14.1 Hormonal Communication Flashcards
1
Q
What is a hormone?
A
A chemical messenger that is transported in the blood
2
Q
What is an endocrine gland?
A
An organ that secretes hormones
3
Q
Describe steroid hormones
A
- lipid soluble
- diffuse through cell surface membrane
- binds to a receptor (in cytoplasm or nucleus)
- promotes or inhibits transcription
- e.g. testosterone, oestrogen, glucocorticoids, mineralocorticoids
4
Q
Describe non-steroid hormones
A
- hydrophilic (e.g. polypeptides or glycoproteins)
- binds to a receptor on the cell surface membrane
- activates a second messenger (e.g. cyclic AMP)
- a cascade of intracellukar reactions activates a transcription factor (for a particular gene)
- e.g. glucagon, insulin, adrenaline
5
Q
Which hormones are secreted from the adrenal cortex
A
Glucocorticoids
Mineralocorticoids
Androgens
6
Q
What is the function of the glucocorticoids?
A
Regulate carbohydrate metabolism
7
Q
What is the function of mineralocorticoids?
A
To regulate salt and water concentrations
8
Q
What is the function of androgens?
A
Various functions:
- regulation of muscle mass
- development of sexual characteristics
9
Q
Which hormones or secreted from the medulla?
A
Adrenaline
Noradrenaline
10
Q
What is the function of adrenaline?
A
Increases heart rate and blood glucose concentration (by stimulating glycogenolysis)
11
Q
What is the function of noradrenaline?
A
Works in concert with adrenaline by:
- increasing heart rate
- widening airways
- increasing blood pressure
