

rotator cuff

supraspinatus, infraspinatus, teres minor, subscapularis

subscapularis

shoulder/arm stabilizer

suprapsinatus

abduct

infrapsinatus

external rotator

teres minor

external rotator + abductor

teres major

arm adductor + internal rotator

coracobrachialis

shoulder flexion

bracialis

arm curls

biceps brachii

arm and forearm flexors *also a supinator*

triceps brachii

arm and forearm extensor

pronator teres, brachioradialis, flexor carpi radialis/ulnaris

wrist flexors + pronators

flexor pollicis muscles/flexor digitorum muscles

thumb/finger flexors

extensor carpi radialis longus/radialis brevis/ularis

wrist/finger extensors

gluteus Maximus/medius/minimus

hip extensors and abductors

piriformis

lateral hip rotators

iliopsoas

hip flexor

adductor group

hip adductor

muscles of posterior thigh (hamstrings)

hip extensors and knee flexors

quadriceps

knee extensor

extensor digitorum/tibialis anterior/extensor hallucis

toe and foot extensors + dorsiflexors

fibularis muscles

foot flexors (plantar flexors)

gastrocnemius

foot flexors (plantar flexors)

muscles of posterior leg

toe flexors

dorsal foot

toe extensors + abductors

plantar foot muscles

toe flexors

functions of the CNS

-interpret sensory information from the PNS

-send motor responses to the PNS

-process and coordinate “higher functions” (consciousness, intelligence, memory, learning, emotions

functions of the PNS

- deliver sensory information

- deliver motor commands

2 divisions of the motor portion of PNS

somatomotor and autonomic

somatomotor

controls skeletal muscles, voluntary/conscious muscle contractions

autonomic

influence smooth/cardiac muscle contractions, involuntary/unconscious contractions, and glandular secretions

2 divisions of the autonomic nervous system

sympathetic and parasympathetic

sympathetic

fight or flight

parasympathetic

rest and digest

neurons

communicate w/ and send signals to other neurons or muscles in the body

Neuroglia

aka glial cells, support the neurons, essential for survival and proper functioning of neurons

cell body of neuron

receives and sums incoming signals from other neurons

dendrites

receive incoming signals from other neurons

axon

carries outgoing signals to other neurons or to muscle

synaptic or nerve terminals

transfer signals to other cells

action potential

electrical signal that travels along the axon

synapse

the site of contact between a neuron’s terminals and another cell

sensory receptors

detect sensations like pain, temperature, and touch

myelin

composed of lipids, insulated axons, increases the speed of action potential

Schwann cells

myelinate axons in the PNS

Oligodendroglial cells

myelinate axons in the CNS

dura mater → arachnoid mater → pia mater

3 layers of meninges that surround the CNS

Cerebral spinal fluid

in the space between the arachnoid and Pia mater, provides chemical protection and physical protection

conus medullaris

caudal end of the spinal cord

cauda equina

spinal nerves inferior to the conus medullaris

gray matter

neuron cell bodies

white matter

myelin

dorsal gray matter

sensory; receives + sums signals form the PNS sensory neurons

ventral gray matter

motor; receives + sums signals from the Brain motor neurons

white matter of the spinal cord

contains ascending and descending pathways

ascending pathways

relay sensory information from the spinal cord to the brain

descending pathways

relay motor commands from the brain to the spinal cord

dorsal root/dorsal root ganglia

carry sensory info form peripheral receptors to the spinal cord

ventral root

carry motor info from the spinal cord to the muscles

epineurium, perineurium, endometrium

connective tissue wrappings of the spinal nerves

epineurium

surrounds entire spinal nerve

perineurium

wraps axons into fascicles

endoneurium

surrounds individual axons

intercostal nerves

innervate muscles of the trunk (motor) and skin of the trunk (sensory)

spinal nerve plexus

innervates muscles and skin of the the neck and limbs

musculocutaneous nerve

innervates muscles of anterior arm and skin of anterior forearm

median nerve

muscles of anterior forearm and skin of hand

ulnar nerve

muscles of hand and skin of hand

radial nerve

muscles of posterior arm and forearm skin of posterior arm, forearm, and hand

axillary nerve

muscles and skin of shoulder

femoral nerve

muscles and skin of anterior thigh

obturator nerve

muscles and skin of medial thigh

sciatic nerve

muscles and skin of posterior thigh, all leg, and foot

ventricles of the brain

fluid filled chambers; function is to synthesize and secrete CSF

cerebrum

largest part of the CNS; associated with conscious thought and behaviors + higher mental functions