What are the 3 basic functions of the nervous tissue?
- Brain/Spinal Cord=integration,coordination,and storage
Discribe nervous tissue.
- made up of cellular tissue comprised of neurons and neuroglia/gilia
What are neurons?
- Single cell.
- wire-like cells that connect all regions of the body to the brain and spinal cord.
- highly specialized cells
- you are born with all of the neurons you will ever have-can not reproduce.
What are neuroglias?
- single cell
- can reproduce-they continue to divide and produce more cells throughout the lifetime of an individual
- they out number neurons
What makes up the Central Nervous System (CNS)?
Brain and spinal cord
What makes up the Peripheral Nervous System (PNS)?
Cranial and Spinal Nerves
What are the two basic parts of a neuron?
cell body and soma
What is a dendrite?
- afferent-towards=carrys impulses towards the cell body
- contain numerous receptor sites for binding chemicl messengers from other cells
What is an Axon?
- a single elongated cytoplasmic extension that carrys signals away from the cell body and eventually terminates at other cells.
- vays in length
What are synaptic knobs or buttons? Where are they located?
- small twig-like branches that release chemical messengers that influence other cells.
- they are at the end of the axon.
List the 3 types of Neurons
- Multipolar- many dendrites, 1 axon- efferent
- Bipolar- 1 dendrite, 1 axon- efferent (sight and smell)
- Unipolar- 1 dendrite, 1 axon- quick response, sends signal and can bypass nucleus= used for pain, pressure and touch
Decribe an afferrent neuron.
- sensory neuron
- Peripheral neuron
- carries input signals towards the brain and spinal cord
- always bipolar or unipolar
Describe efferent neurons.
- begin in brain or spinal cord before sending axons out to the peripheral tissues of the body
- control alot of muscle activity
connect one neuron to another neuron to create the comlex neuronal circuit that is responsible for intergration, processing and storage of the input signals that largely defines our nervous system.