Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BILD 2 - Multicellular Life > Nervous System II > Flashcards

Nervous System II Flashcards

0
Q

I. Electrical signaling -overview (parts)

A

A. Types of electrical signals

B. Types of Connections

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

Nervous System II

A 
I. Electrical signaling
II. Resting Potential
III. Nernst Equation
IV. Action Potentials (AP)
V. Action Potentials Features
VI. Action Potentials Propagation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

I. Electrical signaling

A. Types of Electrical Signals

A
  1. Action potentials
  2. Postsynaptic potentials
  3. Generator potentials (GPs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Action Potentials (APs)

A

Conduct signals over long distances

e.g. always axon

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

Postsynaptic potentials (PsPs)

A

Localized signal at synapses

-in postsynaptic cell

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

Generator Potentials (GPs)

A

Localized signals in sensory neuron; transducer physical stimulus to electrical

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

I. Electrical signaling

B. Types of connections

A
  1. Cell type
  2. Purpose
  3. Signal _> 10^5 interneurons / motor neurons

(Flow Chart)

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

Sensory neurons

Purpose?

A

Detect sensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Sensory neurons

Signal?

A

GP➡️AP

Generator potentials ➡️ action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Inter neurons

Purpose?

A

Process information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inter neurons

Signal?

A

PsPs ➡️ AP

Postsynaptic potentials ➡️ action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Motor neurons

Purpose?

A

Issue commands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Motor neurons

Signal?

A

PSP ➡️ AP

Postsynaptic potentials? ➡️ action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q 
Effector cells (muscle, glands)
Purpose?
A

Carry out commands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q 
Effector cells (muscle, glands)
Signal?
A

PsPs ➡️AP➡️Effect

Postsynaptic potentials ➡️ action potentials ➡️ effector cells?

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

Cell types order (flow chart top line)

A

[sensory neurons] ➡️ [interneurons] ➡️ [motor neurons] ➡️ [effector cells ]

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

II. Resting Potentials (RP) (parts)

A

A. Potentials
B. Magnitude of RP
C. Ionic bases of RP
D. Ionic Bases -schematic

17
Q

II. Resting Potentials

A. Potentials

A

Arise from charge separation
(Note: potential = voltage)
e.g. Na+ + Cl- separated in solution
➡️high voltage: force of attraction

18
Q

II. Resting Potentials

B. Magnitude of RP

A

About 60-70 mV

Drawing: gland, amplifier, oscilloscope
Figure 37.8 research method: intercellular recording
Drawing chart

19
Q

II. Resting Potentials

C. Ionic Bases of Resting Potentials (RP)

A
  1. ion concentration GRADIENTS across membrane at rest
    (produced by ion pumps driven by ATP) / due to pumps: Na+, K+, and
    ATPase
  2. SELECTIVE permeability of membrane to certain ions at rest
    ➡️ charge separation (permeable ions diffusing down their
    concentration gradients) ➡️ Resting Potential (RP)
20
Q

II. Resting Potentials

D. Ionic Bases - schematic

A
  • selective permeability to K+
  • K+ leaves cell (down its concentration gradient)
  • leaves behind net negative charge ➡️ produces RP

Figure: 37.6 the basis of the membrane potential (RP) & drawing

21
Q

III. Nernst Equation - definition

A

How much K+ leaves cell?

How negative will RP be?

22
Q

III. Nernst Equation - parts

A

A. At equilibrium

B. Nernst Equation

23
Q

III. Nernst Equation

A. At Equilibrium

A

equal and opposite forces on an ion.

Diffusional Force OUT (for K+) = Electrical Force IN (for K+)
(down concentration gradient) (charge attraction)
Fick’s Law Coulomb’s Law

24
III. Nernst Equation | B. Nernst Equation
at equilibrium the following occurs: Vm = 2.3 [RT/zF] log[(X)out/(X)in] for monovalent cations (eg.K+) at room temperature: Vm = 58 log [(X)out/(X)in] = Ex = Equilibrium Potential for ion "X"
25
Given the normal ion gradients at rest:
E(K) = about - 90mV proof: 62mV log(5M/140mM) = -90mV E(Na) = about + 62 mV proof: 62mV log(150mM/15mM) = +62
26
at rest the cell is mostly permeable to
K+ ➡ ️E(K) butsome permeability to Na+ ➡ small contribution E(Na)
27
RP is more
positive than E(K) E(K) about = to -90mV RP about= to -70 E(Na) about= to 62 mV
28
Note: very little K+
leaves cell to RP | ➡-70 mV
29
what maintains the concentration gradient?
Na+, K+, ATPase
30
IV. Action Potentials (AP) | parts
A. Electrical events B. Initiation of AP C. Termination of AP
31
IV. Action Potentials | A. Electrical Event
``` drawing of Vm Vs. Time rising phase (depolarization) overshoot falling phase (repolarization) undershoot ```
32
IV. Action Potentials | B. Initiation of AP
1. Input of neuron (PSP or electrical stimulus) - small depolarization - P Vm 2. The
33
IV. Action Potentials | C. Termination of AP
1. Time- dependent inactivation of VGNaCs at high Vm. | 2. Voltage gated K+ channels (VGNaCs)
34
Time- dependent inactivation of VGNaCs at high Vm
diagram circle open -> inactivated -> closed -> open
35
Voltage gated K+ channels (VGKCs)
- open when Vm ⬆️ selective for K+ - slow to open initially - do not inactivate -open, therefore as VGNaCs drive the Vm to E(Na) (peak of AP), VGNaC's INACTIVE while VGKCs open --> drive Vm back down to RP. In fact, Vm goes below RP briefly "undershoot" 1. NEED VGNCs to inactivate so they don't work against VGKC 2. need VGKCs to be SLOWER than VGNaCs or else AP would never get going diagram Figure 37.10 graded potentials and action potential in a neuron Figure37.11 role of voltage-gated ion channels in the AP
36
V. Action Potential Features | parts
A. Threshold for AP B. All-or-none APs (non-additive) C. Normal Activation
37
V. Action Potential Features | A. Threshold for AP
Push Vm > threshold ➡️ generate full AP Push Vm < threshold ➡️ nothing at "threshold" enough VGNaCs open to further depolarize Vm [at "threshold, Vm opens enough VGNaCs to let enough Na+influx to ope more (faster than they close & faster than the depolarization can dissipate) - hence the positive feedback]
38
V. Action Potential Features | B. All-or-none APs (non-additive)
(limited only by E(Na)) trigger an AP - get the full AP. limited only by E(Na) e.g. can't exceed E(Na)
39
V. Action Potential Features | C. Normal Activation
1. APs triggered by electrical signals: PSPs & GPS 2. Alternative: use electrode to drive current into the cell, producing a depolarization to reach threshold for eliciting an AP
40
VI. Action Potential Propagation | define
- active, regenerative, process - serial induction of AP along axons (no reduction in amplitude = active regeneration) diagram Figure 37.12: conduction of an action potential

BILD 2 - Multicellular Life (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions