1. Section 35-3: Divisions of the Nervous System

2. Do Now 3/1/13
What is the process that keeps internal conditions relatively constant despite changes in the external environment?
In a resting membrane of a neuron, what is the overall charge inside? What is the charge outside?
During an action potential, what happens to the charges?
What chemical is released in the synapse?

3. The Central Nervous System (CNS)
The central nervous system relays messages, processes information, and analyzes information
Control center of the body
Consists of the brain and spinal cord

4. The Central Nervous System (CNS)
Meninges = 3 layers wrapped around brain and spinal cord
Cerebrospinal fluid (CSF) = bathes brain and spinal cord and protects the central nervous system

5. The Brain The Cerebrum Largest part of the human brain
Voluntary and conscious activities
Site of intelligence, learning, and judgment
Each half deals with the opposite side of the body

6. The Brain The Cerebellum
2nd largest region of the brain, known as the “little brain.”
Coordinates and balances the actions of the muscles

7. The Brain The Brain Stem Connects the brain and spinal cord
Consists of the Pons and Medulla Oblongata
Controls blood pressure, heart rate, breathing, swallowing, visceral organs (autonomic)

8. The Brain Thalamus Hypothalamus
Receives messages and relays messages to proper regions of the cerebrum for processing
Hypothalamus
Control center for recognition
Analysis of hunger, thirst, fatigue, anger, and body temperature
Coordinates nervous system with the endocrine system

10. The Spinal Cord
Main communication link between the brain and the rest of the body
31 pairs of spinal nerves branch out to communicate information to different parts of the body
Reflexes are processed directly to the spinal cord
Reflex = quick automatic response to a stimulus

11. The Peripheral Nervous System (PNS)
Outside of the Central Nervous System
Divided into the sensory division and motor division
Sensory Division of the PNS transmits impulses from sense organs to the CNS.
Motor Division transmit impulses from the CNS to the muscles or glands.

12. The Peripheral Nervous System (PNS)
Somatic Nervous System
Regulates activities under conscious control
Some somatic nerves are also involved with reflexes that can act with our without conscious control

13. The Peripheral Nervous System (PNS)
Reflex arc = involves sensory neuron, motor neuron and effector (sometimes interneurons)
Neurons in spinal cord automatically activates motor neurons before information relayed to brain

14. The Peripheral Nervous System (PNS)
Autonomic Nervous System
Regulates activities that are automatic, or involuntary (not under conscious control).
Subdivided into 2 parts:
Sympathetic nervous system (fight and flight)
Parasympathetic nervous system (rest)
Opposing effects of sympathetic and parasympathetic help maintain homeostasis.
Ex. Heart rate increased by sympathetic but decreased by parasympathetic

15. Due Today 3/1/13
Do the Quick Lab on page You will need safety goggles, a sheet of scrap paper, and another sheet of paper to answer the questions.
Do 35-3 Section Assessment #1, 3-6 on page 905.

16. Do Now 3/5/13
Which part of the brain is involved in balance and coordination?
Which part of the brain is involved in controlling heart rate, blood pressure, visceral organs, and body temperature?
Which part of the brain is involved in learning?
What is the CNS made of?
What is the PNS made of?
What does the Autonomic Nervous System control?
What does the Somatic Nervous System control?
What are the two parts of the Autonomic Nervous System?
Which one deals with fight or flight?
Which one deals with rest?