Neuroscience Terms 1

Anatomy of the Nervous System

Glial Cells

Support for neurons and participate in information processing

Neuron Doctrine

Brain is composed of independent cells (two types: neural and glial cells)

Input zone

dendrites: collect and process info from environment or other cells

Integration zone

Cell body/soma: Integrate info it recieves, decision to produce neural signal

Conduction zone

Axon: electrical impulse has otuput info

Output zone

Axon terminals

Multipolar neurons

One axon, many dendrites

most in CNS

BRAIN HEAVY

Bipolar neuron

One axon, one dendrite

commonly in sensory system

HIGHLY VISUAL

Unipolar neuron

single extension branches in two directions (input and output)

conduction both sides, then input and output

Sensory: transmit info to CNS

SKIN HEAVY

Dendritic spine

small protrusions from dendrite in which synapses are localized

maximizing surface area

Microtubules maintain:

Shape of neuron

Cytoskeleton

Transports items fromc ell body to terminal

Axoplasmic transport

proteins, organelles, other material move through cytoplasm of a neurons axon

Anterograde axoplasmic transport

soma to terminal

kinesin: attach to molecules

Retrograde axoplasmic transport

dyenin

terminal to soma

What happens with no axoplasmic transport? Weakening axoplasmic transport?

Nutrition is not supported and cells will not survive

Alzheimers: slow death of transport proteins/neuron’s cytoskeleton

Oligodendrocytes

myelin sheaths in CNS

Clear cell body, 2+ extensions (provides multiple sheaths)

Schwann Cells

myelin in PNS (one sheath)

ALS and MS

diseases with degradation of myelin sheaths

impaired coordination

Astrocytes

star-shaped, sit between different nerves

most abundant glial cells

secrete chemicals to protect blood-brain barrier (maintaining chemical balances at synapses)

respond to injury by swelling/edema

Microglial Cells

remove debris from injured/dead cells, primary immune cells of CNS

programmed cell death

FIRST IMMUNE RESPONSE —> produces neural inflammation

cytokines

sterilize potential infection and remove threats

released by microglial

Can cause collateral damage, squeezs blood vessels/glial/neurons (unintentional neuronal death)

Autoimmune disease causes

no signal for clearing if cytokines by microglia: constant inflammation

Includes depression, bipolarr, schizophrenia from early childhood infection/maternal inflection

Motor nerves

Transmit info from spinal cord and brain to muscles and glands (output)

CNS —> out, breath, beat heart

Sensory nerves

info from body to CNS

listening to song, pain, hunger

Cranial nerves

innervate head, neck, visceral organs from brain

one part goes to left, one to right

Spinal nerves

connect to sspinal cord, extending out left and right side of body (each has input AND out put to EACH side of body)

Motor fiber (ventral) and sensory fiber (dorsal)

Cervical

neck, 8

Thoracic

Trunk, 12

Lumbar

lower back, 5

Sacral

pelvis, 5

Coccygeal

bottom ,1

Somatic nervous system

mostly motor nerves and some sensory nerves connected to brain and major muscles/sensory systems

VOLUNTARY control

Autonomic nervous system

Mediates bodily functions that aren’t conciously directed

heart rate, digestion, respiration, urination

different NTS —> different effects

both rely on spinal and cranial nerves

sympathetic nervous system

prepare for action

sympathetic axons innervate small clusters of cell bodies close to spinal cord

parasympathetic nervous system

body relaxes and recuperates

neurons that extend from CNS closer to organs

breathing/digestion restored