Quiz 9 - ANS Flashcards Preview

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Flashcards in Quiz 9 - ANS Deck (27):
1

somatic nervous system

operates under voluntary (conscious) control; controls skeletal muslces

2

autonomic nervous system

operates under involuntary instruction; controls visceral organs

3

what systems does the ANS coordinate

cardiovascular, respiratory, digestive, urinary, reproductive

4

preganglionic neurons

axons of preganglionic neurons; leave CNS and synapse on ganglionic neurons

5

ganglionic neurons

in autonomic ganglia, innervate visceral organs (cardiac muscle, smooth muscle, glands and adipose tissue)

6

postganglionic fibers

axons of ganglionic neurons

7

divisions of the ANS

sympathetic and parasympathetic

8

sympathetic

fight or flight - response to emergency, high-stress, high-exertion situations (utilizes energy stores)

9

parasympathetic

rest and digest - maintains resting conditions, reduces metabolic rate and promotes digestion (conserves energy)

10

parts of sympathetic nervous system

- thoracolumbar
- preganglionic neurons
- ganglia
- ganglionic neurons

11

thoracolumbar

preganglionic neurons originate from the thoracic and lumbar segments (T1-L2) of spinal cord

12

preganglionic neurons in SNS

short preganglionic fibers, (most) ganglia close to spinal cord

13

three types of ganglia

sympathetic chain ganglia
collateral ganglia
adrenal medullae

14

sympathetic chain ganglia

(paravertebral) - on both sides of cerebral column
- control effecters: in body wall, thoracic cavity, head, neck, limbs

15

collateral ganglia

(prevertebral) - anterior to vertebral bodies
- contain ganglionic neurons that innervate tissues and organs in abdominopelvic cavity

16

adrenal medullae

very short postganglionic fibers
- when stimulated, release neurotransmitters (epinephrine and norepinephrine) into bloodstream which affect target cells throughout body

17

ganglionic neurons of SNS

long postganglionic fibers (except in adrenal medullae)
- extensive divergence: allows it to function as a unit (mass activation) and also more diffuse and widespread response

18

specific functions of SNS

- dilation of pupils
- increase in alertness, feelings of energy and euphoria
- increase in cardiovascular activity
- increase in respiratory activity

19

neurotransmitters released in SNS

- both systems release acetylcholine (ACh) at ganglion
- norepinephrine and epinephrine - released by postganglionic fibers to target tissues and bloodstream

20

parts of parasympathetic nervous system

craniosacral
preganglionic neurons
ganglionic neurons
postganglionic fibers

21

craniosacral

brain stem (cranial nerves III, VII, IX, X) and sacral segment (S1-S4) of spinal cord

22

preganglionic neurons in PNS

long

23

ganglionic neurons in PNS

near or at effector organs (short)

24

postganglionic fibers in PNS

short, innervates structures in head and organs in thoracic and abdominopelvic cavities (effects are usually more specific and localized

25

specific functions of PNS

- constriction of pupils
- decrease cardiovascular activity
- increase arousal and stimulation of sexual glands
- decrease digestive activity

26

neurotransmitters released on PNS

parasympathetic: acetylcholine released by postganglionic fibers

27

dual innervations of SNS and PNS

- most visceral organs receive dual innervation (both SNS/PNS)
- usually have opposing effects (antagonistic)
- most prominent in digestive tract, heart and lungs