1. The
HUMAN
NERVOUS SYSTEM

2. Human Nervous System
- is one of the systems in the human body that controls voluntary and involuntary processes inside and outside the body
- is divided into two parts: the Central and the Peripheral Nervous Systems
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3. The Central Nervous System
- the control center of the body responsible for controlling, receiving, and interpreting all stimuli.
- consists of the brain and the spinal cord.
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4. The Peripheral Nervous System
- consists of the cranial and spinal nerves that extend throughout the different parts of the body.
- carries messages from and to (vice versa) the brain.
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5. The two major divisions of the Nervous System
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6. The Human Brain - a mass of 100 billion neurons located in the skull.
- controls bodily functions and interactions with the outside world.
- has four major parts: cerebrum, cerebellum, brainstem and diencephalon
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7. Cerebral cortex Corpus callosum Brain stem Cerebellum
different regions have different functions
Cerebral cortex
Functions include: planning; reasoning; language; recognising sounds and images; memory.
Corpus callosum
connects the brain’s right and left hemispheres
Cerebellum
important for coordination, precision and timing of movement
Brain stem
regulates heart rate, breathing, sleep cycles
and emotions
Credit: Mark Lythgoe & Chloe Hutton, Wellcome Images
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9. CNS: The Spinal Cord
- a column of nerves from the brain to the tailbone that is protected by vertebrae of spine.
- responsible for conducting impulses from the brain to the different parts of the body.
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10. Neurons
- also called nerve cells, are responsible for transmitting electrochemical messages to another neurons..
- consists of three major parts: dendrites, cell body and axon.
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11. axon nerve endings dendrites myelin sheath cell body nucleus
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12. But what happens when the signal reaches the end of the axon?
neurons communicate with each other using a mixture of electrical & chemical signals
nerve endings
dendrites
But what happens when the signal reaches the end of the axon?
myelin sheath
cell body
an electrical signal is transmitted along the axon
nucleus
axon
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13. signals cross between neurons at the synapse
nerve endings
dendrites
neurotransmitter
vesicle
synaptic cleft
receptor
myelin sheath
cell body
the signal
is transmitted to another neurone across a junction called a synapse by chemicals called neurotransmitters.
nucleus
axon
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14. signals cross between neurons at the synapse
electrical impulse triggers vesicles to move to the synapse membrane 1
synapse
vesicles fuse with the membrane and release neurotransmitter into the synaptic cleft 2
nerve endings
dendrites
neurotransmitter diffuses across the cleft and binds to receptors on the other side 3
neurotransmitter
vesicle
synaptic cleft
receptor
myelin sheath
cell body
the signal
is transmitted to another neurone across a junction called a synapse by chemicals called neurotransmitters.
nucleus
Once enough receptors have neurotransmitters bound to them, the signal is transmitted… 4
axon
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15. Types of Neurons Efferent Afferent
- conveys information from CNS to other parts of the body.
Afferent
- carries information from sensory receptors to the CNS.
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16. Checking Understanding
prick
dilate pupil
heartbeat
digestion
coughing
salivate
shivering
sneezing
secrete hormones
Efferent
Afferent
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17. Group Activity 1. Ways to take good care of our nervous system.
2. Activities that disadvantages our nervous system.
3. Importance of our nervous system
CCF Life Academy Foundation INC.

18. The
NERVOUS SYSTEM
- End of the lesson -