1.
Which does not belong to the peripneral nervous system?
Correct Answer
C. Spinal cord
Explanation
The spinal cord does not belong to the peripheral nervous system. The peripheral nervous system consists of nerves and ganglia that are located outside of the brain and spinal cord. The spinal cord, on the other hand, is a part of the central nervous system, along with the brain. It is responsible for transmitting signals between the brain and the rest of the body.
2.
The afferent division of the nervous system is also known as the ___________ division.
Correct Answer
E. Sensory
Explanation
The afferent division of the nervous system is responsible for carrying sensory information from the body to the central nervous system. This includes information such as touch, temperature, pain, and proprioception. Therefore, the correct answer is sensory.
3.
The portion of the nervous system that conducts impulses from the skin, joints, skeletal muscles, and special senses is the _________ division.
Correct Answer
B. Somatic sensory
Explanation
The somatic sensory division of the nervous system is responsible for conducting impulses from the skin, joints, skeletal muscles, and special senses. This division is involved in processing sensory information from these areas and relaying it to the brain for interpretation and response. It allows us to feel sensations such as touch, temperature, pain, and proprioception, which is the sense of body position and movement.
4.
Which two distinct cell types form nervous tissue?
Correct Answer
C. Glial cells and neurons
Explanation
Glial cells and neurons are the two distinct cell types that form nervous tissue. Glial cells provide support and protection to neurons, while neurons are responsible for transmitting electrical signals in the nervous system. Together, they work in coordination to ensure proper functioning of the nervous system.
5.
The neurons that are responsible for integrating information by retrieving, processing, storing, and "deciding" how the body responds to stimuli are
Correct Answer
E. Interneurons
Explanation
Interneurons are responsible for integrating information by retrieving, processing, storing, and deciding how the body responds to stimuli. They act as a bridge between sensory neurons and motor neurons, transmitting signals between them. Unlike sensory neurons that detect stimuli and motor neurons that carry out responses, interneurons are involved in complex processes of information processing and decision-making within the nervous system. They play a crucial role in coordinating and integrating signals to produce appropriate responses to external stimuli.
6.
The most abundant glial cell in CNS is the
Correct Answer
A. Astrocyte
Explanation
Astrocytes are the most abundant glial cells in the central nervous system (CNS). They play a crucial role in supporting and maintaining the neurons. Astrocytes provide structural support, regulate the extracellular environment, and contribute to the blood-brain barrier. They also play a role in neurotransmitter regulation and synaptic function. Astrocytes are involved in various physiological processes, including energy metabolism, ion homeostasis, and neuroprotection. Therefore, astrocytes are the correct answer as they are the most abundant glial cells in the CNS and have multiple essential functions.
7.
The glial cell that helps to form cerebrospinal fluid is the
Correct Answer
B. Ependymal cell
Explanation
Ependymal cells are the glial cells that help to form cerebrospinal fluid. These cells line the ventricles of the brain and the central canal of the spinal cord, and they are responsible for producing and regulating the flow of cerebrospinal fluid. This fluid provides cushioning and support to the brain and spinal cord, as well as helps to remove waste products and deliver nutrients to these structures. Therefore, ependymal cells play a crucial role in maintaining the overall health and function of the central nervous system.
8.
The glial cell that myelinates and insulates axons within the CNS is the
Correct Answer
E. Oligodendrocyte
Explanation
Oligodendrocytes are glial cells that myelinate and insulate axons within the central nervous system (CNS). They form the myelin sheath, which is a fatty substance that wraps around the axons, increasing the speed and efficiency of nerve impulse transmission. Unlike neurolemmocytes (Schwann cells), which myelinate axons in the peripheral nervous system (PNS), oligodendrocytes are responsible for myelination in the CNS. Astrocytes provide support and nourishment to neurons, ependymal cells line the ventricles of the brain and spinal cord, and microglial cells are involved in immune defense in the CNS.
9.
The glial cell that helps to form the blood-brain barrier is the
Correct Answer
A. Astrocyte
Explanation
Astrocytes are a type of glial cell that play a crucial role in forming and maintaining the blood-brain barrier. They have specialized structures called endfeet that wrap around blood vessels in the brain, creating a physical barrier that prevents substances from freely entering or leaving the brain. Astrocytes also regulate the transport of nutrients and waste products between the blood and brain tissue, providing support and protection to the neurons. Therefore, astrocytes are the correct answer as they actively contribute to the formation of the blood-brain barrier.
10.
The portion of the nervous system that has voluntary control over skeletal muscles is the _________ division.
Correct Answer
C. Somatic motor
Explanation
The somatic motor division of the nervous system is responsible for voluntary control over skeletal muscles. This division sends signals from the brain and spinal cord to the skeletal muscles, allowing us to consciously control our movements. Unlike the autonomic motor division, which controls involuntary actions such as heartbeat and digestion, the somatic motor division allows us to move our muscles at will. Therefore, the correct answer is somatic motor.
11.
The neuron conducting an impulse from the stomach wall to the CNS would be classified as a(n) _________ neuron.
Correct Answer
D. Visceral sensory
Explanation
The neuron conducting an impulse from the stomach wall to the CNS would be classified as a visceral sensory neuron. Visceral sensory neurons are responsible for transmitting sensory information from the internal organs to the central nervous system. In this case, the impulse from the stomach wall would be sensed by the visceral sensory neuron and transmitted to the CNS for processing and interpretation.
12.
The glial cell that defends the body against pathogens is the
Correct Answer
D. Microglial Cell
Explanation
Microglial cells are a type of glial cell that defends the body against pathogens. They are the immune cells of the central nervous system and play a crucial role in the brain's immune response. When pathogens or foreign substances are detected, microglial cells become activated and release inflammatory molecules to eliminate the threat. They also help in clearing cellular debris and damaged neurons. Therefore, microglial cells are responsible for the defense against pathogens in the body.
13.
A nerve
Correct Answer
E. Is a cablelike bundle of parallel axons
Explanation
A nerve is a cablelike bundle of parallel axons. This means that it consists of multiple axons that are running parallel to each other, similar to the cables in a cable bundle. Nerves are found throughout the body, both in the central nervous system (CNS) and the peripheral nervous system (PNS). They can carry both sensory and motor information, meaning they transmit signals from both the sensory organs to the CNS and from the CNS to the muscles and glands. Therefore, the statement that a nerve carries only sensory information or is found only in the CNS is incorrect.
14.
What do all glial cells have in common?
Correct Answer
C. They assist neurons in their respective functions
Explanation
All glial cells have in common that they assist neurons in their respective functions. Glial cells are a type of non-neuronal cells that provide support and protection to neurons in the nervous system. They help in regulating the extracellular environment, providing structural support, insulating neurons, and assisting in the transmission of nerve signals.
15.
The glossy-white apperance of most axons is due to
Correct Answer
A. The high lipid content of the myelin sheath
Explanation
The glossy-white appearance of most axons is due to the high lipid content of the myelin sheath. Lipids are a type of fat that make up the myelin sheath, which is a protective covering around the axons. The high lipid content gives the myelin sheath a glossy appearance, resulting in the glossy-white appearance of the axons.
16.
The condition is a disorder of the peripheral nervous system characterized by muscle weakness that begins in the distal limbs, but rapidly advances to involve proximal muscles as well.
Correct Answer
A. Guillani-Barre syndrome
Explanation
Guillain-Barre syndrome is the correct answer because it is a disorder of the peripheral nervous system that is characterized by muscle weakness starting in the distal limbs and progressing to involve proximal muscles. Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis do not match the given description.
17.
The upper motor neurons that control skeletal muscles begin with a soma in
Correct Answer
E. The precentral gyrus of the cerebrum
Explanation
The correct answer is the precentral gyrus of the cerebrum. The precentral gyrus, also known as the primary motor cortex, is responsible for initiating voluntary movements. It sends signals to the lower motor neurons in the spinal cord, which then transmit the signals to the skeletal muscles to produce movement. The other options mentioned, such as the posterior horn of the spinal cord, the anterior horn of the spinal cord, the motor association cortex of the cerebrum, and the postcentral gyrus of the cerebrum, are not directly involved in the initiation of voluntary movements.
18.
Many upper motor neurons synapse with lower motor neurons in
Correct Answer
B. The anterior horns
Explanation
The correct answer is the anterior horns. The anterior horns of the spinal cord contain the cell bodies of lower motor neurons. Upper motor neurons from the brain synapse with these lower motor neurons in the anterior horns, allowing for the transmission of signals from the brain to the muscles. This connection is essential for motor control and movement.
19.
Cerebrospinal fluid fills in the space between
Correct Answer
B. Dural sheath and veterbral bones
Explanation
Cerebrospinal fluid fills in the space between the dural sheath and vertebral bones. The dural sheath is a tough, fibrous membrane that surrounds the spinal cord and provides protection. The vertebral bones form the bony canal that houses the spinal cord. The space between the dural sheath and vertebral bones is known as the epidural space, and it contains cerebrospinal fluid. This fluid acts as a cushion, providing further protection to the spinal cord from any external forces or trauma.
20.
A ganglion is a
Correct Answer
C. Cluster of neurosomas in the PNS
Explanation
A ganglion is a cluster of neurosomas in the PNS. Neurosomas are the cell bodies of neurons, and ganglia are collections of these cell bodies. Ganglia are found outside of the central nervous system (CNS) and are responsible for coordinating and regulating the activities of peripheral nerves. They play a role in sensory processing, motor control, and autonomic functions.
21.
There are ____ pairs of spinal nerves.
Correct Answer
C. 31
Explanation
The spinal cord is divided into different segments, and each segment gives rise to a pair of spinal nerves. There are a total of 31 segments in the spinal cord, which means there are 31 pairs of spinal nerves. Therefore, the correct answer is 31.
22.
The cardiac, vasomotor and repiratory centers are found in
Correct Answer
A. The medulla oblongata
Explanation
The cardiac, vasomotor, and respiratory centers are responsible for regulating heart rate, blood pressure, and breathing respectively. These centers are located in the medulla oblongata, which is the lower part of the brainstem. It controls vital functions and connects the spinal cord to the higher brain structures. The medulla oblongata plays a crucial role in maintaining homeostasis and coordinating involuntary actions necessary for survival.
23.
Which of the following contains the nucleus?
Correct Answer
C. Cell body
Explanation
The cell body contains the nucleus. The nucleus is the control center of the cell and contains the genetic material, DNA, which regulates the cell's activities. The axon and dendrites are extensions of the cell body that transmit signals to and from other cells. Therefore, the correct answer is the cell body.
24.
Which part of a neuron carries impulse away from the cell body?
Correct Answer
A. Axon
Explanation
The axon is the part of a neuron that carries impulses away from the cell body. It is a long, slender projection that extends from the cell body and transmits electrical signals to other neurons or target cells. The axon plays a crucial role in the transmission of information within the nervous system, allowing for communication between different parts of the body.
25.
a bundle of parallel axons in the CNS is called a
Correct Answer
C. Tract
Explanation
A bundle of parallel axons in the central nervous system is called a tract. Nerves are responsible for transmitting signals between different parts of the body and the brain. They are made up of multiple axons, which are long, slender projections of nerve cells that carry electrical impulses. Nerves can be found throughout the body and play a crucial role in coordinating movement, sensation, and other functions.
26.
Within the perpheral nervous system, the myelin sheath is formed by
Correct Answer
A. Schwann Cells
Explanation
The myelin sheath is formed by Schwann Cells. Schwann cells are a type of glial cell found in the peripheral nervous system. They wrap around the axons of neurons, forming a myelin sheath that acts as an insulating layer. This myelin sheath helps to increase the speed of electrical impulses along the axon, allowing for more efficient transmission of signals. Oligodendrocytes, microglial cells, and astrocytes are all types of glial cells found in the central nervous system, and they do not play a role in forming the myelin sheath in the peripheral nervous system.
27.
An interneuron carries impulses
Correct Answer
B. To the CNS
Explanation
Interneurons are a type of neuron that transmit signals between sensory neurons and motor neurons. They are found entirely within the central nervous system (CNS) and play a crucial role in processing and integrating information. Therefore, the correct answer is "to the CNS" because interneurons carry impulses from one part of the CNS to another, facilitating communication and coordination within the nervous system.
28.
A motor neuron carries impulse
Correct Answer
A. To muscles and glands
Explanation
A motor neuron carries impulses from the central nervous system (CNS) to muscles and glands. This is because motor neurons are responsible for transmitting signals that control muscle movement and glandular secretions. They serve as the connection between the CNS and the peripheral nervous system, allowing the brain and spinal cord to communicate with the muscles and glands throughout the body.
29.
What ion is found on the outside of the neuron membrane that mostly contributes to a postive resting potential?
Correct Answer
C. Sodium
Explanation
Sodium ions are found on the outside of the neuron membrane and contribute to a positive resting potential. This is because the concentration of sodium ions is higher outside the neuron compared to the inside. The neuron maintains this concentration gradient through the action of the sodium-potassium pump, which actively transports sodium ions out of the cell. The accumulation of positive sodium ions outside the cell creates a positive resting potential, which is essential for the generation of action potentials and the transmission of nerve impulses.
30.
The resting potential of a neuron is measured at
Correct Answer
D. -70 millivolts
Explanation
The resting potential of a neuron refers to the electrical charge difference between the inside and outside of the neuron when it is not actively sending a signal. A negative value indicates that the inside of the neuron is more negatively charged compared to the outside. In this case, the resting potential is measured at -70 millivolts, suggesting that the inside of the neuron is 70 millivolts more negative than the outside.
31.
What system keeps the neuron at resting potential?
Correct Answer
C. Sodium-potassium pump
Explanation
The sodium-potassium pump is responsible for maintaining the resting potential of a neuron. It actively transports sodium ions out of the cell and potassium ions into the cell, against their concentration gradients. This creates a higher concentration of sodium ions outside the cell and a higher concentration of potassium ions inside the cell. This concentration gradient is essential for generating and maintaining the electrical potential across the neuron's membrane, allowing it to be in a resting state. Osmosis, pinocytosis, and facilitated diffusion are not directly involved in maintaining the resting potential of a neuron.
32.
An action potential begins with a
Correct Answer
A. Stimulus
Explanation
An action potential is an electrical signal that is generated by a stimulus. It is the initial event that triggers the depolarization and subsequent repolarization of a neuron. The stimulus can be any external or internal event that excites the neuron and leads to the generation of an action potential. Therefore, the correct answer is "stimulus".
33.
A stimulus will open ion channels that will allow _________ to flow into the neuron, causing the inside to become _______ charged.
Correct Answer
B. Sodium, positively
Explanation
When a stimulus opens ion channels, it allows sodium ions to flow into the neuron. Sodium ions have a positive charge, so when they enter the neuron, the inside becomes positively charged.
34.
During depolorization
Correct Answer
B. Sodium ions move inside the neuron
Explanation
During depolarization, the neuron's membrane potential becomes less negative as sodium ions move inside the neuron. This occurs due to the opening of sodium channels in the neuron's membrane. The influx of sodium ions results in the reversal of the membrane potential, causing an action potential to be generated and propagated along the axon. This movement of sodium ions inside the neuron is crucial for the transmission of electrical signals in the nervous system.
35.
During repolarization
Correct Answer
C. Potassium ions move outside the neuron
Explanation
During repolarization, potassium ions move outside the neuron. This is because repolarization is the phase in which the membrane potential is restored to its resting state after depolarization. During depolarization, sodium ions move inside the neuron, causing a temporary positive charge inside the cell. To return to the resting state, potassium ions move outside the neuron, repolarizing the membrane and restoring the negative charge inside the cell. This movement of potassium ions outside the neuron helps to reset the neuron for the next action potential.
36.
What does the action potential consist of ?
Correct Answer
D. Depolarization and repolarization
Explanation
The action potential consists of depolarization, which is the phase where the membrane potential becomes less negative, and repolarization, which is the phase where the membrane potential returns to its resting state. Resting potential refers to the stable, negative charge of the cell membrane when it is not transmitting signals. Therefore, the correct answer is depolarization and repolarization.
37.
The "jumping" of an action potential from one node of Ranvier to the next node is called
Correct Answer
C. Saltatory conduction
Explanation
Saltatory conduction is the correct answer because it refers to the process of an action potential "jumping" or rapidly propagating from one node of Ranvier to the next along a myelinated axon. This mode of conduction allows for faster transmission of the electrical signal compared to continuous conduction, where the action potential travels along the entire length of the axon. The myelin sheath insulates the axon, preventing ion leakage and forcing the action potential to "leap" between nodes, increasing the speed and efficiency of signal transmission.
38.
The small gap between two successive neurons is called the
Correct Answer
A. Synaptic cleft
Explanation
The small gap between two successive neurons is called the synaptic cleft. This is the space where communication occurs between neurons. When an electrical signal, known as an action potential, reaches the axon terminal of one neuron, it triggers the release of neurotransmitters into the synaptic cleft. These neurotransmitters then bind to receptors on the dendrite terminal of the next neuron, allowing the signal to be transmitted from one neuron to another. The synaptic cleft plays a crucial role in the transmission of information throughout the nervous system.
39.
What flows across the synaptic cleft?
Correct Answer
C. A neurotransmitter
Explanation
A neurotransmitter is a chemical substance that transmits signals across the synaptic cleft, which is the small gap between two neurons. It carries the signal from the presynaptic neuron to the postsynaptic neuron, allowing for communication between neurons. Sodium ions, potassium ions, and electrons are involved in the electrical signaling within neurons, but they do not directly flow across the synaptic cleft.
40.
What triggers the release of a neurotransmitter from the presynaptic neuron vesicles?
Correct Answer
D. Calcium ions
Explanation
Calcium ions trigger the release of a neurotransmitter from the presynaptic neuron vesicles. When an action potential reaches the presynaptic terminal, it causes voltage-gated calcium channels to open. This allows calcium ions to enter the neuron. The influx of calcium ions leads to the fusion of neurotransmitter-containing vesicles with the presynaptic membrane, releasing the neurotransmitter into the synaptic cleft. This neurotransmitter then binds to receptors on the postsynaptic neuron, allowing for the transmission of the signal across the synapse.
41.
Which of the following is a common neurotransmitter?
Correct Answer
A. Acetylcholine
Explanation
Acetylcholine is a common neurotransmitter in the nervous system. It is a chemical messenger that transmits signals between nerve cells and plays a crucial role in various physiological processes such as muscle movement, memory, and learning. Acetylcholine is released from the presynaptic neuron and binds to receptors on the postsynaptic neuron, allowing for the transmission of the nerve impulse. Therefore, acetylcholine is the correct answer as it is a well-known and widely studied neurotransmitter in the human body.
42.
What is the role of acetylcholinesterase at a synapse?
Correct Answer
B. It breaks down acetylcholine
Explanation
Acetylcholinesterase plays the role of breaking down acetylcholine at a synapse. Acetylcholine is a neurotransmitter that is released by the presynaptic neuron and binds to receptors on the postsynaptic neuron, transmitting the signal. However, to prevent continuous stimulation, acetylcholinesterase breaks down acetylcholine into choline and acetate, terminating the signal transmission. This allows for proper regulation and control of synaptic communication.
43.
In which direction does the transmission cross a synapse?
Correct Answer
B. Axon to dendrite
Explanation
The transmission across a synapse typically occurs from the axon of one neuron to the dendrite of another neuron. This is because the axon of a neuron sends out electrical signals called action potentials, which travel down the axon and reach the synapse. At the synapse, neurotransmitters are released from the axon terminal and bind to receptors on the dendrite of the receiving neuron, allowing the transmission of the signal. While there are rare cases where transmission can occur in the opposite direction, the most common and typical direction is from axon to dendrite.
44.
Which disease is due, in part, to reduced amounts of acetylcholine in the brain?
Correct Answer
D. All of the choices are correct
Explanation
All of the choices are correct because all three diseases (Parkinson's disease, Huntington's disease, and Alzheimer's disease) are associated with reduced amounts of acetylcholine in the brain. Acetylcholine is a neurotransmitter that plays a crucial role in various brain functions, including memory, movement, and cognition. In Parkinson's disease, there is a loss of dopamine-producing cells in the brain, which leads to a decrease in acetylcholine levels. Huntington's disease is characterized by the progressive degeneration of nerve cells, including those that produce acetylcholine. Alzheimer's disease is also linked to a decline in acetylcholine, which contributes to cognitive impairment and memory loss.
45.
Tracts of myelinated axons in the CNS make up the
Correct Answer
A. White matter
Explanation
The tracts of myelinated axons in the CNS are responsible for transmitting signals between different parts of the central nervous system. These axons are coated with a fatty substance called myelin, which gives them a white appearance. Therefore, the correct answer is white matter. Gray matter, on the other hand, consists mainly of cell bodies and unmyelinated axons. Cerebrospinal fluid is a clear liquid that surrounds and cushions the brain and spinal cord, while ventricles are fluid-filled spaces within the brain.
46.
The protective membranes around the brain and the spinal cord are the
Correct Answer
B. Meninges
Explanation
The correct answer is meninges. The meninges are the protective membranes that surround the brain and spinal cord. They consist of three layers: the dura mater, arachnoid mater, and pia mater. The meninges provide cushioning and support for the central nervous system, protecting it from injury and infection.
47.
Which of the following is the correct layering of the meninges from the superficial to deep?
Correct Answer
C. Dura mater, arachnoid mater, pia mater
Explanation
The correct layering of the meninges from the superficial to deep is dura mater, arachnoid mater, pia mater. The dura mater is the outermost layer, followed by the arachnoid mater, and finally the pia mater, which is the innermost layer.
48.
The tough outer meninx is the
Correct Answer
A. Dura mater
Explanation
The correct answer is dura mater. The dura mater is the tough outermost layer of the meninges, which are the protective membranes surrounding the brain and spinal cord. It is composed of dense, fibrous connective tissue and provides strength and protection to the central nervous system. The arachnoid mater is the middle layer, while the pia mater is the innermost layer of the meninges.
49.
The space between the arachnoid and pia maters that is filled with cerebrospinal fluid is the
Correct Answer
C. Subarachnoid space
Explanation
The space between the arachnoid and pia maters is known as the subarachnoid space. This space is filled with cerebrospinal fluid, which acts as a cushion and provides protection to the brain and spinal cord. The subarachnoid space also contains blood vessels and plays a crucial role in the circulation of cerebrospinal fluid.
50.
Cerebrospinal fluid is produced by
Correct Answer
D. Ependymal cells
Explanation
Cerebrospinal fluid is produced by ependymal cells. These cells line the ventricles of the brain and the central canal of the spinal cord. They are specialized in the production and regulation of cerebrospinal fluid, which serves important functions such as cushioning and protecting the brain and spinal cord, removing waste products, and providing nutrients to the nervous system.