5.1.4 hormonal communication

Question 1

What hormones are secreted by the Pituitary gland?

Answer 1

-Growth hormone: controls growth in bones and muscles.
-Anti-diuretic hormone: increases reabsorption of water in kidneys.
-Gonadotrophins: control development of ovaries and testes.

Question 2

What hormones are secreted by the Thyroid gland?

Answer 2

-Thyroxine: controls rate of metabolism and rate that glucose is used up in respiration.

Question 3

What hormones are secreted by the Adrenal gland?

Answer 3

-Adrenaline: increases heart rate and breathing rate and raises blood sugar level.

Question 4

What hormones are secreted by the Testis?

Answer 4

-Testosterone: controls sperm production and secondary sexual characteristics.

Question 5

What hormones are secreted by the Pineal gland?

Answer 5

-Melatonin: affects reproductive development and daily cycles.

Question 6

What hormones are secreted by the Thymus?

Answer 6

-Thymosin: promotes production and maturation of white blood cells.

Question 7

What hormones are secreted by the Pancreas?

Answer 7

-Glucagon: converts glycogen back to glucose in the liver.
-Insulin: converts excess glucose into glycogen in the liver.

Question 8

What hormones are secreted by the Ovary?

Answer 8

-Oestrogen: controls ovulation and secondary sexual characteristics.
-Progesterone: prepared the uterus lining for receiving am embryo.

Question 9

What is meant by endocrine?

Answer 9

Hormones released into bloodstream (plasma).

Question 10

What is meant by exocrine?

Answer 10

Secretes hormone through ducts directly into target organs/surface of the body.

Question 11

Where are the Adrenal glands located?

Answer 11

On the top of each kidney.

Question 12

What are the Adrenal glands made up of?

Answer 12

-The Adrenal cortex
-The Adrenal medulla

Question 13

What is the Adrenal cortex?

Answer 13

The outer region of the glands, produces hormones vital to life.

Question 14

What is the Adrenal medulla?

Answer 14

The inner region of the glands, produces non-essential hormones.

Question 15

What hormones does the Adrenal medulla secrete?

Answer 15

-Adrenaline:
increased heat rate, increased blood glucose concentration.
-Noradrenaline:
increased heart rate, widening of pupils, widening of air passages to the lungs, narrowing of the blood vessels.

Question 16

What hormones are secreted by the Adrenal cortex?

Answer 16

-Glucocorticoids:
e.g. cortisol- regulates metabolism (breakdown of fats, lipids, and proteins). Affects blood pressure.
e.g. corticosterone- regulates inflammatory responses/immune responses.
-Mineralocorticoids:
e.g. aldosterone- regulate the salt and water balance/concentration in the blood, regulates blood pressure (guided by signals from the kidneys).
-Androgens:
Sex hormones (testosterone+oestrogen).

Question 17

Why is the pancreas both an endocrine and an exocrine system?

Answer 17

Endocrine- secretes Insulin and Glucagon into the blood.
Exocrine- produces digestive enzymes (amylase, protease, lipase) into the digestive system.

Question 18

What do the enzymes: Amylase, Protease, and Lipase, break up?

Answer 18

Amylase:
Starch into simple sugars.
Protease:
Proteins into amino acids.
Lipase:
Lipids into fatty acids and glycerol.

Question 19

What are Islets of Langerhans and what do they produce?

Answer 19

Small regions of endocrine tissue within exocrine tissue.
Produces:
Alpha cells- Glucagon.
Beta cells- Insulin.

Question 20

What are the main difference between endocrine and exocrine pancreatic tissue?

Answer 20

Endocrine- Lightly stained, large spherical clusters, produce and secrete hormones, Islets of Langerhans.
Exocrine- darker stained, small berry-like clusters, produce and secrete digestive enzymes, pancreatic acini.

Question 21

What can increase blood glucose concentration?

Answer 21

-Diet
-Glycogenolysis
-Gluconeogenesis

Question 22

What can decrease blood glucose concentration?

Answer 22

-Respiration
-Glycogenesis

Question 23

What is meant by Gluconeogenesis?

Answer 23

Gluconeogenesis is the production of glucose from non-carbohydrates.

Question 24

What is meant by Glycogenolysis?

Answer 24

Glycogenolysis is the breakdown of glycogen into glucose.

Question 25

What is meant by Glycogenosis?

Answer 25

Glycogenosis is the building of glycogen.

Question 26

What happens when blood glucose concentration is too high?

Answer 26

-Detected by beta cells in Islets of Langerhans. -More Insulin released. -Glycogenesis in liver/muscles. -Increase uptake in cells. -Increase rate of cellular respiration. -Convert into fats (lipogenesis).

Question 27

What happens when blood glucose concentration is too low?

Answer 27

-Detected by alpha cells in Islets of Langerhans -Glucagon released. -Glycogenolysis in liver/fat cells. -Gluconeogenesis. -Decrease uptake in cells. -Decrease rate of cellular respiration.

Question 28

How do beta-cells release insulin?

Answer 28

-Increase glucose inside cell. -Increase ATP released by respiration. -Increase ATP causes K+ channels on cell surface to close. -Increase K+ in cell causes cell to be less positive (depolarisation). -Depolarisation causes calcium ion channels to open. -Increase calcium ions inside cells. -Calcium ions move secretory vesicles containing insulin to cell surface. -Vesicles->exocytosis->insulin release.

Question 29

What is meant by Hyperglycaemia?

Answer 29

Too much glucose in the blood.

Question 30

What is meant by Hypoglycaemia?

Answer 30

Too little glucose in the blood.

Question 31

What is the difference between Type 1 and Type 2 diabetes?

Answer 31

Type 1 diabetes is when beta-cells in the Islet of Langerhans do not produce insulin. Whereas, type 2 diabetes is when beta-cells do not produce enough insulin or body cells do not respond properly to insulin (caused by poor lifestyle).

Question 32

How can Type 1 diabetes be treated?

Answer 32

-Regular injections of insulin (insulin-dependent).

Question 33

How can Type 2 diabetes be treated?

Answer 33

-Regulate diet and exercise. -Drugs to stimulate insulin production in some cases.

Question 34

What is medically produced insulin?

Answer 34

Insulin made from genetically modified bacteria-human gene for insulin inserted into bacterial cells.

Question 35

What are the advantages of medically produced insulin?

Answer 35

-Less chance of an allergic reaction than pig/cow insulin. -Make on a mass scale. -Cheaper production costs. -Less ethical/religious concerns.

Question 36

What are the disadvantages of pancreas transplants?

Answer 36

-Long wait for a pancreas transplant because demand outweighs availability. -Immunosuppressant drugs, which increase metabolic demand. -80% effective.

Question 37

How can stem cells be used to treat diabetes?

Answer 37

Totipotent stem cells have the ability to differentiate into any cell type (taken from embryos e.g. 'spares' from fertility treatment and terminations. Could grow into Islet cells.

Question 38

What are the advantages of stem cell therapy for diabetes?

Answer 38

-Donor availability would not be an issue. -Reduced likelihood of rejection problems with embryonic stem cells generally not being rejected. -People no longer have to use insulin injections.