Autonomic nervous system

Question 1

What is the function of the autonomic nervous system?

Answer 1

To control all involuntary responses

Question 2

Is the autonomic nervous system sensory/afferent or motor/efferent or both?

Answer 2

Motor/efferent

Question 3

What is the other division of the motor/efferent nervous system? How is it different?

Answer 3

Somatic nervous system - controls all voluntary responses

Question 4

What are the two divisions of the autonomic nervous system?

Answer 4

Sympathetic nervous system

Parasympathtic nervous system

Question 5

What is the function of the sympathetic nervous system?

Answer 5

To control all involuntary responses to stressful situations

Question 6

What is the function of the parasympathetic nervous system?

Answer 6

To control all involuntary responses in resting conditions

Question 7

Where do the sympathetic nerve fibres originate from?

Answer 7

Lateral horn of spinal cord in thoraco-lumbar regions

Question 8

Where do sympathetic nerve fibres travel to from the spinal cord?

Answer 8

To the paravertebral sympathetic chain

Question 9

Where do sympathetic nerve fibres travel to from the paravertebral sympathetic chain?

Answer 9

To their target tissues

Question 10

Where do parasympathetic nerve fibres originate from?

Answer 10

Lateral horn of spinal cord in medulla and sacral regions of spinal cord

Question 11

How many neurones are there in autonomic nerve fibres?

Answer 11

Two

Question 12

What are the names of the two neurones in autonomic nerve fibres?

Answer 12

First one is called pre-ganglionic

Second one is called post-ganglionic

Question 13

What are ganglia in autonomic nerve fibres?

Answer 13

Where many autonomic neurones synapse

Question 14

Are the pre-ganglionic and post-ganglionic neurones myelinated?

Answer 14

Pre-ganglionic one is myelinated

Post-ganglionic one is unmyelinated

Question 15

What are the relative lengths of the pre-ganglionic and post-ganglionic neurones?

Answer 15

In sympathetic nerve fibres, pre-ganglionic is short and post-ganglionic is long

In parasympathetic nerve fibres, pre-ganglionic is long, post-ganglionic is short

Question 16

How long is the pre-ganglionic neurone in parasympathetic nerve fibres?

Answer 16

So long that it often reaches the target tissue and the ganglion and post-ganglionic neurone both occur in the target tissue

Question 17

Where are sympathetic ganglia located?

Answer 17

Paravertebral sympathetic chain

Question 18

What neurotransmitter do pre-ganglionic neurones release?

Answer 18

Both sympathetic and parasympathetic pre-ganglionic neurones release acetylcholine

Question 19

What type of receptor is found on the post-ganglionic neurones in their synapse with the pre-ganglionic neurone?

Answer 19

Both sympathetic and parasympathetic post-ganglionic neurones have nicotinic acetylcholine receptors

Question 20

What neurotransmitter do post-ganglionic neurones release?

Answer 20

Sympathetic post-ganglionic neurones release noradrenaline

Parasypathetic post-ganglionic neurones release acetylcholine

Question 21

What type of receptor is found in target tissue in their synapse with post-ganglionic neurones?

Answer 21

Sympathetic target tissue has adrenoceptors

Parasympathetic target tissue has muscarinic acetylcholine receptors

Question 22

What is the exception to neurotransmitters released by post-ganglionic neurones and the receptor found in target tissue in the synapse?

Answer 22

Some sympathetic post-ganglionic neurones release acetylcholine
which binds to muscarinic acetylcholine receptors in the target tissue
seen in sweat glands, hair follicles

Question 23

What are neurotransmitters other than acetylcholine and noradrenaline in the autonomic nervous system called? What are some examples?

Answer 23

Non-adrenergic-non-cholinergic transmitters

• ATP
• NO

Question 24

How are non-adrenergic-non-cholinergic neurotransmitters released in the autonomic nervous system?

Answer 24

Co-released with either acetylcholine or noradrenaline

Question 25

What is the exception to there being two neurones in autonomic nerve fibres?

Answer 25

Sympathetic nerve fibres to adrenal glands only contain pre-ganglionic neurone adrenal medulla chromaffin cells act as the post-ganglionic neurones

Question 26

What do chromaffin cells do when stimulated?

Answer 26

Release adrenaline and smaller amounts of noradrenaline into the blood

Question 27

What are the receptors for parasympathetic post-ganglionic neurones in the heart?

Answer 27

M2

Question 28

Where are M2 receptors in the heart located?

Answer 28

SA node AV node

Question 29

What is the outcome of activation of the different M2 receptors in the heart?

Answer 29

SA node - negative chronotropy AV node - reduced cardiac conduction velocity

Question 30

What are the receptors for parasympathetic post-ganglionic neurones in smooth muscle?

Answer 30

M3

Question 31

What is the outcome of activation of M3 receptors in bronchiolar smooth muscle?

Answer 31

Bronchoconstriction

Question 32

What is the outcome of activation of M3 receptors in intestinal smooth muscle?

Answer 32

Contraction of smooth muscle | giving increased motility

Question 33

What is the outcome of activation of M3 receptors in bladder smooth muscle?

Answer 33

Contraction of bladder detrusor muscles relaxation of sphincter muscles giving passing of urine

Question 34

What are the receptors for sympathetic post-ganglionic neurones in the heart?

Answer 34

B1

Question 35

Where are B1 adrenoreceptors located in the heart?

Answer 35

SA node Ventricles

Question 36

What is the outcome of activation of the different B1 adrenoceptors in the heart?

Answer 36

SA node - positive chronotropy Ventricles - positive inotropy

Question 37

What are the receptors for sympathetic post-ganglionic neurones in smooth muscle?

Answer 37

Vascular smooth muscle - A1, B2 Bronchial smooth muscle - B2 Intestinal smooth muscle - B2 Bladder smooth muscle - B2

Question 38

What is the outcome of activation of A1 adrenoceptors in vascular smooth muscle?

Answer 38

Vasoconstriction

Question 39

What is the outcome of activation of B2 adrenoceptors in vascular smooth muscle?

Answer 39

Vasodilation

Question 40

What is the purpose of vasoconstriction and vasodilation stimulates by sympathetic post-ganglionic neurones?

Answer 40

Redirect blood to muscles from other tissues

Question 41

What is the outcome of activation of B2 adrenoceptors in bronchiolar smooth muscle?

Answer 41

Bronchodilation

Question 42

What is the outcome of activation of B2 adrenoceptors in intestinal smooth muscle?

Answer 42

Relaxation of smooth muscle | decreased motility

Question 43

What is the outcome of activation of B2 adrenoceptors in bladder smooth muscle?

Answer 43

Bladder sphincter muscle contracts | urine is contained in bladder

Question 44

What is dysautonomia?

Answer 44

Means malfunctioning of the autonomic nervous system