Anatomy & Physiology I - Midterm Examination (BSN) 2026/2027
UPDATE
1. Which type of epithelial tissue is most likely to be found lining the alveoli of
the lungs where gas exchange occurs?
A. Simple squamous epithelium
B. Stratified squamous epithelium
C. Simple columnar epithelium
D. Transitional epithelium
Answer: A
Rationale: Simple squamous epithelium is a single layer of flat cells that allows for rapid
diffusion and filtration, making it ideal for the air sacs of the lungs.
2. Which organelle is responsible for the synthesis of ATP during aerobic
respiration?
A. Golgi apparatus
B. Mitochondrion
C. Lysosome
D. Smooth endoplasmic reticulum
Answer: B
Rationale: The mitochondrion is the ‘powerhouse’ of the cell where oxygen is used to
produce ATP from nutrients.
,3. In the anatomical position, the thumb is ______ to the pinky finger.
A. Lateral
B. Medial
C. Proximal
D. Distal
Answer: A
Rationale: In anatomical position, palms face forward, placing the thumb on the side away
from the midline, which is lateral.
4. Which of the following is an example of a negative feedback mechanism?
A. Insulin lowering blood glucose levels
B. Blood clotting after an injury
C. Oxytocin release during childbirth
D. Generation of an action potential
Answer: A
Rationale: Negative feedback works to reverse a change and return the system to
homeostasis, such as lowering high blood sugar.
5. The structural unit of compact bone is called the:
A. Osteocyte
B. Canaliculus
C. Trabecula
D. Osteon
Answer: D
Rationale: An osteon (or Haversian system) is the repeating structural unit of compact
bone consisting of concentric lamellae.
, 6. During muscle contraction, calcium ions bind to which protein to expose the
active sites on actin?
A. Myosin
B. Tropomyosin
C. Troponin
D. Titin
Answer: C
Rationale: Calcium binds to troponin, which then shifts tropomyosin away from the
myosin-binding sites on the actin filament.
7. Which layer of the skin contains melanocytes responsible for UV protection?
A. Stratum corneum
B. Stratum basale
C. Papillary dermis
D. Hypodermis
Answer: B
Rationale: Melanocytes are found in the deepest layer of the epidermis, the stratum basale.
8. What is the primary function of the neurotransmitter Acetylcholine at the
neuromuscular junction?
A. To inhibit muscle contraction
B. To bind to receptors and initiate an action potential in the muscle fiber
C. To stimulate the release of calcium from the sarcoplasmic reticulum
D. To cause repolarization of the sarcolemma
Answer: B
Rationale: Acetylcholine binds to nicotinic receptors on the motor end plate to trigger
depolarization of the muscle cell.
UPDATE
1. Which type of epithelial tissue is most likely to be found lining the alveoli of
the lungs where gas exchange occurs?
A. Simple squamous epithelium
B. Stratified squamous epithelium
C. Simple columnar epithelium
D. Transitional epithelium
Answer: A
Rationale: Simple squamous epithelium is a single layer of flat cells that allows for rapid
diffusion and filtration, making it ideal for the air sacs of the lungs.
2. Which organelle is responsible for the synthesis of ATP during aerobic
respiration?
A. Golgi apparatus
B. Mitochondrion
C. Lysosome
D. Smooth endoplasmic reticulum
Answer: B
Rationale: The mitochondrion is the ‘powerhouse’ of the cell where oxygen is used to
produce ATP from nutrients.
,3. In the anatomical position, the thumb is ______ to the pinky finger.
A. Lateral
B. Medial
C. Proximal
D. Distal
Answer: A
Rationale: In anatomical position, palms face forward, placing the thumb on the side away
from the midline, which is lateral.
4. Which of the following is an example of a negative feedback mechanism?
A. Insulin lowering blood glucose levels
B. Blood clotting after an injury
C. Oxytocin release during childbirth
D. Generation of an action potential
Answer: A
Rationale: Negative feedback works to reverse a change and return the system to
homeostasis, such as lowering high blood sugar.
5. The structural unit of compact bone is called the:
A. Osteocyte
B. Canaliculus
C. Trabecula
D. Osteon
Answer: D
Rationale: An osteon (or Haversian system) is the repeating structural unit of compact
bone consisting of concentric lamellae.
, 6. During muscle contraction, calcium ions bind to which protein to expose the
active sites on actin?
A. Myosin
B. Tropomyosin
C. Troponin
D. Titin
Answer: C
Rationale: Calcium binds to troponin, which then shifts tropomyosin away from the
myosin-binding sites on the actin filament.
7. Which layer of the skin contains melanocytes responsible for UV protection?
A. Stratum corneum
B. Stratum basale
C. Papillary dermis
D. Hypodermis
Answer: B
Rationale: Melanocytes are found in the deepest layer of the epidermis, the stratum basale.
8. What is the primary function of the neurotransmitter Acetylcholine at the
neuromuscular junction?
A. To inhibit muscle contraction
B. To bind to receptors and initiate an action potential in the muscle fiber
C. To stimulate the release of calcium from the sarcoplasmic reticulum
D. To cause repolarization of the sarcolemma
Answer: B
Rationale: Acetylcholine binds to nicotinic receptors on the motor end plate to trigger
depolarization of the muscle cell.
