GRE Subject Test: Biology : Understanding Nervous System Functions

Study concepts, example questions & explanations for GRE Subject Test: Biology

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Example Questions

Example Question #3 : Nervous System

The relaxation of bronchial smooth muscle is stimulated by what type of neuron?

Possible Answers:

Parasympathetic motor neurons

Somatic motor neurons

Parasympathetic postganglionic neurons

Sympathetic postganglionic neurons

Sympathetic preganglionic neurons

Correct answer:

Sympathetic postganglionic neurons

Explanation:

Relaxation of bronchial smooth muscle is an involuntary process, which is accomplished by the autonomic system rather than the somatic. It is also a part of the "fight or flight" response, which relates to the sympathetic system. Postganglionic neurons directly stimulate target tissues, while preganglionic neurons stimulate postganglionic neurons.

Example Question #1 : Nervous System

What is the name of the support cell in the nervous system responsible for circulating cerebrospinal fluid?

Possible Answers:

Astrocytes

Schwann cells

Ependymal cells

Microglia

Correct answer:

Ependymal cells

Explanation:

The nervous system has a variety of support cells in addition to neurons. These support cells are collectively called the neuroglia.

Microglia are used to remove debris from the nervous system, astrocytes provide support to neurons, and Schwann cells are used to myelinate the axons in the peripheral nervous system. It is the role of ependymal cells to synthesize and circulate cerebrospinal fluid using their cilia.

Example Question #1 : Understanding Nervous System Functions

Which portion of the brain is responsible for controlling breathing and heart rate?

Possible Answers:

Cerebrum

Brain stem

Hypothalamus

Cerebellum

Correct answer:

Brain stem

Explanation:

The cerebellum is found in the posterior portion of the brain and controls balance and coordination. The cerebrum controls upper level cognition, such as conscious thought, and memory. The hypothalamus is a crucial endocrine structure and helps regulate hormone secretion from the pituitary and body homeostasis. The brain stem controls the most basic duties of the body, which include breathing rate, heart rate, and blood pressure.

Example Question #3 : Nervous System

Which portion of the nervous system is responsible for increasing digestive and excretory activity in the body?

Possible Answers:

Somatic nervous system

Central nervous system

Parasympathetic nervous system

Sympathetic nervous system

Correct answer:

Parasympathetic nervous system

Explanation:

Digestion and excretion are not consciously controlled, which means that they fall under the control of the autonomic nervous system. The autonomic nervous system has two branches: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is involved in "fight or flight" activities, while the parasympathetic nervous system controls "rest and digest" activities. As a result, digestive and excretory activity is increased by the parasympathetic nervous system.

The central nervous system contain components of both the sympathetic and parasympathetic nervous system and controls a variety of nervous functions. Only the brain and spinal cord are considered part of the central nervous system. The somatic nervous system is under voluntary control, and is primarily linked to skeletal muscle.

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