Autonomic Nervous System

Question 0

Ligands:

Norepinephrine
ACh
Histamine

Answer 0

Receptors:

B-adrenergic
Muscarinic ACh
Histamine

Know: Secondary messengers

Question 1

Glycine

Answer 1

Most abundant neurotransmitter in the spinal cord
Mainly inhibitory
Impt in Glutamate NMDA receptor

Question 2

Impt festure of EPSP and IPSP

Answer 2

They only become action potential when they summate
They are localized
They do not propagate

Question 3

How NT are removed in the synaptic cleft?

Answer 3

Diffusion
Reuptake : NT reenters presynaptic terminal
Enzymatic destruction

Question 4

Functions of the ANS

Answer 4

Maintain homeostatic conditions
Coordinate body’s responses to stress, injury, exercise
Assists endocrine system to regulate reproduction

Question 5

Somatic motor neuron which directly innervates skeletal muscles

Answer 5

Alpha motor neurons
NT : ACh
Always excitatory

Question 6

Where are preganglionic fibers found in the spinal cord?

Answer 6

Interomedial column

*there are also in the brainstem

Question 7

Innervate effector cells (not skeletal muscles, but smooth muscle cells, gland cells, cardiac muscle cells)

Answer 7

Postganglionic fibers

Question 8

Skeletal muscles

Answer 8

What type of receptors: Nicotinic
Ionotropic!
Once ACh binds, the Na ions open

Question 9

Mediate the fast ganglionic EPSP

Postganglionic

Answer 9

Nicotinic receptors

Question 10

Mediate the slow EPSP, and sometimes slow EPSP

Postganglionic

Answer 10

Muscarinic receptor

Question 11

Sympathethic

aka Thoracolumbar and Noradrenergic System

Answer 11

Parasympathetic

aka Craniosacral and Cholinergic System

Question 12

2 exceptions in parasympathetic

-instead of noradrenaline, ACh

Answer 12

1 Sweat glands

2 Blood vessels of the skeletal muscles ~ vasodilation

Question 13

Difference:

Sympathetic Pre and Postganglionic
More divergence
Maraming organs (e.g. presence of adrenal medulla–> releases adrenaline and noradrenaline in the bloodstream –> stimulates organs which aren’t usually stimulated (liver- breakdown of glucose for fight and flight; platelets- have receptors for adrenaline and noradrenaline, for clotting, anti-hemorrhage)
Generalized effect

It takes a while before adrenergic NTs are degraded –> results to prolonged effect, as opposed to ACh which is easily degraded in the synaptic cleft

Answer 13

Parasympathetic Pre and Postganglionic
More convergence
Single organ
Localized effect

Question 14

Preganglionic

Answer 14

Sympathetic
T1-L2
NT is ACh

Parasympathetic
S2-S4
NT is ACh

Question 15

Postganglionic

Answer 15

Sympathetic
Prevertebral ganglia
NT is Noradrenaline
Receptor is alpha or beta adrenergic

Parasympathetic
NT is ACh
Receptor is cholinergic

Question 16

Preganglionic of both Sympathetic and Parasympathetic

Answer 16

NT is Ach

Receptors:
Nicotinic receptors
Muscarinic
and so forth

Question 17

Major NT in sympathetic: Noradrenaline and Adrenaline (both are secreted from the adrenal medulla)

Answer 17

In the CNS: noradrenaline/norepinephrine

In the adrenal medulla: adrenaline/epinephrine and noradrenaline but more of adrenaline

Question 18

Major sources of noradrenaline

Answer 18

Locus coeruleus

Ventral tegmental nuclei

Question 19

Alpha 2 receptors

Answer 19

Located in the presynaptic membrane

If inhibited, noradrenaline will be controlled, reduction of blood pressure!

Question 20

B1 receptor

Answer 20

Big effect on the heart

Question 21

B2 receptors

Answer 21

Big effect on the lungs
To increase ventilation

e.g. Prescribing drugs to asthmatic
Prefer Beta2 agonist, than Beta nonspecific (specific to the lungs and not sa heart)

Question 22

Nucleus of the solitary tract

Answer 22

Major afferent neuron of the Autonomic Nervous System

Question 23

Autonomic Reflexes

Baroreceptor : maintains blood pressure
-carotid sinus, carotid arch

Negative Feedback

Answer 23

Nucleus tractus solitarius sends signals to:
Nucleus ambiguus - lowers HR
Caudal ventrolateral medulla - inhibits rostral ventrolateral medulla (WHY?)