High School Biology : Understanding Structures of the Nervous System

Study concepts, example questions & explanations for High School Biology

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Example Questions

Example Question #1 : Organs And Organ Systems

Which of the following depicts the soma of a neuron?

Hs_bio_neuron

Possible Answers:

B

D

C

A

Correct answer:

D

Explanation:

The soma is the cell body of the neuron (D). The soma is the site of neuron metabolism and protein synthesis.

The dendrites of the neuron (A) receive incoming action potential signals. The axon (B) sends the action potential outward from the soma to the axon terminal (C). Vesicles of neurotransmitter are released from the axon terminal to the dendrites of other nearby neurons. Neurons can have numerous dendrites, but will only have one soma and one axon.

Example Question #1 : Nervous System

Which brain structure is responsible for the body's balance and coordination?

Possible Answers:

Cerebellum

Thalamus

Medulla oblongata

Cerebrum

Correct answer:

Cerebellum

Explanation:

The cerebellum is responsible for maintaining balance and coordination.

The medulla oblongata is responsible for maintaining subconscious body functions, such as heart rate and breathing. The cerebrum is responsible for higher level functions such as movement and memory. The thalamus mediates survival instincts, including hunger, thirst, and sexual instinct.

Example Question #1 : Understanding Structures Of The Nervous System

Which of the following structures is NOT part of the central nervous system?

Possible Answers:

The cerebral cortex

The brain stem

Spinal nerves

The spinal cord

Correct answer:

Spinal nerves

Explanation:

The central nervous system is composed of the brain (including the cerebrum and brain stem) and spinal cord. Cranial and spinal nerves branch directly off of these structures, but are considered part of the peripheral nervous system.

Example Question #1 : Organs And Organ Systems

Which of the following is the most basic functional unit found in the nervous system?

Possible Answers:

Mitochondria

The cerebellum

Neurons

Action potentials

Glial cells

Correct answer:

Neurons

Explanation:

The nervous system is used to conduct electrical signals throughout the body. These signals stimulate various functions, frequently causing muscles to contract or carrying sensory signals to the brain. The brain and spinal cord are key components for organizing and interpreting these signals.

Neurons are the cells responsible for conducting electrical impulses. The impulses themselves are known as action potentials.

Glial cells provide support for the nervous system. Different types of glial cells perform different functions, such as myelination of axons, immune activity, and the production of cerebrospinal fluid. The cerebellum is a region of the brain responsible for balance and coordination. Since the cerebellum is a part of the nervous system, its structure is primarily composed of neurons. Mitochondria are organelles found in most eukaryotic cells. They generate ATP, which provides energy to the cell. Their function is not inherently linked to the nervous system.

Example Question #1 : Understanding Structures Of The Nervous System

What type of cell provides support for neurons?

Possible Answers:

Blood vessels

Epithelial cells

Glial cells

Connective tissue

Mitochondria

Correct answer:

Glial cells

Explanation:

Glial cells provide support for neurons. Schwann cells, oligodendrocytes, astrocytes, and ependymal cells are a few examples of glia. Schwann cells and oligodendrocytes provide myelination for neurons. Astrocytes play a key role in supporting the blood-brain barrier, while epedymal cells are responsible for secreting and circulating cerebrospinal fluid.

Blood vessels provide oxygenated blood and nutrients necessary for proper neuronal function. Connective tissue is a large component of the dura surrounding the brain itself, but it doesn't provide support for neurons themselves. Similarly, epithelial cells help structurally support the blood-brain barrier, but do not interact directly with neurons. Mitochondria are not a cell type, but are an organelle found within neurons.

Example Question #2 : Understanding Structures Of The Nervous System

What are the three structural regions of a neuron?

Possible Answers:

Dendrites, cell body, flagellum

Cell body, dendrites, cell wall

Cell body, cell wall, axon

Cell body, dendrites, axon

Axon, dendrites, cell wall

Correct answer:

Cell body, dendrites, axon

Explanation:

The three structural regions of the neuron include the cell body (or soma), dendrites, and axon. The dendrites receive electrical inputs and stimulation and transfer incoming information to the cell body, or soma. Signals accumulate in the soma before triggering the threshold for conducting an action potential down the axon. The axon then interfaces with the dendrites of another neuron, or with the membrane of a neighboring muscle cell.

Cell walls are not found in human cells, including neurons. Though flagella can be found in certain human cells and somewhat resembles the long, narrow structure of an axon, the two are functionally very different. Neurons do not have flagella.

Example Question #1 : Understanding Structures Of The Nervous System

What part of the neuron contains the nucleus and other organelles?

Possible Answers:

The axon terminal

The synapse

The axon

The dendrites

The cell body

Correct answer:

The cell body

Explanation:

The cell body (or soma) contains the nucleus of the neuron, as well as other organelles. Most basic cell processes, such as transcription and translation, take place in the cell body. For example, ribosomes synthesize neurotransmitters in the cell body. The neurotransmitters are then packaged in vesicles and transported to the axon terminal.

The axon of the neuron is responsible for conveying electrical signals away from the cell body, while the dendrites convey electrical signals toward the cell body. The axon terminal is located most distal from the cell body and marks the end of the axon. Neurotransmitters are stored and released from the axon terminal. The synapse is not technically a part of the neuron structure, but is instead the small space between the axon of one neuron and the dendrites of another.

Example Question #4 : Understanding Structures Of The Nervous System

Which of the following refers to a long projection off the cell body of the neuron that is used to conduct electrical signals to neighboring cells?

Possible Answers:

Flagella

Action potential

Dendrite

Axon

Synapse

Correct answer:

Axon

Explanation:

The axon is the long extension of the nerve cell body that transmits nerve impulses to other cells. Neurotransmitters are stored at the end of the axon and released into the synapse to communicate with other neurons and cells.

Dendrites are generally not as long as axons, and are responsible for receiving the nerve impulses rather than transmitting them. Flagella are not related to nerve cells, as nerve cells do not need to travel from one place to another and have no use for motility. Action potentials are the electrical signals that travel down the axons from the cell body to the axon terminal. The synapse is the space between the axon terminal of one neuron and the dendrites of another.

Example Question #8 : Nervous System

Which of the following consists of spinal nerves that pass through the inferior aspect of the vertebral column?

Possible Answers:

Dura mater

Thoracic nerves

Cranial nerves

Cauda equina

Cervical nerves

Correct answer:

Cauda equina

Explanation:

The cauda equina is the batch of spinal nerves that run down through the inferior end of the vertebral column. It is located in the area of the lumbar vertebral column. Cervical and thoracic nerves are located toward the upper part of the vertebral column. The dura mater is the connective tissue covering that surrounds the central nervous system. Cranial nerves come off the brain, and are part of the central nervous system.

Example Question #1 : Nervous System

Which of the cranial nerves is associated with sense of smell?

Possible Answers:

Olfactory

Trigeminal

Facial

Optic

Correct answer:

Olfactory

Explanation:

The olfactory nerve is the first of 12 cranial nerves and is associated with a sense of smell. The optic nerve is associated with vision, the trigeminal nerve is associated with sensation of the head and face, and the facial nerve is associated with control of the facial muscles.

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