Lecture 2 - ANS Flashcards Preview

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Flashcards in Lecture 2 - ANS Deck (63)
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1

Briefly state the 7 steps of synaptic transmission:

1.pre-synaptic membrane depolarizes due to AP
2. NT's packed in vesicles and docked at pre-synaptic v.
3. Voltage gated CA channels open w/depolarization, calcium enters pre-synaptic t.
4. increase in calcium --> fusion of vesicle with pre-synaptic membrane
5. NT released into synaptic cleft
6. NT bind to recepts in post-syn membrane
7. Post-synaptic receptors activated and trigger event

2

After Ca enters the pre-synaptic terminal, what occurs?

Vesicles containing NT's released into cleft

3

What binds the vesicles to the membrane?

SNARE proteins

4

Botulinum toxins and Tetanus cut what proteins and prevent the binding of the vesicle?

SNARE proteins
- prevent synaptic vesicle fusion & NT release

5

What kind of paralysis does Botulinum cause? Tetanus?

1. Flaccid Paralysis

2. Spastic Paralysis

6

Botulinum toxin affects what fibers?

Cholinergic fibers

7

TetX is taken up by inhibitory neurons where? Causing what?

SPinal cord

- SPASTIC paralysis

- UPM

8

NT's released from vesicles bind what kind of receptors when propagating an electrical signal?

IONOTROPIC

- AChR, GABA

- allow ion influx --> Post-synaptic current = PSC

9

What is PSC? PSP?

Post Synaptic Current

Post Synaptic Potential

10

Ionototropic receptors allow ion influx leading to what 2 events?

PSC & PSP

11

Is the release of NT from vesicles an AP?

NO

- it is a PSP
- graded response propagated passively

12

How can one get an AP from a PSP?

integration of signals

13

EPSP's cause what changes in the membrane? Are these AP's? What do they increase the probability of?

1. MEMBRANE DEPOLARIZATION
- influx of cautious bring membrane to zero
2. NOT APs!!! but can generate AP if strong enough

3. increase probability of AP firing

14

What are some inhibitory NT's? What influx do they cause?

1. GABA, Glycine

2. Influx of Cl- (IPSC)

15

What two events can IPSP cause? Do ESPS do the same?

1. membrane depolarization & hyper polarization

ESPS's do NOT cause hyper polarization

16

Which of the two stabilizes the Em at negative potential?IPSP or EPSP?

IPSP!!

- reduce probability of AP firing

- away from AP threshold (graph is upside down)

17

Synaptic integration, or the effect of EPSP's and IPSP's depends on what?

Location at the neuron
- timing

18

Two AP's happening a the same time in different locations are called:

Spatial Summation

19

Sequence of AP's in the same place, close in time are called:

Temporal Summation

20

What are the 2 main functions of ANS?

1. Homeostasis
2. Respond to external stimuli

(light, external threat --> FIGHT OR FLIGHT)

21

In the ANS, what controls cardiac muscle, smooth muscle & glands? What modulates organ activity and are accompanied by visceral afferents?

Effector system

- EFFERENT FIBERS (motor fibers)

22

What are the 8 main Autonomic NT's?

1. Acethylcholine (ACh),
2. Norepinephrine (NE).

3. ATP,
4. NO
5. 5HT,
6. GABA
7. dopamine
8. glutamate

Epinephrine is a central neurotransmitter, but in the ANS its
function is mainly hormonal.

23

What type of post-synaptic receptor does Neuron-Viscera use?

Metabotropic!!!

= slower

- neuron to neuron 7 neuron to SkM both use INOTROPIC (fast)

24

What type of NT effect does Neuron-Viscera have?

Variable

(the other two are direct)

25

Which type of muscle has adventitial (outermost) perivascular varicose nerves? (around a blood vessel)

VASCULAR SMOOTH MUSCLE

- visceral smooth muscle has them all throughout
- VASCULAR ONLY AT THE TOP!!! uses coupled cells

26

What is the only place using NMJ?

Neuron- Skeletal Muscle

27

Which of the two: vascular or visceral, contains connections and highly interconnected neurons?

VISCERAL!!

- ex: better coordination of heart contraction

VASCULAR has coupled cells but NOT interconnected (synapses are found on top)

28

Cardiac myocytes have what type of synapses?

Synapse en-passant

- junctions appear partway along an axon as it extends

29

Describe the following for NE:

1. Where made
2. Termination
3. Location of degrading enzymes

1. in Vesicles, from DOPA

2. interact with adrenergic receptors
- NE action terminated by re-uptake into cytosol & degradation (MAO, COMT)

3. Cytosol, mitochondria, circulation

30

Describe the following for Cholinergic transmission:

1. Where made
2. Termination
3. Location of degrading enzymes

1. CYTOSOL from choline (transported by vesicles)
- rich in egg yolks, liver, soy beans

2. inactivated by HYDROLYSIS via acetyl cholinesterase (AChE)
3. Re-uptake into the PRESYNAPTIC TERMINAL for reuse