APHY 102 Midterm Questions With Complete Solutions

APHY 102 Midterm Questions
With Complete Solutions
Course
APHY 102 (APHY102)
Question 1
Which chamber of the heart pumps oxygenated blood into the systemic circulation?
A. Right atrium
B. Right ventricle
C. Left atrium
D. Left ventricle
Correct Answer: D. Left ventricle
Complete Solution
The left ventricle pumps oxygen-rich blood through the aorta to the entire body. It has the
thickest myocardium because it must generate enough pressure to move blood through systemic
circulation.
Heart blood flow:
1. Right atrium → right ventricle
2. Right ventricle → lungs
3. Left atrium → left ventricle
4. Left ventricle → body tissues


Question 2
Which structure prevents backflow of blood from the left ventricle into the left atrium?
A. Tricuspid valve
B. Pulmonary valve
C. Mitral valve
D. Aortic valve
Correct Answer: C. Mitral valve
Complete Solution
The mitral (bicuspid) valve separates the left atrium and left ventricle. It opens when blood
moves into the ventricle and closes during ventricular contraction to prevent backward flow.

,Question 3
What is the primary function of erythrocytes (red blood cells)?
A. Fight infections
B. Produce antibodies
C. Transport oxygen
D. Initiate blood clotting
Correct Answer: C. Transport oxygen
Complete Solution
Red blood cells contain hemoglobin, a protein that binds oxygen in the lungs and transports it to
tissues.
Other blood components:
 Leukocytes → immune defense
 Platelets → clot formation
 Plasma → transports nutrients and hormones


Question 4
Which hormone increases blood glucose levels during fasting?
A. Insulin
B. Glucagon
C. Melatonin
D. Calcitonin
Correct Answer: B. Glucagon
Complete Solution
The pancreas produces:
 Insulin → lowers blood glucose by promoting glucose uptake
 Glucagon → raises blood glucose by stimulating glycogen breakdown in the liver
Together they maintain glucose homeostasis.

,Question 5
Gas exchange between air and blood occurs primarily in the:
A. Bronchi
B. Trachea
C. Alveoli
D. Larynx
Correct Answer: C. Alveoli
Complete Solution
The alveoli are tiny air sacs where:
 Oxygen diffuses into blood
 Carbon dioxide diffuses out of blood
Their thin walls and large surface area make gas exchange efficient.


Question 6
Which organ is responsible for filtering blood and producing urine?
A. Liver
B. Kidney
C. Pancreas
D. Spleen
Correct Answer: B. Kidney
Complete Solution
The kidneys maintain homeostasis by:
 Removing wastes
 Regulating fluid balance
 Controlling electrolytes
 Producing urine
The functional unit of the kidney is the nephron.


Question 7

, Which immune cell type is responsible for producing antibodies?
A. B lymphocytes
B. Red blood cells
C. Platelets
D. Neutrophils
Correct Answer: A. B lymphocytes
Complete Solution
B lymphocytes become plasma cells that produce antibodies.
Immune cells:
 B cells → antibody production
 T cells → cell-mediated immunity
 Neutrophils → bacterial defense
 Macrophages → engulf pathogens


Question 8
The primary function of the small intestine is:
A. Storing bile
B. Absorbing nutrients
C. Producing urine
D. Filtering blood
Correct Answer: B. Absorbing nutrients
Complete Solution
The small intestine is the major site for:
 Digestion
 Nutrient absorption
 Movement of nutrients into blood and lymph
Structures called villi and microvilli increase absorption surface area.


Question 9