AP Psychology Unit 1 Review: Biological Bases of Behavior and Sensation

Comprehensive practice flashcards for AP Psychology Unit 1, covering biological bases of behavior, neural communication, brain structures, sleep and consciousness, drugs, and sensory systems.

Based on this organizational chart, how is the human nervous system divided hierarchically?

The nervous system divides into the Central Nervous System (Brain and Spinal Cord) and the Peripheral Nervous System, which further divides into the Somatic and Autonomic systems (comprising Sympathetic and Parasympathetic branches).

What is the function of dendrites on a neuron?

To receive incoming neurotransmitters and electrical signals from the axon terminals of other neurons.

Identify the basic structures of a neuron shown in this diagram.

The dendrites (branch-like receiving structures), soma/cell body (containing the nucleus), axon (conduction pathway), myelin sheath (insulating glial coating), and axon terminals (neurotransmitter release site).

What characterizes the resting potential of a neuron?

The neuron is polarized with an overall negative internal charge, maintaining more sodium ions outside the cell and more potassium ions inside.

What event triggers an action potential in a neuron?

Sodium ions flood into the neuron after the neural threshold is surpassed, depolarizing the neuron and sending an electrical charge down the axon.

What is the refractory period of a neuron?

The repolarization phase where sodium ions leave the cell; the neuron is recharging and cannot fire again until it completes this process.

What is the all-or-nothing principle in neural firing?

A neuron either fires completely with a full action potential or does not fire at all; it cannot fire partially or with varying strength.

What is neural reuptake?

The process by which the transmitting presynaptic neuron reabsorbs excess neurotransmitters left in the synaptic cleft after the postsynaptic neuron reaches capacity.

How do Multiple Sclerosis and Myasthenia Gravis differ in terms of their pathology?

Multiple Sclerosis attacks the CNS myelin sheath, decreasing nerve transmission speed, whereas Myasthenia Gravis attacks voluntary muscle control receptors, resulting directly in muscle weakness.

What is the pathway of signals in the reflex arc illustrated here?

Sensory (afferent) nerves carry input from the skin to interneurons in the spinal cord, which immediately send motor signals through efferent nerves back to the muscle without prior brain processing.

According to this diagram, how do agonist drugs differ from antagonist drugs?

Agonist drugs bind to receptors and stimulate them to enhance cellular activity, whereas antagonist drugs bind to receptors to block normal neurotransmitters and prevent cellular activity.

What is the mechanism of action of Selective Serotonin Reuptake Inhibitors (SSRIs)?

SSRIs inhibit the serotonin transporter on the presynaptic axon terminal, allowing an increased amount of serotonin to remain in the synaptic cleft and stimulate postsynaptic receptors longer.

What disorders are linked to a surplus and deficit of Acetylcholine (ACH)?

A surplus can cause muscle spasms, whereas a deficit is linked to Alzheimer's disease.

What disorders are associated with imbalances of Dopamine?

A surplus is associated with schizophrenia and drug addiction, while a deficit is linked to Parkinson's disease.

What is the primary function of GABA and what problems arise from its deficit?

It acts as the brain's main inhibitory neurotransmitter and regulates sleep-wake cycles; a deficit is associated with anxiety, epilepsy, insomnia, and Huntington's disease.

What is the role of Glutamate, and what can happen when there is a surplus?

It is the brain's main excitatory neurotransmitter; an excess causes overstimulation of the brain, leading to migraines and seizures.

What are the roles of Endorphins and Substance P in pain perception?

Endorphins are inhibitory neurotransmitters that control and relieve pain, whereas Substance P is an excitatory neurotransmitter that creates pain signals.

Identify the primary glands and controlling structures of the endocrine system shown in this anatomical diagram.

The hypothalamus, pituitary gland, thyroid gland, parathyroids, adrenal glands, pancreas, and gonads (ovaries in females, testes in males).

How do leptin and ghrelin differ in their regulation of hunger?

Leptin is involved in turning off hunger (satiety), whereas ghrelin is involved in turning on hunger.

Identify the labeled structures of the brainstem and adjacent region shown in this diagram.

Thalamus (at the top), midbrain, pons, reticular formation, medulla, and spinal cord.

What is the primary function of the thalamus?

It acts as the sensory switchboard of the brain, routing incoming sensory signals to the appropriate sensory cortex, with the exception of olfaction.

What are the primary functions of the amygdala, hippocampus, and hypothalamus in the limbic system?

The amygdala controls emotions (specifically fear and aggression), the hippocampus processes memory, and the hypothalamus regulates bodily drives (hunger, sex, thirst) and the endocrine system.

Identify the four main lobes and specialized strips shown on this diagram of the cerebral cortex.

The frontal lobe (with primary motor cortex), parietal lobe (with somatosensory cortex), occipital lobe, temporal lobe, and cerebellum.

What are association areas in the cerebral cortex?

Regions not directly involved in primary motor or sensory functions that connect, interpret, and integrate sensory information and link it with stored memories.

How do Broca's aphasia and Wernicke's aphasia differ?

Broca's aphasia (left frontal lobe damage) impairs the ability to produce fluent speech, while Wernicke's aphasia (left temporal lobe damage) impairs speech comprehension.

What functions are typically lateralized to the left hemisphere versus the right hemisphere?

The left hemisphere controls the right side of the body, language production/speech, math, and logic; the right hemisphere controls the left side of the body, non-literal thinking, spatial awareness, and facial recognition.

What phenomenon in split-brain patients is demonstrated in this visual experiment?

Because the corpus callosum is cut, words shown in the right visual field reach the left (verbal) hemisphere and can be spoken, whereas words shown in the left visual field reach the right hemisphere and cannot be spoken, but can be drawn with the left hand.

What is the difference between structural plasticity and functional plasticity in the brain?

Structural plasticity refers to physical changes in brain structure due to learning or experiences; functional plasticity refers to the brain shifting functions from damaged areas to undamaged areas.

How do MRI and fMRI brain imaging techniques differ in purpose and output?

An MRI captures high-resolution still snapshots of anatomical structure, whereas an fMRI produces dynamic, color-coded maps showing brain activity by measuring blood flow changes.

How does light influence the circadian rhythm pathway illustrated in this diagram?

Light inhibits the suprachiasmatic nucleus (SCN), which signals the pineal gland via the superior cervical ganglion to stop melatonin secretion, while darkness stimulates melatonin release.

Based on this hypnogram of sleep cycles, how do N-REM and REM durations shift across an $8$-hour night?

Deep N-REM (stages $3\text{--}4$) dominates earlier sleep cycles and disappears later, while REM episodes increase in duration and frequency toward the end of the night.

Why is REM sleep referred to as paradoxical sleep?

Because the brain produces active EEG brain waves similar to wakefulness, yet the voluntary muscles of the body are deeply relaxed and paralyzed.

What is REM rebound?

The tendency for REM sleep to increase in both frequency and duration following a period of sleep deprivation.

What symptoms define narcolepsy?

Uncontrollable 'sleep-attacks' where a person collapses directly into REM sleep, often accompanied by cataplexy (temporary paralysis) and hallucinations, typically triggered by emotional excitement.

How does chemical tolerance develop in addiction?

Continued use of a substance causes the brain to adapt (e.g., reducing endogenous neurotransmitter production to maintain homeostasis), leading to reduced effects and requiring higher doses to achieve the same result.

What is the difference between an absolute threshold and a difference threshold?

The absolute threshold is the lowest intensity of a stimulus detectable $50\%$ of the time, whereas the difference threshold (just noticeable difference) is the smallest detectable difference between two stimuli.

What is the core principle of the Weber-Fechner law?

Perceived intensity of a stimulus grows at a slower rate than the actual physical increase in stimulus intensity.

What is sensory adaptation?

The diminishing responsiveness of sensory receptors following prolonged, unchanging exposure to a specific stimulus.

What is the cocktail party effect?

The ability to selectively focus auditory attention on a single conversation while filtering out background noise and other conversations.

What is synesthesia?

A neurological condition where stimulation of one sensory pathway leads to involuntary, simultaneous experiences in another unrelated sense (such as hearing colors or tasting sounds).

What is sensory transduction?

The process by which sensory organs convert physical stimulus energies (light, sound, chemicals) into electrical neural impulses the brain can interpret.

Identify the key optical and neural structures of the eye shown in this diagram.

Cornea, pupil, iris, lens, retina, fovea, and optic nerve.

What anatomical change occurs during visual accommodation for near vision?

Ciliary muscles contract and ligaments relax, allowing the crystalline lens to become thicker and more rounded.

How do rods and cones differ in function and retinal distribution?

Rods are highly sensitive to low light, lack color sensitivity, and reside in the peripheral retina; cones process sharp details and color in bright light and reside primarily in the central retina (fovea).

What are the three cone types recognized by the Young-Helmholtz trichromatic theory?

S-cones (sensitive to blue), M-cones (sensitive to green), and L-cones (sensitive to red).

According to this diagram, what are the three paired opponent systems in Opponent-Process Theory?

The achromatic black-white system, and the chromatic red-green and blue-yellow systems.

What is prosopagnosia?

A cognitive condition ('face blindness') where the ability to recognize familiar faces, including one's own face, is impaired despite intact basic visual processing.

Identify the primary auditory structures of the human ear depicted in this diagram.

Pinna, external auditory canal, tympanic membrane (eardrum), ossicles (malleus, incus, stapes), cochlea, and auditory nerve.

How do Place Theory and Frequency Theory explain pitch perception?

Place Theory posits that different sound frequencies trigger vibrations at specific places along the cochlea's basilar membrane (explaining high pitches); Frequency Theory posits the entire membrane vibrates at the exact frequency of the sound (explaining low pitches).

What is the volley principle in hearing?

A principle stating that auditory neurons alternate firing in rapid succession to process pitches that exceed the firing rate capacity of an individual neuron.

What is the primary difference between sensorineural and conductive hearing loss?

Sensorineural hearing loss stems from damage to inner ear hair cells, the cochlea, or the auditory nerve, whereas conductive hearing loss stems from mechanical blockage or physical damage to outer or middle ear structures.

What makes the olfactory system anatomically unique among human sensory pathways?

Olfactory signals travel directly from olfactory receptor cells and the olfactory bulb to the cortex and limbic system without routing through the thalamus.

What are the five basic taste qualities detected by gustatory receptors?

Sweet, salty, sour, bitter, and umami (savory/meaty).

According to the gate control theory model shown here, how does mechanical stimulation decrease pain transmission?

Non-painful mechanical signals sent via large $A\text{-}\beta$ fibers activate an inhibitory interneuron, which inhibits the projection neuron and blocks incoming pain impulses from C fibers.

What sensory receptors contribute to the kinesthetic sense?

Muscle spindles, Golgi tendon organs, joint receptors, and cutaneous receptors that signal movement and position of specific body parts.

Identify the inner ear structures of the vestibular system shown in this diagram.

The semi-circular canals and otoliths (within the vestibule), which detect head rotation, gravity, and maintain bodily balance.