Summarize the role of parathyroid hormone (PTH) and vitamin D3 (calcitriol) in calcium ion and phosphate ion concentration regulation

What will be an ideal response?


Vitamin D3 (calcitriol) is a potent stimulator of calcium ion absorption by the small intestine. Vitamin D3 also assists PTH in increasing osteoclast activity and calcium ion reabsorption from the kidneys. With regard to phosphate ions, vitamin D3 triggers their absorption from the small intestine. This increases the concentration of phosphate ions in the ECF, in contrast to the effects of PTH, which decreases their level. This helps to ensure that the level of phosphate ions in the ECF does not fall too low.

Anatomy & Physiology

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When the bladder is full, urine is eliminated through the process known as

A) beta-oxidation. B) defecation. C) emesis. D) micturition. E) segmentation.

Anatomy & Physiology

Which of the following types of muscle fatigue are due to calcium imbalances?

A) psychological B) synaptic C) muscular D) axonic

Anatomy & Physiology

The masseter muscle originates on the __________.

A. medial surface of maxilla, but not the zygomatic arch B. inferior border of the zygomatic arch only C. medial surfaces of the maxilla and the zygomatic arch as well as the inferior border of the zygomatic arch D. medial and lateral surfaces of the maxilla and the inferior and superior border of the zygomatic arch

Anatomy & Physiology

The rough endoplasmic reticulum is most abundant in cells specialized for protein secretion, whereas smooth endoplasmic reticulum is abundant in cells that specialize in lipid metabolism

Indicate whether the statement is true or false

Anatomy & Physiology