Neuro Physiology

Receptors

Input: sensory

Special sensory receptors: monitor smell, taste, vision, hearing

visceral sensory receptors: monitor internal organs

somatic sensory receptors: monitor skeletal muscles, joints, and skin surface

Effectors

output: causing change

skeletal muscle

smooth muscle

cardiac muscle

glands

adipose tissue

Dendrites

branches of a neuron that increase surface area and reach out to other areas

Axon terminals

connect to another cell and creates a pathway

Anaxonic Neuron

Doesn't have axons

integrating cell

takes in a bunch of info and decides where it goes

Bipolar Neuron

Special senses: taste, smell, sight

Two processes separated by the cell body

Unipolar neuron

Sensory neurons in spinal cord

quick signal bypasses cell body

single elongated process

cell body located off to the side

Multipolar neuron

Effectors

found in muscles

single axon and multiple dendrites

Ependymal cells

Line ventricles and central canal

assist in producing, circulating, and monitoring cerebrospinal fluid

Astrocytes

Maintain blood- brain barrier

provide structural support

regulate ion, nutrient, and dissolved gas concentrations

Absorb and recycle neurotransmitters

form scar tissue after injury

Oligodendriocytes

myelinate CNS axons

provide structural framework

Microglia

Remove cell debris, wastes and pathogens by phagocytosis

Satellite cells

Surround neuron cell bodies in ganglia

regulate O2, CO2, nutrient, and neurotransmitter levels around neurons in ganglia

Schwann cells

surround all axons in PNS

responsible for myelination of peripheral axons

participate in repair process after injury

Sodium

depolarizes via entering cell through Na channels

Calcium

depolarizes via entering cell through Ca channels

Potassium

hyperpolarizes via exiting cell through K channels

Chloride

Hyperpolarizes via entering cell through Cl channels

Continuous Propagation

Nonmyelinated axons

Saltatory Propagation

large sensory neurons

Myelinated axons

Glutamate

Main Actions: excitatory neurotransmission

Modulation of synaptic plasticity

Activation of second messenger system

GABA

Main Action: Inhibitory neurotransmission

Acetylcholine

Main Actions: Muscle contraction

Autonomic functions

Parasympathetic functions

Neuromodulation

Norepinephrine

Main Action: Sympathetic functions

Neuromodulation

Dopamine

Main Action: Neuromodulation

Serotonin

Main Action: Neuromodulation

Histamine

Main Action: mainly excitatory neuromodulation

Glycine

Main Action: Inhibitory neurotransmission

Peptides

Main Action: Neuromodulation

Direct effects

Binds to chemically gated channel> produces action

Indirect effects

attaches to different types of receptor and cascading effects within cell

Excitatory postsynaptic potential (EPSP)

Leads to quick graded depolarization

Inhibitory postsynaptic potential (IPSP)

leads to quick graded hyperpolarization

Neuromodulation

slow secondary cellular signal cascades that either facilitates or inhibits signal transmission

Temporal summation

two or more stimuli arriving at different times creating an action potential

Spatial summation

two stimuli arriving at the same time creating an action potential

Segmental level

lowest level

reflexes

spinal cord

Projection level

Middle level

voluntary control

can over ride some reflexes

motor cortex and brain stem nuclei

Precommand level

highest level

Preprogrammed response

cerebellum and basal nuclei