Unit 2 - Biological Psychology and Neurotransmission Flashcards
What is phrenology?
The study of bumps on the skull (focused on the localization of function)
What is the purpose of the cell body in a neuron?
The cells life support center
What is the purpose of dendrites in a neuron?
Receives messages from other cells and conducts them toward the cell body
What is the purpose of the axon in a neuron?
Passes messages from the cell body to other neurons, muscles, or glands. It is also where action potential occurs.
What is the purpose of the myelin sheath in a neuron?
- It is made of fatty tissue
- It covers the axon of some neurons
- Helps speed neuro impulses
What is the purpose of the terminal branches in a neuron?
Forms junctions with other neurons and releases neurotransmitters
What is action potential and what is the process?
Also known as a neural impulse, it is the electrical signal traveling down the axon. It moves toward the terminal branches.
1.) Resting period: Axon is polarized and the Na+ ions are on the outside while the K- ions are on the inside of the axon.
2.) Action potential: The neuron fires Na+ and gates in the axon open in a wave. Na+ rushes in the axon and depolarization occurs one section at a time. This causes the release of neurotransmitters into synapses, causing the next neuron to fire.
3.) Refractory period: AKA repolarizing period, the Na+ ions move back outside the axon. This is the time shortly after a neuron is fired. Similar to batteries being removed from a flashlight.
What is the threshold?
The amount of stimulation needed to trigger a neural impulse
What is the “all-or-nothing” response of a neuron?
This refers to the fact that a neuron’s reaction is firing with full strength or not firing at all. A strong stimulus can trigger more neurons to fire more often but doesn’t affect speed.
Who was Sir Charles Sherrington?
- British psychologist
- Observed that neural impulses were taking a long time to travel a neural pathway
- Created the term “synapse”
What is the synaptic gap (synapse)?
The area where the axon terminal of one neuron is separated from receiving neurons (dendrites and terminal buttons don’t touch)
What are neurotransmitters?
Chemical messages that are released when an action potential reaches the terminals at an axon’s end
What is the process of neural communication?
1.) Action potential reaches the terminals at the axon’s end
2.) Neurotransmitters are released
3.) Neurotransmitters cross the synaptic gap and bind to receptors on the receiving neuron
4.) Neurotransmitters unlock tiny channels at the receiving site of an instant
5.) Ions flow in and either excite or inhibits the receiving neuron from firing
6.) Reuptake occurs (excess neurotransmitters are reabsorbed by the sending neuron)
What is acetylcholine (ACh)?
- A neurotransmitter that enables muscle action, learning, and memory
- Is the messenger for functions b/w motor neurons and skeletal muscles
Too little: ACh-producing neurons deteriorate with Alzheimer’s disease. Blockage of ACh can lead to paralysis
What is dopamine?
- A neurotransmitter that influences movement, learning, attention, and emotion
Too many: Schizophrenia
Too little: Tremors + decreased mobility
