Chapter 2: The Biological Basis of Behavior

Vocabulary practice flashcards covering key biological foundations of behavior, brain anatomy, neural communication, divisions of the nervous system, endocrine glands, and genetics from Chapter 2.

Psychobiology

A field that focuses on the biological foundations of behavior and mental processes.

Neuroscience

The study of the brain and nervous system.

Neurons

Individual cells that are the smallest unit of the nervous system.

Neuron Structure

The structural parts of a typical neuron, including dendrites, cell body (soma), cell membrane, axon, myelin sheath, and terminal buttons.

Dendrites

Short fibers that branch out from the cell body and pick up incoming messages.

Axon

A single, long fiber extending from the cell body that carries outgoing messages.

Myelin Sheath

A white fatty covering found on some axons.

Nerve (or Tract)

A group of axons bundled together.

Sensory (Afferent) Neurons

Neurons that carry messages from sensory receptors toward the central nervous system.

Motor (Efferent) Neurons

Neurons that carry messages away from the central nervous system to muscles and glands.

Interneurons (Association Neurons)

Neurons that carry messages from one neuron to another.

Synapse Structure

The connection site between neurons comprising the presynaptic neuron's axon terminal, voltage-gated Ca2+ channels, synaptic vesicles, the synaptic cleft, and postsynaptic ion channel receptors.

Synaptic Space (Synaptic Cleft)

The tiny gap between the axon terminal of one neuron and the dendrites or cell body of another neuron.

Synapse

The structure consisting of the axon terminal of one neuron, the synaptic space, and the dendrite of the next neuron.

Terminal Button (Synaptic Knob)

The structure at the end of an axon terminal branch.

Synaptic Vesicles

Tiny sacs in a terminal button that release neurotransmitter chemicals into the synapse.

Neurotransmitters

Chemicals released by synaptic vesicles that travel across the synaptic space and affect adjacent neurons.

Receptor Sites

Locations on a receiving neuron into which specific neurotransmitters fit like a key into a lock.

Neural Plasticity

The ability of the brain to change in response to experience.

Neurogenesis

The growth and development of new neurons.

Rosenzweig's Rat Experiment

An experiment demonstrating that young rats raised in enriched environments developed larger neurons with more synaptic connections than those in bare, impoverished cages.

Organization of the Nervous System

The division of the nervous system into the Central Nervous System (Brain and Spinal cord) and Peripheral Nervous System (Somatic and Autonomic divisions).

Central Nervous System (CNS)

The primary control center of the body, composed of the brain and the spinal cord.

Peripheral Nervous System (PNS)

The division that links the brain and spinal cord to the rest of the body, consisting of afferent and efferent neurons.

Somatic Nervous System

The division of the PNS that carries information to the CNS from the senses and from the CNS to the skeletal muscles.

Autonomic Nervous System

The division of the PNS that regulates the internal environment by carrying messages from the CNS to organs, blood vessels, and glands.

Sympathetic vs. Parasympathetic Division

The autonomic divisions that respectively arouse the body for emergency action (sympathetic) and calm the body after arousal (parasympathetic).

Limbic System Structures

A interconnected group of brain structures including the cingulate cortex, thalamus, hypothalamus, amygdala, and hippocampus.

Thalamus

Part of the forebrain that relays information from sensory organs to the cerebral cortex.

Hypothalamus

Part of the forebrain that regulates the amount of fear, thirst, sexual drive, and aggression felt.

Amygdala

Limbic structure that influences motivation, emotional control, fear response, and interpretations of nonverbal emotional expressions.

Hippocampus

Limbic structure that plays a role in learning, memory, and the ability to compare sensory information to expectations.

Cingulate Cortex

Primary cortical component of the limbic system involved in emotional and cognitive processing.

Corpus Callosum

A thick band of nerve fibers connecting the left and right cerebral hemispheres.

Left Hemisphere

The hemisphere that controls writing and movement of the right side of the body, dominant in language and symbolic reasoning.

Right Hemisphere

The hemisphere that controls touch and movement of the left side of the body, superior at nonverbal, visual, and spatial tasks.

Broca's Area vs. Wernicke's Area

Broca's area handles speech production (damage affects talking ability), whereas Wernicke's area handles speech comprehension (damage affects language understanding).

Spinal Cord

A complex cable of neurons running down the spine that connects the brain to most of the rest of the body.

Endocrine Glands

Glands including the pineal, pituitary, parathyroid, thyroid, pancreas, adrenal, and gonads (ovaries and testes) that release chemical hormones.

Behavioral Genetics

The study of the relationship between heredity and behavior.

Evolutionary Psychology

The study of the evolutionary roots of behaviors and mental processes.

Transmission of Eye Color

A genetic inheritance model illustrating how two heterozygous brown-eyed parents (Bb) have a 1 in 4 (25%) chance of producing a blue-eyed child (bb).

Human Genome

The full complement of genes within a human cell, consisting of approximately 20,000 to 25,000 genes on 23 pairs of chromosomes.