Chapter 3 NotesChapter 3 Notes

The Endocrine SystemThe Endocrine System

The Endocrine system sends chemical The Endocrine system sends chemical messages called hormones to the brain. messages called hormones to the brain.

The Endocrine System consists of glands that The Endocrine System consists of glands that secrete substances, called hormones, into the secrete substances, called hormones, into the blood stream.blood stream.

These hormones stimulate growth and many These hormones stimulate growth and many kinds of reactions, such as changes in activity kinds of reactions, such as changes in activity levels and moods.levels and moods.

The HypothalamusThe Hypothalamus

This is in your brain and it directs the pituitary This is in your brain and it directs the pituitary gland, which is the “master gland”gland, which is the “master gland”

The pituitary gland secretes a large number of The pituitary gland secretes a large number of hormones which carry messages through the hormones which carry messages through the blood streamblood stream

These hormone messages carry information to These hormone messages carry information to the organs that regulate storing of nutrients, the organs that regulate storing of nutrients, growth and reproduction.growth and reproduction.

The Thyroid GlandThe Thyroid Gland

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

Adrenal GlandsAdrenal Glands

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

Heredity DebateHeredity Debate

Heredity is the transmission of genes from parent Heredity is the transmission of genes from parent to child. Nature vs. Nurture asks the question “ to child. Nature vs. Nurture asks the question “ Do people learn to be good athletes, or are they Do people learn to be good athletes, or are they born that way?” and “Do people learn to do well born that way?” and “Do people learn to do well in school, or are they born good at it?”in school, or are they born good at it?”

In the past, one way to study genes and heredity In the past, one way to study genes and heredity was by studying twins. This is still used today to was by studying twins. This is still used today to conduct research. conduct research.

Look on page 73.Look on page 73.

Twin studiesTwin studies

Identical twins develop from a single fertilized Identical twins develop from a single fertilized egg and share the same genes.egg and share the same genes.

Fraternal twins develop from two separate Fraternal twins develop from two separate eggs and their genes are not more similar than eggs and their genes are not more similar than those of brothers or sisters.those of brothers or sisters.

Read the page 72 and 73 to learn more about Read the page 72 and 73 to learn more about several studies that have been conducted with several studies that have been conducted with twinstwins

Central Nervous SystemCentral Nervous System

Includes are brain and spinal cordIncludes are brain and spinal cord Our nervous system helps control our body Our nervous system helps control our body

movements, behavior, thinking, and emotionsmovements, behavior, thinking, and emotions

Peripheral Nervous SystemPeripheral Nervous System

Consists of smaller branches of nerves that Consists of smaller branches of nerves that extend throughout your body. These nerves extend throughout your body. These nerves carry messages to and from the CNS.carry messages to and from the CNS.

Messages travel to and from the brain through Messages travel to and from the brain through neurons or strings of long thins cellsneurons or strings of long thins cells

How messages travel throughout How messages travel throughout the body continuedthe body continued

Space between the cells is called a synapseSpace between the cells is called a synapse Page 54Page 54 Impulses travel from neuron to neuron via a Impulses travel from neuron to neuron via a

chemical called neurotransmitterschemical called neurotransmitters Sometimes having too many or not enough of Sometimes having too many or not enough of

these chemicals can cause diseasethese chemicals can cause disease Too much dopamine is linked to schizophrenia Too much dopamine is linked to schizophrenia

whereas an undersupply is linked to whereas an undersupply is linked to Parkinson’s disease.Parkinson’s disease.

DepressionDepression

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

Somatic Nervous SystemSomatic Nervous System

Refers to the part of the peripheral nervous Refers to the part of the peripheral nervous system that controls voluntary body system that controls voluntary body movementsmovements

Autonomic Nervous SystemAutonomic Nervous System

Controls involuntary actions like heart beat or Controls involuntary actions like heart beat or pupil dilation.pupil dilation.

THE BRAIN!!THE BRAIN!!

Left hemisphere controls the right side of the Left hemisphere controls the right side of the bodybody

Right hemisphere controls the left side of the Right hemisphere controls the left side of the brainbrain

Composed of three main partComposed of three main part Hind brainHind brain MidbrainMidbrain ForebrainForebrain

HindbrainHindbrain

Controls our most basic processes like posture, Controls our most basic processes like posture, balance and breathingbalance and breathing

MidbrainMidbrain

Intergrates and relays informationIntergrates and relays information

ForebrainForebrain

Controls higher thinking processesControls higher thinking processes

Each hemisphere of the brain has 4 lobes and Each hemisphere of the brain has 4 lobes and two hemispheres that are mirror images of two hemispheres that are mirror images of each othereach other