Chapter 45 Flashcards

1
Q

What types of actvivties occur at the lower brain or subcortical levels?

A

-Subconscious actvities like:

–> aterial pressure, respiration, feeding, salivation, anger, excitement, SEXUAL RESPONSE, pain and pleasure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What functions occur at the higher brain or cortical level?

A

memory storage and thought processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the difference between chemical and electrical synapses?

A

Chemical synapses use neurotrasmitters to excite, inhibit or modify while electrical channels conduct electricy directly through gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What teo structures are present in the axon terminal?

A

Mitochondria and transmitter vessicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two important components of receptor proteins?

A

Binding component and the ionophore component.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the differences between the two ionophores (cation channels and anion channels)?

A

Cation channels- EXCITATORY and typically sodium ion channels that are lined with negative charges

Anion channels- INHIBITORY and typically chloride channels that are lined with positive charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Are second messenger activator receptors typically long acting or short acting? What molecules are they typically associated with?

A
  • Long acting
  • cAMP and cGMP which cause the prolonged effect typically in gene transcription
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 4 changes that can be elicited by a postsynaptic receptor?

A
  1. opening of specific ion channels
  2. activation of cAMP and cGMP
  3. activation of intracellular enzymes
  4. activation of gene transcription
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the typical action elicited by excitatory receptors?

A
  • opening of sodium channels (pushes the membrane potential towards the more + or threshold direction)
  • associated with the depressed conduction through Cl- or K+ channels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the typical response elicited by inhibitory receptors?

A
  • opening of Cl- channels and increased K+ efflux
  • means more negative inside of the cell which= further from threshold potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do small molecule and neuropeptide transmitters act diffferently?

A
  • -small molucules are small and FAST acting
    • –>continually recycled
  • -neuropeptides are large and SLOW acting
    • –>not recycled
    • –>synthesized and transported at a very slow rate via AXONAL STREAMING
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Are small molecule or neuropeptide transmitters more potent?

A

-neuropeptides are about 1000x more potent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What class of small molecule neurotransmiter is acetycholine? Where is it secreated?

A
  • Class I
  • Secreated by neurons in:

–>pyramidal cells of motor cortex

–>basal ganglia

–>skeletal muscle

–>pre-ganglionic of ANS

–> post-ganglionic of PSNS

–>some post-ganglonic of sympa. nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the major effector function of ACh?

A

-mostly excitatory except at some PS nerve endings like CNX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the class II small molecule neurotransmitters?

A

-Amines

–> norepi, epiepherine, dopamine, serotonin, histamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What two areas secrete norepinepherine? Is it excitatory or inhibitory?

A
  • brainstem and hypothalamus (locus ceruleus in the pons) as well as the postganglionic neurons of the sympathetic ANS.
  • Can be either excitatory or inhibitory
17
Q

Where is dopamine secreted? What is it’s effect?

A
  • secreted at substantia nigra and terminate at the basal ganglia
  • inhibitory
18
Q

Location of serotonin secretion? Effect?

A
  • median raphe of the brain stem
  • inhibitor of pain and inhibitory effects controlling sleep and mood
19
Q

What are the class III neurotransmitters?

A

Class III: amino acids

  • GABA
  • Glycine
  • Glutamate
20
Q

Where is GABA secreted and what is the effect?

A
  • secreted by the spinal cord, cerebellum and basal ganglion and cortex
  • inhibition
21
Q

Where is glycine secreted and action?

A
  • spinal cord
  • inhibition
22
Q

Glutamate action and secretion location?

A
  • Presynaptic terminal in the CNS and cerebral cortex
  • Excitation
23
Q

What is the main excitatory neurotransmitter?

A

Glutamate

24
Q

What is the action of NO?

A

-long term behavior and memory

25
Q

What is the resting membrane potential of spinal motor neurons? How is this calculated?

A
  • 65mV
  • EMF(mV)= +/-61xlog ( [inside]/[outside] )
26
Q

What is the effect of the IPSP? What causes it?

A
  • opening of Cl- or K+ channels
  • moves the membrane potential away from threshold (hyperpolarize)
  • Caused by nt like GABA and Glycine
27
Q

What is the cause and effect of the EPSP?

A

-excitatory transmitters cause influx of Na+ and movement of the membrane potential closer to threshold ~20mV from -65mV to -45mV

28
Q

Where does the EPSP orriginate and why?

A
  • The axon hillock
  • high concentration of Na+ channels
29
Q

What is the difference between sptial and temporal summation?

A

Spatial summation is caused my activating multiple terminals in widely spaced areas (spatial)

Temporal summation is the effect of successive discharges from a single pre-synaptic terminal causing them to add together

30
Q

Why do dendrites display decremental conduction?

A

-membranes contain very few Na+ channels and therefore the membrane potential change decreases as distance from the stimulus increases

31
Q

What is synaptic fatigue and what are some causes?

A
  • decrease n firing rate of the post synaptic neuron even though the pre-synaptic stimulation is rapid
  • caused by exhaustion of transmitter stores, inactivation of post-synaptic receptors, and abnormal ion concentrations
32
Q

How does alkylosis and acidosis affect synaptic transmission?

A
  • Alkylosis increases neuronal excitability (Seizures)
  • Acidosis depresses neuronal activity (diabetic acidosis)
33
Q

What does hypoxia do to neuronal excitability?

A

-causes complete loss of excitability after only a few seconds

34
Q

What drugs cause inreases in neuronal excitability?

A

Caffeine, theophylline (tea), theobromine (cocoa)

-reduce threshold

35
Q

What drugs cause decreases in synaptic transmission?

A

Anasthetics

-increase thresholds

36
Q

How does strychnine increase neuronal excitability and cause tonic muscle spasms?

A

-inhibits actions of inhibitory transmitters like glycine