CTBS Anatomy and Physiology 3 — Questions and Answers
Question 1: Which anatomical region of a long bone is the primary site of hematopoiesis in adults?
- Epiphysis
- Diaphysis red marrow (Correct answer)
- Articular cartilage
- Periosteum
Correct answer: Diaphysis red marrow
In adults, red bone marrow in the diaphysis of certain bones (and epiphyses of flat bones) is the primary site of blood cell production.
Question 2: When recovering heart valves, a tissue specialist must know that the aortic valve has how many cusps under normal anatomy?
- Two
- Three (Correct answer)
- Four
- Five
Correct answer: Three
The normal aortic valve has three cusps (right, left, and non-coronary), and a bicuspid aortic valve is considered a congenital anomaly.
Question 3: Osseointegration of allograft bone is facilitated by which property of the bone extracellular matrix?
- High lipid content in osteocyte lacunae
- Hydroxyapatite mineral crystals deposited in collagen (Correct answer)
- Elastic fibers woven between osteons
- Proteoglycan-only matrix without mineral component
Correct answer: Hydroxyapatite mineral crystals deposited in collagen
Hydroxyapatite crystals deposited within the collagen framework of bone provide the mineral scaffold that enables host bone ingrowth and osseointegration.
Question 4: The femoral triangle is a clinically important anatomical region bounded superiorly by the inguinal ligament. Which structure occupies the most medial position within the femoral triangle?
- Femoral nerve
- Femoral artery
- Femoral vein
- Femoral canal (Correct answer)
Correct answer: Femoral canal
From lateral to medial in the femoral triangle: nerve, artery, vein, canal — remembered by the mnemonic NAVY (Nerve, Artery, Vein, Y-fronts/canal).
Question 5: During eye banking, the trabecular meshwork is significant because it regulates which physiological process?
- Accommodation of the lens for focusing
- Aqueous humor drainage and intraocular pressure (Correct answer)
- Photoreception in the peripheral retina
- Tear film production and distribution
Correct answer: Aqueous humor drainage and intraocular pressure
The trabecular meshwork at the iridocorneal angle drains aqueous humor into Schlemm's canal, directly regulating intraocular pressure.
Question 6: Which anatomical feature distinguishes cortical (compact) bone from cancellous (trabecular) bone at the microstructural level?
- Cortical bone lacks osteons; cancellous bone has organized Haversian systems
- Cortical bone has Haversian systems (osteons); cancellous bone has a lattice of trabeculae (Correct answer)
- Both have identical microstructure but differ only in density
- Cancellous bone contains more calcium hydroxyapatite than cortical bone
Correct answer: Cortical bone has Haversian systems (osteons); cancellous bone has a lattice of trabeculae
Cortical bone is organized into Haversian systems (osteons) with central canals, while cancellous bone consists of a porous lattice of trabeculae enclosing marrow spaces.
Question 7: In skin tissue banking, which layer of the skin contains the stem cells responsible for epidermal regeneration?
- Stratum corneum
- Stratum granulosum
- Stratum basale (Correct answer)
- Stratum spinosum
Correct answer: Stratum basale
The stratum basale (basal layer) contains keratinocyte stem cells that continuously divide to replenish the upper epidermal layers.
CTBS Anatomy and Physiology 3
Which anatomical region of a long bone is the primary site of hematopoiesis in adults?