Chapter 16

what are the two divisions of the autonomic nervous system?

• sympathetic division

• parasympathetic division

what does the sympathetic division do?

increases alertness, metabolic rate, and muscular abilities

what does the parasympathetic division do?

reduces metabolic rate and promotes digestion

what are the 7 responses of the sympathetic division

1. heightened mental alertness

2. increases metabolic rate

3. reduced digestive and urinary functions

4. energy reserves activated

5. increased respiratory rate and respiratory passageways dilate

6. increased heart rate and blood pressure

7. sweat glands activated

what are the 5 responses of the parasympathetic division?

1. decreased metabolic rate

2. decreased heart rate and blood pressure

3. increased secretion by salivary and digestive glands

4. increased motility and blood flow in the digestive tract

5. urination and defecation stimulation

which division are the blood vessels controlled by?

only the sympathetic division

what are the two neurotransmitters that are released by the sympathetic division?

ACh or NE

what is the only neurotransmitter released by the parasympathetic division?

ACh

what are the changes caused by the sympathetic division due to epinephrine and norepinephrine?

• increased alertness

• feelings of energy and euphoria

• change in breathing, heart rate, and blood pressure

what are the changes caused by the sympathetic division due to ACh?

• elevation in muscle tone

• mobilization of energy reserves

what effect does ACh have on blood vessels?

causes vasodilation

what effect of NE have on blood vessels?

causes vasoconstriction

what are some major effect of parasympathetic activition

• increase in smooth muscle activity along the digestive tract

• stimulation and coordination of defecation

• contraction of the urinary bladder during urination

• constriction of the respiratory passageways

• reduction in heart rate and in the force of contraction

what are the two outcomes from ACh being released by the parasympathetic division?

can be excitatory or inhibitory

what is dual innervation?

when an organ gets signals from both the sympathetic and parasympathetic divisions

what happens if the nerve is inactive under normal conditions?

it can only increase activity

what do autonomic motor neurons do?

• maintains resting level of activity in the absence of stimuli

• background level of activation determines autonomic tone

what does sympathetic tone do?

keeps smooth muscle partially contracted