Nervous System

define neurotransmitters

travels across synapses

define synapses

junction between 2 neurons or a neuron and a target cell

define synapric cleft

gap between 2 adjacent neurons

How does synaptic transmission work

1. perpetuation of the nerve impulse from one neuron to the next cell

2. depolarization vesicles to dump neurotransmitter into the synaptic cleft

3. neurotransmitters diffuse across the synaptic cleft toward postsynaptic membrane bind the neurotransmitter

what do synapses allow

allows system to react quickly

what are the 2 main divisions of the nervous system

CNS and PNS

what does CNS stand for

brain and spinal cord

what does PNS stand for

peripheral nervous system

what are the 3 functions of the nervous system

1. sesory functions

2. integrating functions

3. motor functions

define integrating functins

integrates info and sends to other body parts

define neurons

nerve cells

neurons are the —,— — of the nervous system

basic, functional unit

neurons have a — oxygen requirement

high

can neurons reproduce

no

neurons have support and protection from —

neuroglial

define soma/perikayton

central cell body

define dendrites

recieve stimuli from other neurons

define afferent

conduct stimuli toward cell body

dendrites may serve as — —

sensory receptors

5 examples of dendrites as sensory receptors

1. heat

2. cold

3. touch

4. pressure

5. stretch

define saltary conduction

impulse jumping between shwann cells

saltary conduction is a — means of conductin an — —

rapid, action potential

depolarization in myelinated axons can only take place at

nodes of ranvier

define axons

conduct nerve impulses away from cell

axons may be covered with

myelin

what are nerve fibers

bundles of axons

define myelinated axons

conduct impulses faster than those with no myelin

define myelin sheath

cell membrane of glial cells tightly wrapped around the axon

define oligodendrocytes

produce and maintain the myelin sheath for axons

define schwann cells

Glial cells that produce and maintain the myelin sheath for axons in the PNS.

what are the gaps between adjacent glial cells

nodes of ranvier

define presynaptic neuron

brings depolarization way to synapse

what does the postsynaptic neuron contain

receptors for the neurotransmitter

what are the 6 types of transmitters

1. excitatory neurotransmitters

2. inhibitory neurotransmitters

3. acetylcholide

4. catecholamines

5. GABA

6. glycine

define excitatory neurotransmitters

cause influx of Na+ so postsynaptic membrane moves toward threshold, beginning a new impulse

define inhibitory neurotransmitters

make inside of cell more negative, moving the charge within the postsynaptic cell farther away from threshold

3 ways to stop neurotransmitters

1. acetylcholinesterase

2. monoamine oxidase (MAO)

3. catechol-O-methyl transferase (COMT)

what are the 2 types in the nervous system

CNS and PNS

what is the CNS made of

Composed of brain and spinal cord

define efferent nerve fibers

Conduct impulses away from CNS

afferent nerves are AKA

sensory nerves

efferent nerve fibers are AKA

motor nerves

what is apart of the PNS

Components away from the central axis outward

where are most mixed nerves

PNS

define mixed nerves

Nerves may contain both kinds of nerve fibers

define ANS

Coordination of automic body functions

what does ANS stand for

autonomic nervous system

define SNS

Conscious or volantary control of skeletal muscles

what does SNS

somatic nervous system

define gray matter

Contains most of the neuron cell bodies

define white matter

Contains most of the myelinated nerve fibers

define cerebrum

Largest part of brain in domestic animals

function of cerebrum

learning and intelligence

what is the surface of the cerebrum covered in

covered with gyri seperated by fissures and sulci

how is each hemisphere divided

divided by sulci into lobes