3. Functions of the Nervous
System
1. Communication and coordination
Adapt and respond to changes from both inside
and outside the body
2. Site of reasoning- your brain
3. Two main divisions
Central nervous system (CNS): brain and spinal
cord
Peripheral nervous system- the nerves
4. Neuron- basic structural
unit of the nervous
system
Dendrites- carry
impulses towards the
cell
Axon-carry impulses
away from the cell
Myelin sheath
Synaptic terminal
Epinephrine
Norepinephrine
Acetylcholine
5. Nerves
Nerves are made of many nerve cells
Afferent-sensory nerves carry message to
brain
Efferent-motor neurons carry message
from brain to muscle
Associate- do both
Heads up
6.
7. The Nervous System
Major division - Central
vs. Peripheral
Central or CNS- brain
and spinal cord
Peripheral- nerves
connecting CNS to
muscles and organs
Central Nervous System
Peripheral Nervous System
9. Cerebrum
Cerebrum-largest
part of brain.
Responsible for
reasoning, thought,
memory, speech,
sensation, etc.
Divided into two
halves.
Further divided into
lobes; occipital,
parietal, temporal
and frontal
11. Cerebellum and Brain Stem
Cerebellum-
responsible for
muscle coordination
Brain stem- most
basic functions;
respiration,
swallowing, blood
pressure. Lower part
(medulla oblongata)
is continuous with
spinal cord
13. Spinal cord
Spinal cord- begins
at foramen magnum
and ends at second
lumbar vertebrae
Contains both
afferent (to the
brain) and efferent
(motor neurons-
away from the brain)
14. Both the brain and spinal cord are covered by
a membrane system called the meninges
In addition, the brain has four hollow areas
called ventricles. Cerebrospinal fluid is
produced in the ventricles and bathes the
brain and spinal column
15. Brain has 2 Hemispheres
Left & Right sides are
Corpus Callosum
separate Right
Corpus Callosum : Hemisphere
major pathway
between hemispheres
Some functions are
‘lateralized’
language on left
math, music on right
Lateralization is never Left
100% Hemisphere
17. Sensory Information sent
to opposite hemisphere
Left visual Right visual
Principle is Contralateral field field
Organization
Sensory data crosses over
in pathways leading to the
cortex
Optic
Visual Crossover nerves
left visual field to right
hemisphere
right field to left
Other senses similar
Left Visual Corpus Right Visual
Cortex Callosum Cortex
18. Contralateral Motor
Control
Movements
controled by motor Motor Cortex Somatosensory Cortex
area
Right hemisphere
controls left side of
body
Left hemisphere
controls right side
Motor nerves cross
sides in spinal cord
19. Corpus Callosum
Major ( but not only) Medial surface of right hemisphere
pathway between sides
Connects comparable
structures on each side
Permits data received on
one side to be
processed in both
hemispheres
Aids motor coordination
of left and right side Corpus Callosum
20. Corpus Callosum
What happens when the corpus
callosum is cut?
Sensory inputs are still crossed
Motor outputs are still crossed
Hemispheres can’t exchange data
21. The ‘Split Brain’ studies
“What did
“Using“Whatleft hand,
your did
Picture to right brain you see?”
Pick up what you saw.”
you see?”
can’t name the object
left hand can identify
by touch
Picture to left brain
can name the object
left hand cannot ??
identify by touch
I saw an
Verbal
Verbal
apple. Nonverbal
left
left right
hemisphere
hemisphere hemisphere
24. Peripheral Nervous System
3 kinds of neurons Brain
Spinal
connect CNS to the body Cord
sensory
motor
interneurons Nerves
Motor - CNS to muscles
and organs
Sensory - sensory
receptors to CNS
Interneurons:
Connections Within CNS
25. Peripheral Nervous System
Peripheral Nervous System
Skeletal Autonomic
(Somatic)
Sympathetic Parasympathetic
26. Somatic System
Nerves to/from Brain
spinal cord
control muscle
movements Sensory
Neuron
somatosensory
inputs
Both Voluntary and
reflex movements Motor
Skin receptors Neuron
Skeletal Reflexes
Interneuron
simplest is spinal
reflex arc
Muscle
27. Autonomic System
Two divisions:
sympathetic
Parasympatheitic
Control involuntary functions
heartbeat
blood pressure
respiration
perspiration
digestion
Can be influenced by thought and emotion
28. Sympathetic
CENTRAL NERVOUS SYSTEM SYMPATHETIC
Brain
“ Fight or flight” Dilates pupil
response Stimulates salivation Salivary
Release adrenaline and Relaxes bronchi
glands
noradrenaline Spinal
Lungs
cord
Increases heart rate and
blood pressure Accelerates heartbeat
Heart
Increases blood flow to Inhibits activity Stomach
skeletal muscles
Pancreas
Inhibits digestive
Stimulates glucose Liver
functions
Secretion of adrenaline, Adrenal
nonadrenaline gland
Kidney
Relaxes bladder
Sympathetic Stimulates ejaculation
ganglia in male
29. Parasympathetic
CENTRAL NERVOUS SYSTEM PARASYMPATHETIC
Brain
“ Rest and digest ”
Contracts pupil
Stimulates salivation
system Constricts bronchi
Spinal
Calms body to cord
conserve and
Slows heartbeat
maintain energy
Lowers heartbeat, Stimulates activity
breathing rate,
blood pressure
Stimulates gallbladder
Gallbladder
Contracts bladder
Stimulates erection
of sex organs
31. Disorders of the nervous system
Meningitis- inflammation of the linings of the
brain and spinal cord
Encephalitis- inflammation of the brain
Epilepsy-seizure disorder. Excessive
discharge from neurons. 1 in 200 suffer. Grand
mal or petit mal seizures
Cerebral palsy- disturbance in voluntary
muscular action
Parkinson’s –decreased neurotransmitter
MS multiple sclerosis- autoimmune
32. The Nervous System:
Summary
Major structures of the
nervous
CNS, Somatic, Autonomic
Two hemispheres & 4 lobes
Organization
contralateral input & output
primary sensory areas
motor areas
Commissure
Localization of functions
Central Nervous System
Peripheral Nervous System
33. Sense organs carry
messages about the
environment to the
central nervous system.
34. The eyes, ears, nose, tongue, and skin are examples of
sense organs.
The sense organs gather information (light, sound,
heat, and pressure) from the environment.
35. The environment is everything outside the body.
The sense organs gather information from outside
the body, then send the messages to the brain.
36. Vision is your ability to see.
Vision involves the eye and the brain.
37. The eye is one of your sense organs.
The eye is made of the iris and the pupil.
The eye gathers pictures and sends them to the brain.
38. The colored part of the eye is the iris.
The black part of the eye is the
pupil.
The pupil becomes larger and
Pupil Iris smaller as it controls the light
coming into the eye.
39. When a sound is made, the air around the sound
vibrates.
Hearing starts when some of the sound waves go into
the ear.
40. There are nine main parts of the ear.
1. Pinna 5. Anvil
2. Ear canal 6. Stirrup
3. Ear drum 7. Cochlea
4. Hammer 8. Eustachian tube
9. Auditory nerve
41.
42. The pinna is the part of the ear that you can see.
The ear canal is the tube between the outside of the ear and the
ear drum.
The ear drum is in the middle ear. It vibrates when sound waves
hit it.
43. The three smallest bones in the body, the hammer,
the anvil, and the stirrup, are in the middle ear.
The hammer gets the vibrations from the
eardrum, then sends them to the anvil.
The anvil passes the vibrations to the stirrup.
The stirrup passes the vibrations
to the inner ear.
44. The Eustachian tube controls the amount of
pressure in the ear.
The inner ear is made of the cochlea and liquid.
The cochlea is in the inner ear. The cochlea
looks like a shell.
The auditory nerve carries the hearing
information to the brain and the brain tells
us what we heard.
45. The ear works with the brain to control your balance.
All of your movements are controlled by
balance and muscles.
The liquid in your inner ear is responsible
for your balance.
The liquid in your ear moves when we move.
The liquid movement sends information to the
brain to tell it how we are moving.
46. The sense of touch is located in the skin.
The nerves in the skin allow us to feel texture,
pressure, heat, cold, and pain.
Texture is how something feels.
47. The nose controls your sense of smell.
The nose is able to smell 80 different kinds of smells.
48. Your sense of taste comes from the taste buds in the
tongue.
Taste buds are the parts on the tongue that
allow us to taste.
The four kinds of taste buds are sweet,
sour, bitter, and salty.
49. Tastes and smells work together to make flavors.
Flavors are the tastes of food and drinks.
Hinweis der Redaktion
key words: central nervous system; brain; spinal cord
key words: left hemisphere; right hemisphere; visual infomation; touch information
Example : You read a geometry problem in a textbook. The words are seen and the visual forms translated into meaning by the language center in the left hemisphere. To solve the problem you have to imagine a cone shaped object. This is accomplished by centers in the right hemisphere. The solution is written down using language generated by the left hemisphere. What would happen in cases like this if the callosum was damaged ?
key words: left hemisphere; right hemisphere; corpus callosum; epilepsy One method used to treat severely epileptic patients involves cutting the corpus callosum to prevent the spread of seizures acorss the entire brain. The video clip on this slide shows a man who has had such a surgery. Double click on video to start video clip. This clip discusses the types of information processing deficits associated with cutting the corpus callosum and shows a task often used to assess corpus callosum damage. This task is also represented in drawing form on the following slide as well.
