Chapter 20 - Hormones

Question 1

What are endocrine glands?

Answer 1

Glands which produce hormones.

Ductless, and releases hormones directly into the blood

Question 2

Name the parts of the endocrine system (and make sure you know where they are situated)

Answer 2

• Pituitary gland (brain
• Thyroid gland (Larynx)
• Adrenal Glands (Kidneys)
• Islets of langerhans (Pancreas)
• Testes
• Ovaries

Question 3

Explain the effects of adrenaline on the respiratory system

Answer 3

• Increases the rate and depth of breathing
• Increased uptake of oxygen in blood
• Bronchioles dilate
• More oxygen for faster respiration
• More carbon dioxide is excreted
• Conversion of glycogen to glucose happens faster
• More glucose = faster respiration

Question 4

Explain the effects of adrenaline on the circulatory system

Answer 4

• Increased heartrate
• Increased blood pressure
• Faster transport of oxygen
• Increased respiration and metabolic rate
• More energy is released
• Increases skeletal muscle tone

Question 5

Explain the effects of adrenaline on the rest of the body`

Answer 5

• Pupils dilate (better vision)
• Diverts blood from gut, causins inhibition
• Hair erector muscles contract, increasing size of organism
• Increased mental awareness and sensory perception
• More repid response is possible

Question 6

Explain, in terms of hormones, what happens when blood glucose levels are too high

Answer 6

• The beta cells in the Islets of Langerhans in the pancreas secrete insulin
• Insulin is transported to the liver
• Insulin instructs the lier to convert excess glucose into glycogen
• Glycogen can be stored in the liver and muscles
• Insulin can increase the rate of respiration

Question 7

Explain, in terms of hormones, what happens when blood glucose levels are too low

Answer 7

• Alpha cells in the Islets of Langerhans in the pancreas release glucagon
• Glucagon is transported to the liver
• Glucagon instructs the liver to convert glycogen into glucose
• Glycogen is stored in liver and muscles
• Glucagon can decrease rate of respiration
• Adrenaline can also be secreted from the adrenal glands to perform this function
• Controlled by homeostasis

Question 8

State the normal concentration of glucose in the blood

Answer 8

90 - 100 mg/100 ml of blood (0.1%)

Question 9

Define a hormone

Answer 9

Chemical messengers produced by endocrine glands, which is released directly into the bloodstream and transported to target organs.