1. The Nervous System Chapter 31 scasatelli@ridgewood.k12.nj.us

2. What is the nervous system? The nervous system collects information about the body’s internal and external environment, processes that information, and responds to it. ◦ Peripheral Nervous System (PNS): consists of nerves (neurons) and supporting cells, collects information about the body’s external and internal environment. ◦ Central Nervous System (CNS): consists of the brain and spinal cord, processes the information from the PNS and creates a response that is delivered to the appropriate place in the body.

3. Peripheral vs Central Nervous Systems

4. Neuron Neurons = Nervous Cell ◦ Neuron: cells that transmit impulses around the body.  3 types of Neurons: Based on the direction the impulse is traveling.  Sensory Neurons: carry impulses from the sensory organ to spinal cord and/or brain.  Motor Neurons: carry impulses from brain and the spinal cord to muscles and glands.  Interneurons: process information from sensory neurons and then send commands to other interneurons or motor neurons.

5. NEURON

6. Nerve Impulse Nerve impulses are like an electric current flowing through a wire.

7. The Brain The control point of the CNS is the brain. ◦ The brain processes and relays information throughout the body. ◦ Most of the neurons that enter and leave the brain are found in large clusters known as the spinal cord.  Reflexes: automatic response to a stimuli  Reflexes are process directly through the spinal cord.

8. The Brain Cerebrum: responsible for voluntary actions. ◦ location of intelligence, learning and judgment. Cerebellum: responsible for coordination and balance allowing the body to move gracefully. Brain Stem: connects the brain and the spinal cord. ◦ Located below the cerebellum

9. The Brain cont. Hypothalamus: control center for recognition and analysis of hunger, thirst, fatigue, anger and body temperature. Pituitary Gland: Hormones secreted from the pituitary gland help control: growth, blood pressure, certain functions of the sex organs, thyroid glands and metabolism as well as some aspects of pregnancy, childbirth, nursing, water/salt concentration and the kidneys, temperature regulation and pain relief. ◦ found off the bottom of the hypothalamus at the base of the brain.

10. The Brain cont. Pineal Gland: (third eye) It produces melatonin, a serotonin derived hormone, which affects the modulation of sleep patterns in both seasonal and circadian rhythms.

11. The Brain & Spinal Cord

12. Brain Stem and Spinal Cord Brain Stem: connects the brain and the spinal cord below the cerebellum ◦ Made up of the midbrain, pons and medulla oblongata.  Function of the Brain Stem parts: regulates the flow of information between the brain and the rest of the body; including blood pressure, heart rate, breathing and swallowing. Spinal Cord: The main communication link between the brain and the rest of the body.

13. The Nervous System!! https://www.youtube.com/watch?v=qPix_ X-9t7E (second) https://www.youtube.com/watch?v=qPix_ X-9t7E https://www.youtube.com/watch?v=sjyI4C mBOA0 (First) https://www.youtube.com/watch?v=sjyI4C mBOA0