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Flashcards in Nervous System Deck (44):
0

What are signs of Frey syndrome?

Gustatory sweating of face

1

What are the actions of the sympathetic nervous system?

Raises heart rate
Increases force of contraction
Constricts most blood vessels
Slows GI transit
Constricts sphincters
Bronchodilates
Increase sweating
Dilates pupil (mydriasis)
Secretion of seminal fluid/movement of sperm

2

What are the actions of the parasympathetic nervous system?

Slows heart rate (no effect on force)
Relaxes blood vessels
Speeds up GI transit
Relaxes sphincters
Increases salivation
Bronchoconstricts
Constricts pupil (miosis)
Erection

3

What are dendrites?

Receptive projections sensitive to neurotransmitter input

4

What is the soma of a neuron?

Metabolic centre

5

What is an axon?

One-way rapid communication between cell body and axon terminals

6

What is an axon terminal?

Form connections with other neurons/effector tissue via synapses

7

What makes up the CNS?

Brain, spinal cord, retina & CNII

8

What makes up the PNS?

Spinal & cranial nerves (all except CNII)
Autonomic nervous system
Somatic sensory and motor nerves

9

What are the 3 branches of motor output?

Somatic motor - skeletal muscle
Brachio motor - pharyngeal arch muscle
Visceral/autonomic motor - organs and vessels

10

What are the 3 branches of sensory input?

Somatic sensory - sensations from somatic tissue
Visceral sensory - sensations from organs and vessels
Special visceral sensory - taste

11

At what levels of the spinal cord is a lateral horn seen?

T1-L2 and S2-4

12

Where do neurons controlling lateral horn cells (or autonomic brainstem nuclei) arise?

Hypothalamus

13

Where does the sympathetic chain extend up to and finish?

Near base of skull
Ends at tip of sacrum

14

Which branch of the ANS would be damaged by vertebral damage at L1 level?

Parasympathetic

15

What does the sympathetic chain communicates with spinal nerves via?

Rami communicans

16

What is the difference between grey and white rami communicans?

White = preganglionic sympathetic neurons passing into chain
Grey = postganglionic sympathetic neurons passing from chain into spinal nerve

17

Give examples of nerves which emerge from the sympathetic chain

Thoracic and cardiac splanchnic nerves

18

What is a dorsal root ganglion?

Cell bodies of sensory neurons

19

At what levels are white rami communicans seen?

T1-L2

20

At what vertebral levels are grey rami communicans seen?

All levels

21

Where can brainstem or spinal cord injury proximal to T1 cord level affect supply to?

Sympathetic supply to head

22

Describe the sympathetic supply to the face

Reticulospinal tract neurons originate in brainstem/hypothalamus
Descend to T1 & synapse with preganglionic neuron in lateral horn
Exit cord with T1 spinal nerve
Travel to sympathetic chain
Run up chain to cervical ganglia & synapse with postganglionic neuron
Postganglionic neurons enter head as plexus around internal carotid artery
Supply face via external carotid artery

23

What are the 3 sympathetic chain ganglia in the neck?

Superior cervical - C1-4
Middle cervical - C5-6
Stellate - C7-T1, near lung apex

24

What are sympathetic nerves in the head distributed with?

Cranial nerves and arteries

25

Describe the distribution of the superior cervical ganglion to the face

Sympathetic neurons form a plexus around the internal carotid artery which join parasympathetic nerves
Distributed with arterial branches
Forms deep petrosal nerve which joins parasympathetic greater petrosal nerve and CN VII
Run to pterygo-palatine ganglion from which they are distributed
Distributed with branches of CN V

26

What can be the effects of a pterygo-palatine fossa tumour?

Can compress pterygo-palatine ganglion causing loss of sympathetic and parasympathetic innervation to the face

27

What does loss of sympathetic supply to the head lead to?

Horners syndrome
Uneven pupil size / Pupil constriction (miosis)
Vasodilation
Ptosis - eyelid droop
Lack of sweating (anhydrosis)

28

Which cells of the adrenal medulla release adrenaline?

Chromaffin cells

29

Describe parasympathetic outflow from the CNS

Parasympathetic nuclei sit in the brainstem
Outflow with CN III, VII, IX & X
Outflow with S2-4 spinal nerves

30

Which cranial nerve do parasympathetic post ganglionic neurons hitchhike with?

CN V

31

What can Frey syndrome be caused by?

Parotid surgery or injury
Parasympathetic nerves regrow to skin so innervate muscarinic receptors of sweat glands

32

What are the 2 principal transmitters in the peripheral nervous system?

Acetylcholine
Noradrenaline

33

What neurotransmitters does the sympathetic nervous system use?

ACh at pre ganglionic terminals
NA at post ganglionic terminals

34

Which neurotransmitters does the parasympathetic nervous system use?

ACh at both pre and post ganglionic terminals

35

Which ACh receptor types does the parasympathetic system use?

Nicotinic at pre ganglionic terminal
Muscarinic at post ganglionic terminal

36

What are the sympathetic exceptions to the use of nicotinic ACh receptors?

Sweat glands & chromaffin cells in adrenal medulla - muscarinic receptors

37

What effects do a1 receptor agonists induce?

Blood vessel constriction
GI smooth muscle relaxation
Sphincter contraction

38

What effects do B1 agonists have?

Increased HR
Increased speed of AV node conduction
increased contraction force
GI smooth muscle relaxation

39

Where are muscarinic M1 receptors located?

Autonomic ganglia, induce EPSP

40

Where are muscarinic M2 receptors located?

Heart
Negative chronotropic effects on sinoatrial node, & dromotropic on AV node & atria

41

Where are muscarinic M3 receptors located?

Smooth muscle and vascular endothelial cells
Cause smooth muscle contraction e.g. Pupil, GI transit
Vascular smooth muscle relaxation - Ca2+ influx and NO release from
endothelial cell – the NO causes decrease in Ca2+ in vascular myocytes)

42

What is the typical ion concentration of Ca2+ inside and outside the cell?

Inside: 0.2μM
Outside: 2mM

43

What is the typical ion concentration of Cl- inside and outside the cell?

Inside: 5mM
Outside: 115mM