Your Nervous System In this lesson, you will Learn About… How the nervous system works. The different parts of the nervous system. Protecting your nervous system from injury.

Bell Work What are the two important jobs that your respiratory system carries out?

Standards 1 : The student will comprehend concepts related to health promotion to enhance health.

Indicators/ E.Q. How does your nervous system function and why is it so important to protect our nervous system?

Relevance Without our nervous system, we can not do anything. Prove why this statement is true or false.

Your Nervous System The Vocabulary terms in this lesson are: Neurons. Neurons Central nervous system (CNS). Peripheral nervous system (PNS). Somatic system. Somatic system Autonomic system. Autonomic system

The Nerve Center The specialized cells that make up the nervous system are called neurons. Neurons carry information. They send messages from the body to the brain, and from the brain to the body. These messages are in the form of electrical signals.

How the Nervous System Works 1.A tap on the shoulder activates sensory neurons in the skin and muscles. The neurons send the message to the spinal cord and from there to the brain. 2.One part of the brain interprets the message received as a touch. 3.Another part of the brain sends a message to motor neurons in muscles in the body. Muscles in the head and neck are activated, and the head turns.

Parts of the Nervous System Your nervous system has two main parts. The central nervous system (CNS) includes the brain and spinal cord. It is the body’s main control center. The peripheral nervous system (PNS) includes the nerves that connect the CNS to all parts of the body.

The Nervous System PNS Cervical nerves Thoracic nerves Lumbar nerves Sacral nerves Coccygeal nerves CNS Brain Cranial nerves Spinal cord Spinal nerves

Central Nervous System The CNS has two main parts: Brain Spinal cord The CNS controls two kinds of actions: Involuntary actions – those that you do not control, such as heartbeat and certain digestive processes Voluntary actions – those that you control, such as walking and talking.

Parts of the Brain The cerebrum is the largest portion of the brain. It controls the senses, movement of muscles, thinking, and speech. The cerebellum controls balance, posture, and coordination. The brain stem controls some important automatic body functions, such as heartbeat, breathing, blood pressure, and digestion. The meninges are membranes that cover the brain and the spinal cord.

Peripheral Nervous System The PNS is composed of neurons throughout the body and the nerves that connect them to the CNS. The PNS has two main parts: The somatic system is a system dealing with actions that you control. The autonomic system is a system dealing with actions you do not usually control.

Problems of the Nervous System Several diseases and disorders—most resulting from injury—can affect the nervous system: Head injury is usually caused by a blow to the head. Spinal cord injury can result from damage to the head, neck, or body. Nerve inflammation can follow a minor injury.

Problems of the Nervous System (cont’d.) Some nervous system disorders are not related to injuries: Meningitis is an infection of the meninges. A brain tumor is an abnormal growth of tissue that kills normal neurons around it. Epilepsy causes a person to have seizures. Multiple sclerosis damages the protective outer coating of nerves, and nerves no longer work properly. Alzheimer’s disease is characterized by inflamed areas in the brain and death of neurons.

Care of the Nervous System Following these strategies can help protect the nervous system and prevent many head and spinal cord injuries: Get enough sleep. Avoid alcohol and other drugs. Play safely. Wear a safety belt. Obey all traffic safety rules.

Neurons Reviewing Terms and Facts 1._________ are the specialized cells that make up the nervous system.

2.What are five ways to protect the nervous system and prevent many head and spinal cord injuries? Reviewing Terms and Facts Get enough sleep. Avoid alcohol and other drugs. Play safely. Wear a safety belt. Obey all traffic safety rules.

Thinking Critically 3.How can strategies such as getting enough sleep and avoiding alcohol and other drugs help protect the nervous system from accidental injury?

Vocabulary Review Neurons or nerve cells are the specialized cells that make up the nervous system.

Vocabulary Review The central nervous system (CNS) includes the brain and spinal cord.

Vocabulary Review The peripheral nervous system (PNS) includes the nerves that connect the CNS to all parts of the body.

Vocabulary Review The somatic system is a system dealing with actions that you control.

Vocabulary Review The autonomic system is a system dealing with actions you do not usually control, such as digestion and breathing.