Unit 3 (Humn Genetics, Cells of the Nervous System, Parts of the Nervous System, The Brain and Spinal Cord, The Endocrine System)

Flashcards for review of key vocabulary and concepts.

All-or-None Law

An action potential either fires completely or not at all, without partial firing. Similar to a gun trigger or a toilet flush

Left Hemisphere Functions

Handles logic, language, and math, especially in right-handed individuals.

Right Hemisphere Functions

Deals with spatial skills, facial recognition, and aesthetic perception.

Inhibitory Messages

Reduce the likelihood that a neuron will fire by hyperpolarizing the membrane.

Thalamus

Relay station for sensory information (except smell), directing it to appropriate brain areas.

Myelin Sheath

Fatty layer that insulates axons, speeding up the transmission of electrical impulses.

Neuroplasticity

Brain's ability to adapt by forming new neurons, connections, or reorganizing areas for different functions across the lifespan.

Central and Peripheral Nervous System (CNS)

Includes the brain and spinal cord. The peripheral nervous system (PNS) connects the CNS to the rest of the body.

Peripheral Nervous System (PNS)

Connects the CNS to the rest of the body.

Parasympathetic Nervous System

Calms the body after stress, restoring rest and digestion functions.

Somatic Nervous System

Controls voluntary movements and transmits sensory info to the CNS, like moving muscles or feeling touch.

Hypothalamus

Regulates vital behaviors such as eating, drinking, body temperature, and sexual activity; maintains homeostasis.

Split-Brain Patients

Individuals with a severed corpus callosum show differences in how each brain hemisphere processes information.

Lateralization

Certain brain functions are more dominant in one hemisphere than the other (e.g., language is usually left-lateralized).

Nervous & Endocrine System Relationship

They influence each other; the hypothalamus links them, coordinating hormonal and neural responses.

Hippocampus

Essential for forming new long-term memories; damage here causes anterograde amnesia.

Action Potential Polarity Shift

During action potential, the neuron's interior becomes positive, switching from resting negative charge.

Somatic Nervous System - Conscious Control

Handles activities like moving your arm or reacting to touch—actions you're aware of.

Fight-or-flight & PNS

Reactions to danger involve motor responses (somatic system) and arousal (autonomic system-specifically sympathetic).

Cerebral Cortex Functions

Involved in reasoning, memory, and emotion; breathing is controlled by the brainstem, not the cortex.

EEG (Electroencephalography)

Brain imaging technique records electrical activity via scalp electrodes, useful in diagnosing epilepsy and some learning disorders; monitors real-time function