15
Chapter 2 pt. 1: Biology, Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery Neurons, and Brain Imagery

Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Embed Size (px)

Citation preview

Page 1: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Chapter 2 pt. 1: Biology, Chapter 2 pt. 1: Biology, Neurons, and Brain ImageryNeurons, and Brain Imagery

Page 2: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Warm Up - Reading Quiz

Study until the bell. You will have 7 minutes for the reading quiz.

Page 3: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

The Neuron The basic building block of the nervous system

is called the neuron or a nerve cell.

Page 4: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Parts of the Neuron

1. Dendrites: branching extensions that receive incoming messages and pass messages toward the cell body. (Dendron = “tree” in Greek)

2. Soma: is the cell body - contains the nucleus. (Soma = “body” in Greek)

Page 5: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Parts of A Neuron 3. Axon: extension of a

neuron which sends messages from the soma to other neuron. Longest part of the neuron. (Think “axis” … a long line.)

4. Terminal Buttons: located on end of the axon. Release neurotransmitters to communicate with other neurons. (“Terminal” just means “end”)

Page 6: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

5. Myelin Sheath: a layer of fatty cells encasing the fibers of many axons which allows faster transmission speeds in neurons.

Parts of A Neuron

Page 7: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

How Does A Neuron How Does A Neuron Communicate?Communicate?

Action Potential: neural impulse or brief electrical charge that travels down an axon at speeds as fast as 200 mph. It happens when you feel something. “ALL OR NOTHING” response (like a gun firing).

Resting Potential: refers to the neuron when it is not active. Is negatively charged.

Threshold: refers to the minimal level of stimulation required for a neural impulse to fire.

Page 8: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Neuron Communication With Neuron Communication With Other NeuronsOther Neurons

For two neurons to communicate, the impulse (the message) from one must jump over a gap called the synapse to the other one.

Synapse: space between the axon which is sending the signal and the dendrite which is receiving the signal.

Page 9: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

At the end of the axon, the terminal buttons release neurotransmitters.

Neurotransmitters are chemicals that carry messages across the synapse. They influence whether another neural impulse will take place. (Epilepsy video)

Neuron Communication

Page 10: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Answer these in your notes:

1) What is epilepsy?

2) How do electrical messages cross the space between nerve endings?

3) What are the two types of neurotransmitters? (Describe what the each do – the video didn’t say their names).

Page 11: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Types of NeurotransmittersTypes of Neurotransmitters

GABA: helps relax and calm down the body. – Shortage may

cause Anxiety or Epilepsy.

Page 12: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Types of NeurotransmittersTypes of Neurotransmitters

1. A-ce-tyl-cho-line– Important in learning and

memory.– Best known for allowing

muscle contraction.

Shortage may lead to Alzheimer’s disease or muscular disorders.

Page 13: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Types of NeurotransmittersTypes of Neurotransmitters

2. Serotonin: mood, hunger, and arousal.– Shortage may lead to

depression

3. Dopamine: movement, attention, and emotion.– Excess may lead to

schizophrenia and Parkinson’s disease.

Page 14: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Types of NeurotransmittersTypes of Neurotransmitters

4. Norepinephrine: helps control alertness and arousal when you are scared or excited.

5. Endorphins: “The morphine within.” Linked to pain control and pleasure. (Runner’s high)

Page 15: Chapter 2 pt. 1: Biology, Neurons, and Brain Imagery

Agonists vs. AntagonistsAgonists vs. Antagonists

Agonists are chemicals that mimic the effects of a neurotransmitter.

Antagonists are chemicals that block the transmission of a neurotransmitter.