Nervous System, Sensation, and Perception Review

Comprehensive vocabulary flashcards covering nerve cells, brain anatomy, sensory thresholds, vision, audition, chemical senses, and perceptual organization based on lecture materials.

Neurons

Cells responsible for receiving and sending messages, comprised of a nucleus, soma, dendrites, an axon, axon terminals, a semipermeable membrane, and a protective myelin sheath.

Astrocytes

Glial cells that synchronize axons, remove waste, and control blood flow.

Microglia

Glial cells that act as an immune system against pathogens.

Oligodendrocytes

Glial cells that build myelin in the Central Nervous System.

Schwann cells

Glial cells that build and repair myelin in the Peripheral Nervous System.

Radial glia

Glial cells that guide neuronal migration during early development.

Resting Potential

The state of a neuron at rest where it maintains a negative charge of $-70\,mV$ relative to the outside.

Sodium-potassium pump

A mechanism that maintains the ionic gradient by pumping $3\,Na^+$ out for every $2\,K^+$ in.

Saltatory Conduction

The process in myelinated axons where the neural impulse jumps from one unmyelinated section, known as a node of Ranvier, to the next.

Excitatory Postsynaptic Potential (EPSP)

A graded depolarization that makes the firing of a neuron more likely.

Inhibitory Postsynaptic Potential (IPSP)

A hyperpolarization that acts as a brake, making neuronal firing less likely.

Agonists

External drugs that act by mimicking or enhancing the effects of neurotransmitters.

Antagonists

External drugs that act by blocking the effects of neurotransmitters.

Somatic Nervous System

A division of the Peripheral Nervous System that controls voluntary muscles through afferent and efferent pathways.

Autonomic Nervous System (ANS)

A division of the Peripheral Nervous System that controls involuntary functions of organs and glands, split into sympathetic and parasympathetic divisions.

Medulla

A hindbrain structure responsible for life-sustaining functions like breathing.

Cerebellum

A hindbrain structure involved in balance, coordination, and learned motor skills.

Thalamus

A forebrain structure that serves as a sensory relay station.

Hippocampus

A limbic system structure involved in long-term declarative memory.

Amygdala

A limbic system structure responsible for fear responses.

Corpus callosum

The structure that connects the two hemispheres of the cerebrum.

Parietal Lobe

The brain lobe housing the somatosensory cortex for touch, temperature, and body position.

Transduction

The transformation of physical outside stimuli into neural activity.

Absolute threshold

The lowest level of stimulation a person can consciously detect $50\%$ of the time.

Just Noticeable Difference (jnd)

The smallest difference between two stimuli that is detectable $50\%$ of the time.

Habituation

The brain's tendency to stop attending to constant, unchanging information while the receptors continue to fire.

Sensory Adaptation

Process where sensory receptor cells become less responsive and stop sending signals to an unchanging stimulus.

Rods

Photoreceptors in the retina responsible for non-color and low-light vision, concentrated in the periphery.

Cones

Photoreceptors in the retina responsible for sharp color vision, concentrated in the fovea.

Trichromatic Theory

The theory proposing three types of cones (red, blue, green) whose ratio of firing determines color perception.

Opponent-Process Theory

The theory proposing visual neurons are stimulated by one color and inhibited by another in pairs: Red-Green and Blue-Yellow.

Organ of Corti

Structure inside the cochlea that contains hair cells which trigger transduction for hearing.

Place Theory

Pitch perception theory stating pitch depends on the specific location stimulated on the Organ of Corti; best for frequencies over $1000\,Hz$.

Volley Principle

Pitch perception theory stating neurons take turns firing in a volley pattern; best for frequencies between $400\,Hz$ and $4000\,Hz$.

Umami

A basic taste describing a brothy flavor generated by glutamate.

Gate-Control Theory of Pain

Proposes that pain signals must pass through a spinal cord gate that can be closed by non-pain competing signals or endorphins.

Kinesthetic Sense

Awareness of body movement and the locations of body parts in space in relation to each other using receptors in muscles, tendons, and joints.

Vestibular Senses

The sense of balance, position, and head movement in relation to gravity, relying on structures in the inner ear.

Perceptual Constancy

The tendency to perceive objects as stable in size, shape, and brightness despite physical changes on the retina.

Top-Down Processing

A perceptual method using preexisting knowledge to organize features into a unified whole.

Bottom-Up Processing

A perceptual method of analyzing small features step-by-step to build up a complete perception.