5.4 HORMONES

Question 1

Define hormone

Answer 1

• Chemical signals released/transported in the bloodstream that act as messengers

Question 2

State the *two** types of hormones

Answer 2

• peptide/protein hormones
• steriod (lipid) hormones

Question 3

State the difference between endocrine and exocrine glands

Answer 3

• Endocrine glands release their hormones (protein or steriod) into the bloodstream
• Exocrine glands have a duct that carriers their hormones away

Question 4

Define first messenger

Answer 4

• A protein hormone that binds to a receptor on plasma cell surface membrane and activates the second messenger

Question 5

Define second messenger

Answer 5

• A signalling molecule which stimulates** a change in activity of a cell

Question 6

State the first messenger in adrenaline release

Answer 6

• Adrenaline

Question 7

State the second messenger in adrenaline release

Answer 7

• Cyclic AMP (cAMP)

Question 8

Describe the route of protein/peptide hormones

Answer 8

• From adrenal medulla it attaches to complementary receptor of glycoprotein in plasma cell membrane of target cell
• G protein attached to receptor becomes activated
• Activated G protein now activates the enzyme adenyl cyclase
• Activated adenyl cylases converts ATP to cAMP
• cAMP acts directly on channel protein or initates a cascade of enzyme-controlled reactions

Question 9

Describe the route of steriod (lipid) hormones

Answer 9

• From adrenal cortex through plasma cell membrane of target cell
• Steroid hormone binds with specific receptor in cytoplasm
• Receptor-steroid compex forms, enters nucleus
• Binds to promoter region of a gene which increases production of mRNA

Question 10

State why protein hormones are unable to enter cells

Answer 10

• Not lipid soluble
• Polar

Question 11

State why steriod hormones can enter cells

Answer 11

• Lipid soluble
• Nonpolar

Question 12

Draw the two types of adrenal glands

Answer 12

• Adrenal cortex
• Adrenal medulla

Question 13

State the type of hormone secreted by the adrenal medulla

Answer 13

• Protein/peptide hormones

Question 14

State the type of hormone secreted by the adrenal cortex

Answer 14

• Steroid/lipid hormones

Question 15

Draw the structure of the adrenal cortex

Answer 15

• Zona glomerulosa
• Zona fasciculata
• Zona reticularis
• (GFR)

Question 16

State the molecule adrenal cortex uses to create steroid hormones

Answer 16

• Cholesterol

Question 17

Which hormone does zona glomerulosa release?

Answer 17

• Mineralcorticoids

Question 18

Which hormone does zona fasciculata release?

Answer 18

• Glucocorticoids

Question 19

Which hormone does zona reticularis release?

Answer 19

• Precursor androgens

Question 20

State the role of the mineralcorticoids hormones

Answer 20

• Maintains blood pressure by controlling concentrations of Na- and K+

Question 21

State the role of the glucocorticoids hormones

Answer 21

• Regulates metabolism of carbohydrates, proteins and fats in the liver

Question 22

State the role of the precursor androgens hormones

Answer 22

• Taken up by ovaries or testes to develop sexual characteristics

Question 23

Which part of the adrenal glands release adrenaline

Answer 23

• Adrenal medulla

Question 24

Describe the structure of adrenaline

Answer 24

• Amino acid derivative
• Polar
• Lipid insoluble

Question 25

State the effects of adrenaline release in fight or flight response

Answer 25

• Increased heart rate
• Increased stroke rate
• Increased blood pressure (via vasoconstriction)
• Pupil dilation ( increases sensory information)
• Relaxed smooth muscle in bronchioles (increases ventilation)
• Mental alertness increased
• Decreased digestion function
• Glycogenolysis (glycogen to glucose in liver) to increase blood glucose concentration (more energy)