SCI 221 Exam 2 V2 | SCI 221 Human
Physiology with Intervention Skill-Based
(ISB) Experiential Learning | Q&A with
Rationale (SCI221 Exam 2) | Nightingale
College
1. During the depolarization phase of an action potential, which of the following events
occurs in a typical neuron?
A. Voltage-gated potassium channels open rapidly.
B. Voltage-gated sodium channels open and sodium enters the cell.
C. The sodium-potassium pump stops functioning.
D. Calcium ions leave the cell via facilitated diffusion.
Correct Answer: B
Rationale: Depolarization is characterized by a rapid influx of sodium ions through
voltage-gated channels. This shift in ion concentration makes the interior of the cell more
positive compared to the exterior. This process is essential for the propagation of nerve
impulses along the axon.
2. Which neuroglial cell is responsible for forming the myelin sheath around axons within the
Central Nervous System (CNS)?
A. Schwann cells
,B. Oligodendrocytes
C. Astrocytes
D. Microglia
Correct Answer: B
Rationale: Oligodendrocytes are the specific glial cells that provide myelination for
multiple axons in the brain and spinal cord. In contrast, Schwann cells perform this
function in the peripheral nervous system. Myelination is vital for increasing the speed of
signal transmission through saltatory conduction.
3. The hypothalamus is often referred to as the master regulator of the endocrine system.
Which statement best describes its role?
A. It secretes hormones directly into the general circulation to reach target organs.
B. It produces releasing and inhibiting hormones that control the anterior pituitary.
C. It stores all hormones produced by the thyroid gland.
D. It functions independently of the nervous system to regulate metabolism.
Correct Answer: B
Rationale: The hypothalamus communicates with the anterior pituitary via the
hypophyseal portal system. It releases specific hormones that either stimulate or inhibit
the secretion of pituitary hormones. This connection serves as the primary link between
the nervous and endocrine systems.
,4. Which hormone is primarily responsible for lowering blood calcium levels by inhibiting
osteoclast activity?
A. Parathyroid hormone (PTH)
B. Glucagon
C. Aldosterone
D. Calcitonin
Correct Answer: D
Rationale: Calcitonin is produced by the parafollicular cells of the thyroid gland. It acts to
decrease blood calcium levels when they are too high by promoting bone deposition. This
hormone works in opposition to parathyroid hormone to maintain calcium homeostasis.
5. Which part of the brain is primarily associated with the coordination of complex motor
movements and the maintenance of posture and balance?
A. Cerebrum
B. Thalamus
C. Cerebellum
D. Medulla oblongata
Correct Answer: C
, Rationale: The cerebellum processes sensory input from the muscles and joints to fine-
tune motor activity. It ensures that movements are smooth and coordinated rather than
jerky. Dysfunction in this area often leads to ataxia or loss of balance.
6. What is the primary physiological effect of insulin secretion by the pancreas?
A. Stimulation of gluconeogenesis in the liver.
B. Inhibition of protein synthesis in skeletal muscle.
C. Increasing the breakdown of glycogen into glucose.
D. Promotion of glucose uptake by body cells via GLUT4 translocation.
Correct Answer: D
Rationale: Insulin is released by beta cells in response to high blood glucose levels. It
facilitates the transport of glucose into cells, particularly muscle and adipose tissue, for
energy or storage. This mechanism effectively lowers the concentration of glucose in the
bloodstream.
7. In the autonomic nervous system, which neurotransmitter is released by all preganglionic
neurons?
A. Acetylcholine
B. Norepinephrine
C. Epinephrine
D. Dopamine
Physiology with Intervention Skill-Based
(ISB) Experiential Learning | Q&A with
Rationale (SCI221 Exam 2) | Nightingale
College
1. During the depolarization phase of an action potential, which of the following events
occurs in a typical neuron?
A. Voltage-gated potassium channels open rapidly.
B. Voltage-gated sodium channels open and sodium enters the cell.
C. The sodium-potassium pump stops functioning.
D. Calcium ions leave the cell via facilitated diffusion.
Correct Answer: B
Rationale: Depolarization is characterized by a rapid influx of sodium ions through
voltage-gated channels. This shift in ion concentration makes the interior of the cell more
positive compared to the exterior. This process is essential for the propagation of nerve
impulses along the axon.
2. Which neuroglial cell is responsible for forming the myelin sheath around axons within the
Central Nervous System (CNS)?
A. Schwann cells
,B. Oligodendrocytes
C. Astrocytes
D. Microglia
Correct Answer: B
Rationale: Oligodendrocytes are the specific glial cells that provide myelination for
multiple axons in the brain and spinal cord. In contrast, Schwann cells perform this
function in the peripheral nervous system. Myelination is vital for increasing the speed of
signal transmission through saltatory conduction.
3. The hypothalamus is often referred to as the master regulator of the endocrine system.
Which statement best describes its role?
A. It secretes hormones directly into the general circulation to reach target organs.
B. It produces releasing and inhibiting hormones that control the anterior pituitary.
C. It stores all hormones produced by the thyroid gland.
D. It functions independently of the nervous system to regulate metabolism.
Correct Answer: B
Rationale: The hypothalamus communicates with the anterior pituitary via the
hypophyseal portal system. It releases specific hormones that either stimulate or inhibit
the secretion of pituitary hormones. This connection serves as the primary link between
the nervous and endocrine systems.
,4. Which hormone is primarily responsible for lowering blood calcium levels by inhibiting
osteoclast activity?
A. Parathyroid hormone (PTH)
B. Glucagon
C. Aldosterone
D. Calcitonin
Correct Answer: D
Rationale: Calcitonin is produced by the parafollicular cells of the thyroid gland. It acts to
decrease blood calcium levels when they are too high by promoting bone deposition. This
hormone works in opposition to parathyroid hormone to maintain calcium homeostasis.
5. Which part of the brain is primarily associated with the coordination of complex motor
movements and the maintenance of posture and balance?
A. Cerebrum
B. Thalamus
C. Cerebellum
D. Medulla oblongata
Correct Answer: C
, Rationale: The cerebellum processes sensory input from the muscles and joints to fine-
tune motor activity. It ensures that movements are smooth and coordinated rather than
jerky. Dysfunction in this area often leads to ataxia or loss of balance.
6. What is the primary physiological effect of insulin secretion by the pancreas?
A. Stimulation of gluconeogenesis in the liver.
B. Inhibition of protein synthesis in skeletal muscle.
C. Increasing the breakdown of glycogen into glucose.
D. Promotion of glucose uptake by body cells via GLUT4 translocation.
Correct Answer: D
Rationale: Insulin is released by beta cells in response to high blood glucose levels. It
facilitates the transport of glucose into cells, particularly muscle and adipose tissue, for
energy or storage. This mechanism effectively lowers the concentration of glucose in the
bloodstream.
7. In the autonomic nervous system, which neurotransmitter is released by all preganglionic
neurons?
A. Acetylcholine
B. Norepinephrine
C. Epinephrine
D. Dopamine
