Nokea
Peristalsis in the muscle component of the human esophagus is produced by:
- A. A gradient in slow waves going from the top to the bottom
- B. Gravity moving swallowed food down the esophagus
- C. Simultaneous contraction of the entire longitudinal muscle layer
- D. Sequential firing of the extrinsic nerves from the nucleus ambiguous
Correct Answer: D
Rationale: Sequential firing of vagal nerves from the nucleus ambiguus coordinates esophageal peristalsis, moving food downward.
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The cells of the proximal convoluted tubule contain a lot of mitochondria. Why?
- A. Mitochondria produce the energy required for the passive transport of compounds across the membrane
- B. Mitochondria produce the energy required for the diffusion of compounds across the membrane
- C. Mitochondria produce the energy required for the pumping of compounds through the tubules
- D. Mitochondria produce the energy required for the active transport of compounds across the membrane
Correct Answer: D
Rationale: Mitochondria provide ATP for active transport of nutrients like glucose in the proximal convoluted tubule.
Food and chyme are pushed through the digestive system by:
- A. ingestion
- B. mastication
- C. assimilation
- D. peristalsis
Correct Answer: D
Rationale: Peristalsis refers to the rhythmic contractions of smooth muscle that propel food and chyme through the digestive tract.
Which process matches the definition: The process of distributing absorbed nutrients to the cells of the body for growth and repair?
- A. Ingestion
- B. Absorption
- C. Assimilation
- D. Peristalsis
Correct Answer: C
Rationale: Assimilation involves distributing absorbed nutrients to body cells for use.
The diagram shows a section through a villus. Y X What is a function of structure X and of structure Y?
- A. X: to absorb amino acids, Y: to digest starch
- B. X: to carry blood, Y: to secrete mucus
- C. X: to transport fats, Y: to secrete enzymes
- D. X: to transport glucose, Y: to help peristalsis
Correct Answer: A
Rationale: Structure X (epithelial cells) absorbs amino acids, while structure Y (goblet cells) secretes mucus.
Match each term with the correct description: filtering units of kidney
- A. urethra
- B. nephrons
- C. bladder
- D. kidneys
Correct Answer: B
Rationale: Nephrons are the filtering units within the kidneys.