Anatomy: Neural Tissue

The approximate resting potential of a typical neuron is ____ mv

-70

Depolarization of a membrane will shift the membrane potential from ______ mv to ____ mv

-70 +30

Name the 2 parts (organs) of the CNS

A) brain B) spinal cord

Name the 2 major subdivisions of the nervous system

A) central nervous system B) peripheral nervous system

The speed of an impulse is based upon what 2 factors

A) diameter of axon B) degree of myelination

What are the 3 functions of the nervous sytem

A) gathers sensory information B) makes decision of what shold be done at each moment C) effects responsible by activating effector organs

During rabies, what symptom causes the mammal to.... A) act "crazy" B) foam at the mouth

A) hallucinations B) saliva build-up

What are the 3 classifications of neurons based upon their structure

A) multipolar B) bipolar C) unipolar

What are the 3 classifications of neurons based upon their functions

A) sensory B) motor C) association

Ach is broken down by ______ (abbreviation)

AchE

Conducts impusles away from the soma

Axon

Longer Processes (up to 3-4 feet long)

Axon

Releases neurotransmitters

Axon terminal

Conducts local currents towards the soma

Dendrite

Shorter branches that taper off the cell body

Dendrite

The resting membrane potential consists of a cell cytoplasm that contains a higher concentration of ______ ions and a lower concentration of ____ ions than the surrounding extracellular fluid

K Na

Oligodendrocyte

Location: CNS Function: cover the fibers of the CNS neurons with myelin sheaths

Microglia

Location: CNS and PNS Function: phagocyte cell that protect neurons form invading microorganism

Astrocytes

Location: CNS and PNS Function: star-shaped cell that connect neurons to capillaries and help exchange nutrients between capillaries and neurons

Schwann Cells

Location: PNS Function: cover the fibers of the PNS neurons with myelin sheaths

Causes white matter of the brain

Myelin Sheath

Formed by the Schwann cells in the PNS

Myelin Sheath

Increases the speed of impulse transmission

Myelin Sheath

Gaps in the myelin sheath

Node of Ranvier

The spaces between the myelin sheaths are called

Nodes of Ranvier

What cells produce myelin sheaths in the CNS

Oligodendrocyte

What cells produce myelin sheaths in the PNS

Schwann

Location of the nucleus

Soma

Junction between nerve cells

Synapse

The most common excitatory neurotransmitter is _________

acetycholine

Impulses are carried towards the soma of a nerve cell by the

dendrites

the neurotransmitters cause ______ to occur in the post-synaptic membrane

depolarization

Motor (_________) neurons carry impulses _______ from the CNS and ________ muscles or glands.

efferent away towards

What is the function of myelin sheaths around the axons

increase the speed of impulse transmission

associative neurons are also called _______ and are found in the ____.

interneurons CNS

Rabies is a viral infection that is absorbed through the synaptic _______

knob

Polio is a viral infection that attacks _______ neurons

motor

Damaged during multiple sclerosis

myelin sheath

Multiple sclerosis is an autoimmune disorder that destroys the _______

myelin sheaths

Chemicals that are released by the axon knob and the receptor membrane called

neurotransmitters

What neuroglial cell is responsible for the presence of white matter in the brain

oligodendrocytes

Sodium-potassium pumps transport Na ____ of a cell and K ______ of a cell

out of into

The movement of the membrane potential back to the resting potential level is called

repolarization

Where are bipolar neurons found in the body

retina of the eye and the olfactory mycosa

The Latin phrase for the "leaping" of axon impulse over the myelin sheaths is known as __________

saltatory conduction

What type of neuron carries impulses to the brain and spinal cord

sensor

Summation is the adding of ______ stimuli until a minimum level is reached thus causing depolarization.

subthreshold

The junction or space between the axon of one neuron and the dendrite of the next neuron is called a _______

synapses

What is the space between the axon knob and the receptor membrane called

synaptic cleft

The minimum level of a stimulus at which depolarization of an axon will occur is called the ______ stimulus.

threshold