1. Chapter 3 Notes

2. The Endocrine System
The Endocrine system sends chemical messages called hormones to the brain.
The Endocrine System consists of glands that secrete substances, called hormones, into the blood stream.
These hormones stimulate growth and many kinds of reactions, such as changes in activity levels and moods.

3. The Hypothalamus
This is in your brain and it directs the pituitary gland, which is the “master gland”
The pituitary gland secretes a large number of hormones which carry messages through the blood stream
These hormone messages carry information to the organs that regulate storing of nutrients, growth and reproduction.

4. The Thyroid Gland
Produces the hormone thyroxine. Too little thyroxine makes people feel lazy and lethargic which is a condition called hypothyroidism. Too much thyroxine causes people to lose weight and become overactive. This is known as hyperthyroidism.

5. Adrenal Glands
Become active when you are frightened or angry. They secrete adrenaline. This prepares your body to handle emergencies.

6. Heredity Debate
Heredity is the transmission of genes from parent to child. Nature vs. Nurture asks the question “ Do people learn to be good athletes, or are they born that way?” and “Do people learn to do well in school, or are they born good at it?”
In the past, one way to study genes and heredity was by studying twins. This is still used today to conduct research.
Look on page 73.

7. Twin studies
Identical twins develop from a single fertilized egg and share the same genes.
Fraternal twins develop from two separate eggs and their genes are not more similar than those of brothers or sisters.
Read the page 72 and 73 to learn more about several studies that have been conducted with twins

8. Central Nervous System
Includes are brain and spinal cord
Our nervous system helps control our body movements, behavior, thinking, and emotions

9. Peripheral Nervous System
Consists of smaller branches of nerves that extend throughout your body. These nerves carry messages to and from the CNS.
Messages travel to and from the brain through neurons or strings of long thins cells

10. How messages travel throughout the body continued
Space between the cells is called a synapse
Page 54
Impulses travel from neuron to neuron via a chemical called neurotransmitters
Sometimes having too many or not enough of these chemicals can cause disease
Too much dopamine is linked to schizophrenia whereas an undersupply is linked to Parkinson’s disease.

11. Depression
Depression is caused by an undersupply of norepinephrine or serotonin.

12. Somatic Nervous System
Refers to the part of the peripheral nervous system that controls voluntary body movements

13. Autonomic Nervous System
Controls involuntary actions like heart beat or pupil dilation.

14. THE BRAIN!! Left hemisphere controls the right side of the body
Right hemisphere controls the left side of the brain
Composed of three main part
Hind brain
Midbrain
Forebrain

15. Hindbrain
Controls our most basic processes like posture, balance and breathing

16. Midbrain
Intergrates and relays information

17. Forebrain Controls higher thinking processes
Each hemisphere of the brain has 4 lobes and two hemispheres that are mirror images of each other