L12 - ANS

Question 1

What are four characteristics of the ANS?

Answer 1

1. autonomous
2. unconscious control e.g. digestion, cardiovascular system, glands
3. rest: parasympathetic
4. activity: sympathetic

Question 2

Is one branch of the ANS ever at 100% activity while the other branch is at 0% activity or are the branches balanced?

Answer 2

there is a dynamic balance between the autonomic branches

Question 3

Where do sympathetic neurons originate?

Answer 3

from the spinal cord

Question 4

Where do parasympathetic neurons originate?

Answer 4

from the brainstem and sacral roots

Question 5

How close are sympathetic preganglionic neurons to the CNS?

Answer 5

closer to CNS, further from target

Question 6

How close are parasympathetic preganglionic neurons to the CNS?

Answer 6

further from CNS, closer to target

Question 7

What is an exception found in the sympathetic nervous system in regards to the location of preganglionic neurons?

Answer 7

travel directly to and are located within adrenal glands (modified PG neurons)

Question 8

Where is acetylcholine used?

Answer 8

all autonomic preganglionic terminals

parasympathetic postganglionic terminals

Question 9

Where is noradrenaline used? (= norepinephrine)

Answer 9

sympathetic postganglionic terminals

Question 10

What is adrenaline (= epinephrine)?

Answer 10

hormone released into general circulation from adrenal glands

Question 11

Which neurotransmitter is sympathetic and parasympathetic preganglionic?

Answer 11

acetylcholine

Question 12

Which neurotransmitter is parasympathetic postganglionic?

Answer 12

acetylcholine

Question 13

Which neurotransmitter is sympathetic postganglionic?

Answer 13

noradrenaline

Question 14

What are the two types of cholinergic receptors?

Answer 14

nicotinic receptors and muscarinic receptors

Question 15

Where are nicotinic receptors found?

Answer 15

sympathetic and parasympathetic postganglionic cells

Question 16

Where are muscarinic receptors found?

Answer 16

parasympathetic target cells

Question 17

What are four characteristics of adrenal glands?

Answer 17

sit on top of kidneys
neuroendocrine tissue
complex organ
adrenaline (80%) and noradrenaline (20%) is released from the medulla

Question 18

What stimulates release of adrenaline into the body and what implications does this have?

Answer 18

release is stimulated by sympathetic preganglionic neurons
released into the bloodstream so there is general and non-specific distribution
reaches cells without specific autonomic innervation but cells need to have specific receptors

Question 19

What are the two types of adrenergic (sympathetic) receptors?

Answer 19

alpha and beta adrenoceptors

Question 20

Do alpha-1 and beta-1 adrenoceptors result in stimulation or inhibition?

Answer 20

stimulation

Question 21

Do alpha-2 and beta-2 adrenoceptors result in stimulation or inhibition?

Answer 21

inhibition

Question 22

What response does activation of alpha-1 adrenoceptor result in? What does it respond to? Is this the most common adrenoceptor?

Answer 22

stimulation of blood vessels and smooth muscle (contraction)
noradrenaline > adrenaline
yes

Question 23

What response does activation of alpha-2 adrenoceptor result in? What does it respond to?

Answer 23

inhibition of gut and pancreas

noradrenaline > adrenaline

Question 24

What response does activation of beta-1 adrenoceptor result in? What does it respond to?

Answer 24

stimulation of the heart (contraction)

noradrenaline and adrenaline

Question 25

What response does activation of beta-2 adrenoceptor result in? What does it respond to?

Answer 25

inhibition of bronchial smooth muscle and blood vessels of heart, liver and skeletal muscles (relaxation)
adrenaline&raquo_space; noradrenaline

Question 26

What response does activation of beta-2 adrenoceptor result in? What does it respond to?

Answer 26

inhibition of bronchial smooth muscle and blood vessels of heart, liver and skeletal muscles (relaxation)
adrenaline&raquo_space; noradrenaline

Question 27

How is a wide range of responses able to occur in different parts of the body?

Answer 27

different adrenoceptors are commonly found in different areas of the body where they would be able to take effect if activated by their respective ligand

Question 28

During exercise will there be activation of alpha-1 adrenergic receptors in blood vessels except for those found at skeletal muscles, heart and liver?

Answer 28

no, because activation of alpha-1 adrenergic receptors will occur in blood vessels including those found at skeletal muscles, heart and liver

Question 29

You want to create a drug that will decrease blood pressure by decreasing stimulation of the heart, with minimum side-effects. Which of the adrenergic receptors should you try to block?

Answer 29

beta-1 receptors

Question 30

If you choose a drug that blocks both types of beta receptors, what side-effect might you expect to see?

Answer 30

asthma from narrowing of the bronchioles

Question 31

What is basal activity?

Answer 31

constant input from both parasympathetic and sympathetic (not all or nothing)
also adrenals are never zero

Question 32

What does basal activity enable us to do?

Answer 32

deliver a message to a specific tissue using direct nervous innervation or cover a wider range of targets by sending out a more generalised hormonal message but receptor is essential for response (sympathetic)