Topic: Nervous System

Aim: Use textual evidence to describe the structure of a neuron.

Do Now: Take out your neurons reading notes. Work on the Respiratory ditto. Label all structures.

HW: Finish CNS and PNS reading notes

 

1.Trachea

2.Nostrils

3.Nasal cavity

4.Pharynx

5.Epiglottis

6.Larynx

7.Bronchus

8.Bronchiole

9.Bronchiole

10.Diaphragm

11.13.

12.

14.

15.

Bronchiole

Alveoli

Alveolus

capillary

Alveolus

You are sound asleep and a loud alarm clock goes off…you wake up. Identify the stimulus, receptor, effector and response.

Did you know...

• There are millions of nerve cells in the human body. This number even exceeds the number of stars in the Milky Way.

• The nervous system is very quick, it can transmit impulses at a tremendous speed of 100 meters per second. The speed of message transmission to the brain can be as high as 180 miles per hour.

• Neurons, which are the largest cells in the human body, do not undergo the process of mitosis.

1. Describe the nature of an

impulse.

• Electrochemical message

2. Label the neuron in the diagram. 4

5

4

5

Cell body

Cell body

• Largest part of neuron• Contains nucleus, cytoplasm and

other structures• Produces proteins needed for the

constriction of other parts of neuron

4

5

Dendrites

Cell body

Dendrites • Carry signals toward cell body

4

5

Dendrites

Cell body

Axon

Axon• Carry signals away from cell body

Did you know:

The longest axon of a neuron is approximately around 15 feet (Giraffe primary afferent axon from toe to neck)

4

5

Dendrites

Cell bodySchwann cell

Axon

Schwann Cells

• Wrap axons• Form myelin sheath assists in the

conduction of impulses (faster)

4

5

Dendrites

Cell bodySchwann cell

Axon

Terminal branches

Terminal branches

• End of neuron

4. Identify the space between 2 neurons.

• Synapse

5. Identify the chemical released by terminal branches into the synapse.

• Neurotransmitters

Neurotransmitters

cellbody

muscle tissue

TYPICAL MOTOR NEURON

Axondendrite

synapse

cell body

6. Describe how an impulse is transmitted to the next

neuron.

• Neurotransmitters released into the synapse to stimulate the next neuron

Describe the relationship between the shape of the neurotransmitters the shape of the receptors.

Receptors

• Neurotransmitters attach to receptors on next neuron

https://www.youtube.com/watch?v=p5zFgT4aofA

http://www.youtube.com/watch?v=haNoq8UbSyc&NR=1&feature=endscreen

DIFFERENT NEUROTRANSMITTERSDopamine: main focus neurotransmitter  -When either elevated or low – we can have focus issues such as not remembering where we put our keys or simply daydreaming and not being able to stay on task.  -It is also responsible for our drive or desire to get things done – or motivation.  -Stimulants such as medications for ADD/ADHD and caffeine cause dopamine to be pushed into the synapse so that focus is improved. 

Epinephrine: an excitatory neurotransmitter that is reflective of stress-It will often be elevated when ADHD like symptoms are present.  -Long term STRESS or INSOMNIA can cause epinephrine levels to be depleted (low).  -It also regulates HEART RATE and BLOOD PRESSURE

NOREPINEPHRINE: excitatory neurotransmitter •It is responsible for stimulatory processes in the body.  •It helps to make epinephrine as well.  •It can cause ANXIETY at elevated excretion levels as well as some “MOOD DAMPENING” effects.  •Low levels of norepinephrine are associated with LOW ENERGY, DECREASED FOCUS ability and sleep cycle problems.

There are different types of ADHD.•Patients with ADHD may have changes in norepinephrine levels in their brains. •Patients may have changes in their dopamine levels in the brain. •Medications on the market for ADHD target these particular neurotransmitters.

– Stimulants such as Ritalin and Adderall increase dopamine.

– Nonstimulant, such as Strattera, also increase norepinephrine.

Seratonin – inhibitory neurotransmitters that regulates moods-Adequate amounts necessary for a stable mood and to balance any excessive excitatory (stimulating) neurotransmitter firing in the brain.  -Stimulant medications or caffeine in your daily can cause a depletion of serotonin over time. -It also regulates many other processes such as carbohydrate cravings, sleep cycle, pain control and appropriate digestion.  -Many researchers believe that an imbalance in serotonin levels may lead to depression. Possible problems include low brain cell production of serotonin, a lack of receptor sites able to receive the serotonin that is made, inability of serotonin to reach the receptor sites, or a shortage in tryptophan, the chemical from which serotonin is made.

GABA – leading inhibitory neurotransmitter•It is often referred to as “nature’s VALIUM-like substance”.  •High or low levels os GABA most likely occur when an excitatory neurotransmitter is firing too often in the brain.  GABA will be sent out to attempt to balance this stimulating over-firing•Researchers believe an imbalance may play a role in epilepsy

Glutamate – leading excitatory neurotransmitter in the brain •It involved in most aspects of normal brain function including cognition, memory and learning•Regarding epilepsy, researchers also are studying this excitatory neurotransmitter.

.

Endorphin – block pain messages

•Stress and pain are the two most common factors leading to the release of endorphins.

•Endorphins interact with receptors in the brain to reduce our perception of pain and act similarly to drugs such as morphine and codeine.

•Leads to feelings of euphoria, modulation of appetite, release of sex hormones, and enhancement of the immune response

Let’s summarize…

1. What are nerve cells called?

2. Identify the five parts of a neuron we discussed.

3. Identify the part of the neuron that receives the impulse.

4. Identify the long part of the neuron.

5. Identify the part of the neuron that helps send the impulse to the next neuron.

6. Identify the space between 2 neurons.

7. Identify the chemical that is secreted into the space.

8. Identify the structures that this chemical will attach to on the next neuron.

Review: Identify the part of the neuron being described.

1. Long part of neuron that carries the impulse to the terminal branches.

2. First part of the neuron that receives the impulse.

3. Release neurotransmitters.

4. Contains the nucleus.

5. Helps the impulse travel faster.

6. The space in between two neurons.

Identify the structures labeled in the diagram.

A – nasal cavityB – pharynxC – larynxD – tracheaE – bronchiF – bronchiolesG – lungH - diaphragm

A

BC

D

EF

G

H

1. Identify all labeled structures in the diagram of the urinary system.

2. Describe three functions of the kidneys.

3. Identify the structures that temporarily store urine.

4. Identify the structures that transport urine from the kidneys to the urinary bladder.

5. Identify the structure that transports urine out of the body.