Nervous System Made Of Flashcards
Where is gray matter
Cell bodies in the cortex and sub cortex
Cell bodies are either neurons or glial cells
Brain tissue made of?
Gray matter(cell bodies of neurons) White matter (axons, dendrites)
What is white matter
Covered in myelin which is white in color
What is a neuron
Excitable nerve cells
Capable of communicating with other nerve cells (neurons)
What do neurons do
Receive, conduct, or transmit neural impulses to a muscle, gland or other neuron
Neurons metabolize
Metabolic rate of cells on the nervous system is higher than any other cells in human body
Energy must be constant for metabolism
What do cells metabolize
Neurotransmiters
How do neurons communicate neural impulses
Bilipid cell membrane allows only certain things in using specialty channels
Cell bodies
Contains organelles made of molecules including the nucleus
Nucleus
Made of proteins
Keep DNA
Nucleolus
Contain cell RNA support/messenger for DNA protein synthesis
Cytoplasm
Protein synthesis/deliverer: energy
Cytoskeleton.
Maintain structure of entire cell
Comprised of protein
Cell membrane
Bilipid membrane insulates the nucleus from extracellular chemicals but allow Neurotransmiters in
Dendrite
Receive incoming transmission from other neurons
1 dendrite per body- unipolar
More than 1- multipolar
Forms dendritic tree, greater area to receive input
Axon
Conducts impulses away from neuron, to other neurons
Only one per cell body
Divides into terminal branches (terminal boutons)
Myelin sheath
Glial cells which grow to form sheath of electrical insulation around axon
Support/increase speed of neural transmission along axon
Synaptic cleft
The site where terminal boutons from the axon form one cell meets the densities of another cell
How do neurons communicate
By transmission of chemicals which occurs at the synaptic cleft
Neurotransmiters are released by action potential or electrical potential crossing the cell membrane
What are neuroglial cells
Are cells which provide various support services to the nervous system
Have same intracellular stricture as neurons
Glial cells pit numbers neurons 10:1
What do glial cells not do
They do out conduct neural impulses (like Neurons do )
Astrocyte (defense)
Provide structural matrix to neurons in cns
Form right walls creating a blood Brain barrier so that substances cannot just pass from bloodstream directly into neural tissue
Plasticity/neural growth
Oligodendrocytes (transport speed)
Form and support myelin (processing speed) to cover axons
Exist in the pns where called Schwann to support myelin for nerves
Microglia (zombies, doctors)
Scavenger cells which clean up dead neurons
Migrate to site of lesion m, turn into macrophages, eat
Orchestrate immune system responses to infection
Bleed, infant, necrotic tissue
Ependyma (packing gel)
Line the ventricles of the Brian and spinal cord
Form the choroid plexus which make csf
Help clear away toxins from brain tissues itself
Crucial for boyancy
