Ch. 15 Sensory Pathways and the Somatic Nervous System

Question 1

Autonomic nervous system regulates activity of…

Answer 1

smooth muscle, cardiac muscle, and certain glands

Question 2

Operation of the ANS to maintain homeostasis

Answer 2

depends on a continual flow of sensory afferent input, from receptors in organs, and efferent motor output to the same effector organs

Question 3

Structural components of ANS

Answer 3

autonomic sensory neurons, integrating centers in CNS, and autonomic motor neurons

Question 4

The ANS is regulated by…

Answer 4

centers in the brain, mainly the hypothalamus and medulla oblongata, which receive input from limbic system

Question 5

The somatic nervous system contains both…

Answer 5

sensory and motor neurons

Question 6

Where do somatic sensory neurons receive input from?

Answer 6

receptors of the special and somatic senses

Question 7

Somatic motor neurons

Answer 7

innervate skeletal muscle to produce conscious, voluntary movements

Question 8

What is the effect of a motor neuron

Answer 8

always excitation

Question 9

What type of neurons do the ANS contain?

Answer 9

autonomic sensory and motor neurons

Question 10

The ANS also receives input from…

Answer 10

somatic senses and special sensory neurons

Question 11

How do autonomic responses regulate visceral activities?

Answer 11

by either increasing (exciting) or decreasing (inhibiting) ongoing activities of cardiac muscle, smooth muscle, and glands

Question 12

What do all autonomic motor pathways consist of?

Answer 12

two motor neurons in series

Question 13

Autonomic motor pathway series

Answer 13

1. The axon of the first motor neuron of ANS extends from CNS and synapses in a ganglion with the second neuron
2. second neuron synapses on an effector
3. efferent part of the ANS is divided into sympathetic and parasympathetic divisions

Question 14

What do preganglionic fibers release?

Answer 14

acetylcholine

Question 15

What do postganglionic fibers release?

Answer 15

acetylcholine and norepinephrine

Question 16

Dual innervation

Answer 16

when organs receive impulses from both sympathetic and parasympathetic fibers

Question 17

Where is the cell body of a preganglionic neuron?

Answer 17

in the brain or spinal cord

Question 18

Myelinated axon of a preganglionic neuron

Answer 18

called a preganglionic fiber, passes out of the CNS as part of a cranial or spinal nerve

Question 19

Where is postganglionic neuron?

Answer 19

it lies entirely outside the CNS

Question 20

Where is cell body and dendrites of postganglionic neuron?

Answer 20

in an autonomic ganglion where it makes synapses with one or more preganglionic fibers

Question 21

The axon of a postganglionic neuron

Answer 21

unmyelinated and terminates in a visceral effector

Question 22

Where are the cell bodies of sympathetic preganglionic neurons?

Answer 22

in the lateral gray horns of the 12 thoracic and first 2 or 3 lumbar segments

Question 23

Parasympathetic ganglia

Answer 23

the terminal or intramural ganglia that are located very close to or actually within the wall of a visceral organ

Question 24

Examples of parasympathetic ganglia

Answer 24

ciliary, pterygopalatine, submandibular, and otic ganglia