Chapter 14 (Hormonal Communication)

Question 1

What defines a steroid hormone and how does it affect target cells?

Answer 1

They are lipid soluble, so can pass through the cell membrane and bind to a receptor protein in the cytoplasm. This complex acts as a transcription factor

Question 2

How do non steroids hormones affect target cells?

Answer 2

Bind to receptors on the CSM, causing second messengers to operate within the cell

Question 3

What are the three main types of hormones produced in the adrenal cortex?

Answer 3

Glucocorticoids
Mineralocorticoids
Androgens

Question 4

What are the hormes secreted by the adrenal medulla?

Answer 4

Adrenaline
Noradrenaline

Question 5

When are hormones from the adrenal medulla secreted?

Answer 5

When the sympathetic nervous system is stimulated

Question 6

What is glycogenolysis?

Answer 6

When glycogen is broken down into glucose, releasing into the bloodstream

Question 7

What is gluconeogenesis?

Answer 7

Creating of glucose from non carbohydrate sources

Question 8

What is glycogenesis?

Answer 8

The creation of glycogen

Question 9

What is the normal blood glucose level?

Answer 9

90mg per 100cm3 of blood

Question 10

How is the secretion of insulin controlled?

Answer 10

1) At a normal blood glucose conc., K+ channels are open, causing an inside potential of -70mv
2) Increase in blood glucose conc. = Glucose enters cell by glucose transporter
3) Glucose metabolised, producing ATP
4) ATP binds to K+ channels, closing them
5) P.d reduces to -30mv, depolarisation occures
6) V-G Ca2+ channels open
7) Calcium ions cause secretory vesicles to secrete insulin