Physiological Psychology Exam III Flashcards

Questions and Answers

The resting potential is _____________ and nothing happens at this state.

-70mV

What happens at the resting potential?

Nothing

What is the trigger point of a neuron called?

Threshold of excitation

What is fired after reaching the threshold of excitation?

Action potential Signup and view all the answers

Threshold of excitation is the level of ___ () necessary to generate an action potential.

Depolarization (positive charge) Signup and view all the answers

What does hyperpolarization do to the resting membrane potential?

Increases it Signup and view all the answers

What is IPSP?

Inhibitory postsynaptic potential Signup and view all the answers

Depolarization makes the neuron _____________.

More positive Signup and view all the answers

What maintains the resting potential?

Ionic balance Signup and view all the answers

On the outside of a cell, there are _______ () and _ (____).

Na+ (sodium ion) and Cl- (chloride ion) Signup and view all the answers

On the inside of the cell, there are _____ () and _ (____).

K+ (potassium) and A-- (anion) Signup and view all the answers

Neurotransmission starts __ (Before the synapse): the threshold of excitation is reached and an _ fires.

Presynaptically (Before the synapse) and action potential Signup and view all the answers

After the action potential, __ () enters the presynaptic terminal bouton.

Ca++ (calcium) Signup and view all the answers

The neurotransmitter crosses the synapse and attaches to a ___________ on the postsynaptic dendritic spine.

Receptor site Signup and view all the answers

Can neurotransmitters bind to any receptors?

No Signup and view all the answers

Presynaptic terminal bouton: _ (_) enters the cell and causes vesicles to fuse to the membrane.

Ca++ (calcium) Signup and view all the answers

There are ** types of receptors: * and ______*.

Two, Ionotropic and Metabotropic Signup and view all the answers

Most neurotransmitters are dealt with by _____________ (recycling of neurotransmitters).

Reuptake Signup and view all the answers

The exception is ACh (Acetylcholine), which gets broken down by _____________.

Enzymatic degradation Signup and view all the answers

Axons with myelin sheaths conduct ____________ than axons without myelin sheaths.

Faster Signup and view all the answers

Do dendrites have myelin sheaths?

Do not Signup and view all the answers

The sodium-potassium pump (Na+ K+ pump): It resets the resting potential at -70mV.

3 Na+ (sodium) ions out and 2 K+ (potassium) ions in Signup and view all the answers

The absolute refractory period means that a neuron ____________ generate an action potential.

Cannot Signup and view all the answers

The relative refractory period is when the neuron can generate an action potential but it requires ____________ of stimulation (EPSP).

A lot Signup and view all the answers

Study Notes

Resting Potential

Resting potential is approximately -70mV; no action occurs at this state.
The threshold of excitation is the critical point for a neuron to fire, usually around -65mV.
Hyperpolarization increases the negativity of the resting membrane potential.
IPSP (Inhibitory Postsynaptic Potential) causes a neuron to become more negative, inhibiting firing.
Depolarization decreases the resting membrane potential, making it more positive.
EPSP (Excitatory Postsynaptic Potential) increases positivity, promoting action potential firing.

Ionic Balance

Resting potential is maintained through ionic balance.
Outside the cell: Na+ (sodium ions) and Cl- (chloride ions).
Inside the cell: K+ (potassium ions) and A- (anions).

Neurotransmission Process

Begins with reaching the threshold of excitation, leading to an action potential firing in the axon.
Ca++ (calcium ions) enter the presynaptic terminal bouton, causing vesicles to release neurotransmitters into the synapse.
Neurotransmitters bind to receptor sites on the postsynaptic dendritic spine, triggering postsynaptic potentials (IPSP or EPSP).
Presynaptic autoreceptors detect neurotransmitter levels and regulate release by closing Ca++ channels.
Receptors are specific; each type fits only certain neurotransmitters, akin to a lock and key design.

Presynaptic Terminal Bouton

Ca++ entering the presynaptic terminal bouton facilitates neurotransmitter release into the synapse.

Receptor Types

Two types of receptors on the postsynaptic side: Ionotropic and Metabotropic.
Only Metabotropic autoreceptors exist on the presynaptic side.

Deactivation of Neurotransmitters

Most neurotransmitters are deactivated through reuptake (recycling).
ACh (Acetylcholine) is an exception, undergoing enzymatic degradation by acetylcholinesterase (AChE), which breaks it down and reassembles it for reuse.

Myelinated vs Unmyelinated Axons

Axons with myelin sheaths conduct signals faster than those without.
Dendrites lack myelin sheaths entirely; only axons are myelinated.

Sodium-Potassium Pump

The sodium-potassium pump resets the resting potential at -70mV after action potential firing and hyperpolarization.
It actively pumps 3 Na+ ions out for every 2 K+ ions taken in.
The absolute refractory period occurs when a neuron cannot generate another action potential due to hyperpolarization.
The relative refractory period follows, during which an action potential can occur but requires increased stimulation (EPSP).

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Description

Prepare for your Exam III in Physiological Psychology with these flashcards. This set focuses on key concepts such as resting potential, action potentials, and the threshold of excitation. Enhance your understanding of neuronal functions and prepare effectively for your exam.