Ficks law, describes the effects of various factors on the rate of diffusion. Which statement is true?
- A. The smaller the difference in concentrations the greater the rate of diffusion
- B. The larger the surface area/volume ratio the greater the rate of diffusion
- C. The use of a Transporter Room (as seen in Star Trek) the greater the rate of diffusion
- D. The thicker the exchange surface the greater the rate of diffusion
Correct Answer: B
Rationale: Fick's law states that diffusion rate increases with a larger surface area, steeper concentration gradient, and thinner membrane.
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Exocrine portion of pancreas show the following EXCEPT:
- A. Formed of pure serous acini with centroacinar cells
- B. Its duct system is rich in striated ducts
- C. Secretion of bicarbonate is stimulated by secretin hormone.
- D. Secretion of enzymes is stimulated by cholecystokinin
Correct Answer: B
Rationale: The pancreatic duct system has intercalated ducts, not striated ducts, which are characteristic of salivary glands.
Amylase is an example of a(n)
- A. accessory organ
- B. carbohydrate
- C. enzyme
- D. vitamin
Correct Answer: C
Rationale: Amylase is an enzyme that breaks down starches into sugars.
What additional role does the pancreas play?
- A. Regulates blood sugar
- B. Produces bile
- C. Stores vitamins
- D. Secretes mucus
Correct Answer: A
Rationale: The pancreas has an endocrine role, releasing insulin and glucagon to regulate blood sugar.
Which features make a villus well adapted for absorbing amino acids from the ileum?
- A. large surface area, thin walls, lacteal
- B. large surface area: volume ratio, good blood supply, thin walls
- C. small surface area, good blood supply, lacteal
- D. small surface area: volume ratio, good blood supply, thin walls
Correct Answer: B
Rationale: Villi have a large surface area to volume ratio, good blood supply, and thin walls, facilitating efficient absorption of nutrients such as amino acids.
Teeth adapted to shear food are:
- A. premolars
- B. canines
- C. incisors
- D. molars
Correct Answer: C
Rationale: Incisors are sharp-edged teeth designed for cutting or shearing food.