CHAPTER 07: PNS, EFFERENT DIVISION

Question 1

Acetylcholine (ACh)

Answer 1

The neurotransmitter released from all autonomic preganglionic fibers, parasympathetic postganglionic fibers, and motor neurons.

Question 2

Acetylcholinesterase (AChE)

Answer 2

An enzyme present in the motor end plate membrane of a skeletal muscle fiber that inactivates Acetylcholine.

Question 3

Adrenal Medulla

Answer 3

The inner portion of the adrenal gland; an endocrine gland that is a modified sympathetic ganglion that secretes the hormones epinephrine and norepinephrine Into the blood in response to sympathetic stimulation.

Question 4

Adrenergic fiber

Answer 4

Nerve fibers that release norepinephrine as their neurotransmitter.

Question 5

Autonomic Nervous System

Answer 5

The portion of the efferent division of the Peripheral nervous system that innervates smooth muscle, cardiac muscle, and exocrine glands. Composed of two subdivisions, the sympathetic nervous system and the parasympathetic nervous system.

Question 6

Cholinergic fibers

Answer 6

Nerve fibers that release Acetylcholine as their neurotransmitter.

Question 7

End- plate potential

Answer 7

The graded receptor potential that occurs at The motor end plate of a skeletal muscle fiber in response to binding with acetylcholine.

Question 8

Epinephrine

Answer 8

The primary hormone secreted by the adrenal medulla, important in preparing the body for fight-or-flight response and in regulation of arterial blood pressure; adrenaline.

Question 9

fight-or-flight response

Answer 9

The changes in activity of the various organs innervated by the autonomic nervous system in response to sympathetic stimulation, which collectively prepare the body for strenuous physical activity in the face of an emergency or stressful situation, such as a physical threat from the outside environment

Question 10

motor end plate

Answer 10

The specialized portion of a skeletal muscle fiber that lies immediately underneath the terminal button of the motor neuron and possesses receptor sites for binding acetylcholine released from the terminal button

Question 11

motor neurons

Answer 11

The neurons that innervate skeletal muscle and whose axons constitute the somatic nervous system

Question 12

muscarinic receptor

Answer 12

Type of cholinergic receptor found at the effector organs of all parasympathetic postganglionic fibers

Question 13

nervous system

Answer 13

One of the two major regulatory systems of the body; in general, coordinates rapid activities of the body, especially those involving interactions with the external environment

Question 14

neuromuscular junction

Answer 14

The juncture between a motor neuron and a skeletal muscle fiber

Question 15

nicotinic receptor

Answer 15

Type of cholinergic receptor found at all autonomic ganglia and the motor end plates of skeletal muscle fibers

Question 16

norepinephrine

Answer 16

The neurotransmitter released from sympathetic postganglionic fibers; noradrenaline

Question 17

parasympathetic nervous system

Answer 17

The subdivision of the autonomic nervous system that dominates in quiet, relaxed situations and promotes body maintenance activities such as digestion and emptying of the urinary bladder

Question 18

postganglionic fiber

Answer 18

The second neuron in the two-neuron autonomic nerve pathway; originates in an autonomic ganglion and terminates on an effector organ

Question 19

preganglionic fiber

Answer 19

The first neuron in the two-neuron autonomic nerve pathway; originates in the central nervous system and terminates on an autonomic ganglion

Question 20

somatic nervous system

Answer 20

The portion of the efferent division of the peripheral nervous system that innervates skeletal muscles; consists of the axonal fibers of the alpha motor neurons

Question 21

sympathetic nervous system

Answer 21

The subdivision of the autonomic nervous system that dominates in emergency (Rfight- or-flightS) or stressful situations and prepares the body for strenuous physical activity

Question 22

terminal button

Answer 22

A motor neuronUs enlarged knoblike ending that terminates near a skeletal muscle fiber and releases acetylcholine in response to an action potential in the neuron