Ch 2: Essential Nervous System

Axons conduct information _______ cell body

away from

Dendrites conduct information _______ cell body

towards

Fascicles form when

axons are bundled together

The CNS consists of the ______ and ______.

brain and spinal cord

The PNS consists of __________ and ___________.

motor neurons and sensory neurons

What is the autonomic nervous system responsible for?

Directs and regulates subconscious, involuntary processes such as heart rate, digestion, and breathing

What is the somatic nervous system responsible for?

Controls voluntary muscle contraction and movement such as moving your arm to grab something

The sympathetic nervous system is characterized by

“fight or flight,” expending energy in the body and reacting quickly

The parasympathetic nervous system is characterized by

"rest and digest," allowing you to rest, digest, and store energy

The endoneurium wraps around

each axon

The perineurium wraps around

each fascicle

The epineurium wraps around

groups of fascicles (nerves)

Afferent neurons send what type of information towards the CNS?

sensory

Efferent neurons send what type of impulses away from the CNS?

motor

The mixed nerve contains both afferent and efferent neurons

True

Cranial nerves emerge from the

brainstem within the skull

Spinal nerves emerge from the

spinal cord

Name CN I and its primary function.

Olfactory; olfaction (smell)

Name CN II and its primary function.

Optic; vision

Name CN III and its primary function.

Oculomotor; moving eye up, down, medially; raising eyelid; constricting pupil

Name CN IV and its primary function.

Trochlear; moving eye down, medially

Name CN V and its primary function.

Trigeminal; Mastication

Name CN VI and its primary function.

Abducent; abducting eye

Name CN VII and its primary function.

Facial; facial expression, taste

Name CN VIII and its primary function.

Vestibulocochlear; hearing, vestibular sense

Name CN IX and its primary function.

Glossopharyngeal; swallowing, taste, speech

Name CN X and its primary function.

Vagus; visceral regulation, speech

Name CN XI and its primary function.

Accessory; scapular elevation, rotation of head

Name CN XII and its primary function.

Hypoglossal; movements of tongue

Spinal nerves originate at the

spinal cord

Name the 5 groups/regions of spinal nerves.

Cervical, thoracic, lumbar, sacral, coccygeal

Ventral nerve roots are sensory.

False: it carries motor signals out to the muscles

The spinal nerve branches into rami; the ventral rami

supply the front of the body and the limbs

What is an area of skin supplied by an individual spinal nerve referred to as?

Dermatome

Proprioceptors are located in the joints and control information about

the body’s position and movement

The cervical plexus contains nerves that

supply sensation to the skin of the neck and shoulders and motor control to the neck muscles 

Which nerve is responsible for keeping the diaphragm working?

Phrenic nerve

What is neurotmesis?

Interruption of the entire nerve; the most severe nerve injury as the entire nerve is cut; recovery is very limited

What is axonotmesis?

Interruption of the axons; the outer covering of the nerve stays intact; chance of regrowth over time

What is neuropraxia?

Mild, temporary nerve injury often due to compression; usually recovers fully

The lumbar plexus innervates the muscles of the

pelvis and thigh

The quadriceps muscles are innervated by the _______ nerve.

femoral

The obturator nerve mainly controls the __________________.

hip adductor muscles

An injury to the obturator nerve may cause which type of gait?

Scissor gait

The sciatic nerve branches into which two nerves?

Tibial and common fibular

Which muscles do the sciatic nerve innervate?

Hamstrings

What nerve powers the gastrocnemius and soleus?

Tibial nerve

What purposeful movement is controlled by the tibial nerve?

Toe flexion

What sacral nerve wraps around the outside of the knee and splits into deep and superficial branches?

Common fibular nerve

What movement or movements are controlled by the common fibular nerve?

Ankle dorsiflexion and toe extension