BIOS 256 ANATOMY AND PHYSIOLOGY
II MIDTERM EXAMINATION STUDY
GUIDE QUESTIONS AND VERIFIED
ANSWERS |GRADE A+| CHAMBERLAIN
COLLEGE OF NURSING
1. When a water-soluble hormone binds to its receptor on the plasma membrane, what is
typically the next step in the signal transduction pathway?
A. Activation of a G-protein
B. The hormone-receptor complex moves into the nucleus
C. Direct activation of gene transcription
D. Diffusion through the lipid bilayer
Answer: A
Conceptual Explanation: Water-soluble hormones cannot cross the plasma membrane;
they bind to surface receptors which then activate G-proteins to initiate a second
messenger cascade.
2. Which region of the brain is responsible for synthesizing Oxytocin and Antidiuretic
Hormone (ADH) before they are stored in the posterior pituitary?
A. Hypothalamus
,B. Thalamus
C. Adenohypophysis
D. Pineal gland
Answer: A
Conceptual Explanation: Oxytocin and ADH are produced by neurosecretory cells in the
hypothalamus and transported via the hypothalamo-hypophyseal tract to the posterior
pituitary for release.
3. In the synthesis of thyroid hormones, which enzyme is responsible for the oxidation of
iodide and the attachment of iodine to tyrosine residues on thyroglobulin?
A. Angiotensin converting enzyme
B. Monoamine oxidase
C. Thyroid peroxidase
D. Carbonic anhydrase
Answer: C
Conceptual Explanation: Thyroid peroxidase (TPO) is the key enzyme that oxidizes iodide
and mediates the iodination of tyrosine on thyroglobulin.
4. Which zone of the adrenal cortex is specifically responsible for the secretion of
mineralocorticoids like aldosterone?
A. Zona fasciculata
, B. Zona reticularis
C. Adrenal medulla
D. Zona glomerulosa
Answer: D
Conceptual Explanation: The zona glomerulosa is the outermost layer of the adrenal
cortex and produces mineralocorticoids, primarily aldosterone, to regulate electrolyte
balance.
5. What is the primary physiological effect of Glucagon secretion from the alpha cells of the
pancreas?
A. Stimulation of glycogenesis
B. Stimulation of glycogenolysis in the liver
C. Increased glucose uptake by skeletal muscle
D. Inhibition of gluconeogenesis
Answer: B
Conceptual Explanation: Glucagon acts to increase blood glucose levels primarily by
stimulating the breakdown of glycogen (glycogenolysis) and the synthesis of glucose from
non-carbohydrates (gluconeogenesis) in the liver.
II MIDTERM EXAMINATION STUDY
GUIDE QUESTIONS AND VERIFIED
ANSWERS |GRADE A+| CHAMBERLAIN
COLLEGE OF NURSING
1. When a water-soluble hormone binds to its receptor on the plasma membrane, what is
typically the next step in the signal transduction pathway?
A. Activation of a G-protein
B. The hormone-receptor complex moves into the nucleus
C. Direct activation of gene transcription
D. Diffusion through the lipid bilayer
Answer: A
Conceptual Explanation: Water-soluble hormones cannot cross the plasma membrane;
they bind to surface receptors which then activate G-proteins to initiate a second
messenger cascade.
2. Which region of the brain is responsible for synthesizing Oxytocin and Antidiuretic
Hormone (ADH) before they are stored in the posterior pituitary?
A. Hypothalamus
,B. Thalamus
C. Adenohypophysis
D. Pineal gland
Answer: A
Conceptual Explanation: Oxytocin and ADH are produced by neurosecretory cells in the
hypothalamus and transported via the hypothalamo-hypophyseal tract to the posterior
pituitary for release.
3. In the synthesis of thyroid hormones, which enzyme is responsible for the oxidation of
iodide and the attachment of iodine to tyrosine residues on thyroglobulin?
A. Angiotensin converting enzyme
B. Monoamine oxidase
C. Thyroid peroxidase
D. Carbonic anhydrase
Answer: C
Conceptual Explanation: Thyroid peroxidase (TPO) is the key enzyme that oxidizes iodide
and mediates the iodination of tyrosine on thyroglobulin.
4. Which zone of the adrenal cortex is specifically responsible for the secretion of
mineralocorticoids like aldosterone?
A. Zona fasciculata
, B. Zona reticularis
C. Adrenal medulla
D. Zona glomerulosa
Answer: D
Conceptual Explanation: The zona glomerulosa is the outermost layer of the adrenal
cortex and produces mineralocorticoids, primarily aldosterone, to regulate electrolyte
balance.
5. What is the primary physiological effect of Glucagon secretion from the alpha cells of the
pancreas?
A. Stimulation of glycogenesis
B. Stimulation of glycogenolysis in the liver
C. Increased glucose uptake by skeletal muscle
D. Inhibition of gluconeogenesis
Answer: B
Conceptual Explanation: Glucagon acts to increase blood glucose levels primarily by
stimulating the breakdown of glycogen (glycogenolysis) and the synthesis of glucose from
non-carbohydrates (gluconeogenesis) in the liver.
