The nervous system consists of the brain, spinal cord, and nerves. It has three major functions - to receive and process sensory information, control responses to this information, and coordinate voluntary and involuntary actions. It has two main divisions - the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves). The basic functional unit of the nervous system is the neuron, which transmits electrochemical signals.

1. Reporters:
Ablanzar, Rachelmae
Enilo, Shaira
Fado, Jeralyn
Ponan, Cristene Joy
Robles, Jaypee
Tuvillara, John Rovee
The Nervous System

2. Objectives
At the end of the report, the
students are expected to;
• Describe the nervous system
• Describe the structure of a
neuron and how it conducts
electrical impulses
• Distinguish sensory,
interneuron and motor neurons
• Describe the parts and
functions of the brain

3. It is examination time. The room is
so silent that you can almost hear
your breathing. For almost an hour,
you have been sitting there on your
chair reading the questions, occasionally staring at the
ceiling, and scribing your answer on your paper. You can feel
your stomach churning and tension slowly building up in your
neck and back muscles.
Scene

4. You look at your watch and you have
barely three minutes to finish your
exam. In a haste, you review your
paper and finalized your answers.
As you race against time, your heartbeat and breathing
becomes faster. Seconds later, the bell rings. You take a deep
breath, stand up, and pass your paper to your teacher. Your
heartbeat and breathing rates slowly return to normal.
Scene

5. The scene you’ve read shows how your nervous system
functions.
Nervous System
-a complex network of nerves
and cells that carry messages
to and from the brain and
spinal cord to various parts of the
body.
The Nervous System makes you think, act, and feel.
It enables your body to detect changes in the
environment and causes it to respond and adjust itself.

6. Brain Teaser
If you were running a race, and you passed the
person in 2nd place, what place would you be
in now?
Second

7. Neuron
A neuron or nerve cell is the basic functional
unit of the nervous system. Our nervous system
contains hundreds of billions of neurons.
A neuron consists of a
cell body and several
fibrous extensions
called nerve fibers.
2 types of nerve fibers
• Axons
• Dendrites

8. • Dendrites: branch-like
extensions that receive
impulses and carry them
toward cell body.
• Axon: single extension of the neuron that carries
impulses away from the cell body.
Some neurons have axons that are wrapped with a
fatty membrane called myelin sheath. The myelin
sheath is interrupted by gaps called nodes.
Neurons

9. Neurons do NOT touch; there is
a gap between them called a
synapse
Messages are sent across the
synapses by special chemicals
called neurotransmitters
Neurons

10. 1. Sensory neurons
transmit impulses from sensory
organs to the brain and spinal cord.
2. Interneurons – to process and interpret
sensory input and decide if action is needed.
3. Motor neurons- conduct the impulses to the muscles or to
glands through out the body, causing for response.
Types of Neurons

12. You saw your “crush”, structures in your eyes
called receptors were stimulated. The stimulus
traveled as an impulse in the sensory neurons
toward the interneurons in your brain. Your
brain processed the information and responded
by sending back impulses along
motor neurons to your muscles.
Your heart began to beat faster
and your breathing rate increased.
Example

13. In short, the three
types of neurons act
like a relay team,
passing information
throughout the body
from the moment the stimulus is received
until response is made by the body.

14. Brain Teaser
A H I M N O T U V W
Which of the letters above does not belong
with the rest?
N It is not a mirror-image of itself

15. Divisions of the Nervous System

16. • Central Nervous System
(CNS)
• Peripheral Nervous System
(PNS)
Divisions of the
Nervous System

17. CENTRAL NERVOUS SYSTEM
-Consists of the brain and
spinal cord
-Acts as body’s control
center, coordinates body’s
activities
• Impulses travel through the
neurons in your body to
reach the brain
Divisions of the
Nervous System

18. Brain is similar to computers
in many ways. Computers send
electrical signals through wires
to control devices. Brain also sends
electrical signals to our body parts through neurons.
In an average human adult, the brain weighs from
1.3 to 1.4kg. Contains about 100 billion neurons and
trillions of supporting cells called glia.
CENTRAL NERVOUS SYSTEM Brain

19. Parts of the Brain:
Cerebrum
frontal lobe
parental lobe
occipital lobe
temporal lobe
Cerebellum
Brainstem
CENTRAL NERVOUS SYSTEM Brain

20. Part of the Brain: CEREBRUM
-Largest part of the brain
-Divided into two halves called
hemispheres. The right hemisphere
controls the left side of the body
and the left hemisphere
controls the right side of
the body. When motor areas in one
hemispheres are damaged, one side of the
body may be paralyzed depending on the
injury.
CENTRAL NERVOUS SYSTEM Brain

21. Parts of the Brain: Lobes of the Cerebrum
Frontal Lobe- located in front of the central
sulcus. Our frontal lobe is at
work when we:
talk
move
plan
reason out
solve problems
CENTRAL NERVOUS SYSTEM Brain

22. Parts of the Brain: Lobes of the Cerebrum
Parental Lobe- located behind
the central sulcus. Allows us
to distinguish:
sensations of touch
pressure
temperature
pain
CENTRAL NERVOUS SYSTEM Brain

23. Parts of the Brain: Lobes of the Cerebrum
Occipital Lobe- behind the
parental lobe and at the back
Of our brain. It is the center
Of vision.
Temporal Lobe- located below
the lateral fissure. helps us
to hear and recognize different
sounds.
CENTRAL NERVOUS SYSTEM Brain

24. Part of the Brain: CEREBELLUM
-located behind and under the cereb-
rum
-comes from Latin word for “little
brain”
-responsible for motor coordination,
balance and posture.
CENTRAL NERVOUS SYSTEM Brain

25. Part of the Brain: BRAINSTEM
-connects brain to spinal cord
Structures of the Brainstem:
thalamus, midbrain, medulla and
pons
CENTRAL NERVOUS SYSTEM Brain

26. Part of the Brain: BRAINSTEM
Structure of the Brainstem:
Thalamus- acts as a messenger. It
Receives sensory information and
Relay it to the cerebral cortex.
The cerebral cortex also sends
Information to the thalamus. The
Thalamus then transmit the info
To other area of the brain and spinal cord.
CENTRAL NERVOUS SYSTEM Brain

27. Part of the Brain: BRAINSTEM
Structure of the Brainstem:
Midbrain or hypothalamus- is a
Collection of specialized cells
That are located in the lower
Central portion of the brain.
Responsible for the control of
The body temperature, emotions
And sensations like hunger and thirst.
CENTRAL NERVOUS SYSTEM Brain

28. Part of the Brain: BRAINSTEM
Structure of the Brainstem:
Medulla Oblongata- connected to
The spinal cord. It regulates our
And heartbeat rate. It also regu-
Lates bloodflow in the blood
Vessels by allowing their
Contraction and expansion.
CENTRAL NERVOUS SYSTEM Brain

29. Part of the Brain: BRAINSTEM
Structure of the Brainstem:
Pons- connects the cerebrum and
The medulla oblongata.
-The bulging center part of the
brain stem. Mostly composed of
fiber tracts including nuclei
involved in the control of
breathing.
CENTRAL NERVOUS SYSTEM Brain

30. Brain Teaser
There is a town where all the people living
there have unlisted phone numbers. If you
selected 100 names at random from the town’s
phone directory, how many of these people
would have unlisted phone numbers?
0 They would not be in the phone book if
their number was unlisted

31. the Spinal Cord is about 42-45 cm
Long from the brainstem to tailbone.
The spinal cord enables our body to
perform reflex action. A reflex action
is an automatic, involuntary response
to the stimulus. This is called a
withdrawal reflex, our spinal cord
Allows our body to respond without
Having to think of what to do.
CENTRAL NERVOUS SYSTEM Spinal cord

32. CENTRAL NERVOUS SYSTEM Spinal cord
BIO- TRIVIA
A nerve impulse can travel up to two
hundred fifty (50) miles per second. One
brain cell can communicate with 25,000
other brain cells.

33. For example, when you accidentally touch
a hot object, you quickly pull back your
hand in response to the heat.
Sensory receptors in your skin are stimulated by
the hot object and the impulse is
transmitted to the Spinal cord by way of
sensory neuron. The impulse passes to the Interneuron then
immediately passes the impulse to Motor neuron to transmit
the impulse to the muscles of the arm causing you to pull
back your hand.
CENTRAL NERVOUS SYSTEM Spinal cord

34. Divisions of the Nervous System

35. PERIPHERAL NERVOUS SYSTEM
-consists of the nerves that
lie outside the brain and
spinal cord. Each nerve is a
bundle of motor and sensory
neuron.
Divisions of the
Nervous System

36. PNS is divided
into the
Autonomic and
Somatic System.
Divisions of the
Nervous System
PERIPHERAL NERVOUS
SYSTEM

37. Somatic System – consists of the cranial nerves (12
pairs) and spinal nerves (31 pairs) that control
voluntary muscles.
PERIPHERAL NERVOUS SYSTEM Somatic System

38. Autonomic System- consist of cranial nerves and
spinal nerves that control involuntary muscles.
Autonomic System is sub-divided into:
• Sympathetic System- works during emergency
situations that cause stress and require us to
fight or take flight
• Parasympathetic System- works during nonemergency
situation that allows us to rest and digest.
PERIPHERAL NERVOUS SYSTEM Autonomic System

39. Functions of the Sympathetic and Parasympathetic
Nervous System
PERIPHERAL NERVOUS SYSTEM Autonomic System
SYMPATHETIC NERVOUS SYSTEM PARASYMPATHETIC NERVOUS
SYSTEM
Increase heartbeat rate Decrease heartbeat rate
Increase breathing rate Decrease breathing rate
Slows down digestion Speeds up digestion
Increase muscle tension Decrease muscle tension
Dilates the pupil of the
eyes
Constricts the pupil of
the eyes
Decrease urine secretion Increase urine secretion

40. Concussion
A temporary disturbance of the
brain’s ability to function due
to a hard blow to the head
Problems of the Nervous System

41. Paralysis
A loss of sensation and movement
of part of the body due to an
injury of the spinal cord or
brain.
Problems of the Nervous System

42. Parkinson’s Disease
The brain does not produce enough of the
neurotransmitter that transmits messages from
the brain to the muscles
Symptoms: tremors,
rigid muscles,
shuffling walk and
loss of facial
expression
Problems of the Nervous System

43. Alzheimer’s Disease
A gradual shrinking of the
neurons in the cerebrum
Symptoms: memory loss,
emotional disturbances,
inability to function on
own, death
Problems of the Nervous System

44. Epilepsy
Abnormal transmission of
messages between the neurons
in the brain
Symptoms: seizures
Problems of the Nervous System