5.1.4 - Hormonal communication

Question 1

Endocrine gland

Answer 1

Hormones (sometimes enzymes) are released by endocrine glands directly into blood
- They are ductless

Question 2

Exocrine gland

Answer 2

Produce hormone that is not directly released into the blood
- Ducts carry the secretion to another place

Question 3

Two types of hormones

Answer 3

Peptide/water soluble hormones
- Do not pass through the cell membrane -> receptors on cell membrane surface
- Use the first messenger, second messenger model

Steroid/lipid soluble hormones
- Pass through the cell membrane -> Receptors inside cell
- Act upon DNA in the nucleus

Question 4

Structure of adrenal glands

Answer 4

• The centre is called the medulla (produces non essential hormone)
• Surrounding the medulla is the Cortex (produces essential hormones)

Question 5

Hormones produced in the adrenal cortex & functions

Answer 5

Cortisol: Stimulates glycogenolysis, reduces inflammation & regulates blood pressure

Aldosterone: Na & K ion reabsorption in the kidneys, water reabsorption and controls blood pressure

Sex hormones (oestrogen & testosterone): Aid the development of gametes

Question 6

Hormones produced in the adrenal medulla & functions

Answer 6

Adrenaline and noradrenaline: Increases heart rate, stimulates glycogeonlysis, trigger fight or flight response

Question 7

Why is the pancreas considered endocrine and exocrine?

Answer 7

Exocrine: Enzymes are carried to the gall bladder in the pancreatic duct

Endocrine: Insulin & glucagon are released directly into the bloodstream

Question 8

What areas of the pancreas secrete hormones?

Answer 8

Islet of Langerhans cells

Two types of cells -> Alpha & beta
Alpha: Glucagon
Beta: Insulin

Question 9

Acini

Answer 9

Enzyme secreting cells around islets of Langerhans & Pancreatic ducts