Introduction to Veterinary Anatomy and Physiology- Nervous System- Membrane Channels and Potentials

channels that allow ions to filter in on their own

gated channels which open in response to chemical, voltage, or mechanical changes presented to the cell membrane

the post-synaptic cell membrane has receptors for neurotransmitters allowing them to open or close and mostly used when the action potential has arrived at its destination.

receptors that the messenger from one side of the membrane to the other using direct ion exchange, which is supposed to be much faster.

sends out a protein once the transmitter has docked, which in turn ignites functions in the cell

receptor releases a protein (G protein) that in turn starts the production of energy

what is normal resting potential?

__?__ open when the membrane potential (charge) reaches about -55 to +50 mV, becoming less negative and stimulate membranes that need to generate an action potential themselves.

Na, K, and Ca are the most common ions involved in the ion-gated channels. Positive ions start hanging around and push negative ions away and help perpetuate the action potential and stimulate skeletal and cardiac muscle.

toxins such as as the curare frog skin and the puffer fish work by blocking these ion-gated channels causing

a physical change that causes the distortion in the cells to open the gate, like tactile senses

__?__ receive transmitters such as GABA, glycine, and serotonin

the amount of change depends on the __?__ of the change and __?__ of the neurotransmitter.

If there is a lot of neurotransmitter, there is a strong response. Too much of a neurotransmitter inhibits the response all together.

An excitatory neurotransmitter is one that causes the membrane potential to head back to 0 mV, or other wise called depolarization because it makes it more positive.

__?__ causes the channel to open so the Na may flow in kicking out K, depolarizing the cell. Dendrites and cell bodies work with voltage-gated channels. The action potential is instant.

Certain neurotransmitters causes the membrane potential to become more negative, other wise called hyperpolarized. This inhibits or "turns off" the response. the different ways of making the cell back away from the threshold.

Open K channels to let K leak in and make cell more negative. Open Cl channels and let Cl leak in and make cell more negative.

The 4 phases of the action potential

when the voltage-gate channels have close and theres passive ion movement across the membrane

when chemical or mechanically-gated channels are stimulated open and produce PSPs, summating or adding up to a big charge.

Signals meet at the dendrite and are transfered to the axon hillock.

when actual generation of the action potential is the third step and the threshold reaches the voltage-gated channels open and Na flows in.

when the Na channels are inactivated at the peak of the AP and no stimulus of any kind can initate a new AP

when only a large stimulus can initiate a new AP

periods of the rising phase

when the peak of the action potential inactivates the Na channel and activates the K channel, so now K may flow in, repolarizing the cell. As K keeps flowing, there is a point where the cell becomes hyperpolarized, referred to as the undershoot.

2 phases an AP can initiate.

Correctly order the following:
A. Hyperpolar
B. Spike
C. Normal (-75 mV)
D. Action Potential

True or False:
The K in the cell during the rising phase is attracted to the normal negativity of the charged cell along the membrane, causing the depolarization that allows the K channels in the new area to open.
True False

True or False:
The wave can move backwards if it has a strong enough signal.

Conduction velocity relies on

fatty material that works as an insulator for the axons

small gaps between each section of myelin on the axon

__?__ channels are concentrated on the nodes. The node allows the AP to skip across it at a fast rate.

Neurotransmitters only work for what __?__ exist to decipher them.

The frequency and speed of the stimulus mostly has to do with __?__.

regional divisions of the brain

subdivisions of the forebrain

subdivisions of the midbrain

subdivisions of the hindbrain

division of brain that deals with memory, learning, and has some control of periodic things.

division of brain that deals with emotion

division of brain that deals with master sensory relay

division of brain that deals with the control of many things including the endocrine glands

division of brain that deals with integration of sensory information

division of brain that deals with our internal clock of 24/7 hour period

division of brain that deals with motor and autonomic functions

Circadian rhythms controls:

__?__ have free running rhythms lasting more then 24/7.

anticipation of change instead of waiting to respond to some things external

Major nerves:

cranial nerve I

cranial nerve V

cranial nerve VII

cranial nerve X

the longest nerve

decrease in sensitivity in response of a stimulus presented repeatedly

prolonged enhancement of a reflex by introducing a second, often noxious stimulus to "ramp out" the response.

uses both habituation and sensitization to get a conditioned response

what experiment is this a representation of?