MCAT Biology : Divisions of the Nervous System

Study concepts, example questions & explanations for MCAT Biology

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Example Questions

Example Question #141 : Biology

Which of the following glial cells produces cerebrospinal fluid?

Possible Answers:

Astrocytes

Oligodendrocytes

Microglia

Satellite cells

Ependymal cells

Correct answer:

Ependymal cells

Explanation:

Ependymal cells, which line cerebral cavities and the central canal, produce cerebrospinal fluid (CSF). CSF is a colorless liquid that protects the brain and spinal cord against injury.

Microglia protect the central nervous system from microbes and debris of injured cells. Astrocytes, located in the central nervous system, provide structural support for neurons in addition to many other tasks involving nutrient and ion regulation. Oligodrendrocytes produce the myelin sheath around the axons of the central nervous system. Satellite cells are not found in the central nervous system, and therefore cannot produce CSF.

Example Question #12 : Divisions Of The Nervous System

What is the major difference between Schwann cells and oligodendrocytes?

Possible Answers:

Schwann cells are the most common glial cell type

Oligodendrocytes myelinate central nervous system axons, whereas Schwann cells myelinate peripheral nervous system axons

Action potentials propagate faster down axons myelinated by Schwann cells

Oligodendrocytes myelinate axons and dendrites, whereas Schwann cells only myelinate axons

Schwann cells myelinate axons, while oligodendocytes myelinate dendrites

Correct answer:

Oligodendrocytes myelinate central nervous system axons, whereas Schwann cells myelinate peripheral nervous system axons

Explanation:

Both oligodendrocytes and Schwann cells produce and maintain myelin along axons. Oligodendrocytes are the most common glial cell type, and provide myelination for all neural axons in the central nervous system. Schwann cells provide myelination for neurons in the peripheral nervous system.

Example Question #1 : Nervous System

An individual presents to his physician with an abnormal breathing rhythm. The physician suspects that the problem may be originating from his brain. What part of his brain is most likely not functioning properly?

Possible Answers:

Hippocampus

Midbrain

Cerebellum

Hypothalamus

Medulla oblongata

Correct answer:

Medulla oblongata

Explanation:

The medulla oblongata is responsible for autonomic functions, such as breathing rate and heart rate regulation. Dysfunction of the medulla oblongata could result in problems with breathing rhythm.

The cerebellum is responsible for coordination and balance. The hypothalamus regulates the fight-or-flight response, sex drive, thirst, and hunger. The midbrain is the center for auditory and visual signal relay to the cortex. The hippocampus functions in the retention of memories.

Example Question #11 : Divisions Of The Nervous System

Which of the following structures connects the right and left hemispheres of the brain?

Possible Answers:

Stria terminalis

Corpus collosum

Olfactory bulb

Mammillary Body

Hypothalamus

Correct answer:

Corpus collosum

Explanation:

The MCAT contains minimal questions regarding brain anatomy, however, you should have an understanding of a select few structures, one of which is the corpus collosum. The corpus collosum is a bundle of neurons connecting the left and right brain, allowing communication between the left and right hemispheres. If these neurons were damaged somehow, the result would be split-brain syndrome, a condition in which the two halves of the brain do not communicate with one another.

Example Question #171 : Mcat Biological Sciences

Which of the following activities would you expect to be controlled by the cerebral cortex?

Possible Answers:

Memory

Heart rate

Breathing while asleep

Salivation

Correct answer:

Memory

Explanation:

The cerebral cortex is also referred to as the "higher brain." It acts to process thoughts and store memories. More basic, vital activities such as heart beat and breathing are controlled by other, less developed regions of the brain. Note that the hippocampus plays a role in creating memories, but most memories are stored in the cerebrum; this is the link between long term and short term memory storage.

Example Question #1 : Brain And Central Nervous System

Which part of the brain is responsible for controlling body temperature, and adjusting to external temperature conditions?

Possible Answers:

Cerebrum

Hypothalamus

Cerebellum

Thalamus

Correct answer:

Hypothalamus

Explanation:

The hypothalamus is responsible for cooling and heating mechanisms in the body, and thus is the correct answer. 

The cerebrum is responsible for higher brain functions, like conscious thought. The cerebellum is essential for balance and coordination. The thalamus is primarily responsible for integrating and coordinating sensory input to the brain.

Example Question #172 : Mcat Biological Sciences

An individual presents to his physician with a complaint of "uncoordinated muscle movements." After running proper tests, the physician suspects that this individual has some degree of brain injury. Which portion of the brain is most likely to be injured?

Possible Answers:

Midbrain

Hippocampus

Medulla oblongata

Cerebellum

Hypothalamus

Correct answer:

Cerebellum

Explanation:

The cerebellum is responsible for coordination and balance. Injury to the cerebellum can result in a loss of motor coordination.

The medulla oblongata controls autonomic activities, such as regulating heart and respiration rates. The hypothalamus regulates the fight-or-flight response, sex drive, thirst, and hunger. The midbrain is the center for auditory and visual signal relay to the cortex. The hippocampus functions in the retention of memories.

Example Question #12 : Divisions Of The Nervous System

A lesion to which brain region would result in a lack of coordinated movement?

Possible Answers:

The medulla oblongata

The hypothalamus

The cerebellum

The left temporal lobe

Correct answer:

The cerebellum

Explanation:

The cerebellum is responsible for the coordination of movement between the motor and sensory cortices. It helps account for movements and correct the magnitude of stimulation of skeletal muscle. The cerebellum is essential for fine-tuning functions like balance and hand-eye coordination.

The medulla, or medulla oblongata, is mainly responsible for the modulation of involuntary vital functions like ventilation rate and heart rate. The hypothalamus plays a key role in the activation of the sympathetic nervous system and also plays a key role in hunger, sexual reproduction, and endocrine function. The temporal lobe is a region of the cerebrum, and is associated with auditory and speech function as well as memory formation.

Example Question #2 : Brain And Central Nervous System

Which section of the brain is responsible for regulating temperature?

Possible Answers:

Hypothalamus

Frontal cortex

Medulla

Limbic system

Cerebrum

Correct answer:

Hypothalamus

Explanation:

Receptors in the hypothalamus regulate temperature by sending nerve signals to muscles and sweat glands in the body. The hypothalamus is located deep within the center of the brain, at the very top of the brain stem. The other answers are different sections of the brain responsible for other tasks. For instance, the cerebrum is the largest section of the brain responsible for memory, consciousness, language and intellect.

Example Question #151 : Biology

Which of the following is part of the hindbrain?

Possible Answers:

Hypothalamus

Cerebrum

Thalamus

Cerebellum

Broca's area

Correct answer:

Cerebellum

Explanation:

The hindbrain consists of the pons, medulla oblongata, and cerebellum.

The cerebrum, thalamus, and hypothalamus are part of the forebrain. Broca's area is a specific region of the cerebrum dedicated to understanding language.

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