Kin 224 Chapter 15 Study Guide

What are the two major divisions of our peripheral nervous system?

Somatic and autonomic

What is the somatic nervous system?

the division of the peripheral nervous system that controls conscious processes via somatic sensory information.

What is the autonomic nervous system?

the division of the peripheral nervous system that controls processes below the conscious level via visceral sensory influences.

(T/F) The autonomic nervous system is responsible for maintaining homeostasis

True

How many lower motor neurons are in the somatic pathway?

1

How many lower motor neurons are in the autonomic pathway?

2

What is significant about the axons of the somatic pathway?

They are myelinated and have a large diameter. Excited by ACh

What is significant about the preganglionic axons in the ANS?

They are myelinated but rather small in diameter. Excited by ACh

Autonomic ganglion

Site of the synapse between the axon of the preganglionic neuron and the cell body of the postganglionic neuron

Ganglionic neuron

specifically refers to the cell body of a neuron in the autonomic system that is located in a ganglion

Postganglionic axon

an axon that will extend from the ganglionic neuron to the effector

What is significant about the postganglionic axon?

It is unmyelinated and very small in diameter. Excited by ACh or NE

What make the ANS motor pathway significant?

It allows for increased communication and control via neuronal convergence and divergence

Neuronal convergence

Axons from numerous preganglionic neurons synapse at a single ganglionic neuron

Neuronal divergence

Axons from a single preganglionic neuron synapse and influence multiple different ganglionic neurons

(T/F) ANS is not controlled by CNS

False

What are the regions of the CNS that control the ANS?

Hypothalamus, brain stem, and spinal cord

How does the hypothalamus play a role in controlling the ANS?

It is the integration and command center, it is also involved with emotions

How does the brainstem play a role in controlling the ANS?

Major ANS refelx centers

How does the spinal cord play a role in controlling teh ANS?

ANS reflex centers for defecation and urination

(T/F) The parasympathetic nervous system is involved in fight or flight

False

What is the nickname for the parasympathetic nervous system?

Rest and digest

What is the nickname for the sympathetic nervous sytem?

Fight or flight

What is significant about the axons of the parasympathetic pathway?

The preganglionic axons are long and the postganglionic axons are short. There can be up to 4 preganglionic axon branches

What is significant about the axons of the sympathetic pathway?

The preganglionic axons are short and the postganglionic axons are long. There are many preganglionic axon branches

Where in the body are preganglionic neuron cell bodies for the parasympathetic pathway?

Brainstem and lateral gray matter of S2-S4

Where in the body are preganglionic neuron cell bodies for the sympathetic pathway?

Lateral horns of T1-L2

Which division of the ANS is responsible for maintaining homeostasis during rest?

Parasympathetic

Which division of the ANS is responsible for maintaining homeostasis during exercise and stress?

Sympathetic

What is the degree of response in relation to the parasympathetic division of the ANS?

There are long preganglionic axons with very few branches which results in a local response

What is the degree of response in relation to the sympathetic division of the ANS?

There are short preganglionic axons with many branches which results in significant neuronal divergence and allows for mass activation

Mass activation

activation of many effectors simultaneously. this includes stimulation of the medulla which results in the release of its two hormones, epinephrine and norepinephrine

Terminal ganglia

close to the effector

Intramural ganglia

located within the wall of the effector

Which cranial nerve is associated with ciliary ganglion?

CN III (oculomotor)

Which cranial nerve is associated with pteerygopalatine ganglion?

CN VII (facial)

Which cranial nerve is associated with submandibular ganglion?

CN VII (facial)

Which cranial nerve is associated with otic ganglion?

CN X (vagus)

Which cranial nerve is CN IX?

Glossopharyngeal

Preganglionic neurons of the oculomotor nerve extend from the midbrain to what?

Ciliary

Autonomic ganglia of the oculomotor nerve

Ciliary ganglia

What to ciliary ganglia do?

postganglionic axons innervate smooth muscle in the eye (ciliary muscle and iris)

What results from ciliary stimulation?

There is lens adjustments for vision of close-up objects

What results from iris stimulation?

Sphincter pupillae muscle of the iris constricts the pupil so less light goes into the eye

Preganglionic neurons of the facial nerve extend from the pons to what?

Submandibular and sublingual salivary glands along with lacrimal and small glands

pterygopalatine ganglion

postganglionic axons synapse with lacrimal glands and small glands in the nasal, oral and palate to increase secretions

Submandibular ganglion

postganglionic axons synapse with submandibular and sublingual salivary glands to increase secretions

Otic ganglia

postganglionic axons extends from the medulla oblongata to the otic to increase secretions of the parotid salivary gland

Otic

anterior to the ear

Vagus ganglia

innervates thoracic organs and many abdominal organs and gonads

Vagus ganglia (Heart)

lowers the heart rate

Vagus ganglia (Bronchi)

constricts to decrease air flow to lung alveoli

Vagus ganglia (GI tract)

increases motility, secretions, and relaxes the sphincter for defecation

Vagus ganglia (Pancreas)

release of pancreatic juice to the small intestine and release of insulin into the bloodstream

Vagus ganglia (Liver)

glycogenesis

Vagus ganglia (Gallbladder)

contraction of the gall bladder for bile release

Preganglionic nerves of the Vagus nerve extends from the medulla oblongata through plexuses to a ?

Terminal or intramural ganglion

pelvic splanchnic nerves (S2-S4) innervation

extends from S2-S4 segments of the spinal cord to terminal or intramural ganglion

pelvic splanchnic nerves (S2-S4)

contribute to the hypogastric plexus on each side of the body

pelvic splanchnic nerves (Large intestine + rectum)

Increases motility via secretions

pelvic splanchnic nerves (bladder)

contracts the bladder and relaxes the urethral sphincter in order for urination to occur

pelvic splanchnic nerves (ureters)

Smooth muscle relaxation for the movement of urine through ureters

pelvic splanchnic nerves (gonads)

vasodilates blood vessels in order for erections to occur in the penis and clitoris