Physio Chapter Two

All movement and behavior is a function of what?

What is the most common neuron in the nervous system?

Receives information from external or internal environment and sends info to the brain. 

Controls contraction of the muscles

Connect sensory neurons and motor neurons and give us reflexes.

These neurons are prominent in the spinal cord.

Branches attached to soma, receives info from other neurons

The cell body, contains the nucleus and other structures.

Long tube-like appendage, propagates electrical impulses from soma to terminal button.

What are electrical impulses that are propagated by the axon?

Some axons have this as insulation.

Mylinated axons contain this, the only place where ion exchange takes place.

The end of the axon, releases neurotransmitters

Chemical that either excited or inhibits other neurons

Membrane that releases neurotransmitters into the synaptic cleft.

The receiver of neurotransmitters

The junction between terminal buttons of one neuron and dendrite, soma, or axon.

One axon and many dendrites attached to the soma. Some of the longest axons in the human body. They are mylinated.

An axon and one dendirte attached to soma, usually conducting sensory info from environment to CNS. They are unmyelinated and examples are the eye, inner ear, etc.

The axon and dendrite branches form one long appendage with a short stock attaching it to the soma, transmits sensory info from outside the peripheral nervous system.

Layer of lipis aroud the cell.

Jelly-like substance in the cell, holds other structures in place.

Breaks down nutrients for energy for cell by producing ATP. The Power House.

Contains chromosomes, which contain DNA, that make proteins, also contain genes.

Strands of protein, give shape to the cell.

Combines or breaks apart substances in cells. Also used for transport.

Protein strands in axon used to transport substances along the axon; bidirectional.

These cells support and hold neurons in place.

These CNS glia cells provide physical support, clean up debris and dead cells, get nutrients from blood and give to neurons, control speed of neurotransmitters, perform as a kind of immune system for neurons, can travel around CNS --> its appendages can extend to new neurons.

A CNS glia cell that supports axons, produces myelin sheath. Nodes of Ranvier are gaps between myelin sheath.

A peripheral NS glia cell that supports axons and produces myelin in PNS. Helps regenerate axons.

This puts scar tissue down in the CNS, inhibiting the growth of chutes that a nucleus is trying to grow back that have been damage. This eventually kills the nucleus.

In PNS, if part of the axon is destroyed, the axon will start sending out sprouts and attach to what?

Capillaries in the brain and spinal cord and do not allow substances to flow in and out of it, prevets chemicals from entering the brain, used to regulate composition of extracellular fluid to regulate message transmission in the brain. 

Safety system - gag reflex makes us throw up.

Are pores for the blood-brain barrier the same size?

This is sent from the dendrites, soma, or axon down the axon to the terminal buttons which releases various neurotransmitters into the synaptic cleft.

The electrical charge across a cell membrane. It is the difference in electrical potential inside the cell in comparison to the fluid bathing the outside of the cell.

Sodium and potassium channels all over neurons and in cerebral spinal fluid are important to...

Membrane potential at rest (-70 mV)

If we have a sub-threshold stimulus, will it fire and give off an action potential? 

Membrane potential that must be reached for action potential to occur (-60 mV)

Rapid recution of membrane potential (+30 mV)

Rapid increase in membrane potential

Membrane potential becomes greater than its resting potential (overshoots)

When threshold of excitation is reached, what is achieved when sodium channels open and sodium floods across the cell membrane into the cell?

At the peak of action potential, this occurs are sodium channels begin clsoing and potassium channels fully open, and potassium starts rushing out of the cell.

When membrane potential returns to -70mV, what begins closing?

When hyperpolarization occurs, sodium and potassium transporters pump in to what ions, and pump out three what ions until the membrane returns to the original resting potential.

Action potential is either generated or not and does not decrease in size as it travels down the axon.

More neurons that fire = 

Action potentials propagate faster through myelinated axons in comparison to non-myelinated axons via:

An elextrical charge in the membrane of the postsynaptic neuron caused by the binding of an exctatory neurotransmitter from a presynaptic cell to a postsynaptic receptor; making it more likely for a postsynaptic neuron to generate an action potential.

An electrical charge in the membrane of a postsynaptic neuron caused by the binding of inhibitory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more difficult for a postsynaptic neuron  to generate an action potential.

Removal of neurotransmitter from synaptic cleft by the terminal button

Enzyme destroys the neurotransmitter

These are neurotranmitters that contracts the muslces

Destroys Acetylcholine