Chapter 15

Question 1

interoceptors

Answer 1

sensory receptors located in blood vessels, visceral organs, muscles and the nervous system that monitor conditions in the internal environment

Question 2

autonomic motor neurons

Answer 2

regulate visceral activities by either increasing (exciting) or decreasing (inhibiting) ongoing activities in their effector tissues (cardiac muscle, smooth muscle and glands)

Question 3

autonomic gangion

Answer 3

a collection of neuronal cell bodies in the PNS

Question 4

dual innervation

Answer 4

receive nerve impulses from both sympathetic and parasympathetic neurons

Question 5

preganglionic neuron

Answer 5

the first of the two motor neurons in any autonomic motor pathway

Question 6

thoracolumbar division

Answer 6

In the sympathetic division, the preganglionic neurons have their cell bodies in the lateral horns of the gray matter in the 12 thoracic segments and the first two (and sometimes three) lumbar seg- ments of the spinal cord (Figure 15.2). For this reason, the sympathetic division is also called the thoracolumbar division

Question 7

craniosacral division

Answer 7

Cell bodies of preganglionic neurons of the parasympathetic division are located in the nuclei of four cranial nerves in the brain stem (III, VII, IX, and X) and in the lateral gray matter of the second through fourth sacral segments of the spinal cord so the parasympathetic division is also called the craniosacral division

Question 8

craniosacral outflow

Answer 8

the axons of the parasympathetic preganglionic neurons

Question 9

autonomic ganglia

Answer 9

2 major groups: sympathetic ganglia (components of the sympathetic division of the ANS) and parasympathetic ganglia ( components of parasympathetic division of the ANS)

Question 10

sympathetic trunk ganglia

Answer 10

lie in a vertical row on either side of the vertebral column; extend from the base of the skull to the coccyx

Question 11

prevertebral ganglia (or collateral ganglia)

Answer 11

lies anterior to the vertebral column and close to the large abdominal arteries

Question 12

terminal ganglia (or intramural ganglia)

Answer 12

preganglionic axons of the parasympathetic division synapse with post ganglionic neurons

Question 13

autonomic plexuses

Answer 13

tangled networks of axons of both the sympathetic and parasympathetic neurons in the thorax, abdomen and pelvis

Question 14

cholinergic neurons

Answer 14

release NT acetylcholine

Question 15

cholinergic receptors

Answer 15

ACh is stored in synaptic vesicles and released by exocytosis. It then diffuses across the synaptic cleft and binds with specific cholinergic receptors, integral membrane proteins in the postsynaptic plasma membrane.

Question 16

nicotinic receptors

Answer 16

present in the plasma membrane of dendrites and cell bodies of both sympathetic and parasympathetic postganglionic neurons

Question 17

muscarinic receptors

Answer 17

present in plasma membranes of all effectors innervated by parasympathetic posganglionic axons

Question 18

adrenergic neurons

Answer 18

release norepinephrine

Question 19

adrenergic receptors

Answer 19

Adrenergic receptors bind both norepinephrine and epineph- rine. The norepinephrine can be either released as a neurotrans- mitter by sympathetic postganglionic neurons or released as a hormone into the blood by chromaffin cells of the adrenal medul- lae; epinephrine is released as a hormone.

Question 20

Alpha and Beta Receptors

Answer 20

2 main types of adrenergic receptors; found on visceral effectors innervated by most sympathetic postganglionic axons

Question 21

receptor agonist

Answer 21

a substance that binds to and activates a receptor, in the process mimicking the effect of a natural NT or hormone

Question 22

receptor antagonist

Answer 22

a substance that binds to and blocks a receptor, preventing a natural NT or hormone from exerting its effect

Question 23

autonomic tone

Answer 23

balance between sypathetic and parasympathetic activity; regulated by hypothalamus

Question 24

sympathetic responses

Answer 24

during physical or emotional stress

Question 25

fight or flight response

Answer 25

The pupils of the eyes dilate. • Heart rate, force of heart contraction, and blood pressure increase. • The airways dilate, allowing faster movement of air into and out of the lungs. • The blood vessels that supply the kidneys and gastrointestinal tract constrict, which decreases blood flow through these tissues. The result is a slowing of urine formation and digestive activities, which are not essential during exercise. • Blood vessels that supply organs involved in exercise or fight- ing off danger—skeletal muscles, cardiac muscle, liver, and adipose tissue—dilate, allowing greater blood flow through these tissues. • Liver cells perform glycogenolysis (breakdown of glycogen to glucose), and adipose tissue cells perform lipolysis (break- down of triglycerides to fatty acids and glycerol). • Release of glucose by the liver increases blood glucose level. • Processes that are not essential for meeting the stressful situa- tion are inhibited. For example, muscular movements of the gastrointestinal tract and digestive secretions slow down or even stop.

Question 26

parasympathetic responses

Answer 26

enhances rest and digest activities; conserve and restore body during times of rest and recovery

Question 27

comparison of Sympathetic and Parasympathetic Divisions

Answer 27

Table 15.3 on page 597

Question 28

autonomic reflexes

Answer 28

responses that occur when nerve impulses pass through an autonomic reflex arc;play a role in regulating controlled conditions in the body (i.e. blood pressure, heart rate, digestion etc.)

Question 29

receptor in an autonomic reflex arc

Answer 29

the distal end of a sensory neuron, which responds to a stimulus and produces a change that will ultimately trigger nerve impulses

Question 30

sensory neuron in an autonomic reflex arc

Answer 30

conducts nerve impulses from receptors to the CNS

Question 31

integrating centre in an autonomic reflex arc

Answer 31

interneurons within the CNS relay signals from sensory neurons to motor neurons; most are located in the hypothalamus and brain stem; urination and defecation integrating centres in the spinal cord

Question 32

motor neuron in an autonomic reflex arc

Answer 32

Nerve impulses triggered by the integrating center propagate out of the CNS along motor neurons to an effector. In an autonomic reflex arc, two motor neurons connect the CNS to an effector: The preganglionic neuron conducts motor impulses from the CNS to an autonomic ganglion, and the postganglionic neuron conducts motor impulses from an autonomic ganglion to an effector

Question 33

effector in a autonomic reflex arc

Answer 33

smooth muscle, cardiac muscle and glands