Autonomic nervous sytem

Question 0

Different kind of ANS

Answer 0

Sympathetic - fight or flight, increased alertness and metabolic activities in order to prepare the body for an emergency situation

parasympathetic - rest and digest, activities conserve and restore body energy, most output is to smooth muscle and glands of GI tract and respiratory tract

Question 1

the different kinds of PNS

Answer 1

Somatic nervous system - consciously controlled, voluntary, sensory receptors and motor neurons to skeletal mm

Autonomic nervous system -involuntary, sensory from visceral organ, motor to smooth mm, cardiac mm and glands

Enteric nervous system - involuntary, sensory from chemical changes in GI tract and stretching it, motor to GI smooth muscle

Question 2

what is autonomic tone

Answer 2

most organs receive innervation from both divisions of ANS, which typically work in opposition to one another
autonomic tone is the balance between Sympathetic and parasympathetic activity

Question 3

what regulates Autonomic tone

Answer 3

by hypothalamus

Question 4

which structures only receive sympathetic innervation?

Answer 4

Sweat glands
Arrector pili mm
kidneys
spleen
most blood vessels
adrenal medulla
They exhibit responses by decreasing and increasing sympathetic tone

Question 5

Sympathetic responses

Answer 5

during physical or emotional stress, Sympathetic division dominates the parasympathetic system

high sympathetic tone favors body functions that can support vigorous physical activity and rapid production of ATP

reduction in body functions that favor storage of energy

emotions can stimulate sympathetic division (fear, embarrassement, rage)

Question 6

what is the body’s response to Sympathetic response?

Answer 6

fight or flight
pupils dilate
heart rate , force of heart contraction and BP increases
airways dilate (faster movement of air into and out of lungs)
BV to skeletal mm dilate
BV to cardiac mm dilate
BV to GI tract constrict
BV to kidneys constrict
BV to liver dilate (glucogenesis)
BV to adipose tissue dilate

Question 7

Parasympathetic responses

Answer 7

rest and digest

body functions that conserve and restore body energy during times of rest and recovery

Question 8

What is the body response to parasympathetic response

Answer 8

Salivation
Lacrimation
Urination
Digestion
Defecation

decreased heart rate
decreased diameter of airways
decreased diameter of pupils

Question 9

classification of nerve fibers

Answer 9

A fibers: largest diameter, myelinated, brief absolute refectory period, fast, sensory neurons, motor neurons to skeletal mm

B fibers: medium diameter, myelinated, medium absolute refractory period, conduct nerve impulses from visceral to CNS

C fibers: smallest diameter, Unmyelinated, longest absolute refractory period, pain from viscera, all postganglionic neurons

Question 10

Sensory input for somatic nervous system

Answer 10

From receptors for somatic senses (tactile, thermal, pain, proprioceptive sensations) and from receptors for special senses (sight, hearing, taste, smell, equilibrium). consciously received

Question 11

Autonomic nervous system sensory input

Answer 11

from interoreceptors (sensory receptors located in BVs, visceral organs, mm and nn that monitor conditions in the internal environment)
not usually consciously perceived.)
Chemo, baro, mechano (bv) receptors

Question 12

Somatic Nervous system control of motor output

Answer 12

Primary motor area of cerebral cortex

voluntary (with contributions from basal nuclei, cerebellum, brain stem and SC)

Question 13

Autonomic nervous system control of motor output

Answer 13

involuntary control from hypothalamus

Question 14

Somatic nervous system motor neuron pathway

Answer 14

one neuron path way
somatic motor neuron goes from CNS to skeletal mm
myelinated
from anterior horn
release Ach

Question 15

Autonomic Nervous system Motor neuron pathway

Answer 15

Preganglionic neuron is myelinated but postganglionic neuron is not
two neuron pathway
Either release Ach or Norepinephrine (or NE or Einephrine in Chromaffin cell in adrenal gland)

Question 16

autonomic motor pathways 3 may parts

Answer 16

1. preganglionic neuron (Thorocolumbar division/sympathetic division)
2. Postganglionic neuron
3. Autonomic ganglia (Sympathetic division and parasympathetic division)

Question 17

Types of sympathetic division

Answer 17

1. sympathetic trunk ganglia/vertebral chain ganglia/paravertebral ganglia (superior, middle, inferior cervical ganglia) for organs above diaphragm T1-L2 or 3
2. Prevertebral (collateral) ganglia (Celiac, superior mesentric, inferior mesentric, Aorticorenal, Renal ganglia) for organs below diaphragm

Question 18

Parasympathetic division

Answer 18

Terminal (intramural) ganglia
most of these are located close to or within the wall of a visceral organ 
Ciliary ganglion
Otic ganglion
Pterygopalatine ganglion
Submandibular ganglion

Question 19

4 ways Sympathetic preganglionic neurons connect with postganglionic neurons

Answer 19

1. In the first ganglion it reaches
2. the axon may ascend or decend to a higher or lower ganglion nd synapse there
3. The axon may go through the sypathetic trunk ganglion to synapse in a prevertebral ganglion
4. The axon may pass through the sympathetic trunk ganglion and prevertebral ganglion to synapse with chromaffin cells of the adrenal medulla

Question 20

What is divergence

Answer 20

a single sympathetic preganglionic fiber has many axon collaterals and may synapse with 20 + post ganglionic neurons. that’s how sympathetic responses affect almost the entire body simultaneously

Question 21

Where does parasympathetic preganglionic neurons pass?

Answer 21

To terminal ganglia near or within a visceral effector

Question 22

why are parasympathetic response localised to a single effector

Answer 22

because it only synapses with 4 or 5 postsynaptic neurons and all of them supply a single effector

Question 23

what is autonomic plexuses

Answer 23

Tangled neworks of axons of sympathetic and parasympathetic neurons in thorax, abdomen and pelvis
also contain sympathetic ganglia and axons of autonomic sensory neurons