Author Question: What is the significance of a transient ischemic attack (TIA)? A) It is a warning sign that a ... (Read 101 times)

2125004343 · **on:** Aug 21, 2018

What is the significance of a transient ischemic attack (TIA)?
A) It is a warning sign that a severe stroke will follow.
B) It causes permanent damage to the neurological system.
C) It requires intravenous tissue plasminogen activator.
D) It requires frequent monitoring, but no other treatment.

Question 2

Describe the process by which vitamin D from the diet is activated in order to function fully. How does this differ from vitamin D derived from a precursor to cholesterol, 7-dehydrocholesterol?

yeungji · **Reply #1 on:** Aug 21, 2018

Answer to Question 1

A

Answer to Question 2

Vitamin D is ingested from either plants or animals as either vitamin D2 or D3, respectively, and is transported to the liver, where one hydroxyl group is added (now called calcidiol), and then transported to the kidney for a second hydroxyl group is added (now called calcitriol, or the active form of vitamin D). This differs from vitamin D that is derived from 7-dehydrocholesterol, in that this compound is converted by UV light in skin cells to previtamin D3, which is then converted to vitamin D3 using heat in the body. The vitamin D3 is then converted in the liver and kidney in the same manner that dietary vitamin D is converted to its active form.