Nerve cell |Science 10 | Third Quarter.pptx

The basic unit of communication in the nervous system is the nerve cell (neuron). Each nerve cell consists of the cell body, which includes the nucleus, a major branching fiber (axon) and numerous smaller branching fibers (dendrites).
Science 10 Third Quarter Lesson about Nerve Cell

1. The Nerve Cell Science 10 Third Quarter

2. Every person's body contains billions of nerve cells  (neurons). There are about 100 billion in the brain and 13.5 million in the spinal cord. The body's neurons take up and send out electric and chemical signals (electrochemical energy) to other neurons.

3. What are nerve cells? It is the basic unit of the nervous system. Nerve cells are also called neurons. They are cells with special ability to carry signals and impulses. They send messages all over the body to allow us to do everything from breathing to talking, eating, walking, thinking and many body functions that are carried by a nerve impulse .

4. What are the basic parts of a Neuron? Dendrites Cell body Axon

5. Cell body The main part of a nerve cell. It contains the main control center of the cell, the nucleus. The cell body controls the cell’s functions.

6. Dendrites A re the finger-like cells present on the end of a neuron. They are short, branching fibres extending from the cell body of the nerve cell. It carry impulses towards the cell body.

7. Axon It carry impulses away from the cell body. It pass impulses to the dendrites of other neurons or cell body muscles. Axons can be grouped together into cable-like bundles called nerves.

8. Types of Neurons There are different types of neurons, including motor, sensory, and interneurons.

9. Motor Neurons Motor neurons transmit electrical impulses and information from the CNS to muscles in the body. Motor neurons control all of our body movements. There are two main motor neurons subtypes: Upper motor neurons : Send data from the brain to the lower motor neurons. Lower motor neurons : Send data from the upper motor neurons to muscles in the body.

10. Sensory Neurons Sensory neurons are neurons that allow us to feel sensation. For example, if you stub your toe, sensory neurons will send chemical and electrical impulses back through the nervous system to tell your brain that you feel pain in your toe. Sensory neurons can be activated physically, such as feeling touch, or chemically, such as tasting a piece of cake. All five of our senses—sound, sight, touch, smell, and taste—are impacted by sensory neurons.

11. Interneurons Interneurons are nerve cells that connect between motor neurons and sensory neurons. Interneurons can also send information to and from other interneurons.

12. Nerve Impulse An electrical signal that travels along a nerve fiber in response to a stimulus and serves to transmit a record of sensation from a receptor or an instruction to act to an effector.  Is a combination of an electrical charge and chemical reaction. It is not a flow of electricity, but an electrochemical signal moving along a neuron.

13. A nerve impulse cannot jump from one neuron to another. When a nerve impulse comes to the end of an axon, it produces the chemical, called Neurotransmitter , to be released. What are neurotransmitters? They are the body’s chemical messengers. They carry messages from one nerve cell across a space to the next nerve, muscle or gland cell. 

14. The chemical crosses the space between neurons called synapse and stimulates the nerve impulse to start in the next dendrite. Once at the end of the axon the signal will be transmitted to the next neuron. No two neurons touch each other. A space called the synaptic gap separates the dendrites of one neuron from the axon of another neuron. Messages do not travel in both directions along the same neuron. Only the axon of the neuron releases neurotransmitters that cross the space between neurons.

15. The nervous system is assisted by five sense organ- the eyes, ears, nose, tongue, and skin. These sense organs are constantly receiving information from the environment and sending messages to the brain. These senses aid in the survival of human beings.

16. What body functions do nerves and neurotransmitters help control? Heartbeat and blood pressure. Breathing. Muscle movements. Thoughts, memory, learning and feelings, Sleep, healing and aging. Stress response. Hormone regulation. Digestion, sense of hunger and thirst. Senses (response to what you see, hear, feel, touch and taste).

17. Summary Nerve cells also called neurons is the basic unit of the nervous system. They are cells with special ability to carry signals and impulses. Most neurons have three parts, including a cell body, which contains the nucleus and the cytoplasm, an axon, which transmits information away from the nucleus, and dendrites, which receive messages from other neurons. Neurons are essential to human life. They allow our body and brain to communicate and enable us to think, feel, and move. The main types of neurons include motor neurons, which transmit information to our muscles, sensory neurons, which transmit information to enable our senses, and interneurons, which aid transmission between motor and sensory neurons.