Traffic - week 7 - Efferent

Question 1

PNS: Efferent Division (NT)

Answer 1

autonomic, somatic, 2 neutrotransmitters - acetylcholine (ACh) norepinephrine (NE)

Question 2

autonomic (short answer)

Answer 2

involuntary. innervates cardiac and smooth muscle, glands

Question 3

somatic (short answer)

Answer 3

voluntary - innervates skeletal muscle

Question 4

ANS pathways…

Answer 4

typically have a 2 neuron chain extending from CNS to the innervated organ

Question 5

ANS preganglionic fiber has..(body in city)

Answer 5

cell body in CNS, synapses with postganglionic fiber in a ganglion

Question 6

sympathetic (tommy - spinal spinal)

Answer 6

pre and post ganglionic
pre - short, in spine. synapse in sympathetic in spine and release ACh
some synapse in collateral ganglion near organ
post - long end at effector and release NE

a. pre ganglionic fibers originate in thoracic and lumbar regions of the spinal cord
b. they are short, synapse in a sympathetic chain ganglion along the spinal
cord (release ACh)
(1) some pass through the ganglion and synapse later in collateral ganglion nearer to the innervated organ
c. post ganglionic fibers are long, terminate on effector organ (release NE)

Question 7

parasympathetic

Answer 7

a. pre ganglionic fibers originate in brain stem or sacral spinal cord
b. pre ganglionic fibers are long, synapse in terminal ganglia in or near effector organs (release ACh)
c. post ganglionic fibers are short, end on the effector organ (release ACh)

Question 8

ANS fibers releasing ACh called…

Answer 8

cholinergic fibers

Question 9

ANS postganglionic fibers terminate…

Answer 9

in many swellings called varicosities, which release nt over a large area of the organ (influence whole organs)

Question 10

dual innervation

Answer 10

1. most visceral organs innervated by both sympathetic and parasympathetic fibers
2. generally have opposite effects
3. either can be excitatory or inhibitory depending on which organ
4. both systems usually partially active
   a. called sympathetic or parasympathetic tone,or
   tonic activity

Question 11

dual innervation - when one increases its rate of firing

Answer 11

and the other decreases it is called dominance

Question 12

dual innervation - sympathetic dominance results in (physical changes)

Answer 12

blood flow, blood pressure, lung increase, digestive and urinary stops, pupils dilate,
sweating

increase of oxygen/nutrient rich blood flow to skeletal muscles (vessels dilate), heart beats faster and more forcefully, blood pressure increases, respiratory airways dilate, glycogen and fat stores broken down, digestive and urinary activities inhibited, pupils dilate, sweating

Question 13

dual innervation - parasympathetic dominance results in.

Answer 13

normal resting functions like digestion and urinary function being increased, while inhibiting sympathetic activities

Question 14

allows precise control over body functions

Answer 14

dual innervation

Question 15

exceptions to dual innervation..

Answer 15

blood vessels, sweat glands, salivary

a. innervated blood vessels (most arterioles and veins) have only sympathetic fibers (regulated by increasing/decreasing rate from tonic level)
b. most sweat glands have only sympathetic fibers, and postganglionic fibers release ACh
c. salivary glands have dual innervation,but both stimulate secretion

Question 16

role of adrenal gland

Answer 16

1. an endocrine gland with cortex and medulla
2. adrenal medulla secretes hormones when stimulated by sympathetic preganglionic fibers
   a. NE and epinephrine released (reinforce sympathetic activity)

Question 17

receptor proteins…(mail)

Answer 17

response of tissue to nt depends on type of receptor
on tissue cells
a. binding of nt induces response via second messenger

Question 18

ACh receptors (cholinergic) (chol)

Answer 18

a. nicotinic- on post ganglionic cell bodies in all autonomic ganglia and on cells of adrenal medulla (in sympathetic and parasympathetic)
(1) always excitatory response
b. muscarinic-on effector cell
membranes (parasympathetic)
(1) excitatory or inhibitory depending on organ

Question 19

adrenergic receptors on effector organs (sympathetic)

Answer 19

a. alpha (α) receptors - bind with NE and E
(1) usually an excitatory response (constriction
of arterioles in non fight-or-flight organs) b. beta (β) receptors
(1) β1 binds with NE and E, found mostly in heart, excitatory response (increased rate/force of contraction)
(2) β2 bind mostly with E, response inhibitory (e.g., dilation of arterioles and bronchioles)

Question 20

(PACHM) regulates ANS

Answer 20

1. medulla in brain stem
2. hypothalamus
3. prefrontal association cortex

Question 21

Somatic Nervous System (to the vent)

Answer 21

ventral horn and spinal, end in muscles (ACh), excited (nicotinic), EPSP and ISPS, conscious and subconscious

cell bodies of motor neurons in ventral horn of spinal cord, terminates on skeletal muscle cell (releases ACh)

1. effects are always excitatory (nicotinic receptors)
2. inhibition due to presynaptic inhibition
3. each motor neuron influenced by EPSPs and IPSPs from brain and spinal cord
4. subject to conscious and subconscious control (posture, balance, stereotypical movements)

Question 22

postganglionic fiber innervates…

Answer 22

the effector organ

Question 23

ANS fibers releasing NE called…

Answer 23

adrenergic fibers

Question 24

ganglion

Answer 24

group of cell bodies in pns