Anatomy & Physiology Nervous System Test

What are the divisions of the nervous system?

Central Nervous System & Peripheral Nervous System

What are the functions of the CNS?

Sensory nerves bring info to CNS. Then CNS processes info & makes decisions

What is the function of the neuroglia cells?

To insulate, support, nourish & protect the neurons

Neuron

The primary cell of the nervous system

What do neurons do?

Generate & transmit the nerve impulse

What is the three neuron pathway?

Sensory, motor and interneuron

Dendrite

Carry information TOWARD the cell body

Axon

Carries information AWAY from the cell body toward the axon terminal

The number of Thorasic nerves is

12

Spinal nerves have ______ pairs

31 pairs

The Brain Stem

Contains the medulla, pons & midbrain

The Brain has four major areas

Cerebrum, diencephalon, brain stem & cerebellum

Spinal Cord

Carries information to and from the brain

Two divisions of the peripheral nervous system

Somatic Nervous System & Autosomatic Nervous System

Somatic Nervous System

supplies motor impulses to the skeletal muscles

Autosomatic Nervous System

supplies motor impulses to cardiac muscle, to smooth muscle & to glandular epithelium

Three major functions of the nervous system

Sensory Function: brings info to the CNS

Interneuron: analyze & makes decisions

Motor nerve function: carries out orders of the CNS

What is the function of neuralgia cells

to insulate, support & nourish. They DO NOT transmit impulses

What are nodes of Ranvier

area of axon that don't contain myelin sheaths, nerve jumps from node to node

Myelin Sheath

increases the volocity of neurons

Synapse

gap between the axon of one neuron & the dendrites or cell body of the next neuron. During a nerve impulse, neurotransmitters carry the impulse from the presynaptic neuron to the post synaptic neuron

Axon terminal

the end of the axon that forms a synapse with another neuron

Neurotransmitters

package the chemicals

receptors

use the chemicals

Level of stimulation for resting membrane

Action Potential carries a charge of -70 mV

Level of stimulation for resting potential

Stimuli threshhold of -55mV

what is a nerve

bundle of connective tissue that contain nerve fibers

Polarization

Negative relative to the outside -70mV (outward leak of K)

Depolarization

Inside neuron becomes less negative -50mV due to inward movement of Na

Repolarization

goes back to resting membrane -70mV

Frontal Lobe

portion of brain responsible for thinking, planning, problem solving, judgement, voluntary movement

Parietal lobe

portion of brain responsible for touch, pain, pressure

Temporal Lobe

responsible for hearing, understanding speech, reading, visual memory & music

Occipital lobe

responsible for vision

hypothalamus

exerts control over all internal organs, controls body temperature, sleep-wake cycle, H20 & electrolyte balance, apptite

cerebellum

2nd largest structure of the brain. Coordinates skeletal muscle movement. Responsible for learning new motor tasks (i.e. throwing a ball). Located lower back part of brain

meninges

three layers of protective tissue that cover the brain & spinal cord

Olfactory nerve I

Cranial nerve controls olfaction, taste & hearing

Optic nerve II

Cranial nerve Sight & visual field

Oculomotor (III)

Cranial nerve controls pupillary reaction

Trochlear (IV)

Controls eyeball movement

Trigeminal (V)

has 3 branches...controles facial sensation

Abducens (VI)

controls lateral eye movement

Facial (VII)

Controls facial expressions & taste

Acoustic (VIII)

Controls Hearing & Balance

Glossopharyngeal (IX)

Controls swallowing and voice

Vagus (X)

Gag reflex, breathing, heart & digestion

Spinal Accessory (XI)

Controls neck motions (i.e. shoulder shrugging)

Hypoglossal (XII)

Controls tongue movement & strength

Name the 3 major plexuses

Cervical, Brachial and lumbosacral

The Cervical Plexuses

C1 to C4

Controls breathing

Stimulus

any change in the environment

purpose of a reflex

a reflex is a sequence of actions designed to sense a change and to respond to the change in a way to restore homeostasis (i.e. gag reflex, corneal reflex, pupillary reflex)

Spinal cord

acts as a relay for all sensory information traveling to the brain

central canal

the hole in the center of the spinal cord

gray matter

composed of cell bodies and unmyelinated interneurons

white matter

composed of ascending and descending tracts

pyramidial tract

major motor tract

Sympathetic Nervous System (SNS)

the "Flight or fight" system. Activates all body systems as through they were ready to meet a dangerous system

Parasympathetic Nervous System (PNS)

the "Feed and Breed" system....exerts a calming effect on the body

Iris

The colored part of the eye

Pupil

Regulates the amount of light that enters the eye

Retina

Innermost layer of the eyeball; contains photoreceptor cells for vision

Photoreceptors

react to bright light

Rods

sensitive to dim light

Cones

Activation of cones causes color vision

Interneuron

nerve cell that carries impulses from a sensory neuron to a motor neuron