review of the sympathetic nervous system

Question 1

where does the cell body of preganglionic neuron lie generally?

Answer 1

in the brain or spinal cord

Question 2

where do axons of the preganglionic neuron go?

Answer 2

through white ramps to get to sympathetic ganglia where it synapses with a postganglionic neurone

Question 3

what is another name for preganglionic neuron?

Answer 3

visceral motor neuron

Question 4

what are sympathetic ganglia?

Answer 4

sites of synapses between pre and post ganglionic neurons

Question 5

where does the sympathetic trunk ganglia lie?

Answer 5

either side of the vertebral column

Question 6

what makes up the sympathetic chain?

Answer 6

sympathetic ganglia and sympathetic trunk

Question 7

where does the postganglionic neutron lie?

Answer 7

outside the CNS in the PNS

Question 8

where does the cell body of a postganglionic neuron lie?

Answer 8

in autonomic ganglia

Question 9

where do postganglionic axons terminate?

Answer 9

visceral effectors (mainly to smooth muscle surrounding blood vessels)

Question 10

where do the cell bodies of preganglionic neurons in the thoracolumbar division lie?

Answer 10

the lateral horns of the grey matter

Question 11

which vertebral segments make up the thoracolumbar division?

Answer 11

12 thoracic segments

first 2 lumbar segments

Question 12

what is the thoracolumbar outflow?

Answer 12

axons of the preganglionic neurons of the thoracolumbar division

Question 13

name the three cervical ganglia

Answer 13

superior, middle and inferior cervical ganglia

Question 14

what does the superior cervical ganglia innervate and what action does this bring around?

Answer 14

innervates iris of the eye, skin of face and salivary gland

causes pupil dilation, blushing and reduction of saliva

Question 15

what are the cervical ganglia attached to?

Answer 15

thoracic chain below

Question 16

what does the cardiac plexus do?

Answer 16

provides sympathetic innervation of the heart

plexus forms around the aorta and atria

Question 17

what nerves make up the cardiac plexus?

Answer 17

branches of the upper thoracic chain

Question 18

what does the pulmonary plexus do?

Answer 18

sympathetic innervation of the lungs

plexus forms around the large pulmonary arteries

Question 19

what neurotransmitter do preganglionic neurons release and what effect does it have?

Answer 19

acetylcholine

activates postganglionic

Question 20

what type of receptors are on autonomic ganglia?

Answer 20

cholinergic nicotinic types

Question 21

what neurotransmitter do postganglionic neurons release and what effect does it have?

Answer 21

noradrenaline

makes arterial smooth muscle contract

Question 22

what receptors on smooth muscle does noradrenaline act on?

Answer 22

alpha-1 adrenoreceptors

Question 23

what additions to the sympathetic chain are there below the diaphragm?

Answer 23

prevertebral ganglia

Question 24

what makes up the prevertebral ganglia?

Answer 24

celiac plexus

superior and inferior mesenteric ganglion

Question 25

what are the greater and lesser splanchnic nerves?

Answer 25

long preganglionic sympathetic axons to the celiac and mesenteric ganglia

Question 26

what does the coeliac plexus supply?

Answer 26

vasoconstrictor nerves to the stomach and duodenum

Question 27

what does the superior mesenteric plexus supply?

Answer 27

ascending and descending colon

Question 28

what does the inferior mesenteric plexus supply?

Answer 28

bladder and reproductive organs

Question 29

where are the adrenal glands found?

Answer 29

on top of the kidneys

Question 30

what are the names of the outer and inner parts of the adrenal glands?

Answer 30

outer - cortex | inner - medulla

Question 31

describe how adrenaline is made from tyrosine

Answer 31

tyrosine --> DOPA --> dopamine + OH --> noradrenaline + methyl --> adrenaline

Question 32

what are catecholamines and name the main ones?

Answer 32

hormones produced by the adrenal glands dopamine, noradrenaline and adrenaline

Question 33

which sympathetic neurons are noradrenergic?

Answer 33

sympathetic post ganglionic apart from the sweat glands

Question 34

which hormone do sweat glands use?

Answer 34

acetylcholine

Question 35

how does the sympathetic NS regulate the distribution of blood around the body?

Answer 35

active at all times ongoing amounts of vasoconstriction operates at a low level when youre resting or stressed

Question 36

give an example of drugs that block the resting tone of sympathetic output

Answer 36

alpha blockers like prazosin

Question 37

what are side effects of alpha blockers?

Answer 37

postural hypotension

Question 38

what is postural hypotension and how does it occur?

Answer 38

when you faint when you stand up | body cannot increase vasoconstrictor tone in leg muscle when you stand up so the BP drops and you faint

Question 39

what adrenoreceptors are found in the brain and heart?

Answer 39

beta-adrenoreceptors

Question 40

explain how and why sympathetic activity increases during exercise

Answer 40

exercising muscle release local chemical vasodilators vasodilation would cause low bp and drop in total peripheral resistance sympathetic outflow increases at start of exercise global vasoconstriction via noradrenaline esp of non-exercising muscle cardiac output redirected to exercising muscle total peripheral resistance is maintained

Question 41

what are adrenoreceptors?

Answer 41

receptors for adrenaline and noradrenaline

Question 42

what are the types of adrenoreceptors?

Answer 42

alpha - a1, a2 beta - b1, b2, b3

Question 43

what types of receptors does noradrenaline act on?

Answer 43

alpha

Question 44

what action does alpha 1 receptors bring about?

Answer 44

increases contraction

Question 45

what receptor is mainly found on vascular smooth muscle?

Answer 45

alpha 1

Question 46

what do alpha 1 antagonists do?

Answer 46

reduce blood pressure

Question 47

give an example of an alpha 1 antagonist

Answer 47

prazosin

Question 48

what action does alpha 2 receptors bring about?

Answer 48

reducing noradrenaline release by negative feedback inhibit insulin release in the pancreas stimulate glucagon release contraction of sphincters of gastrointestinal tract increased thrombocyte aggregation

Question 49

what receptors are found on presynaptic sympathetic nerve terminals?

Answer 49

alpha 2

Question 50

what do alpha 2 agonists do?

Answer 50

reduce blood pressure by inhibiting noradrenaline release

Question 51

give an example of alpha 2 agonist

Answer 51

clonidine

Question 52

what type of receptors does adrenaline act on?

Answer 52

beta

Question 53

what do beta 1 receptors do and where are they found?

Answer 53

increase fore and rate of contraction of myocardium found mainly on heart and kidneys

Question 54

what do beta 2 receptors do and where are they found?

Answer 54

relax muscle found mainly in bronchial smooth muscle, gastrointestinal tract, liver and uterus

Question 55

what do beta 3 receptors do?

Answer 55

increase lipolysis and gluconeogenesis in adipose tissue

Question 56

what receptors are beta blockers selective for?

Answer 56

beta 1

Question 57

what are beta blockers used to treat?

Answer 57

manage abnormal heart rhythms prevent second heart attack reduce HR and force of contraction in hypertensive patients

Question 58

what are side effects of beta blockers?

Answer 58

``` bronchoconstriction fatigue dizziness depression loss of libido exacerbating diabetes ```

Question 59

why are beta blockers not the first choice of treatment for hypertension?

Answer 59

not as effective as diuretics, ACE inhibitors and calcium channel blockers

Question 60

what is the effect of blocking beta 2 and beta 3 receptors?

Answer 60

exacerbating diabetes

Question 61

what does salbutamol do?

Answer 61

relaxes bronchial smooth muscle in asthmatics by acting on beta 2 receptors

Question 62

how does the sympathetic nervous system react in severe blood loss?

Answer 62

arterial vasoconstriction in non-essential organs to maintain BP and perfusion of vital organs kidneys release renin to maintain blood pressure ADH stimulated to reduce urine output

Question 63

what do alpha receptors do in severe blood loss?

Answer 63

causes smooth muscle to constrict | platelets become more sensitive to collagen to increase clotting

Question 64

what does cortisol do?

Answer 64

stimulates adrenaline and noradrenaline synthesis

Question 65

how is cortisol released

Answer 65

psychological stressors activate the sympathetic NS and the hypothlaamo-pituitary-adrenal axis HPA releases adrenocorticotrophic hormone ACTH stimulates cortisol release from adrenal cortex

Question 66

where is cortisol released from

Answer 66

adrenal cortex