UExcel Anatomy and Physiology 3

Question 1

The bicarbonate buffer system in the blood primarily regulates:

Accepted Answer

Blood pH

Answer

The bicarbonate buffer system (CO2/HCO3−) is the primary blood buffer, maintaining pH near 7.4.

Question 2

Which type of cartilage is found in the intervertebral discs?

Accepted Answer

Fibrocartilage

Answer

Fibrocartilage, which is tough and compressible, makes up the intervertebral discs and pubic symphysis.

Question 3

During depolarization of a neuron, which ion rapidly moves INTO the cell?

Accepted Answer

Sodium (Na+)

Answer

During depolarization, voltage-gated Na+ channels open and sodium ions rush into the cell, making the interior more positive.

Question 4

Which organ produces bile salts used in fat digestion?

Accepted Answer

Liver

Answer

The liver synthesizes bile salts; the gallbladder only stores and concentrates bile before releasing it into the duodenum.

Question 5

Which hormone, produced by the adrenal cortex, promotes sodium retention and potassium excretion by the kidneys?

Accepted Answer

Aldosterone

Answer

Aldosterone, a mineralocorticoid, acts on the distal tubule and collecting duct to increase Na+ reabsorption and K+ secretion.

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