HBS: Nervous System

Functions of the nervous system

-detect incoming stimuli (sensory input)

-interpret stimuli (brain)

-respond to stimuli (motor output)

Nervous system flowchart

(see image)

Regions of the brain

cerebrum, diencephalon, brain stem, cerebellum

Gyri

ridges of the brain

Sulci

grooves of the brain

Where is gray matter in relation to white matter?

Gray matter is 1/4 inch before the white matter

longitudinal fissure

separates left and right hemispheres

corpus callosum

connects the two hemispheres

gray matter (in cerebrum)

unmyelinated neurons that control somatic sensory receptors/motor receptors

white matter (in cerebrum)

myelinated neurons that send impulses throughout the brain from one hemisphere to the other

Lobes of cerebrum

frontal, parietal, temporal, occipital

Frontal lobe function

higher intellectual reasoning, socially acceptable behavior, voluntary movement control

Parietal lobe function

interprets somatosensory sensations (skin... perception of touch, pressure, pain, temperature, position, movement, and vibration)

temporal lobe function

interprets hearing/smell

Occipital lobe function

visual cortex, interprets sight

brain stem function

attaches brain to spinal cord

medulla oblongata function

Control center for heart rate, blood pressure, breathing, swallowing, vomiting (vital functions)

pons function

composed of fiber tracts, controls breathing

midbrain function

composed of tracts/nerve fibers that control reflex centers for vision/hearing

thalamus function

relay station for sensory impulses, pain... transfers impulses to correct cortex for interpretation

hypothalamus function

Regulates body temperature, metabolism, controls water balance, important in emotions

Cerebellum function

Controls muscle balance and coordination

iris

Muscle that controls size of pupil, pigmentation gives color to the eye, regulates amount of light entering the eye

Cornea

transparent tissue covering the front of the eye

pupil

hole in the center of the eye where light passes through

Fovea

focal point of the eye

optic nerve

sends image to the brain

aqueous humor

clear watery fluid found in anterior side of eye

vitreous humor

clear, jelly-like fluid that keeps the shape of the eye

lens

transparent tissue that bends light passing through the eye

retina

layer of tissue on back side of eye that contains cells responsive to light

choroid

Middle layer that contains blood vessels in eye

Sclera

outer covering that helps maintain the shape of the eye (whites of the eyes)

Optic disk

Blind spot... A hole in the retina where the optic nerve connects to the retina

cilliary body

Contains a ring of muscles that surround the lens and control its shape

Eye diagram

(see image. the image doesn't have all of the parts we need to know... make sure you look at your colored diagrams!)

Dendrites

detect stimuli

Axon hillock

Acts like a funnel for info to travel down the axon

Axon

directs stimulus down the neuron

myelin sheath

protective layer to axon

Nodes of Ranvier

helps move the stimulus down the axon

Cell body of neuron

contains nucleus and organelles

Nucleus of neuron

Contains genetic info

Axon terminal

end of axon, sends stimulus to the next neuron

Neurillema

protects Schwann cells

Schwann cells

produce myelin sheath

neuron diagram

(see image + your own diagram)

Synapse

Gap between neurons

Neurotransmitters

what is released from the axon terminal... neurotransmitters cross the gaps between neurons (synapses)