The thyroid gland is under the control of the pituitary gland. When the level of thyroid hormones (T3 and T4) drop the pituitary gland produces thyroid stimulating hormone (TSH), which stimulates the thyroid to produce more hormones. Under the influence of TSH, the thyroid will manufacture and secrete more T3 and T4, thus raising blood levels of thyroid hormones. The pituitary gland senses this and will decrease TSH production. This cycle is an example of a(n):

An example of a gland that utilizes apocrine secretion is: 

Erythrocytes do not have a nucleus.

Sudoriferous and sebaceous glands are examples of:

In order to connect the ________ containing the ___________, there are networks of tiny canals called _________ .

The human body obtains vitamin D either from the diet or sun exposure. Darker-skinned individuals require more sunlight to create adequate vitamin D stores as the increased melanin in their skin acts like sunscreen; thus, it blocks the necessary UV required for vitamin D synthesis. Therefore, if these individuals spend inadequate time in the light, dietary sources of vitamin D are necessary. What form of vitamin D requires sunlight for its formation?

What ends the positive feedback loop after a damaged endothelium starts the clotting cascade and aggregation of platelets to repair the integrity of the artery wall?

The reticular layer of the dermis of the skin is composed of dense irregular connective tissue. Where else is dense irregular connective tissue located in the body?

What type of connective tissue is a common injection site for drugs?

You decide to go for a jog on the trail near your house. Prior to your jog, you decide to get in a quick warmup. You start by doing lateral lunges out to each side to stretch out the upper part of your inner thigh. This motion would be in what type of plane?