The Neuron, Neurotransmitters and the Nervous System
The Neuron, Neurotransmitters and the Nervous System
Neurons Role & Function
Explain these, including their role and function.
Dendrites
Soma
Axon
Myelin Sheath
Terminal Buttons
Synapse
Label the neuron below.
Important Neurotransmitters
• Excitatory Neurotransmitter - chemical secreted at terminal button that causes the neuron on the other side of the synapse to generate an action potential (to fire).
• Inhibitory Neurotransmitter – chemical secreted at terminal button that reduces or prevents neural impulses in the postsynaptic neuron
Instructions – read the about each neurotransmitter below. Create a drawing or mnemonic to help you remember the role of each neurotransmitter.
Please note that these associations are merely correlations, and do not necessarily demonstrate any cause and effect relationship. We don’t know what other variables may be affecting both the neurotransmitter and the mental illness, and we don’t know if the change in the neurotransmitter causes the illness, or the illness causes the change in the neurotransmitter.
Neurotransmitter / Functions / Effects of Excess/Deficit / Drawing or mnemonic1. Acetylcholine
(Ah-seat-ta-coal-leen) / Voluntary movement and muscle contraction
Learning
Memory
Sleep / Excess – may be linked to depression
Deficit – Dementia & Alzheimer’s disease
2. Dopamine / Movement
Attention & alertness
Rewards (related to addictions) / Excess – Schizophrenia
Deficit- Parkinson’s disease (tremors and muscular rigidity)
3. GABA (gamma-aminobutyric acid) / Inhibits excitation and anxiety (calming) / Excess – seizures, insomnia
Deficit – anxiety disorders
4. Endorphins / Pain relief and feelings of pleasure
Stress reduction
“Natural opiates” / Deficit – may be involved in addiction
5. Serotonin / Mood regulation
Hunger/appetite
Sleep / Deficit – depression and some anxiety disorders (especially OCD)
6. Epinephrine/ Norepinephrine / “Fight or flight” response (increased heart rate, circulation, respiration)
Alertness/arousal
Norepinephrine slows down appetite and digestion during fight or flight / Excess – high blood pressure. Too much norepinephrine has been linked to schizophrenia
Deficit – depression
Are you in balance? What does over or under abundance of these neurotransmitters mean for your health?
Neurotransmitter / Role / Too many? / Too few?Dopamine
Serotonin
Endorphin
Acetylcholine
Norepinephrine
Foreign Substance / Effects on Neurotransmitters
Alcohol
Opiates
Cocaine
Ecstasy
Nicotine
Caffeine
The Nervous System
On the figure label the
- Central Nervous System
- Peripheral Nervous System
- Motor Neurons
Sensory Neuron
Sending Messages
Types of Cells in the Nervous SystemGlial Cells / The four main functions of glial cells are: to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy and remove the carcasses of dead neurons (clean up).
Schwann Cells / Schwann cells are the supporting cells of the PNS. Schwann cells make up an axon's myelin sheath. Schwann cells also aid in cleaning up PNS debris and guide the regrowth of PNS axons.
Types of Neurons (Sensory, Motor, Inter) / -Afferent neuron (Sensory Neurons) – carry nerve impulses from receptors or sense organs toward the central nervous system.
-Efferent neuron (Motor Neurons) -- carry nerve impulses away from the central nervous system to effectors such as muscles or glands
-Interneuron – is a neuron that forms a connection between other neurons. Interneurons are neither motor nor sensory.
1. If you stub your toe, which type of neurons will carry this message from your toe to the brain?
2. If you go to the gym and lift weights, which division of the nervous system carries the messages to your muscles?
3. If you are nervous for a test, which division of the nervous system will make your heart beat faster?
4. Which of the terms does not send any messages and simply supplies neurons in the brain with nutrition?
5. Which division of the nervous system works without conscious thought or decision making?