1.4 Major Endocrine Glands and Pathways

Question 1

What is an exocrine gland?

Answer 1

Glands have secretory cells arranged so that their apical membranes face the external world in the form of a duct.

Question 2

What kind of secretions do exocrine glands produce?

Answer 2

Sweat, sebum, milk, digestive enzymes, pheromones (never hormones). Collect material from the fluids that bather them, ultimately communicating with the blood

Question 3

What is an endocrine gland?

Answer 3

Produce and secrete hormones into the extracellular fluid, where they move into capillary walls and into the blood.

Question 4

What is the difference between the exocrine and endocrine pancreas?

Answer 4

• Exocrine pancreas cells secrete digestive enzymes

- Endocrine pancreas cells secrete glucagon and insulin

Question 5

Whats is the difference between alpha and beta pancreas cells?

Answer 5

• Alpha cells produce and secrete the peptide hormone glucagon. Glucagon tells cells to contribute more glucose into the bloodstream when concentrations are low.
• Beta cells produce and secrete the peptide insulin. Insulin works at target tissues to decrease blood glucose concentrations.

Question 6

Do glucagon and insulin have a great impact on the brain?

Answer 6

No. Glucose is in a fairly constant supply thanks to all other tissues.

Question 7

How do glucagon and insulin affect muscles and adipose?

Answer 7

Since muscle is not a source of glucose for the blood, there is no role for glucagon in muscle metabolism. Adipose does not produce glucose so glucagon does not really affect adipose.

Question 8

Are glucose and insulin important for the liver?

Answer 8

Yes. When glucose is high, insulin causes the liver to become much better able to take up glucose. Insulin blocks glycogen breakdown which favors glycogen synthesis.

Question 9

What are antagonistic hormones?

Answer 9

Antagonistic hormones are hormones that work to exert opposite change but they do so through different pathways.

Question 10

What is additivity?

Answer 10

Additivity is when two hormones work together to create a response that is equal to the sum of both of their individual responses.

Question 11

What is synergy?

Answer 11

Synergy is when hormones work together and their response is greater than the sum of their individual responses.

Question 12

What are tropic hormones?

Answer 12

Tropic hormones are those whose main job is to regulate the release of other hormones. ex. hypothalamic hormones