PRINCIPLES OF MEDICAL SCIENCE

The Nervous System

What the nervous system?

ComplexHighly organizedCoordinates activities of the body

Structure of Nervous System

Neuron (nerve cell) Body dendrites Axon Myelin sheath

How they connect

Synapses Space between neurons Impuslses come from

one _____ jump the synapses to get to the _______ of another neuron

Neurotransmitters Special chemicals At end of each _____ Allow nerve impuslses

to pass from one ______ to the next

Nerves

Combination of lots of nerve fibers located outside the brain and spine

Three kinds Afferent (sensory): message from _____ to _____ Efferent (motor): message from _____ to ______ Associative: nerves that carry both ____ and ____

Central Peripheral

Brain and spinal cord

The nerves Divides into

autonomic system Involuntary body

functions

Divisions to Nervous System

Brain

CerebrumCerebellum PonsMedullaThalamusHypothalamusmidbrain

cerebrum

Brain & Spine

Spinal cord connects with medulla oblongataMeninges- three (3) membranes that protect

and cover the brain Dura matter- outer layer Arachnoid-middle layer Pia-inner layer

VentriclesCSF

Peripheral-Somatic Nervous System

Cranial and spinal nerves Cranial nerves: senses

What are examples?Cranial nerves: sensations

What are examples?Spinal nerves

Carry messages to and from spinal cord - MIXED

Sympathetic Parasympathetic

In emergency: Body acts

by increasing heart rate respiration, & blood pressure; slows digestive

After emergency: Counteracts

the actions by slowing heart rate, decreasing respiration, lowering blood pressure, and increasing activity in digestive tract

Peripheral-Autonomic Nerves System

WORK TOGETHERMaintain

homeostasisControl involuntary

body functions

Diseases & Abnormal Conditions

Cerebral palsy What? Symptoms?

Cerebrovascular accident (CVA) … aka: ______ What? Symptoms? Need treatment within 3 hours Treatment: thrombolytic drugs usually, when do you not use

this?Encephalitis

What?Symptoms?Epilepsy

What? Symptoms?Hydrocephalus

What?Symptoms?

Diseases & Abnormal Conditions

Meningitis What?Symptoms?

Multiple sclerosis What?Symptoms?

Neuralgia What?Symptoms?

Paralysis What?Symptoms?

Parkinson’s disease What?Symptoms?

Shingles What?Symptoms

Special Senses

What are your special senses?

SightHearingTasteSmellBalance maintenance

Sight & the Eye

OrganBased off light rays transmits impulses to

optic nerve interpreted as visionWhat keeps dirt out of eye?Lacrimal glandsConjunctiva

Parts of the eye

Disease or Abnormal Condition of Eye

Amblyopia- poor vision in one eye, dominance of other eye

Astigmatism- abnormal shape of cornea, what does it do?

Cataract- leans turns cloudyConjunctivitis – HIGHLY CONTAGIOUSGlaucoma – increased pressure, excess

aqueous humor, leading cause of __________. HyperopiaMyopia

Hearing & the Ear

OrganImpulses auditory nerve brain to interpret AuricleAuditory canalTympanic membrane

An

ato

my o

f th

e E

AR

Diseases & Abnormal Conditions of the Ear

Hearing loss Conductive – deafness happens when __________ Sensory – deafness from _______

Meniere’s disease Vertigo, tinnitus, nausea, vomiting, loss of balance

Otitis externa Caused by pathogenic organism

Otitis media Can cause sore throat. Why/how do you think this happens? Sometimes people have tubes put in the ear. How does this help?

Otosclerosis What does Oto mean? What does sclerosis mean? Gradual hearing loss, tinnitus, surgical removal of the stapes and

insertion of artificial stapes

Tubes in the ear

for Otitis media, called a myringotom

y

Taste & the Tongue

MUSCLEHas projections called papillae

Stimulated by flavors of food moistened by saliva

Influenced by sense of smell

Smell & the Nose

Olfactory receptorsImpulses olfactory nerve brainMore sensitive than _____

Skin and General Senses

PressureHeat Cold Touch PainReceptor perceives ______ type of senseAre they different receptors or the sameWhat is the use of these receptors?

Neuron meningitis parasympathtic

Medulla oblongata paraplegia

quadriplegia central shingles sympathetic cerebellum

cerebrum temporal meninges Occipital hydrocephalus

Cerebrospinal fluid Spinal cord Multiple

sclerosisCerebrovascular accident autonomic

lens hyperopia astigmatism

myopia sclera

astigmatism Auditory canal

Lacrimal gland Eustachian

tubeVitreous humor

retina pupil ossicles amblyopia conjunctivitis

glaucoma stapes cataract auricle iris

sweet Auditory nerve

otosclerosis Tympanic membrane

Sensory hearing

myringotomy cochlea Organ muscle sour

papillae olfactory taste Semicircular canals bitter

Conductive hearing

Olfactory nerve smell lacrimal Otitis media