Lecture 7 Flashcards
What are neurons?
Basic wiring of the brain & nervous system. They are like information messengers that use electrical impulses and chemical signals to transmit info. to different parts of the brain.
How do neurons communicate with each other?
They communicate via an action potential denotes a change in the relative electric charge from inside to outside the cell.
What is the difference between transmission and conduction?
Conduction allows the transmission of an impulse, first step of an action potential. Transmission is the process where one neuron communicates with another.
What is an action potential?
An action potential is like dominoes, no single one travels all the way through the cell, it takes a bunch of them to transmit an impulse.
What role does potassium & sodium anions play?
A sodium-potassium pump is an information processing element in brain computation. Brain neurons can transmit signals using a flow of Na+ & K+ ions, which produce an electrical spike called an action potential.
What are neurotransmitters? Discuss each of their functions.
Chemical messengers that your body cannot function without. Carries chemical messages from on neuron to the next target cell.
- Noradrenaline; flight/flight, concentration
- Dopamine; mood/sleep/learning
- Serotonin; mood regulation/sleep
- GABA; sleep/anxiety
- Acetylcholine; muscle/memory/walk/talk
- Glutamate; memory/learning
- Endorphins; (block pain) pain/pleasure
Distinguish excitatory neurotransmitters.
Increases positive charge (Dopamine, Norepinephrine, Glutamate, Acetylcholine).
Differentiate between agonists & antagonists.
Agonists increase the function of a neurotransmitter. Cocaine increases amount of dopamine & norepinephrine which are both agnonists. Antagonists decrease the function of a neurotransmitter. Caffeine is an adenosine antagonist.
What role do chlorine & protein ions play?
Calcium ions entering the cell initiate a signalling cascade that causes small membrane-bound vesicles, called synaptic vesicles, containing neurotransmitter molecules to fuse with the presynaptic membrane.
Distinguish inhibitory neurotransmitters.
Decreases positive charge (Serotonin, GABA, Endorphins).
What happens when action potential reaches its peak?
It activates the next action potential.
What happens when you don’t need a neuron anymore?
It starts to degrade.
What are vesicles?
Filled w/ neurotransmitters that unlock gates & release then into synapse, once gate is open sodium flows into dendrite & action potential occurs.
What happens to left over neurotransmitters?
They are either sucked back in (re-uptake), others stay & some float away & are broken down
What is Heterochromia?
One form (congenital) is that a person has two sets of DNA in their cells, absorbs fraternal twin.
