SCI 221 Exam 3 V2 | SCI 221 Human
Physiology with Intervention Skill-Based
(ISB) Experiential Learning | Q&A with
Rationale (SCI221 Exam 3) | Nightingale
College
1. Which of the following hormones is synthesized in the hypothalamus but released by the
posterior pituitary gland?
A. Growth Hormone
B. Adrenocorticotropic Hormone (ACTH)
C. Thyroid Stimulating Hormone (TSH)
D. Antidiuretic Hormone (ADH)
Correct Answer: D
Rationale: Antidiuretic Hormone (ADH) is produced by the supraoptic nuclei in the
hypothalamus. It travels down the hypothalamo-hypophyseal tract to be stored and
eventually released by the posterior pituitary. This mechanism differentiates it from
anterior pituitary hormones which are synthesized locally in the adenohypophysis.
2. In the renin-angiotensin-aldosterone system (RAAS), which enzyme is responsible for
converting Angiotensin I into the active vasoconstrictor Angiotensin II?
A. Renin
,B. Angiotensin-converting enzyme (ACE)
C. Erythropoietin
D. Aldosterone synthase
Correct Answer: B
Rationale: Angiotensin-converting enzyme (ACE) is primarily found in the pulmonary
capillaries and catalyzes the conversion of Angiotensin I to Angiotensin II. Angiotensin II is
a potent vasoconstrictor that also stimulates the release of aldosterone from the adrenal
cortex. This pathway is a critical regulator of systemic blood pressure and fluid balance.
3. What is the primary physiological function of the hormone Glucagon?
A. To stimulate glycogenesis in the liver
B. To increase blood glucose levels by promoting glycogenolysis
C. To promote the storage of glucose as triglycerides
D. To increase cellular uptake of glucose through GLUT4 transporters
Correct Answer: B
Rationale: Glucagon is secreted by the alpha cells of the pancreas in response to low blood
glucose levels. Its primary action is to stimulate the liver to break down glycogen into
glucose, a process known as glycogenolysis. Additionally, it promotes gluconeogenesis to
ensure adequate blood sugar levels during fasting states.
,4. Which part of the nephron is responsible for the majority of water and nutrient
reabsorption, including 100% of filtered glucose under normal conditions?
A. Proximal Convoluted Tubule
B. Loop of Henle
C. Distal Convoluted Tubule
D. Collecting Duct
Correct Answer: A
Rationale: The proximal convoluted tubule (PCT) is the main site for reabsorption in the
kidney. It reabsorbs approximately 65% of water and electrolytes, as well as all filtered
glucose and amino acids via secondary active transport. Failure of this system often results
in glycosuria, which is a clinical indicator of exceeding the renal threshold.
5. During the ovarian cycle, which hormone surge directly triggers the process of ovulation?
A. Estrogen
B. Progesterone
C. Luteinizing Hormone (LH)
D. Follicle Stimulating Hormone (FSH)
Correct Answer: C
Rationale: A significant spike in Luteinizing Hormone (LH), known as the LH surge, occurs
mid-cycle due to positive feedback from high estrogen levels. This surge induces the
, rupture of the Graafian follicle and the release of the secondary oocyte. Without this
specific hormonal peak, the transition from the follicular phase to the luteal phase cannot
occur.
6. Which cell type in the stomach is responsible for the secretion of Hydrochloric Acid (HCl)
and Intrinsic Factor?
A. Chief Cells
B. Parietal Cells
C. G Cells
D. Mucous Neck Cells
Correct Answer: B
Rationale: Parietal cells located in the gastric glands secrete both HCl and intrinsic factor.
HCl is necessary for activating pepsinogen into pepsin, while intrinsic factor is essential for
the absorption of Vitamin B12 in the ileum. Dysfunction in these cells can lead to digestive
issues and pernicious anemia.
7. What is the effect of Parathyroid Hormone (PTH) on blood calcium levels?
A. It decreases blood calcium by stimulating osteoblasts
B. It increases blood calcium by inhibiting Vitamin D activation
C. It increases blood calcium by stimulating osteoclast activity
D. It decreases blood calcium by increasing renal excretion
Physiology with Intervention Skill-Based
(ISB) Experiential Learning | Q&A with
Rationale (SCI221 Exam 3) | Nightingale
College
1. Which of the following hormones is synthesized in the hypothalamus but released by the
posterior pituitary gland?
A. Growth Hormone
B. Adrenocorticotropic Hormone (ACTH)
C. Thyroid Stimulating Hormone (TSH)
D. Antidiuretic Hormone (ADH)
Correct Answer: D
Rationale: Antidiuretic Hormone (ADH) is produced by the supraoptic nuclei in the
hypothalamus. It travels down the hypothalamo-hypophyseal tract to be stored and
eventually released by the posterior pituitary. This mechanism differentiates it from
anterior pituitary hormones which are synthesized locally in the adenohypophysis.
2. In the renin-angiotensin-aldosterone system (RAAS), which enzyme is responsible for
converting Angiotensin I into the active vasoconstrictor Angiotensin II?
A. Renin
,B. Angiotensin-converting enzyme (ACE)
C. Erythropoietin
D. Aldosterone synthase
Correct Answer: B
Rationale: Angiotensin-converting enzyme (ACE) is primarily found in the pulmonary
capillaries and catalyzes the conversion of Angiotensin I to Angiotensin II. Angiotensin II is
a potent vasoconstrictor that also stimulates the release of aldosterone from the adrenal
cortex. This pathway is a critical regulator of systemic blood pressure and fluid balance.
3. What is the primary physiological function of the hormone Glucagon?
A. To stimulate glycogenesis in the liver
B. To increase blood glucose levels by promoting glycogenolysis
C. To promote the storage of glucose as triglycerides
D. To increase cellular uptake of glucose through GLUT4 transporters
Correct Answer: B
Rationale: Glucagon is secreted by the alpha cells of the pancreas in response to low blood
glucose levels. Its primary action is to stimulate the liver to break down glycogen into
glucose, a process known as glycogenolysis. Additionally, it promotes gluconeogenesis to
ensure adequate blood sugar levels during fasting states.
,4. Which part of the nephron is responsible for the majority of water and nutrient
reabsorption, including 100% of filtered glucose under normal conditions?
A. Proximal Convoluted Tubule
B. Loop of Henle
C. Distal Convoluted Tubule
D. Collecting Duct
Correct Answer: A
Rationale: The proximal convoluted tubule (PCT) is the main site for reabsorption in the
kidney. It reabsorbs approximately 65% of water and electrolytes, as well as all filtered
glucose and amino acids via secondary active transport. Failure of this system often results
in glycosuria, which is a clinical indicator of exceeding the renal threshold.
5. During the ovarian cycle, which hormone surge directly triggers the process of ovulation?
A. Estrogen
B. Progesterone
C. Luteinizing Hormone (LH)
D. Follicle Stimulating Hormone (FSH)
Correct Answer: C
Rationale: A significant spike in Luteinizing Hormone (LH), known as the LH surge, occurs
mid-cycle due to positive feedback from high estrogen levels. This surge induces the
, rupture of the Graafian follicle and the release of the secondary oocyte. Without this
specific hormonal peak, the transition from the follicular phase to the luteal phase cannot
occur.
6. Which cell type in the stomach is responsible for the secretion of Hydrochloric Acid (HCl)
and Intrinsic Factor?
A. Chief Cells
B. Parietal Cells
C. G Cells
D. Mucous Neck Cells
Correct Answer: B
Rationale: Parietal cells located in the gastric glands secrete both HCl and intrinsic factor.
HCl is necessary for activating pepsinogen into pepsin, while intrinsic factor is essential for
the absorption of Vitamin B12 in the ileum. Dysfunction in these cells can lead to digestive
issues and pernicious anemia.
7. What is the effect of Parathyroid Hormone (PTH) on blood calcium levels?
A. It decreases blood calcium by stimulating osteoblasts
B. It increases blood calcium by inhibiting Vitamin D activation
C. It increases blood calcium by stimulating osteoclast activity
D. It decreases blood calcium by increasing renal excretion
