9.1: The Endocrine System

Question 1

What is the role of the endocrine system?

Answer 1

Works with the nervous system to maintain homeostasis by releasing hormones directly into the blood

Question 2

What is the function of the pituitary gland?

Answer 2

Is a control centre and coordinates the endocrine and nervous system

Question 3

Where is the pituitary gland located?

Answer 3

At the base of the hypothalamus

Question 4

Explain the difference between the anterior and posterior pituitary

Answer 4

Anterior- Produces and secretes hormones into the bloodstream
Posterior- Stores and transports ADH and oxytocin

Question 5

Where is the thyroid gland located?

Answer 5

Located in the middle of the neck

Question 6

What is the main role of the thyroid gland?

Answer 6

Secretes a hormone that controls the speed that the body cells work

Question 7

Explain the secretion of thyroid hormones

Answer 7

Is regulated by a negative feedback system from the hypothalamus via the TSH (thyroid-secreting hormone)

Question 8

What is groiter?

Answer 8

An iodine deficiency where the thyroid enlarges as it attempts to make thyroxine (T4)

Question 9

What does T4 and T3 do?

Answer 9

Regulates the rate glucose is oxidized within body cells

Question 10

What does calcitonin do?

Answer 10

Decreases the amount of calcium in the blood

Question 11

What is the role of the parathyroid glands?

Answer 11

Regulates the amount of calcium in the blood

Question 12

Where is the parathyroid gland?

Answer 12

Has 4 glands which are located inside the thyroid

Question 13

What does the parathyroid hormone do?

Answer 13

Increases the amount of calcium in the blood

Question 14

What is the difference between target and non-target hormones?

Answer 14

Target: Affect specific cells and target tissues
Non-Target: Affect many cells throughout the body

Question 15

What are the main characteristic differences between steroid and peptide hormones?

Answer 15

Steroid: Fat-soluble, made from cholesterol, can easily diffuse through lipid bilayer of the cell membrane
Peptide: Water-soluble, made from an amino acid chain, cannot diffuse through cell membrane

Question 16

How do steroid proteins act?

Answer 16

Diffusing directly into the target cell which activates specific genes to elicit a response

Question 17

What does the steroid hormone affect?

Answer 17

Gene expression

Question 18

How does a peptide hormone act?

Answer 18

Binding to receptors on the surface of the cell membrane which causes a chain reaction inside the target cell

Question 19

What do peptide hormones affect?

Answer 19

Metabolic enzyme activity

Question 20

How does adenyl cyclase work?

Answer 20

Catalyzes the conversion of ATP into cyclic AMP (cyclic adenosine monophosphate)

Question 21

Why is the hypothalamus important for the pituitary?

Answer 21

1. Pituitary is located on the hypothalamus
2. Hypothalamus regulates the secretions of the anterior pituitary

Question 22

Where is oxytocin and ADH produced and released from?

Answer 22

• Produced in the hypothalamus
• Released from the posterior pituitary gland

Question 23

What are the 6 hormones produced and released from the anterior pituitary gland?

Answer 23

1. Thyroid-Secreting Hormone (TSH)
2. Follicle-Secreting Hormone (FSH)
3. Human-Growth Hormone (hGH)
4. Adrenocorticotropic Hormone (ACTH)
5. Prolactin (PRL)
6. Leutenizing Hormone (LH)

Question 24

What is the relevance of cyclic monophosphate (cAMP)?

Answer 24

Is the second chemical messenger that directs protein synthesis by ribosomes

Question 25

What is the role of adrenal glands and where are they located?

Answer 25

- Regulate the use of carbohydrates, salts, and prepare the body for emergencies (fight/flight) - Located above each kidney

Question 26

What does the adrenal medulla do? Give an example.

Answer 26

- Produces epinephrine and norepinephrine - Regulates short-term stress response (fight/flight) - Ex: Increases blood pressure

Question 27

What does the adrenal cortex do? Give an example.

Answer 27

- Produces glucocorticoids and mineralcorticoids - Regulates long-term stress response - Inflammation reduces and and immune cells supress

Question 28

Give an example of a glucocorticoid

Answer 28

Cortisol

Question 29

Give an example of a mineralocorticoid

Answer 29

Aldosterone

Question 30

What does cortisol do?

Answer 30

- Raises blood glucose - Released when the body is under stress - Acts as a natural anti-inflammatory

Question 31

What does aldosterone do?

Answer 31

- Increases the absorption of sodium in the blood - Increases blood pressure and ion concentration in the blood - More osmosis is required

Question 32

Why does aldosterone require more osmosis?

Answer 32

Since Na dehydrates the body, the body needs more water to circulate throughout the body, requiring osmosis

Question 33

What are Islets of Langerhans

Answer 33

A cluster of endocrine cells which is found in the pancreas

Question 34

What 2 hormones does Islets of Langerhans secrete?

Answer 34

1. Insulin 2. Glucagon

Question 35

What are the 2 types of cells in the Islets of langerhans

Answer 35

1. Alpha Cells 2. Beta Cells

Question 36

What do alpha cells do?

Answer 36

Secretes glucagon which increases blood glucose

Question 37

What do beta cells do?

Answer 37

Secretes insulin which decreases blood glucose

Question 38

Which feedback system is insulin and glucagon regulated by?

Answer 38

A negative feedback system

Question 39

Explain the process of blood glucose homeostasis

Answer 39

When blood glucose gets too high, beta cells secrete insulin, which makes the cell membrane more permeable so it decreases blood glucose. When blood sugar gets too low, alpha cells secrete glucagon. Glucagon stimulates the liver which converts glycogen to glucose which is released.

Question 40

Explain type 1 diabetes

Answer 40

- Diagnosed usually as a child - Beta cells are degenerated, causing no production of insulin - This makes the person insulin dependent

Question 41

Explain type 2 diabetes

Answer 41

- Is diagnosed typically as an adult - Caused by unhealthy diets, - Beta cells do not produce as much insulin, but the person is not insulin-dependent - They must take oral pills to stimulate the islets of Langerhans

Question 42

What is diabetes inspidus?

Answer 42

- A condition where the kidney does not concentrate urine well - Can be caused by inadequate production of ADH by the hypothalamus - This results in the kidneys to lack the reabsorption of water