AP Psychology Quiz: Overview Of The Nervous System

What this quiz covers

This quiz focuses on Overview Of The Nervous System, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Psychology.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Carry afferent signals from receptors to the spinal cord, serving as the first neuron in the reflex pathway.
2. Transmit efferent commands from the spinal cord to skeletal muscle fibers, causing contraction and movement.
3. Integrate and relay information within the CNS, connecting sensory neurons to motor neurons during processing or reflexes. (correct answer)
4. Activate sympathetic arousal by directly increasing heart rate and inhibiting digestion through voluntary motor control.

Explanation: Interneurons are specialized neurons found exclusively within the central nervous system that serve as connectors and processors between other neurons. In reflexes and neural circuits, interneurons receive input from sensory (afferent) neurons and integrate this information before relaying appropriate signals to motor (efferent) neurons. They enable complex processing by creating networks that can modify, amplify, or inhibit signals, allowing for more sophisticated responses than simple input-output connections. In a spinal reflex, for example, an interneuron might receive pain signals from sensory neurons and quickly activate motor neurons to withdraw from danger. Interneurons don't directly carry sensory input from receptors or motor output to muscles—they work entirely within the CNS. They're distinct from autonomic neurons that control involuntary functions like heart rate.

Question 2

1. Motor (efferent) neurons, which transmit commands from the CNS to muscles and glands, carry touch signals inward.
2. Sensory (afferent) neurons, which transmit information from receptors to the CNS, carry pressure signals to the spinal cord. (correct answer)
3. Interneurons, which relay signals within the CNS, directly connect skin receptors to the spinal cord without sensory neurons.
4. Sympathetic neurons, which slow heart rate and promote digestion, carry pressure information from the skin to the brain.

Explanation: Sensory (afferent) neurons are responsible for carrying information from sensory receptors toward the central nervous system. When you feel pressure on your skin, specialized receptors detect this mechanical stimulus and generate signals that sensory neurons transmit to the spinal cord and brain for processing and interpretation. The term 'afferent' means 'toward the center,' indicating the direction of information flow from the periphery to the CNS. Motor (efferent) neurons carry commands in the opposite direction, from the CNS to muscles and glands. Interneurons are found within the CNS and relay signals between sensory and motor neurons. The sympathetic nervous system regulates arousal responses but doesn't carry sensory information from skin receptors.

Question 3

1. Reduced ability to increase heart rate quickly during stress, because sympathetic activation normally raises heart rate. (correct answer)
2. A sudden increase in heart rate during stress, because parasympathetic activation normally drives fight-or-flight responses.
3. Loss of voluntary skeletal movement, because sympathetic nerves are required to activate somatic motor neurons.
4. Inability to feel pain, because sympathetic neurons carry sensory information from receptors to the spinal cord.

Explanation: If sympathetic activity is blocked during a stressful event, the person would have reduced ability to increase heart rate quickly, since sympathetic activation normally raises heart rate as part of the fight-or-flight response. The sympathetic system prepares the body for action by increasing heart rate, breathing rate, and alertness while redirecting blood flow to muscles. Without this sympathetic response, the cardiovascular system couldn't adapt as effectively to meet the increased demands of a stressful situation. The parasympathetic system promotes calm rather than stress responses and doesn't drive fight-or-flight reactions. Sympathetic nerves regulate autonomic functions but aren't required for voluntary skeletal movement, which is controlled by the somatic system. Sympathetic neurons don't carry sensory information - that's the function of sensory neurons.

Question 4

1. The autonomic nervous system, especially sympathetic activation, which increases sweating as part of arousal responses. (correct answer)
2. The somatic nervous system, which voluntarily contracts sweat glands using skeletal muscle to produce perspiration.
3. The central nervous system alone, which directly secretes sweat onto the skin without peripheral nerve involvement.
4. Sensory (afferent) neurons, which carry information to the CNS, directly stimulate sweat glands to increase output.

Explanation: During panic responses, increased sweating is primarily controlled by the autonomic nervous system, specifically through sympathetic activation. The sympathetic branch stimulates sweat glands as part of the overall fight-or-flight response, helping to cool the body in preparation for intense physical activity and increasing arousal-related physiological changes. Sweating occurs involuntarily during emotional stress and is not under conscious control. The somatic nervous system controls voluntary skeletal muscle movements but cannot voluntarily control sweat glands, which are regulated by smooth muscle and glandular tissue. The central nervous system coordinates responses but requires peripheral autonomic pathways to activate sweat glands. Sensory neurons carry information toward the CNS but don't directly stimulate glandular secretion.

Question 5

1. Afferent (sensory) direction, carrying information from receptors toward the CNS to inform it about muscle contraction.
2. Efferent (motor) direction, carrying commands from the CNS to skeletal muscle fibers to produce contraction. (correct answer)
3. Interneuron direction, carrying signals from muscles to the spinal cord within the CNS without peripheral nerves.
4. Parasympathetic direction, carrying involuntary commands that increase heart rate and redirect blood to the biceps.

Explanation: This describes the efferent (motor) direction of neural transmission, where commands travel from the central nervous system toward muscles and glands in the periphery. When the spinal cord sends signals to contract the biceps muscle, motor neurons carry these commands away from the CNS to cause muscle contraction. The term 'efferent' means 'away from the center,' indicating the outward flow of motor commands. Afferent (sensory) signals flow in the opposite direction, carrying information from receptors toward the CNS. Interneurons remain within the CNS and don't extend to peripheral muscles. The parasympathetic system regulates involuntary functions but doesn't control voluntary skeletal muscle contractions like biceps movement.

Question 6

1. Transmission of signals between the brain and peripheral nerves, impairing sensation, movement, and many reflexes below injury level. (correct answer)
2. Production of digestive enzymes in the stomach, which is primarily controlled by voluntary somatic muscle contractions.
3. Detection of light by retinal receptors, which occurs entirely within motor neurons leaving the spinal cord.
4. Release of adrenaline from glands by sensory neurons, which bypass the CNS and act directly on target organs.

Explanation: The spinal cord serves as a crucial relay center between the brain and peripheral nerves, transmitting signals in both directions throughout the body. Damage to the spinal cord would severely disrupt this communication pathway, impairing sensation below the injury level (as sensory signals couldn't reach the brain) and movement (as motor commands couldn't reach muscles). Many reflexes would also be affected since they rely on spinal cord circuits. The spinal cord is part of the central nervous system and is essential for coordinating nervous system function throughout the body. Digestive enzyme production, visual detection, and hormone release involve different systems and pathways that may be less directly affected by spinal cord damage.

Question 7

1. Spinal cord circuits in the CNS coordinating a reflex arc, linking sensory input to motor output quickly. (correct answer)
2. The parasympathetic branch increasing heart rate and initiating voluntary leg extension during the reflex.
3. The brain's cortex exclusively, because all reflexes require conscious decision‑making before movement occurs.
4. Sensory neurons only, because motor neurons are not involved in reflexes that move skeletal muscles.

Explanation: The knee-jerk reflex is coordinated by spinal cord circuits within the central nervous system that form a reflex arc linking sensory input to motor output. When the tendon below the kneecap is tapped, sensory neurons detect the stretch and carry this information to the spinal cord, where interneurons immediately relay the signal to motor neurons that cause the quadriceps muscle to contract and extend the leg. This reflex occurs at the spinal cord level without requiring brain involvement, enabling a rapid protective response. The reflex demonstrates how the CNS can coordinate automatic responses through spinal circuits. The parasympathetic system regulates involuntary organ functions but doesn't control skeletal muscle reflexes. While the brain can influence reflexes, the basic reflex arc operates through spinal cord circuits rather than requiring cortical decision-making.

Question 8

1. Increased heart rate with reduced digestive activity, preparing the body for rapid action and energy mobilization.
2. Decreased heart rate with increased digestive activity, supporting restorative processes and nutrient processing after a meal. (correct answer)
3. Increased heart rate due to parasympathetic activation, while sympathetic activity slows breathing and stimulates digestion.
4. Voluntary slowing of heart rate by the somatic nervous system, which directly controls cardiac muscle contraction patterns.

Explanation: Parasympathetic dominance is characterized by physiological responses that promote rest, recovery, and digestion. The hallmark pattern includes decreased heart rate (bradycardia) and increased digestive activity, as the body diverts resources toward nutrient processing and energy storage. During parasympathetic activation, blood flow increases to digestive organs, salivation increases, and intestinal motility enhances to facilitate digestion. This contrasts sharply with sympathetic arousal, which increases heart rate and inhibits digestion to prepare for action. The parasympathetic system uses acetylcholine as its primary neurotransmitter, promoting these restorative functions. Neither the sympathetic nor somatic systems can produce this specific pattern—the somatic system controls voluntary skeletal muscles, not cardiac muscle or digestive organs. These involuntary responses are mediated exclusively through the autonomic nervous system.

Question 9

1. Brain and spinal cord, responsible for integrating information and coordinating responses across sensory and motor systems. (correct answer)
2. Cranial and spinal nerves, responsible for transmitting signals between the body and brain as the CNS.
3. Autonomic ganglia and endocrine glands, responsible for reflexes and voluntary movement as the central nervous system.
4. Skeletal muscles and sensory receptors, responsible for processing information and generating decisions within the CNS.

Explanation: The central nervous system (CNS) consists of the brain and spinal cord, serving as the body's main processing and integration center. The brain interprets sensory information, makes decisions, stores memories, and generates motor commands, while the spinal cord acts as a highway for signals between the brain and body while also coordinating reflexes. Together, these structures integrate incoming sensory information and coordinate appropriate motor responses. The CNS is distinct from the peripheral nervous system (PNS), which includes all nerves outside the brain and spinal cord. Cranial and spinal nerves belong to the PNS, not the CNS. The CNS processes information internally but requires the PNS to communicate with muscles, glands, and sensory receptors throughout the body.

Question 10

1. Peripheral nervous system, including nerves outside the CNS that transmit sensory input and motor output to the body. (correct answer)
2. Central nervous system, consisting of brain and spinal cord, which physically extends into the limbs as peripheral nerves.
3. Parasympathetic system, which includes the brain and spinal cord and controls all sensory and motor signaling to limbs.
4. Somatic system, which only carries signals to glands and smooth muscle, not sensory messages from the skin.

Explanation: The peripheral nervous system (PNS) encompasses all neural tissue outside the brain and spinal cord, serving as the communication network between the CNS and the rest of the body. It includes cranial nerves, spinal nerves, and ganglia that carry both sensory (afferent) signals from receptors to the CNS and motor (efferent) commands from the CNS to muscles and glands. The PNS is divided into the somatic system (voluntary muscle control) and autonomic system (involuntary organ control). The central nervous system doesn't physically extend into limbs—it remains protected within the skull and vertebral column. The parasympathetic system is only one subdivision of the autonomic nervous system, not the entire peripheral system. The somatic system specifically controls skeletal muscles and receives sensory input, contrary to option D.

Question 11

1. Afferent = motor neuron carrying commands from CNS to muscles; efferent = sensory neuron carrying input from receptors.
2. Afferent = sensory neuron carrying input to CNS; efferent = motor neuron carrying commands from CNS to muscles and glands. (correct answer)
3. Afferent = interneuron within spinal cord; efferent = sympathetic neuron increasing heart rate during fight-or-flight.
4. Afferent = parasympathetic neuron slowing heart rate; efferent = sympathetic neuron increasing digestion after eating.

Explanation: In neuroscience terminology, 'afferent' and 'efferent' describe the direction of neural signal transmission relative to the central nervous system. Afferent neurons, also called sensory neurons, carry information toward (approaching) the CNS from sensory receptors throughout the body, transmitting data about touch, temperature, pain, and other stimuli. Efferent neurons, also called motor neurons, carry commands away (exiting) from the CNS to muscles and glands, producing movement or secretion. A helpful mnemonic is that 'Afferent Arrives' at the CNS while 'Efferent Exits' from it. This directional terminology applies across both somatic and autonomic divisions of the nervous system. Interneurons work within the CNS and aren't classified as afferent or efferent, while sympathetic and parasympathetic refer to autonomic functions, not signal direction.

Question 12

1. Reflex arc: sensory (afferent) neuron to spinal cord interneuron, then motor (efferent) neuron to muscles, producing quick withdrawal. (correct answer)
2. Conscious cortical loop: motor cortex initiates movement, then sensory neurons inform the spinal cord after the hand withdraws.
3. Autonomic pathway: sympathetic preganglionic neuron activates glands, and parasympathetic neurons contract skeletal muscles to pull away.
4. Motor-first sequence: efferent neurons detect heat, relay to the spinal cord, then afferent neurons activate muscles to withdraw.

Explanation: A reflex arc represents the fastest possible neural response to potentially harmful stimuli. When touching something hot, sensory (afferent) neurons detect the heat and immediately transmit this information to the spinal cord. There, interneurons quickly relay the signal to motor (efferent) neurons, which command the muscles to contract and withdraw the hand. This entire process occurs at the spinal level without requiring conscious brain involvement, which is why the hand pulls away before you're even aware of the pain. The reflex arc demonstrates the efficiency of the nervous system in protecting the body from harm. Only after the reflex occurs does the pain signal reach the brain for conscious processing.

Question 13

1. Increased heart rate and faster breathing, with energy mobilization to skeletal muscles for rapid defensive action. (correct answer)
2. Decreased heart rate and increased intestinal activity, promoting digestion while reducing alertness during danger.
3. Voluntary contraction of the stomach and glands controlled by the somatic system to calm the body immediately.
4. Sensory neurons sending commands from the brain to the heart, directly causing the heart muscle to slow down.

Explanation: During a near-car accident, the sympathetic nervous system activates to produce a rapid 'fight-or-flight' response. This includes increased heart rate to pump more blood, faster breathing to increase oxygen intake, and mobilization of energy resources to skeletal muscles for potential emergency action. These changes prepare the body to respond quickly to dangerous situations by enhancing physical performance and alertness. The parasympathetic system would have opposite effects, slowing heart rate and promoting digestion, which would be counterproductive during an emergency. The somatic system controls voluntary movements but doesn't automatically regulate heart rate or breathing. Sensory neurons carry information toward the CNS but don't send commands to organs like the heart.

Question 14

1. Heart rate increases when frightened, reflecting autonomic (sympathetic) regulation without conscious control. (correct answer)
2. Choosing to type on a keyboard, reflecting voluntary control of skeletal muscles through the somatic system.
3. Deciding to stand up from a chair, reflecting planned voluntary movement executed by somatic motor pathways.
4. Feeling a tap on the shoulder, reflecting sensory input carried to the CNS rather than autonomic motor regulation.

Explanation: Autonomic regulation operates automatically without conscious control, managing vital functions like heart rate, breathing, digestion, and glandular secretion. When heart rate increases during fear, this represents sympathetic activation occurring involuntarily as part of the fight-or-flight response. The person doesn't consciously decide to increase their heart rate - it happens automatically through autonomic pathways. In contrast, somatic control involves voluntary, conscious decisions to move skeletal muscles, such as typing on a keyboard or standing up from a chair. Feeling a tap on the shoulder represents sensory input rather than motor regulation. The autonomic system's involuntary nature distinguishes it from the somatic system's voluntary control of skeletal muscles.

Question 15

1. Sensory (afferent) neurons transmit the touch information from receptors in the foot toward the spinal cord and brain. (correct answer)
2. Motor (efferent) neurons transmit the touch information from the foot to the CNS to generate perception.
3. Parasympathetic neurons transmit touch information to the brain while decreasing heart rate and stimulating digestion.
4. Interneurons in the PNS transmit touch information directly from the foot to the brain without sensory neurons.

Explanation: When testing sensation by touching a patient's foot, sensory (afferent) neurons carry the touch signal from receptors in the skin toward the central nervous system. These specialized neurons detect mechanical pressure and convert it into electrical signals that travel along peripheral nerves to the spinal cord and brain for processing and interpretation. The term 'afferent' means 'toward the center,' describing how sensory information flows from the periphery to the CNS. Motor (efferent) neurons carry commands in the opposite direction, from the CNS to muscles and glands. Parasympathetic neurons regulate involuntary functions like digestion but don't carry sensory information from the skin. Interneurons are found within the CNS and connect other neurons but don't extend to peripheral sensory receptors.

Question 16

1. Decreased heart rate and increased digestive activity, preparing the body for rest-and-digest after the threat has passed.
2. Increased heart rate and inhibited digestion, mobilizing energy and redirecting blood flow during fight-or-flight arousal. (correct answer)
3. Increased heart rate caused by parasympathetic activation, while sympathetic activity slows breathing and promotes salivation.
4. Voluntary skeletal muscle commands increase heart rate, because the somatic nervous system directly controls cardiac muscle.

Explanation: The sympathetic nervous system is the branch of the autonomic nervous system responsible for the 'fight-or-flight' response during threatening situations. When suddenly scared, sympathetic activation causes increased heart rate, dilated pupils, and inhibited digestion as the body mobilizes energy for potential action. Blood flow is redirected from digestive organs to skeletal muscles, and glucose is released into the bloodstream for quick energy. This contrasts with the parasympathetic system, which promotes 'rest-and-digest' functions like decreased heart rate and increased digestive activity. The sympathetic response is involuntary and occurs through the autonomic nervous system, not through voluntary somatic control. These physiological changes prepare the body to either confront danger or escape from it.

Question 17

1. Parasympathetic nervous system, which slows heart rate and stimulates digestion while sending voluntary movement commands to skeletal muscles.
2. Somatic nervous system, which transmits motor commands from the CNS to skeletal muscles for voluntary actions like walking or writing. (correct answer)
3. Central nervous system, which includes brain and spinal cord and directly innervates skeletal muscles without peripheral nerves.
4. Sympathetic nervous system, which increases heart rate and redirects blood flow while controlling precise voluntary muscle contractions.

Explanation: The somatic nervous system is the division of the peripheral nervous system responsible for voluntary movement. It carries motor commands from the central nervous system (brain and spinal cord) to skeletal muscles, enabling conscious actions like walking, writing, or reaching. The somatic system uses motor (efferent) neurons to transmit these signals directly to muscle fibers without intermediate synapses. In contrast, the autonomic nervous system (including sympathetic and parasympathetic branches) controls involuntary functions like heart rate and digestion. The central nervous system processes information but doesn't directly innervate muscles—it requires the peripheral nervous system to carry signals to target tissues.

Question 18

1. Heart rate increases to support greater oxygen delivery, consistent with sympathetic arousal and energy mobilization. (correct answer)
2. Heart rate decreases sharply, consistent with parasympathetic dominance preparing the body for deep sleep.
3. Skeletal muscles stop receiving motor commands because the autonomic system replaces the somatic system entirely.
4. Sensory neurons begin sending commands from the brain to muscles, reversing afferent and efferent directions.

Explanation: During intense exercise, sympathetic nervous system activity increases dramatically to support the body's heightened metabolic demands. Sympathetic activation causes heart rate to increase significantly, delivering more oxygen and nutrients to active skeletal muscles. This is part of the fight-or-flight response that mobilizes energy resources and enhances physical performance during periods of high demand. Other sympathetic effects during exercise include increased breathing rate, dilation of blood vessels in muscles, and release of stress hormones like adrenaline. The parasympathetic system would have opposite effects, slowing heart rate and promoting rest, which would be counterproductive during intense physical activity. The somatic system controls voluntary muscle contractions during exercise but doesn't regulate heart rate automatically.

Question 19

1. Sensory (afferent) neuron → interneuron in spinal cord → motor (efferent) neuron → skeletal muscle contracts. (correct answer)
2. Motor (efferent) neuron → sensory (afferent) neuron → interneuron in brain → skeletal muscle contracts.
3. Interneuron in spinal cord → sensory neuron → parasympathetic neuron → skeletal muscle relaxes slowly.
4. Sympathetic neuron → sensory neuron → motor neuron → gland secretion increases to withdraw the limb.

Explanation: A simple spinal reflex follows a basic pathway that allows rapid responses without brain involvement. The sequence begins when a sensory (afferent) neuron detects a painful stimulus and carries this information toward the spinal cord. Within the spinal cord, an interneuron receives the sensory input and immediately relays a signal to a motor (efferent) neuron. The motor neuron then carries commands away from the spinal cord to skeletal muscles, causing them to contract and withdraw the affected body part from the painful stimulus. This reflex arc enables protective responses to occur within milliseconds, much faster than conscious reactions that require brain processing. The reflex involves the central nervous system (spinal cord interneurons) and peripheral nervous system (sensory and motor neurons) working together.

Question 20

1. Sympathetic generally increases arousal like heart rate; parasympathetic generally decreases heart rate and supports rest-and-digest functions. (correct answer)
2. Sympathetic always decreases heart rate; parasympathetic always increases heart rate, so they are exact opposites in every organ.
3. Sympathetic controls voluntary skeletal muscles; parasympathetic controls sensory input from skin and joints to the CNS.
4. Sympathetic and parasympathetic are divisions of the CNS, while autonomic and somatic are divisions of the PNS.

Explanation: The sympathetic and parasympathetic branches of the autonomic nervous system generally have complementary and often opposing effects on organs. The sympathetic branch typically increases arousal-related functions like heart rate, breathing rate, and alertness while decreasing digestive activity during fight-or-flight responses. The parasympathetic branch generally decreases heart rate and promotes rest-and-digest functions like increased digestive activity and glandular secretion during calm periods. However, they don't always have exactly opposite effects in every organ - their relationship is more accurately described as complementary regulation that maintains homeostasis. Both branches control involuntary functions in glands and smooth muscle, not voluntary skeletal muscles (which are controlled by the somatic system). They are divisions of the autonomic system within the PNS, not the CNS.