Endocrine system Part 1

Question 1

What is the difference between exocrine and endocrine glands?

Answer 1

Exocrine glands secrete their products into ducts (e.g., sweat or intestines) whereas endocrine glands are ductless and release hormones into the blood

Question 2

What is the definition of a hormone?

Answer 2

A chemical messenger carried by the blood to target cells.

Question 3

What 5 things do hormones help to regulate?

Answer 3

1) Chemical composition and volume of internal environment
2) Metabolism and energy balance
3) Contraction of smooth and cardiac muscle fibres
4) Glandular secretions
5) Some immune system activities

Question 4

Other than regulation of different factors in the body, what are the 3 other functions of hormones?

Answer 4

Control growth and development
Regulate operation and reproductive system
Help establish circadian rhythm

Question 5

Hormones operate in synchrony with the nervous system. Compare endocrine and the nervous system.

Answer 5

Endocrines are chemical messengers whereas the nervous system is an electrical conduit system

The nervous system acts instantaneously whereas endocrine acts slower (relatively)

Endocrine often has longer lasting effects whereas nervous system has short-lived response

Question 6

What are the 3 major structural classes hormones fall into?

Answer 6

1) Amines (e.g., thyroid hormones, catecholamines)
2) Peptides and proteins (e.g., insulin)
3) Steroid (e.g., testosterone (largely derived of cholesterol))

Question 7

What 2 major organs remove hormones from the blood plasma by metabolizing or excreting them?

Answer 7

Liver and Kidneys

Question 8

What 2 types of hormones are water soluble and circulate dissolved in plasma?

Answer 8

Peptide and catecholamine

Question 9

What 2 types of hormones circulate bound to plasma proteins

Answer 9

Steroid and thyroid hormones

Question 10

What 3 things do the responsiveness of a target cell to a hormone depend on?

Answer 10

1) Hormone concentration in blood
2) Abundance of target cell’s hormone receptors
3) Influences exterted by other hormones

Question 11

What 3 types of effects can hormonal interactions have?

Answer 11

Permissive - when the action of one hormone requires another hormone to stimulate a response
Synergistic - when 2 hormones act together to create a greater effect on each other
Antagonistic - e.g., insulin and glucagon

Question 12

What 3 factors is hormone secretion controlled by?

Answer 12

1) Plasma concentration of an ion or nutrient that the hormone regulates
2) Neural input to the endocrine cells
3) Other hormones