AP Biology : Systems Physiology

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #1 : Nervous System

Which of the following is responsible for creating myelin, for the myelin sheaths of axons?

Possible Answers:

Oligodendrocytes only

None of the other answers are correct

Schwann cells and oligodendrocytes

Schwann cells only

Correct answer:

Schwann cells and oligodendrocytes

Explanation:

Schwann cells produce myelin for neurons of the peripheral nervous system, while oligodendrocytes produce myelin for neurons of the central nervous system.

Example Question #1 : Neural Anatomy

Which of the following best describes the order of information processing in a neuron?

Possible Answers:

Synaptic terminal, dendrite, cell body, axon

Dendrite, axon, cell body, synaptic terminal

Dendrite, synaptic terminal, cell body, axon

Dendrite, cell body, axon, synaptic terminal

Dendrite, axon, synaptic terminal, cell body

Correct answer:

Dendrite, cell body, axon, synaptic terminal

Explanation:

A neuron receives input from other neurons at the dendrites. Neurotransmitters released by other neurons bind to receptors on the dendrites, which carry the signal to the cell body. The signal is then amplified in the cell body before being transferred to the axon. Once the signal transitions to the axon, it is considered an action potential. The signal eventually reaches the end of the axon, where the synaptic vesicles are located, and stimulates release of neurotransmitters to the next neuron's dendrites.

Example Question #1371 : Ap Biology

Which of the following is true regarding a neuron?

Possible Answers:

If an electrical disturbance is large enough in the cell body, the signal generates an action potential at the dendrite

The propagation of signal through a neuron initiates at the dendrite, enters the cell body, and is transmitted from the axon

Neurons transmit electrical signals from one cell to the other at the cell body

Neurons contain multiple dendrites and cell bodies

Correct answer:

The propagation of signal through a neuron initiates at the dendrite, enters the cell body, and is transmitted from the axon

Explanation:

Neurons have many dendrites, one cell body, and a single axon with several terminal branches. A dendrite receives an external stimulus and causes an electrical disturbance in the cell body. This electrical disturbance is transmitted to the axon, where an action potential is generated if the stimulus is large enough. The action potential is propagated through the axon and is transmitted to a neighboring neuron at the synapse.

A large enough electrical disturbance will generate an action potential in the axon, but no magnitude of stimulus can create an action potential in the dendrites. Neurons do contain multiple dendrites, but they only contain one cell body and one axon. Finally, neurons transmit electrical signals to other neurons at the synapse, not at the cell body.

Example Question #2 : Neural Anatomy

An electrical synapse uses __________ to transmit electrical signals between neurons.

Possible Answers:

anchoring junctions

gap junctions

desmosomes

tight junctions

Correct answer:

gap junctions

Explanation:

There are two types of synapses: chemical and electrical. Chemical synapses use chemical signals called neurotransmitters to transmit nerve signals between neurons, whereas electrical synapses use electrical signals. These electrical signals are transmitted through a gap junction that connects adjacent neurons. Intercalated discs in cardiac muscle contain gap junctions for the purpose of propagating electrical signals to cause systole.

Example Question #1 : Understanding Neurons

Which of the following cells is found in the peripheral nervous system?

Possible Answers:

Astrocytes

Ependymal cells

Oligodendrocytes

Microglia

Schwann cells

Correct answer:

Schwann cells

Explanation:

While both oligodendrocytes and Schwann cells produce myelin sheaths that insulate nervous system signals, only the Schwann cells are found in the peripheral nervous system.

All other cells listed are found only in the central nervous system. Microglia act as immune cells within the cerebrospinal fluid, since lymphocytes are barred entry by the blood-brain barrier. Astrocytes support the neural cells and provide nutrients. Ependymal cells are responsible for secreting cerebrospinal fluid.

Example Question #401 : Systems Physiology

Which of the following cells are responsible for speeding up the action potentials along the axon of a neuron?

Possible Answers:

Schwann cells

Myocytes

Astrocytes

Ependymal cells

Glial cells

Correct answer:

Schwann cells

Explanation:

The correct answer is Schwann cells. Schwann cells are cells that produce the myelination present on the outer covering of the axon of the neuron. This lipid-rich material helps facilitate the movement of the action potential along the axon from the axon hillock to the axon terminal branches.

Example Question #1 : Nervous System

The functional units of the nervous system are __________.

Possible Answers:

nephrons

gray matter

 

neurotransmitters

neurons

Correct answer:

neurons

Explanation:

Neurons are the functional unit of the nervous system. Dendrites of the neuron accept incoming action potentials and stimuli, and propagate the signal down the cell axon to stimulate other nearby neurons.

Nephrons are the functional unit of the kidney. Gray matter refers to the regions in the central nervous system where the axonal cell bodies are located, while white matter refers to the regions that contain axons. Neurotransmitters are the particles used to transmit signals across synapses from one neuron to another.

Example Question #11 : Nervous System

Which of the following is not part of the peripheral nervous system?

Possible Answers:

Prefrontal cortex

Tibial nerve

Lumbar Plexus

Intercostal nerves

Radial nerve

Correct answer:

Prefrontal cortex

Explanation:

The central nervous system consists of the brain and spinal cord. The peripheral nervous system consists of any nerves or ganglia, not including the brain and spinal cord. The prefrontal cortex is a structure in the cerebrum of the brain, and is thus part of the central nervous system.

General nerves throughout the body are part of the peripheral nervous system.

Example Question #12 : Nervous System

What are the vertebral classifications, from superior to inferior?

Possible Answers:

Lumbar, thoracic, cervical, sacral

Cervical, sacral, thoracic, lumbar

Cervical, thoracic, lumbar, sacral

Thoracic, lumbar, sacral, cervical

Cervical, lumbar, thoracic, sacral

Correct answer:

Cervical, thoracic, lumbar, sacral

Explanation:

The spinal cord and vertebrae is broken down into four regions: cervical, thoracic, lumbar, and sacral. There are seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae, and five sacral vertebrae. Cervical vertebrae are located in the neck, thoracic vertebrae in the trunk or upper back, lumbar vertebrae in the lower back, and sacral vertebrae in the gluteal region. The sacral vertebrae are fused into a single unit known as the sacrum.

Example Question #11 : Nervous System

Which portion of the spinal cord sends sensory information to the brain?

Possible Answers:

Central canal

Dorsal horn

Lateral horn

Ventral horn

Correct answer:

Dorsal horn

Explanation:

The spinal cord consists of functional horns that help send information to the brain, as well as to the parts of the body. The dorsal horns send sensory information to the brain, while the ventral horns contain motor neurons.

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