biosz memory sleep sensory organs action potential gpt1

What is the limbic system associated with?

Personality, emotions, memory, and learning

Which brain structures make up the limbic system?

Hippocampus, amygdala, thalamus, hypothalamus, and cortical connections

What is the function of the hippocampus?

Formation of new memories and strengthening synaptic connections

What is the function of the amygdala?

Regulation of emotions and emotional responses

What is synaptic plasticity?

The ability of synapses to strengthen, weaken, or form new connections

How do synapses change during learning?

Frequently used synapses strengthen, unused ones weaken

What factors strengthen memory formation?

Repetition, associations, and emotional state

What is short-term memory?

Temporary storage of information in the cerebral cortex

How long does short-term memory last?

A few minutes

What role does the hippocampus play in memory transfer?

Transfers information from short-term to long-term memory

What is long-term memory?

Stable storage of information in the cerebral cortex

What are the two main types of long-term memory?

Implicit and explicit memory

What is implicit memory?

Unconscious memory such as motor skills

Which brain structure also stores implicit memories?

Cerebellum

What is explicit memory?

Conscious recollection of information

What are the two types of explicit memory?

Semantic and episodic memory

What is semantic memory?

General factual knowledge about the world

What is episodic memory?

Memory of personal events and experiences

Which lifestyle factors improve memory?

Exercise, quality sleep, fulfilling basic needs

Which lifestyle factors impair memory?

Lack of sleep, poor nutrition, drugs, prolonged stress

What is sleep?

A state of suspended consciousness and reduced perception of surroundings

Which body systems are influenced by sleep?

Blood pressure, breathing, metabolism, endocrine system, mood, and memory

How does sleep affect memory?

Improves consolidation of long-term memories

What is the circadian rhythm?

Approximately 24-hour sleep–wake cycle

What body temperature change helps initiate sleep?

A decrease of about 1–2 °C

What are microsleep cycles?

Repeating sleep cycles lasting about 90 minutes

What are the two main stages of sleep?

NREM and REM sleep

What does NREM stand for?

Non-rapid eye movement sleep

What characterizes REM sleep?

Dreaming, active brain, very low muscle tone

During which sleep stage does dreaming mainly occur?

REM sleep

Which brain waves dominate deep sleep?

Delta waves

Why is deep sleep important?

Memory consolidation and physical recovery

What are sensory organs used for?

Perceiving the external environment

What types of receptors exist in sensory organs?

Mechano-, chemo-, thermo-, photo-, and electroreceptors

What do mechanoreceptors detect?

Mechanical stimuli such as pressure, movement, and sound

What do chemoreceptors detect?

Chemical stimuli such as smell and taste

What do thermoreceptors detect?

Temperature changes

What do photoreceptors detect?

Light

Action Potential — MORE DETAILED FLASHCARDS

What is a resting potential?

The negative charge inside a neuron at rest

What is the typical value of resting potential?

−70 mV

Why is the inside of a neuron negatively charged at rest?

Due to protein anions and selective membrane permeability

What triggers an action potential?

A stimulus that raises membrane potential to threshold

What is the threshold level?

The minimum membrane potential required to trigger an action potential

What happens first during an action potential?

Voltage-gated sodium channels open

What ion moves into the neuron during depolarization?

Sodium (Na⁺)

What is depolarization?

The membrane potential becoming less negative

What is the peak voltage of an action potential?

+30 mV

Why do sodium channels close at the peak?

They become inactivated due to voltage change

What happens after sodium channels close?

Voltage-gated potassium channels open

What ion leaves the neuron during repolarization?

Potassium (K⁺)

What is repolarization?

The membrane potential returning toward negative values

What is hyperpolarization?

When membrane potential becomes more negative than resting potential

Why does hyperpolarization occur?

Potassium channels remain open longer than necessary

How is resting potential restored after an action potential?

By sodium–potassium pumps

How does the sodium–potassium pump work?

Pumps 3 Na⁺ out and 2 K⁺ into the cell

Why does this pump maintain a negative interior?

More positive charge leaves than enters

What law do action potentials obey?

All-or-none law

What does the all-or-none law state?

Action potentials are identical once threshold is reached

Why does action potential travel in one direction?

Sodium channels behind the impulse are inactivated

How does myelination affect action potential speed?

Greatly increases conduction speed

What is saltatory conduction?

Action potential jumping between nodes of Ranvier

Why is conduction slower in unmyelinated axons?

The impulse must travel along the entire membrane surface