Transcript The Nervous System

The Nervous System
Unit 6
Objectives
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1. Describe the 3 parts to the neuron
2. List the main divisions of the
nervous system
3. List the functions of the nervous
system
4.Identify and label parts of the brain
and major nerve
5. List some common brain disorders
General Divisions of
Labor
• Central Nervous System
• Peripheral Nervous System
• Autonomic Nervous System
Central Nervous System
• Named for: Location
• Consists of: Brain and Spinal
Cord
• Function: Control Center
Peripheral Nervous
System
• Named for: Location
• Consists of: Spinal, Somatic, and
Cranial Nerves (Receptors)
• Function: Relay Center
Autonomic Nervous
System
• Named for: Function
• Consists of: Midbrain, Pons,
Medulla Oblongata, Spinal Cord,
and Peripheral Branches
• Functions: Independent Life
Functions
ANS
• Broken down into
– Sympathetic NS- activates for F/F
– Parasympathetic NS- calms body
down
Organ
Sympathetic
Parasympathetic
Pupil
Dilate
Constrict
Glands
Sweat
Salivary, Tears
Heart Rate
Accelerates
Slows
Bronchial
Tubes
Dilate
Constrict
Digestion
Inhibited
Stimulated
Urine
Volumes drops
Volume Increases
Liver Glucose
Stims. Release
Inhibits Release
Main Functions
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Communication
Coordination
Orientation
Assimilation
What’s It Made of?
• Neuron: Functional unit that
makes up the nervous system,
triggers to transmit information
Neuron Structure
Neuroglia: Supporting cells that aid
the neuron by feeding, protecting, and
speeding up transmissions
• 65% of
brain tissue
• To surround neurons
and hold them in place
• To supply nutrients and
oxygen to neurons
• To insulate one neuron
from another
• To destroy pathogens
and remove dead
neurons.
How do neurons
communicate?
• Neurons “connect” at a space
called a SYNAPSE
• They create action potentials
that send a signal (from ions)
that causes a release of
neurotransmitters (chemical
signals) that either excite or
inhibit the next neuron
All or Nothing Response
• Neurons “rest” at -70mV
• When voltage changes to +40
mV, the “threshold” has been
reached
• The neuron fires!
• Neurotransmitters
Are released!
Neurotransmitters
• Acetylcholine- excitatory
(arousal, attention, memory)
• Dopamine- inhibitory (attention,
learning, movement, pleasure)
• Serotonin –inhibitory (anxiety,
dreaming, eating, sleep, mood,
pain)
• Noradrenalin/Norepinephrineexcitatory (activity, alert, heart)
More Vocab…
• Brain: Control center of nervous
system, also called cerebrum
• Lobes: Division of the brain with
specific functions
• Cranial Nerves: 12 pairs abbrev.
By roman numerals that control
head and neck
Brain Terms
Lobes of the Brain
• Frontal Lobe
– Location: Front 50% of brain
– Function: Intellect, Reasoning,
Creativity, Social Awareness,
Language and
Personality
(movement as well)
Lobes of the Brain
• Parietal Lobe
– Location: Top, Posterior portion
– Function: Sensory Information
(pain and touch), spatial
relationships
Sensory Maps
• All sensory information is
received in the parietal cortex
• Is there an even amount of
neurons dedicated to every
sense and body part?
• NO!
• Homonculus: diagram that
represents the amount of space
dedicated to each body part
Sensory Homunculus
Lobes of the Brain
• Occipital Lobe:
– Location: Posterior Back, bottom
– Function: Visual area that
interprets shape, color, distance,
etc. and sends info. to be
recognized
Lobes of the Brain
• Temporal Lobe:
– Location: Posterior lateral portions
– Function: Smell, taste, hearing
(music, noise, speech  word to
thought, memory)
Overall View of Function
Cerebral Hemispheres
• Location: Rt. vs. Lt., separated by
longitudinal fissure
• Function:
Left= language and
reasoning
Right=Space, pattern,
artistic, music,
imagination
Corpus Callosum: nerve
fibers that connect the 2
hemispheres
Hypothalamus
“Master Gland”
• Location: Deep, inner portion of
brain
• Function: Regulates metabolism
and glands
Pituitary Gland
• Location: Deep in the sella
tursica
• Function: Secretes hormones
including ADH, oxytocin, TSH,
LH, ACTH
• Extremely important gland for
both nervous and endocrine
system
Brain Anatomy and Phys
• Pineal Gland:
– Location: Superior to brainstem
– Function: Circadian Rhythms
•Pons:
–Location: Brain Stem
–Function: Relays sensory
information b/t cerebrum and
cerebellum (possibly involved in
dreaming)
Brain Anatomy and Phys
• Medulla Oblongata:
– Location: on the brain stem
– Function: Autonomic Fxn’s (heart
and lungs)
• Cerebellum:
– Location: Base of brain
– Function: Sensory Input vs. Motor,
coordinate movement, posture,
balance, and equilibrium
Cranial Nerves
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I-Smell
II-Vision
III-Eye Movement
IV-Eye Rotation
V-Face Sensations
VI-Eye Move Away
VII-Face
Expressions and
2/3 tongue
Cranial Nerves
• VIII- Sound,
rotation, gravity,
balance
• IX-taste, salivary
gland
• X-heart and other
ANS organs
• XI-Neck Muscles
• XII-Tongue Muscles
Ear Drum HairsReceptors
Retina of Eye
Nervous System
Disorders
• Can be environmental, genetic,
or both
• Common disorders include:
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Parkinson’s Disease
Stroke
Alzheimer’s Disease
Meningitis
What does the line show us?
Brain “terms”
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Gyrus: bump/bulge on cortex
Sulcus: Groove in the cortex
Cortex: Outer most layer of brain
Afferent Nerves: bring in
somatic info
• Efferent Nerves: Take out info
(motor, gland, etc.)
Terms Revisited
Cerebral Cortex
• Dark Purple
Off Topics…
• The Science Of Heartache
• Brain Tricks
• Can you live with half a brain?
Make the connection…
• Lower mammals tend to have a
thinner cortex with fewer gyri
and sulci