ANAT 101 Lecture Notes - Lecture 11: Stone Skipping, Myelin, Membrane Potential

24 views3 pages

golddinosaur542

3 Apr 2016

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Every neuron has a resting membrane potential-an electrical potential diference(voltage) that exists across a plasma membrane of an excitable cell when the cell is in an undisturbed (resting) Graded potential-small deviations that make membrane more polarized (more negative) or less polarized(less negative) could either make the membrane even more negative(hyperpolarizing). To make the inside more negative, we need negative ions inside or more positive ions than normal would have to leave the cell. When you decrease polarity, bring the membrane closer to 0. When you want to make it even more polar, we need the inside cell to become more negative (-75) hyperpolarizing. Occurs in ligand gated or mechanically gated. Or depolarizing graded potential makes it 0 or less negative. Channels- found on cell bodies and the dendrites (making the interior more positive. Mechanical gated (depolarizing graded potential)-inside of the cell, negative more close to membrane and then positive coming in.

Related Questions

**Please only answer if you are 100% correct!

1. Why are Na+, K+, and Clâ the only ions considered in the GK equation when calculating resting membrane potential (Vm)?

A. These ions are found in the highest concentrations inside the cell

B. These are the ions to which cell membranes are permeable at rest

C. Only these ions have enough charge to influence Vm

D. These ions bind to receptors that increase the charge on the membrane

2. Voltage-regulated channels are located

A. on the neuron cell body only

B. within the cytosol only

C. in the membranes of axons only

D. in the membranes of dendrites only

E. in the membranes of dendrites, in the membranes of axons, and on the neuron cell body

3. As the charge on the membrane of a typical neuron approaches 0 from -70 mV, the cell is

A. hyperpolarizing and becoming more difficult to stimulate

B. only becoming more difficult to stimulate

C. only hyperpolarizing

D. only depolarizing

E. only repolarizing

During active transport in the neuron, the outside of the cell is _________________ and the inside is _______________.

positive, negative

more positive, less positive

more negative, less negative

negative, positive

In active transport, _____________ provides the energy to move molecules against their concentration gradient.

nucleus

potassium

sodium

adenosine triphosphate

________________ proteins can change shape when moving substances across the membrane.

Proteins that can be open or closed, based on different conditions, are called ___________.

bypass proteins

channel proteins

selective proteins

gated

Tunnels that allow charged ions to move easily across the plasma membrane without the use of energy are called ____________________.

channel proteins

glycolypipd proteins

phospholipid proteins

carbohydrate chains

____________ and ____________ make it easier for molecules to move across the plasma membrane.

small, negatively charged

small, positively charged

small, no charge

large, negatively charged

large, positively charged

Santiago Ramon y Cajalâs theory of dynamic polarization refers to the:

(a)membrane potential of a neuron at rest.

(b)membrane potential of a neuron firing action potentials.

(c)opening and closing of gated channels in the membrane.

(d)one way flow of information in neurons from dendrites to axon terminals.

(e)one way flow of information in neurons from axon terminals to dendrites.

Over the course of scientific history, there are many examples of scientists reaching the right conclusion for the wrong reasons. When Schwann first proposed that the nervous system was made of individual cells, he based it on observations of:

(a)synapses.

(b)dendrites

(c)axon terminals.

(d)astrocytes.

(e)Nodes of Ranvier.

The synaptic cleft was finally seen in the 1950s. What prevented scientists from seeing it earlier?

(a)The resolution of the light microscope.

(b)They were looking in the wrong place.

(c)Their tissue was not appropriately stained.

(d)Myelination of the axons.

(e)all of the above

The resting membrane potential of a neuron is approximately:

(a) +65 V

(b) +65 mV

(d) -65 mV

What is largely responsible for the resting membrane potential in a neuron?

(a)Axonal insulation by myelin

(b)Voltage-Gated Sodium Channels

(c)The Action Potential

(d)Potassium Leak Channels

Which of the following would DECREASE the propagation velocity of an action potential down an axon?

(a)Increase in axon diameter

(b)Increase myelination between nodes of Ranvier

(c)Remove myelination between nodes of Ranvier

(d)Decrease density of voltage-gated Na+ channels except at the Nodes of Ranvier

The resting membrane potential of a neuron can be estimated using the:

(a)Nernst equation

(b)Goldman equation

(c)Hodgkin and Huxley equation

(d)Ohmâs law

18. What would happen to the resting membrane potential of a neuron if you added K+ to the extracellular fluid?

(a)Resting membrane potential would increase (become more positive)

(b)Resting membrane potential would decrease (become more negative)

(c)Resting membrane potential would not change

(d)Resting membrane potential would be abolished

. Which of the following statements is FALSE for Graded Potentials

(a)Magnitude changes with magnitude of triggering stimulus

(b)Magnitude decreases with distance from initial site

(c)Cannot be summed

(d)No refractory period

In the nervous system, the strength of the stimulus is coded into:

(a)The frequency of action potentials generated

(b)The amplitude of action potentials generated

(c)Both the frequency and amplitude of action potentials generated

(d)The duration of individual action potentials generated

Ion movement during both the depolarization and repolarization phases of an action potential are the result of:

(a)active transport pumps along the neuron membrane.

(b)diffusion of ions down their electrochemical concentration gradients.

(c)negative feedback loops.

(d)All of the above

At the peak of the action potential, the membrane potential is:

(a)Exactly at the Na+ equilibrium potential

(b)Greater (more positive) than the Na+ equilibrium potential

(c)Above 0 mV but less positive than the Na+ equilibrium potential

(d)0 mV

ANAT 101 Lecture Notes - Lecture 11: Stone Skipping, Myelin, Membrane Potential

Document Summary

Get access

Related Documents

ANAT 101 Lecture Notes - Lecture 16: Resting Potential, Cell Membrane, Depolarization

ANAT 101 Lecture Notes - Lecture 18: Voltage-Gated Potassium Channel, Resting Potential, Peripheral Nervous System

ANAT 101 Lecture Notes - Lecture 9: Resting Potential, Membrane Potential

Related Questions