Psychology Unit 3 Study Guide-Biological Bases of Behavior

Genes

Segments of DNA that influence traits and behaviors in an organism.

Environment

External factors

Epigenetics

The study of environmental factors that can cause changes in gene expression without altering the DNA sequence.

Genotype

The genetic makeup of an organism

Phenotype

The observable traits or characteristics of an organism resulting from the interaction of its genotype and environment.

Range Reaction

A concept suggesting that genes establish limits for traits

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord responsible for processing information and controlling body functions.

Peripheral Nervous System (PNS)

The division of the nervous system that includes all the nerves outside the CNS

Somatic Nervous System

The subdivision of the PNS that controls voluntary muscle movements.

Autonomic Nervous System

The subdivision of the PNS that controls involuntary bodily functions

Sympathetic Nervous System

A branch of the autonomic nervous system that prepares the body for "fight or flight" responses in stressful situations.

Parasympathetic Nervous System

A branch of the autonomic nervous system responsible for "rest and digest" functions that restore the body to a state of calm.

Dendrites

Branch-like structures of a neuron that receive messages from other neurons.

Soma

The cell body of a neuron that maintains its health and function.

Axon

A long projection of a neuron that transmits electrical signals away from the soma to other neurons or muscles.

Myelin Sheath

A fatty layer that covers axons to insulate them and increase the speed of signal transmission.

Axon Terminals

The ends of an axon that release neurotransmitters to communicate with other neurons.

Synapse

The gap between two neurons where neurotransmitters are released for communication.

Resting Potential

The state of a neuron when it is not actively sending a signal

Threshold

The level of stimulation required to trigger an action potential in a neuron.

Action Potential

A rapid change in the electrical charge of a neuron that occurs when it receives a strong enough stimulus.

All-or-Nothing Principle

The principle stating that if a neuron reaches its threshold

if not

it will not fire at all.

Neurotransmitters

Chemical messengers released from neurons that transmit signals across the synapse to other neurons.

Reuptake

The process by which neurotransmitters are reabsorbed back into the presynaptic neuron after transmitting their signal.

Acetylcholine (ACh)

A neurotransmitter involved in movement and memory

low levels are associated with Alzheimer's disease.

Dopamine

A neurotransmitter associated with pleasure and movement

imbalances can lead to schizophrenia or Parkinson's disease.

Serotonin

A neurotransmitter that regulates mood and sleep

low levels are linked to depression.

Norepinephrine

A neurotransmitter involved in alertness and arousal

GABA

An inhibitory neurotransmitter that prevents excessive neural activity

low levels are associated with anxiety and seizures.

Glutamate

An excitatory neurotransmitter important for learning and memory

high levels can lead to migraines and seizures.

Brain Stem

A structure that controls basic life functions such as breathing and heart rate.

Medulla

A part of the brain stem responsible for regulating vital functions like breathing and heart rate.

Pons

A part of the brain stem involved in regulating sleep and arousal.

Cerebellum

A brain structure that coordinates balance and motor control.

Reticular Formation

A network of neurons in the brain stem involved in alertness and the sleep-wake cycle.

Thalamus

A subcortical brain structure that acts as a relay station for sensory information.

Hypothalamus

A subcortical structure that regulates hunger

Amygdala

A subcortical structure involved in processing emotions

Hippocampus

A subcortical structure essential for memory formation.

Cerebral Cortex

The outer layer of the brain responsible for higher-level functions like planning

Frontal Lobe

The region of the cerebral cortex involved in planning

Parietal Lobe

The region of the cerebral cortex that processes sensory information.

Occipital Lobe

The region of the cerebral cortex primarily responsible for vision.

Temporal Lobe

The region of the cerebral cortex involved in hearing and language comprehension (Wernicke's area).

Left Hemisphere

The side of the brain that specializes in language and logical reasoning while controlling the right side of the body.

Right Hemisphere

The side of the brain that specializes in creativity and spatial awareness while controlling the left side of the body.

Split-Brain Studies

Research findings showing that the left visual field is processed by the right hemisphere (nonverbal) and the right visual field by the left hemisphere (verbal identification).

EEG (Electroencephalogram)

A technique for measuring electrical activity in the brain.

CT (Computed Tomography)

An imaging technique that uses X-rays to create detailed images of the brain's structure.

PET (Positron Emission Tomography)

An imaging technique that measures brain activity based on glucose consumption.

MRI (Magnetic Resonance Imaging)

An imaging technology that produces detailed structural images of the brain without using X-rays.

fMRI (Functional Magnetic Resonance Imaging)

An imaging technique that measures brain activity by detecting changes in blood flow.