1. 31.2 The Central Nervous System
Lesson Overview
31.2 The Central Nervous System

2. The Brain and Spinal Cord
Where does processing of information occur in the nervous system?

3. The Brain and Spinal Cord
1. The control point of the central nervous system =brain.
Information processing is the brain’s principal task.
The brain is constantly changed by its interactions with the environment.

4. The Brain and Spinal Cord
A large cluster of neurons and other cells make up the spinal cord.
3. The spinal cord
communication link between the brain and the rest of the body.
reflexes

5. Cerebrum The largest region of the human brain is the cerebrum.
voluntary activities
ex: intelligence, learning, and judgment.

6. Hemispheres cerebrum divided into left and right hemispheres:
each with 4 lobes.
are connected by a band of tissue = corpus callosum.
Each hemisphere deals mainly with the opposite side of the body.

7. Hemispheres
Each hemisphere is divided into regions called lobes. The four lobes are named for the skull bones that cover them.
frontal lobe:
consequences,
making judgments,
forming plans.

8. Hemispheres 8. The temporal lobe - hearing and smell,
The occipital lobe - vision.
The parietal lobe -reading and speech.

9. Cerebral Cortex The cerebrum consists of two layers.
The 9. outer layer of the cerebrum = cerebral cortex (grey matter)
information from the sense organs
controls body movements.
Folds and grooves on the outer surface of the cerebral cortex greatly increase its surface area.

10. White Matter The inner layer of the cerebrum= white matter.
connects the cerebrum to other areas of the brain

11. Limbic System LIMBIC SYSTEM: Emotion, behavior, and Memory
pleasure center,

12. Thalamus and Hypothalamus
11. The thalamus:
receives messages from sensory receptors
Sends info to the proper region of the cerebrum

13. Thalamus and Hypothalamus
The 12. hypothalamus:
Recognition of hunger, thirst, fatigue, anger
body temperature.
coordinate the nervous and endocrine systems.

14. Cerebellum The second largest region of the brain is the cerebellum.
Information about muscle and joint position, coordination

15. Brain Stem The 14. brain stem:
controls regulation of blood pressure, heart rate, breathing, and swallowing

16. Addiction and the Brain
How do drugs change the brain and lead to addiction?

17. Addiction and the Brain
Nearly every addictive substance—including illegal drugs such as heroin, methamphetamine, and cocaine, and legal drugs such as tobacco and alcohol—affects brain synapses.
drugs:
produce changes in synapses that use the neurotransmitter dopamine
involves the brain’s pleasure center

18. Addiction and the Brain
Methamphetamine releases a flood of dopamine, = instant “high.”
Cocaine keeps dopamine in the synaptic region longer, = pleasure and suppressing pain.
heroin, stimulate receptors that lead to dopamine release.
Nicotine and alcohol > dopamine release.

19. Addiction and the Brain
brain reacts to excessive dopamine levels by reducing the number of receptors for it.
result is normal activities no longer produce pleasure.
result: larger amounts of drugs are required to produce a high. = addiction