Ch 7 - Peripheral Nervous System (Exam 4)

Question 1

PNS

Answer 1

Nerve fibers carry info between CNS and body; Afferent-to CNS; Efferent-from CNS, Somatic-motor fibers-skeletal muscle, Autonomic-smooth muscle, cardiac muscle, glands (involuntary)-Sympathetic/Parasympathetic

Question 2

ANS

Answer 2

Efferent division of PNS; Link between brain to body; CNS initiates action potentials in effector neuron whose axons terminate on organs; Cardiac m, smooth m, most exocrine, endocrine, adipose innervated by ANS; Neurotransmitters-Acetylcholine, Norepinephrine

Question 3

Two-neuron Chain

Answer 3

Each autonomic nerve pathway extending from CNS to body is two-neuron chain (except medulla); cell body of 1st neuron in CNS; Axon (preganglionic fiber) synapses w cell body of 2nd neuron (w/in ganglion); Axon 2nd neuron (postganglionic fiber) innervates organ

Question 4

Sympathetic ANS

Answer 4

Originate in thoracic and lumbar regions of spinal cord; short, complicated

Question 5

Parasympathetic ANS

Answer 5

Arise from brain and sacral region of spinal cord; long, simple

Question 6

Preganglionic Fibers

Answer 6

Acetylcholine

Question 7

Postganglionic Fibers

Answer 7

Parasympathetic-Acetylcholine; Cholinergic; Most sympathetic-NE; Adrenergic

Question 8

Sympathetic Dominance

Answer 8

Fight/flight; Inc HR, BP-vasoconstriction, bronchodilation, glycogen and fat stores broken down to gluc, dilate blood vessels to skeletal muscles, pupils dilate, sweat, inhibit GI/GU

Question 9

Parasympathetic Dominance

Answer 9

Quiet, relaxed situations; digestion, etc

Question 10

Receptors

Answer 10

Each autonomic neurotransmitter (and medullary hormones) stimulates activity in some tissues but inhibits in others; Particular response depends on specialization of target cells rather than properties of chemicals

Question 11

Cholinergic Receptors

Answer 11

Acetylcholine-2 types; Nicotinic-postganglionic cell bodies of all autonomic ganglia, respond to ACh released from S and P preganglionic fibers; Muscarinic-cell membranes of smooth m, cardiac m, glands, bind w ACh released from P postganglionic fibers

Question 12

Agonist

Answer 12

mimics neurotransmitter’s response

Question 13

Antagonist

Answer 13

blocks neurotransmitter’s response

Question 14

Salbutamol

Answer 14

selectively activates beta2 receptors-bronchodilation in asthma

Question 15

Metoprolol

Answer 15

blocks beta1-treat HTN by dec amount of blood heart pumps