BIOS 251
Anatomy & Physiology I
Final Exams Review (Qns & Ans)
2025
1. Which of the following structures is primarily responsible for
the blood-brain barrier?
- a) Astrocytes
- b) Oligodendrocytes
- c) Ependymal cells
- d) Microglia
ANS: a) Astrocytes
Rationale: Astrocytes are glial cells that contribute to the
formation and maintenance of the blood-brain barrier, essential in
©2025
,protecting the central nervous system from potentially harmful
substances.
2. What is the primary function of parathyroid hormone (PTH)?
- a) To decrease blood calcium levels
- b) To increase blood calcium levels
- c) To decrease blood sodium levels
- d) To increase blood potassium levels
ANS: b) To increase blood calcium levels
Rationale: PTH is secreted by the parathyroid glands and
plays a crucial role in raising blood calcium levels by stimulating
osteoclast activity, increasing intestinal absorption of calcium,
and reabsorbing calcium in the kidneys.
3. In which part of the nephron does the majority of solute
reabsorption occur?
- a) Distal convoluted tubule
- b) Collecting duct
- c) Proximal convoluted tubule
- d) Loop of Henle
ANS: c) Proximal convoluted tubule
©2025
, Rationale: The proximal convoluted tubule reabsorbs
approximately 65-70% of the filtrate, making it the primary site
for solute reabsorption in the nephron.
4. What is the primary role of myoglobin in muscle cells?
- a) To transport calcium ions
- b) To store oxygen
- c) To release neurotransmitters
- d) To form cross-bridges during muscle contraction
ANS: b) To store oxygen
Rationale: Myoglobin is a muscle protein that stores oxygen
and facilitates oxygen transport within muscles, essential for
aerobic respiration.
5. Which type of muscle fiber is usually thicker and designed for
short bursts of power and speed?
- a) Type I fibers
- b) Type IIa fibers
- c) Type IIx fibers
- d) Type III fibers
ANS: c) Type IIx fibers
©2025
, Rationale: Type IIx fibers (fast-twitch glycolytic fibers) are
adapted for short-duration high-intensity activities such as
sprinting or weightlifting.
Fill-in-the-Blank Questions
6. The main function of the __________ lobe of the brain is the
processing of visual information.
ANS: occipital
Rationale: The occipital lobe is located at the back of the
brain and is primarily responsible for interpreting visual stimuli.
7. In the cardiac cycle, the __________ node is known as the
primary pacemaker of the heart.
ANS: sinoatrial (SA)
Rationale: The SA node generates electrical impulses that
initiate each heartbeat and sets the pace for the entire heart.
8. The process by which white blood cells move toward the site of
an infection in response to chemical signals is called __________.
ANS: chemotaxis
Rationale: Chemotaxis is the movement of cells toward a
chemical stimulus and is critical for an immune response.
©2025
Anatomy & Physiology I
Final Exams Review (Qns & Ans)
2025
1. Which of the following structures is primarily responsible for
the blood-brain barrier?
- a) Astrocytes
- b) Oligodendrocytes
- c) Ependymal cells
- d) Microglia
ANS: a) Astrocytes
Rationale: Astrocytes are glial cells that contribute to the
formation and maintenance of the blood-brain barrier, essential in
©2025
,protecting the central nervous system from potentially harmful
substances.
2. What is the primary function of parathyroid hormone (PTH)?
- a) To decrease blood calcium levels
- b) To increase blood calcium levels
- c) To decrease blood sodium levels
- d) To increase blood potassium levels
ANS: b) To increase blood calcium levels
Rationale: PTH is secreted by the parathyroid glands and
plays a crucial role in raising blood calcium levels by stimulating
osteoclast activity, increasing intestinal absorption of calcium,
and reabsorbing calcium in the kidneys.
3. In which part of the nephron does the majority of solute
reabsorption occur?
- a) Distal convoluted tubule
- b) Collecting duct
- c) Proximal convoluted tubule
- d) Loop of Henle
ANS: c) Proximal convoluted tubule
©2025
, Rationale: The proximal convoluted tubule reabsorbs
approximately 65-70% of the filtrate, making it the primary site
for solute reabsorption in the nephron.
4. What is the primary role of myoglobin in muscle cells?
- a) To transport calcium ions
- b) To store oxygen
- c) To release neurotransmitters
- d) To form cross-bridges during muscle contraction
ANS: b) To store oxygen
Rationale: Myoglobin is a muscle protein that stores oxygen
and facilitates oxygen transport within muscles, essential for
aerobic respiration.
5. Which type of muscle fiber is usually thicker and designed for
short bursts of power and speed?
- a) Type I fibers
- b) Type IIa fibers
- c) Type IIx fibers
- d) Type III fibers
ANS: c) Type IIx fibers
©2025
, Rationale: Type IIx fibers (fast-twitch glycolytic fibers) are
adapted for short-duration high-intensity activities such as
sprinting or weightlifting.
Fill-in-the-Blank Questions
6. The main function of the __________ lobe of the brain is the
processing of visual information.
ANS: occipital
Rationale: The occipital lobe is located at the back of the
brain and is primarily responsible for interpreting visual stimuli.
7. In the cardiac cycle, the __________ node is known as the
primary pacemaker of the heart.
ANS: sinoatrial (SA)
Rationale: The SA node generates electrical impulses that
initiate each heartbeat and sets the pace for the entire heart.
8. The process by which white blood cells move toward the site of
an infection in response to chemical signals is called __________.
ANS: chemotaxis
Rationale: Chemotaxis is the movement of cells toward a
chemical stimulus and is critical for an immune response.
©2025
