Science 10
Quarter 3 – Week 3 –
Module: 3 NERVOUS SYSTEM: The Control System of the Body
The Nervous System controls and coordinates all essential functions of the
body. It sends special signals to and receives responses from every organ and tissue
of the body and allowing the body to maintain homeostasis or its delicate balance.
This system makes it possible for you to process information discussed by your
teacher, raise your hands, or simply avoid getting burned.
Functions of the Nervous System
1. Gathers information from both inside and outside the body- Sensory Function
2. Transmits information to the processing areas of the brain and spine
3. Processes the information in the brain and spine – Integration Function
4. Sends information to the muscles, glands, and organs so they can respond
appropriately – Motor Function
The Nervous System is divided into two main divisions:
System (CNS) and the Peripheral Nervous System (PNS)
Central
Nervous
1. Central Nervous System (CNS) - the central nervous system serves as the
main processing center for the entire nervous system. It consists of two
components:
a. Brain – acts as the control center of the body. It is connected with sensors
that detects changes in our environment. The three main parts of the brain
are:
Cerebrum – the largest part of the brain is the cerebrum. It receives, stores
and recalls all the information the body picks up. Cognitive processes such
as thinking, memorizing and decision making occur in the outer gray part
of the cerebrum, which is called the cerebral cortex. Cortex means
“covering.” The inner white part of the cerebrum relays electrical signals to
other parts of the brain
Cerebellum – the cerebellum is a highly folded mass of nerve tissue located
just below the cerebrum. It controls muscle coordination and balance.
When you play basketball, the cerebellum helps you in making your
moves. Imagine a drunken man walking. He sways in an unbalanced,
uncoordinated way. That is how you would be if your cerebellum were not
working
Brain stem – The brainstem is the hind part of the brain. It holds the
medulla oblongata and the pons. The medulla oblongata or medulla
transmits signals between the spinal cord and the brain. It also controls
autonomic or involuntary functions such as heartbeat and breathing. The
pons is partly made up of tracts that connect the spinal cord with higher
brain levels. It also contains cell groups that transfer information from the
cerebrum to the cerebellum.
https://www.nbia.ca/brain-structure-function/
b. Spinal cord – link between the brain and the nerves in the rest of the body.
It also controls basic musculoskeletal reflexes without input coming from
the brain. Without the spinal cord, the brain could not receive nor send
information. Without the spinal cord, the brain would lose its ability to
control the body
https://www.seattlecca.org/diseases/brain-spinal-cord-cancers/facts
2. Peripheral Nervous System (PNS) – the peripheral nervous system is a
collection of nerves that connect the brain and spinal cord to other parts of
the body and the external environment. It is subdivided into the somatic
nervous system and the autonomic nervous system.
a. Somatic Nervous System – responsible for carrying motor and sensory
information (voluntary movements). It is made up of nerves that connect
to the skin, sensory organ, and skeletal muscles.
Spinal Nerves – (12 pairs) the nerves that carry motor and sensory signals
between the spinal cord and the body.
Cranial Nerves – (31 pairs) the nerve fibers that carry information into and
out of the brain stem.
b. Autonomic nervous System – works on an involuntary control of body
movements. It has two divisions:
Sympathetic Nervous System – impulses propagated in this system
prepare the body for an emergency. (increased heart rate and breathing,
dilation of pupil, sweating)
Parasympathetic Nervous System – impulses in this system return the
body to normal or relax mode after an emergency has occurred.
https://my.clevelandclinic.org/health/diseases/14737-neuropathy
The Nerve Cell (Neuron)
The basic unit of the nervous system. Neurons have the special ability to carry
signals or impulses. Cell body, dendrites and axon are the basic parts of a neuron.
The dendrites carry impulses towards the cell body while the axon carries
impulses away from the cell body.
The fibers that branch out from the nerve cell are the dendrites. These fibers
pick up information from the receptors. (Receptors are parts of the body, either
nerves or sense organs, that can pick up stimuli from the environment or from within
the body).
The information received by the dendrites is then carried to the cell body or
soma in the form of an electrical signal. The cell body contains the nucleus of the cell
as well as other structures that help keep the cell alive.
https://www.sciencefacts.net/parts-of-a-neuron.html
A nerve impulse is an electrochemical signal moving along a neuron. The space
between neurons is called synapse. A stimulus is any factor in the environment that
influences behavior. A response is a reaction to a condition or stimulus. An organism
must be able to respond to a stimulus in order to survive. Reaction time is the length
of time between application of a stimulus and detection of a response.
The electrical signal continues along the cell body and moves to a single, long
fiber called an axon. From the axon, the electrical signal is transmitted to another
nerve cell. Between the axon of one cell and the dendrite of another is a small gap
called synapse. When the electrical signal reaches the tip of the axon of one cell, a
chemical spill into the synapse. This chemical receives and carries the electrical
signal to the dendrite of the next nerve cell.
https://www.researchgate.net/figure/A-diagram-showing-a-neuron-making-asynaptic-connection-with-another-neuron_fig1_258023902
When a receptor such as an organ perceives a stimulus, the impulse is sent to
the brain by the sensory neurons, which then transmit information from one nerve
cell to another. As the message reaches the brain, it processes the information and
commands an effector such as a muscle or an organ to respond. The message
coming from the brain is sent through the motor neurons.
Three Types of Neurons
1. Sensory neurons - These are the type of neurons that are activated by external
physical or chemical stimuli. This, therefore, involves sensory activation of
any of the five senses (feel, smell, sound, sight, hear).
2. Motor Neurons - Motor neurons are the type of neurons in the spinal cord that
connects the organs, muscles and different types of glands in the body. As
such, they function to transmit impulses from the Central Nervous System to
the organs, glands, and muscles. This, in turn, controls the movement of
different types of muscles as well as the activity of organs and glands in the
body. Motor neurons are composed of multipolar neurons.
3. Intermediate neurons - These are the type of neurons that connect the motor
neurons to the sensory neurons thus allowing for signals to be transmitted
between the two. Like motor neurons, this system is composed of multipolar
neurons.
Explore
Enrichment Activity 1: The Nervous Break Down!
Directions: Using the given graphic organizer, fill in the missing parts to complete
the entire concept showing the structure of the nervous system.
(Adapted from DepEd Project EASE, Module 9: Life Support Systems, pp. 4-6)
Guide Questions:
1. How will you differentiate the Central Nervous System (CNS) and the Peripheral
Nervous System (PNS) in terms of their functions?
2. What might happen to the human body if one part of the nervous system fails to
carry out its function properly?
Enrichment Activity 2: One for all, All for One
Direction: Number the comic strips from 1-8 to complete the pathway of the nerve
impulse.
A big snake is moving
towards me! Oh no! (
Yes, I see it too. I’ll inform
the rest. ( )
)
Hey, miss spinal
cord! My brother
says eye sees a
snake moving
towards him! ( )
Thanks Brain! Hey motor
neurons! Can you please do
a favor for me? Please tell
the “legs” to run away.
Thank you! ( )
Snake? Uhuh?
Really?! One moment
please and I’ll pass the
message to Ms. Brain.
( )
Sure, sister spinal cord…
at your service anytime.
( )
What's your message
spinal cord? (“eye” sees a
big snake”) Okay,
okay...calm down...tell
the “legs” to run away.
( )
...as the motor neurons
followed the request,
the “legs” ran away
( )
LR Portal. (n.d.). Deped LR Portal. Retrieved December 18, 2020, from
https://lrmds.deped.gov.ph/detail/6400
Deepen
At this point you are now ready for your last activity. Remember the things that
you learned in this lesson. Good luck!!!
Direction: Discuss each of the following questions briefly.
Scoring Rubrics
2
1
0
Discussions are conceptually complete
Discussions are conceptually incomplete
There were no discussions shown
1. What is the function of the spinal cord?
2. How does the Central Nervous System (CNS) function similarly to the Central
Processing Unit (CPU) of a computer?
3. What will likely to happen if one of the neurons will not pass on the message?
4. Summarize the events involved in the synaptic transmission of a nerve
impulse.
Gauge
Directions: Read each item carefully. Choose the letter of the best answer.
1. Which is NOT a part of the central nervous system?
A. Cranial nerves
B. Hypothalamus
C. Spinal cord
D. Thalamus
2. Which of the following can conduct impulses away from the neuron’s cell body
or toward it?
A. Axon
B. Dendrite
C. Both A and B
D. Neither A or B
3. Jonathan is playing chess with Jan Lloyd. Which part of his brain is working
while thinking of his next move?
A. Cerebellum
B. Cerebrum
C. Diencephalon
D. Medulla Oblongata
4. Which part of the brain control the involuntary physiologic activities such as
digestion, breathing, and heart beat?
A. Cerebellum
B. Cerebrum
C. Diencephalon
D. Medulla Oblongata
5. Mario went home drunk from a party, which part of his brain controls his
motion, balance, and coordination?
A. Cerebellum
B. Cerebrum
C. Diencephalon
D. Medulla Oblongata
6. In which direction does an impulse travel along a neuron?
A. From an axon to a dendrite
B. From a dendrite to another dendrite
C. From an axon to another axon
D. From a dendrite to an axon
7. A reflex arc is usually consists of
.
A. sensory neurons only
B. motor neurons only
C. sensory and motor neurons only
D. sensory neurons, moor neurons, and their synapse in the spinal cord
8. Which of the following is/are the correct descriptions of nerve impulse?
I. A nerve impulse is a flow of electricity
II. A nerve impulse can jump from one neuron to another.
III. A nerve impulse is combination of an electrical charge and chemical
reaction.
IV. A nerve impulse from one neuron is stimulated in the next dendrite
because of neurotransmitter that crosses the synapse.
A.
B.
C.
D.
I and II
II and III
III and IV
II and IV
9. Marianne accidentally touched a hot iron. Upon touching the iron, she pulled
her arm right away. Which of the following best explains this situation?
A. Marianne was aware that the iron was hot.
B. Marianne’s reflex action caused him to pull his arm quickly.
C. Marianne’s brain sent a message to his arm that the iron is hot.
D. Marianne is intelligent enough to pull his arm from the iron.
10. Which of the following divisions generally acts to conserve energy?
A. Parasympathetic nervous system
B. Peripheral nervous system
C. Somatic nervous system
D. Parasympathetic nervous system
11.Which of the following statements best describe the function of the autonomic
nervous system?
A. Autonomic nervous system enables to act on the external environment.
B. Autonomic nervous system is located within the brain,
C. Autonomic nervous system regulates the internal environment.
D. Autonomic nervous system transmits motor information to the brain.
12. The “fight or flight” response is the term used to describe the action of the
.
A. central nervous system
B. parasympathetic division
C. somatic nervous system
D. sympathetic division
13.If the sympathetic nerve widens the pupil of the eye, the parasympathetic
nerve functions to
.
a. narrows the pupil of the eye
b. maintains the widening of the pupil of the eye
c. receives impulses from the pupil to the eye
d. sends messages from the eye to the brain
14.The structures that receive messages from the central nervous system and
carry them to an area of the body are called
.
a. dura mater
b. effectors
c. pia mater
d. receptors
15.An impulse travel by chemical messenger across the small space between
two neurons are called
.
a. axon terminal
b. cell body
c. myelin sheath
d. synapse