BIO 254 EXAM 2 (HONDROS) NEWEST 2026 ACTUAL
EXAM| BIO 254 EXAM 2 REVIEW WITH 250 REAL
EXAM QUESTIONS AND CORRECT VERIFIED ANSWERS/
ALREADY GRADED A+ (BRAND NEW!!)
1. Which hormone is released by the anterior pituitary in
response to thyrotropin-releasing hormone (TRH)?
A. TSH
B. T3
C. T4
D. TRH itself
Correct Answer: A
Rationale: TRH is secreted by the hypothalamus into the
hypophyseal portal system. It travels to the anterior pituitary and
binds to receptors on thyrotroph cells, stimulating them to release
thyroid-stimulating hormone (TSH). TSH then acts on the thyroid
gland to produce T3 and T4. T3/T4 provide negative feedback
to suppress TRH and TSH.
2. A patient has high blood glucose, excessive thirst, and
frequent urination. Labs show low insulin and high glucagon.
Most likely diagnosis?
A. Diabetes insipidus
1
,B. Type 1 diabetes mellitus
C. Type 2 diabetes mellitus
D. Hyperaldosteronism
Correct Answer: B
Rationale: The combination of low insulin and high glucagon
indicates destruction of pancreatic beta cells, which is
pathognomonic for type 1 diabetes mellitus. In type 2 diabetes,
insulin levels are usually normal or elevated early in the disease
due to insulin resistance. Diabetes insipidus involves ADH
deficiency, not glucose abnormalities. Hyperaldosteronism causes
hypertension and hypokalemia, not hyperglycemia.
3. Which layer of the heart is responsible for the contractile
force?
A. Epicardium
B. Myocardium
C. Endocardium
D. Pericardium
Correct Answer: B
Rationale: The myocardium is the middle, thickest layer of the
heart wall and is composed of cardiac muscle cells
(cardiomyocytes) that contain sarcomeres with actin and myosin
filaments. Contraction occurs via the sliding filament mechanism
2
,when calcium enters the cytosol. The epicardium is the visceral
pericardium (protective), the endocardium lines the chambers
(prevents clotting), and the pericardium is a sac around the heart.
4. The P wave on an ECG represents:
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. AV nodal delay
Correct Answer: B
Rationale: The P wave is produced by the spread of electrical
depolarization from the sinoatrial (SA) node through both atria
via Bachmann’s bundle and interatrial pathways. Atrial
depolarization causes atrial contraction. Ventricular
depolarization produces the QRS complex, and ventricular
repolarization produces the T wave. The PR segment (not the P
wave) represents the AV nodal delay.
5. Which of the following vessels carries deoxygenated blood
to the lungs?
A. Aorta
B. Pulmonary vein
C. Pulmonary artery
3
, D. Coronary artery
Correct Answer: C
Rationale: The pulmonary artery is the only artery in the adult
body that carries deoxygenated blood. It arises from the right
ventricle and splits into left and right pulmonary arteries,
delivering blood to the lungs for oxygenation. The aorta carries
oxygenated blood to the body. Pulmonary veins carry
oxygenated blood from lungs to left atrium. Coronary arteries
supply heart muscle with oxygenated blood.
6. A decrease in plasma volume (e.g., hemorrhage) triggers:
A. Decreased ADH
B. Increased ANP
C. Increased aldosterone
D. Decreased renin
Correct Answer: C
Rationale: Hypovolemia is detected by baroreceptors in the
carotid sinus, aortic arch, and juxtaglomerular cells of the kidney.
This triggers renin release from the kidneys, leading to
angiotensin II formation, which stimulates aldosterone secretion
from the adrenal cortex. Aldosterone increases sodium and
water reabsorption in the distal tubule and collecting duct,
4
EXAM| BIO 254 EXAM 2 REVIEW WITH 250 REAL
EXAM QUESTIONS AND CORRECT VERIFIED ANSWERS/
ALREADY GRADED A+ (BRAND NEW!!)
1. Which hormone is released by the anterior pituitary in
response to thyrotropin-releasing hormone (TRH)?
A. TSH
B. T3
C. T4
D. TRH itself
Correct Answer: A
Rationale: TRH is secreted by the hypothalamus into the
hypophyseal portal system. It travels to the anterior pituitary and
binds to receptors on thyrotroph cells, stimulating them to release
thyroid-stimulating hormone (TSH). TSH then acts on the thyroid
gland to produce T3 and T4. T3/T4 provide negative feedback
to suppress TRH and TSH.
2. A patient has high blood glucose, excessive thirst, and
frequent urination. Labs show low insulin and high glucagon.
Most likely diagnosis?
A. Diabetes insipidus
1
,B. Type 1 diabetes mellitus
C. Type 2 diabetes mellitus
D. Hyperaldosteronism
Correct Answer: B
Rationale: The combination of low insulin and high glucagon
indicates destruction of pancreatic beta cells, which is
pathognomonic for type 1 diabetes mellitus. In type 2 diabetes,
insulin levels are usually normal or elevated early in the disease
due to insulin resistance. Diabetes insipidus involves ADH
deficiency, not glucose abnormalities. Hyperaldosteronism causes
hypertension and hypokalemia, not hyperglycemia.
3. Which layer of the heart is responsible for the contractile
force?
A. Epicardium
B. Myocardium
C. Endocardium
D. Pericardium
Correct Answer: B
Rationale: The myocardium is the middle, thickest layer of the
heart wall and is composed of cardiac muscle cells
(cardiomyocytes) that contain sarcomeres with actin and myosin
filaments. Contraction occurs via the sliding filament mechanism
2
,when calcium enters the cytosol. The epicardium is the visceral
pericardium (protective), the endocardium lines the chambers
(prevents clotting), and the pericardium is a sac around the heart.
4. The P wave on an ECG represents:
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. AV nodal delay
Correct Answer: B
Rationale: The P wave is produced by the spread of electrical
depolarization from the sinoatrial (SA) node through both atria
via Bachmann’s bundle and interatrial pathways. Atrial
depolarization causes atrial contraction. Ventricular
depolarization produces the QRS complex, and ventricular
repolarization produces the T wave. The PR segment (not the P
wave) represents the AV nodal delay.
5. Which of the following vessels carries deoxygenated blood
to the lungs?
A. Aorta
B. Pulmonary vein
C. Pulmonary artery
3
, D. Coronary artery
Correct Answer: C
Rationale: The pulmonary artery is the only artery in the adult
body that carries deoxygenated blood. It arises from the right
ventricle and splits into left and right pulmonary arteries,
delivering blood to the lungs for oxygenation. The aorta carries
oxygenated blood to the body. Pulmonary veins carry
oxygenated blood from lungs to left atrium. Coronary arteries
supply heart muscle with oxygenated blood.
6. A decrease in plasma volume (e.g., hemorrhage) triggers:
A. Decreased ADH
B. Increased ANP
C. Increased aldosterone
D. Decreased renin
Correct Answer: C
Rationale: Hypovolemia is detected by baroreceptors in the
carotid sinus, aortic arch, and juxtaglomerular cells of the kidney.
This triggers renin release from the kidneys, leading to
angiotensin II formation, which stimulates aldosterone secretion
from the adrenal cortex. Aldosterone increases sodium and
water reabsorption in the distal tubule and collecting duct,
4
