Transcript The Nervous System

The Nervous System
PRINCIPLES OF MEDICAL SCIENCE
What the nervous system?
 Complex
 Highly organized
 Coordinates activities of the body
Structure of Nervous System
 Neuron (nerve cell)
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Body
dendrites
Axon
Myelin sheath
How they connect
 Synapses
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Space between neurons
Impuslses come from one
_____ jump the synapses
to get to the _______ of
another neuron
 Neurotransmitters
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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
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Afferent (sensory): message from _____ to _____
Efferent (motor): message from _____ to ______
Associative: nerves that carry both ____ and ____
Divisions to Nervous System
Central
Peripheral
 Brain and spinal cord
 The nerves
 Divides into autonomic
system
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Involuntary body
functions
Brain
 Cerebrum
 Cerebellum
 Pons
 Medulla
cerebru
m
 Thalamus
 Hypothalamus
 midbrain
Brain & Spine
 Spinal cord connects with medulla oblongata
 Meninges- three (3) membranes that protect and
cover the brain
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Dura matter- outer layer
Arachnoid-middle layer
Pia-inner layer
 Ventricles
 CSF
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
Peripheral-Autonomic Nerves System
Sympathetic
Parasympathetic
 After
 In
emergency:
emergency:

Body acts by
increasing
heart rate
respiration,
& blood
pressure;
slows
digestive
WORK TOGETHER
Maintain homeostasis
Control involuntary
body functions

Counteracts the
actions by
slowing heart
rate, decreasing
respiration,
lowering blood
pressure, and
increasing
activity in
digestive tract
Diseases & Abnormal Conditions
 Cerebral palsy
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What?
Symptoms?
 Cerebrovascular accident (CVA) … aka: ______
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What?
Symptoms?
Need treatment within 3 hours
Treatment: thrombolytic drugs usually, when do you not use this?
 Encephalitis
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What?
Symptoms?
 Epilepsy
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What?
Symptoms?
 Hydrocephalus
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What?
Symptoms?
Diseases & Abnormal Conditions
 Meningitis
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What?
Symptoms?
 Multiple sclerosis
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What?
Symptoms?
 Neuralgia
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What?
Symptoms?
 Paralysis
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What?
Symptoms?
 Parkinson’s disease
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What?
Symptoms?
 Shingles

What?
Symptoms
Special Senses
What are your special senses?
 Sight
 Hearing
 Taste
 Smell
 Balance maintenance
Sight & the Eye
 Organ
 Based off light rays  transmits impulses to optic
nerve  interpreted as vision
 What keeps dirt out of eye?
 Lacrimal glands
 Conjunctiva
Parts of the eye
Disease or Abnormal Condition of Eye
 Amblyopia- poor vision in one eye, dominance of
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other eye
Astigmatism- abnormal shape of cornea, what does it
do?
Cataract- leans turns cloudy
Conjunctivitis – HIGHLY CONTAGIOUS
Glaucoma – increased pressure, excess aqueous
humor, leading cause of __________.
Hyperopia
Myopia
Hearing & the Ear
 Organ
 Impulses  auditory nerve  brain to interpret
 Auricle
 Auditory canal
 Tympanic membrane
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
Taste & the Tongue
 MUSCLE
 Has projections called papillae
 Stimulated by flavors of food
moistened by saliva
 Influenced
by sense of
smell
Smell & the Nose
 Olfactory receptors
 Impulses  olfactory nerve  brain
 More sensitive than _____
Skin and General Senses
 Pressure
 Heat
 Cold
 Touch
 Pain
 Receptor perceives ______ type of sense
 Are they different receptors or the same
 What is the use of these receptors?
Neuron
meningitis
parasympathtic
Medulla
oblongata
quadriplegia
central
shingles
sympathetic
cerebellum
cerebrum
temporal
meninges
Occipital
hydrocephalus
Cerebrospinal
fluid
Spinal cord
Multiple
sclerosis
Cerebrovascular
accident
paraplegia
autonomic
lens
hyperopia
astigmatism
myopia
sclera
astigmatism
Auditory canal
Lacrimal gland
Eustachian
tube
Vitreous
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