Exercise Physiology Exam: Practice Quiz

The cerebellum is a region of the brain that is responsible for coordinating voluntary movements, balance, and posture. It receives input from the motor cortex, which is involved in planning and executing movements, as well as from the brain stem and spinal cord, which are important for relaying sensory information and controlling basic motor functions. These connections allow the cerebellum to receive and integrate information from various parts of the nervous system, enabling it to fine-tune and regulate motor activities. Therefore, the statement that the cerebellum has connections to the motor cortex, brain stem, and spinal cord is true.

Skeletal muscles are innervated by neurons in the motor division because motor neurons are responsible for transmitting signals from the central nervous system to the muscles, causing them to contract. These neurons form synapses with muscle fibers, allowing for the control and coordination of voluntary movements. Without the innervation from motor neurons, skeletal muscles would not be able to receive the necessary signals to contract and perform their functions.

The dendrites are the branch-like structures that extend from the cell body of a neuron. They receive incoming signals from other neurons or sensory receptors and transmit them to the cell body. These signals can be either excitatory or inhibitory, and they determine whether the neuron will generate an action potential or not. Therefore, the statement that dendrites are the receptive regions of the neuron is true.

The autonomic nervous system is responsible for maintaining the constancy of the body's internal environment. This is because it regulates involuntary bodily functions such as heart rate, blood pressure, digestion, and body temperature. It ensures that these functions remain within a narrow range, regardless of external factors. Therefore, the statement is true.

The statement is true. The gaps between Schwann cells along the length of a myelinated nerve fiber are called nodes of Ranvier. These nodes play a crucial role in the conduction of nerve impulses. The myelin sheath formed by Schwann cells insulates the nerve fiber, and the nodes of Ranvier allow for the rapid and efficient propagation of the electrical signal along the nerve fiber.

Afferent fibers are a type of nerve fibers that carry sensory information from receptors in the body to the central nervous system (CNS). These fibers transmit impulses, such as touch, pain, or temperature, from the sensory organs or receptors to the brain and spinal cord for processing and interpretation. This allows the CNS to receive and analyze sensory information, enabling appropriate responses and reactions. Therefore, the statement that afferent fibers transmit impulses from receptors to the CNS is true.

Acetylcholine is indeed a cholinergic neurotransmitter. It is responsible for transmitting signals across the synapses between nerve cells and plays a crucial role in the functioning of the nervous system. Acetylcholine is involved in various processes such as muscle contraction, memory, and learning. It is synthesized from choline and is found in both the central and peripheral nervous systems.

The sarcolemma is indeed the membrane of a muscle fiber. It surrounds the muscle fiber and acts as a barrier, regulating the flow of substances in and out of the cell. It is responsible for maintaining the integrity of the muscle fiber and is essential for muscle contraction and relaxation.

The statement is true because Parkinson's Disease is primarily caused by the degeneration of neurons in the basal ganglia, a region of the brain involved in motor control. This degeneration leads to a decrease in dopamine production, resulting in the characteristic symptoms of Parkinson's Disease such as tremors, stiffness, and difficulty with movement. Therefore, a disorder of the basal ganglia can indeed cause Parkinson's Disease.

The muscle spindle is a sensory receptor located within the muscle that detects changes in muscle length. It provides important information to the central nervous system about the position and movement of our muscles. When a muscle is stretched, the muscle spindle sends signals to the brain, allowing it to adjust muscle contraction and maintain balance and coordination. Therefore, it is accurate to refer to the muscle spindle as the "length detector."

The endocrine system controls the internal environment by secreting hormones that regulate various bodily functions and maintain homeostasis. Hormones are chemical messengers that travel through the bloodstream to target cells or organs, where they initiate specific responses. This system plays a crucial role in regulating metabolism, growth and development, reproduction, and response to stress. It works in coordination with the nervous system to ensure the body's internal environment remains stable and balanced.

The "All or none" law states that once a nerve impulse is initiated, it will travel the length of the neuron. This means that if a stimulus reaches the threshold level required to generate an action potential, the neuron will fire at its maximum intensity. If the stimulus does not reach the threshold level, the neuron will not fire at all. This law ensures that the transmission of signals within the nervous system is reliable and consistent.

This statement is true because sympathetic neurons, which are part of the autonomic nervous system, have short preganglionic fibers that originate in the spinal cord and long postganglionic fibers that extend to their target organs. This allows for a rapid and widespread response to stress or danger, as the sympathetic nervous system is responsible for the "fight or flight" response.

CNS consist of brain and spinal cord

The brain stem is the correct answer because it is the part of the brain that connects the brain and spinal cord. It is responsible for many vital functions such as controlling breathing, heart rate, and blood pressure. The brain stem also serves as a pathway for nerve fibers to travel between the brain and spinal cord, allowing for communication and coordination between the two. The other options, including the medulla, thalamus, hypothalamus, and none of the above, do not directly connect the brain and spinal cord.

When norepinephrine is released, it tends to excite an organ. Norepinephrine is a neurotransmitter that is involved in the "fight or flight" response of the sympathetic nervous system. It increases heart rate, blood pressure, and blood flow to muscles, preparing the body for action. Therefore, the statement is true as norepinephrine generally has an excitatory effect on organs.

During exercise, the body's metabolic rate increases, resulting in increased blood flow to the salivary glands. This increased blood flow leads to an increase in the production of saliva. Additionally, exercise stimulates the sympathetic nervous system, which can cause changes in the composition of saliva, including an increase in viscosity. Therefore, the statement that the viscosity of saliva increases with exercise is true.

Acetylcholine is the neurotransmitter that stimulates the muscle to depolarize. Depolarization is the process by which the electrical potential across the muscle cell membrane becomes more positive, leading to muscle contraction. Acetylcholine is released from the nerve endings at the neuromuscular junction and binds to receptors on the muscle cell membrane, triggering depolarization and subsequent muscle contraction.

This statement is true. A ganglion is a cluster of nerve cell bodies located outside the central nervous system. In the ganglion, the presynaptic neuron releases acetylcholine, a neurotransmitter, which then synapses with the postsynaptic neuron. This allows for the transmission of signals between neurons.

The parasympathetic division of the autonomic nervous system is responsible for rest and digest activities. It promotes salivation by increasing the volume of saliva secreted by the salivary glands and reducing its viscosity. This division activates the release of acetylcholine, which stimulates the production of watery saliva, making it less viscous. On the other hand, the sympathetic division of the ANS is responsible for the fight or flight response and does not play a role in increasing salivary gland volume or reducing viscosity.

The vestibular apparatus is located in the inner ear. This is the part of the ear that is responsible for maintaining balance and spatial orientation. It consists of the semicircular canals and the otolith organs, which detect changes in head position and movement. The inner ear also contains the cochlea, which is responsible for hearing.

Multiple Sclerosis is a neurological disease that causes the destruction of the myelin sheath, which is the protective covering of nerve fibers in the central nervous system. This destruction disrupts the normal flow of electrical impulses along the nerves, leading to a wide range of symptoms such as muscle weakness, fatigue, and problems with coordination and balance. Parkinson's disease, Huntington's disease, and epilepsy do not directly involve the destruction of the myelin sheath.

The sarcoplasmic reticulum is a specialized organelle found in muscle cells that plays a crucial role in muscle contraction. It is responsible for storing and releasing calcium ions (Ca2+), which are necessary for the initiation and regulation of muscle contraction. When a muscle is stimulated to contract, calcium ions are released from the sarcoplasmic reticulum into the muscle fibers, allowing the actin and myosin filaments to interact and generate force. Therefore, the correct answer is calcium (Ca2+).

Acetylcholine is a neurotransmitter that is commonly secreted by presynaptic neurons. It is involved in various functions such as muscle movement, memory, and learning. While there are other neurotransmitters that can be secreted by presynaptic neurons, such as dopamine or serotonin, acetylcholine is one of the most widely distributed and commonly found neurotransmitters in the nervous system. Therefore, the statement that presynaptic neurons always secrete acetylcholine is true.

Post-ganglionic fibers of the autonomic nervous system are indeed non-myelinated. Myelin is a fatty substance that wraps around nerve fibers, providing insulation and increasing the speed of electrical signal transmission. However, in the autonomic nervous system, the post-ganglionic fibers do not have myelin sheaths. This lack of myelination allows for slower conduction of signals, which is important for the fine-tuning and regulation of involuntary bodily functions controlled by the autonomic nervous system.

During an action potential, the inside of the axon becomes more positive due to an influx of sodium. This occurs when the neuron reaches its threshold and voltage-gated sodium channels open, allowing sodium ions to rush into the axon. This influx of positive ions depolarizes the membrane, creating an electrical signal that travels along the axon.

Glands are not innervated by the somatic motor system. The somatic motor system controls voluntary movements of skeletal muscles, while the autonomic nervous system controls involuntary functions such as the activity of glands. Therefore, the correct answer is false.

The sympathetic system causes an increase in glucose uptake for energy utilization. This is because the sympathetic system is responsible for the "fight or flight" response, which prepares the body for action. During this response, the sympathetic system increases heart rate, dilates blood vessels, and stimulates the release of glucose from storage sites in the body. This glucose is then taken up by cells for energy utilization, allowing the body to respond effectively to perceived threats or challenges.

Free nerve endings are the proprioceptors that are sensitive to touch and pressure. These nerve endings are found throughout the body and are responsible for detecting and transmitting information about mechanical stimuli such as pressure, vibration, and touch. They are particularly abundant in the skin and mucous membranes, allowing us to sense and respond to external stimuli. Free nerve endings play a crucial role in our ability to perceive and interpret tactile sensations.

This statement is false. The muscle spindle is a sensory receptor located within the muscle that detects changes in muscle length and triggers a reflex contraction of the muscle, not relaxation. On the other hand, the Golgi tendon organ is a sensory receptor located in the tendon that detects tension or force applied to the muscle and triggers a reflex relaxation of the muscle, not contraction. Therefore, the muscle spindle causes muscle contraction while the Golgi tendon causes muscle relaxation.

Somatic motor neurons primarily innervate skeletal muscles, not glandular tissue. Glandular tissue is controlled by autonomic motor neurons, specifically the sympathetic and parasympathetic divisions of the autonomic nervous system. Therefore, the statement that somatic motor neurons also innervate glandular tissue is false.

Muscle chemoreceptors are sensory receptors located in the muscles that detect changes in the chemical composition of the muscle tissue. When muscles are active, they produce metabolic byproducts such as lactic acid and carbon dioxide. Muscle chemoreceptors sense these changes and send information back to the central nervous system (CNS) about the metabolic rate of muscular activity. This information allows the CNS to regulate and adjust the body's response to the level of muscle activity, such as adjusting heart rate and respiration.

During reciprocal inhibition, both excitatory and inhibitory activities occur simultaneously. This means that while certain neurons are being stimulated and excited, others are being inhibited and prevented from firing. This process allows for the regulation and coordination of muscle movements. By inhibiting certain muscles while exciting others, reciprocal inhibition helps to ensure smooth and coordinated movements.

The M line does not separate each sarcomere. Instead, it runs through the center of the sarcomere and connects the myosin filaments. The Z line is the structure that separates each sarcomere, marking the boundaries between them. Therefore, the statement is false.

When Ca2+ channels open in the axons, it allows calcium ions to enter the axon. This influx of calcium ions triggers the release of AcH (acetylcholine) from the synaptic vesicles. Acetylcholine is a neurotransmitter that plays a crucial role in transmitting signals between neurons and muscle cells. Therefore, the opening of Ca2+ channels in the axons leads to the release of AcH from the synaptic vesicles.

The sympathetic division of the autonomic nervous system is responsible for the fight-or-flight response, which involves the dilation of the pupils to allow more light to enter the eyes and improve vision. Therefore, the correct answer is false, as the sympathetic division does not cause pupil constriction.

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Type IIa muscle fibers are known as intermediate fibers and have a combination of characteristics of both fast-twitch (anaerobic) and slow-twitch (aerobic) muscle fibers. These muscle fibers can generate energy through both aerobic and anaerobic processes, depending on the intensity and duration of the exercise. This combination allows them to be more versatile and adapt to different types of physical activities, making them suitable for activities that require both endurance and power.

The myelin sheath in the peripheral nervous system is not formed by oligodendrocytes, but by a different type of glial cell called Schwann cells. Oligodendrocytes are responsible for forming the myelin sheath in the central nervous system.

The statement is false because sympathetic neurons are actually found in the thoracic and lumbar spinal cord, while parasympathetic neurons are found in the brain and sacral spinal cord.

The sodium-potassium pump is an active transport mechanism found in cell membranes. It utilizes ATP to pump 2 potassium ions (K+) into the cell and 3 sodium ions (Na+) out of the cell. This process helps maintain the electrochemical gradient across the cell membrane and is essential for various cellular functions, such as nerve impulse transmission and maintaining proper cell volume.

The correct answer is 40 to 50. This means that approximately 40 to 50 percent of the total weight of the human body is made up of skeletal muscles. These muscles are responsible for movement, posture, and stability, and they play a crucial role in the body's overall function and structure.

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The synapse of a neuron is where the preganglionic fiber transmits neurotransmitters to the postganglionic fiber. (depolarization)

Inhibitory post-synaptic potential (IPSP) causes hyperpolarization. When an IPSP occurs, the post-synaptic neuron becomes more negative, making it less likely to generate an action potential. This is because IPSPs increase the permeability of the post-synaptic membrane to negatively charged ions (e.g., chloride ions), making the inside of the neuron more negative. As a result, the membrane potential moves further away from the threshold required for an action potential to occur, leading to hyperpolarization.

The basal ganglia do not produce fast, ballistic movement. They are involved in the planning and initiation of movement, but the execution of movement is primarily controlled by the motor cortex. Therefore, the statement is false.

The brain stem is responsible for cardiorespiratory control. It controls vital functions such as heart rate, blood pressure, and breathing. It contains various nuclei that regulate these functions, including the medulla oblongata and the pons. The brain stem receives input from higher brain regions and sends signals to the heart, lungs, and blood vessels to maintain homeostasis.

The axon hillock is the structure in the neuron that generates the action potential. It is located at the junction between the cell body and the axon. The axon hillock contains a high concentration of voltage-gated ion channels, which are responsible for initiating and propagating the electrical signal known as the action potential. These ion channels open in response to changes in the membrane potential, allowing ions to flow in and out of the cell, which generates the electrical impulse that travels down the axon.

Spatial summation is summing from several different presynaptic neurons

The band that represents myosin and actin is band A.