Chapter 3: Biological Basis of Behaviour Flashcards

Vocabulary flashcards covering the biological foundations of behavior, including cells of the nervous system, neural communication mechanisms, functional brain anatomy, and neuroimaging methods.

Glia (Glial Cells)

Cells in addition to neurons that make up the nervous system, serving functions such as structural support (astrocytes, ependymal), insulation (oligodendrocytes in CNS, Schwann cells in PNS), promoting neural communication (astrocytes), and cleaning up waste (microglia).

Neuron

The fundamental building block of the nervous system responsible for processing all motor, sensory, and cognitive information.

Cell Body (Soma)

The region of a neuron that receives information from dendrites and passes it to the axon if sufficient stimulation is received.

Dendrites

Branch-like extensions extending from the neuronal cell body that receive signals from other neurons.

Axon

A single long extension from the cell body that carries electrical information away toward other cells.

Myelin Sheath

A layer of specialized glial cells covering the axon that insulates it and speeds up the transmission of neural impulses.

Axon Terminal / Terminal Buttons

The specialized endpoints of an axon from which chemical messengers known as neurotransmitters are released.

Structural Types of Neurons

The three morphological classifications of neurons: (a) Multipolar neuron, (b) Bipolar neuron, and (c) Unipolar neuron.

Nodes of Ranvier

Regularly spaced regions of bare axon membrane located between segments wrapped in myelin sheath.

Resting Potential

The electrical charge difference across a neuron's membrane when at rest ($-70\,mV$), where the intracellular area is negatively charged relative to the extracellular area (polarized state).

Sodium-Potassium Pump

A active transport mechanism that maintains membrane potential by moving $3\,Na^+$ ions out of the cell for every $2\,K^+$ ions brought in.

Phases of the Action Potential

The sequence of voltage changes during neuronal firing: starting at resting potential ($-70\,mV$), passing the threshold of excitation ($-55\,mV$), reaching peak action potential ($+30\,mV$), followed by repolarization and hyperpolarization.

All-or-None Principle

The principle stating that an action potential is either initiated completely when stimulation reaches threshold, or does not fire at all, with no variation in impulse strength.

Reuptake

A mechanism of neurotransmitter termination where excess neurotransmitters are reabsorbed into the presynaptic neuron to be recycled for future use.

Enzymatic Degradation

The termination of neurotransmitter action through breakdown by specific enzymes (e.g., acetylcholine broken down by acetylcholinesterase).

Agonists

Drugs or chemicals that mimic or increase the activity of a specific neurotransmitter.

Antagonists

Drugs or chemicals that block, impede, or decrease the action of a specific neurotransmitter.

Acetylcholine (ACh)

A neurotransmitter regulating muscle action, memory, learning, and attention; associated with nicotine and increased arousal.

Dopamine

A neurotransmitter involved in mood, sleep, learning, and movement; associated with increased pleasure and appetite suppression, and targeted by cocaine and methamphetamine.

GABA (Gamma-aminobutyric acid)

A major inhibitory neurotransmitter regulating brain function, sleep, learning, and anxiety; associated with drugs like Valium and Ambien.

Serotonin

A neurotransmitter involved in mood regulation and sleep; influenced by drugs such as MDMA, LSD, and SSRIs (Prozac).

Somatic Nervous System

A sub-division of the Peripheral Nervous System under voluntary control that gathers sensory information via afferent neurons and transmits motor commands via efferent neurons.

Autonomic Nervous System

A sub-division of the Peripheral Nervous System controlling involuntary processes and basic life functions, divided into the sympathetic and parasympathetic systems.

Autonomic Nervous System Divisions

The contrasting autonomic subsystems: the Sympathetic system triggers stress responses (dilating pupils, increasing heart rate), while the Parasympathetic system restores the body to normalcy and homeostasis.

Reflex Arc

An automatic spinal cord circuit that initiates a muscle response directly through sensory neurons, interneurons, and motor neurons without needing initial processing from the brain.

Major Brain Divisions

The primary structural divisions of the brain: Forebrain, Midbrain, and Hindbrain.

Lobes of the Cerebral Cortex

The primary anatomical divisions of the cerebral cortex: Frontal Lobe (complex thinking, motor function), Parietal Lobe (sensory integration), Temporal Lobe (hearing, memory, language), and Occipital Lobe (vision).

Broca's Area

A region located in the left frontal lobe essential for speech production.

Wernicke's Area

A region situated in the temporal lobe responsible for language comprehension.

Corpus Callosum

A thick band of axon fibers connecting the left and right cerebral hemispheres, enabling interhemispheric communication.

Neuroplasticity

The ability of the nervous system to adapt and reorganize its structure through experience, development, or recovery from trauma.

Positron Emission Tomography (PET) Scan

A neuroimaging technique that tracks brain activity by monitoring the flow of an ingested or injected radioactive tracer isotope in the bloodstream.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging technique that measures brain function by tracking changes in oxygenated blood flow without requiring injections.

Electroencephalogram (EEG)

A non-invasive method measuring electrical activity and event-related potentials (ERPs) across the scalp to determine the timing and location of brain responses.