Revision lecture endocrinology

Question 1

Name four types of hormones

P-Gas

Answer 1

Peptides
Glycoproteins
Amino Acid derivatives
Steroids

Question 2

Example of peptide hormones (3). What are the properties of these hormones (Solubility)

Answer 2

Insulin, Glucagon, GH

Small and soluble, so don’t have to be bound to a carrier in the blood

Question 3

Example of glycoprotein hormones (3). What are the properties of these hormones (Solubility)

Answer 3

LH, FSH, TSH

Water soluble

Question 4

Example of Amino Acid derivatives hormones (2). What are the properties of these hormones (Solubility)

Answer 4

Adrenaline, thyroxine
From adrenal medulla, water soluble

From thyroid, lipid soluble

Question 5

Example of steroid hormones(4). what are these hormones derived from? Solubility?

Answer 5

Cortisol, aldosterone, testosterone, oestrogen
Cholesterol
Lipid soluble

Question 6

What two Amino Acids is adrenaline produced from? What metabolic disease can affect its production?

Answer 6

Tyrosine and Phenylalanine

Phenylketouria

Question 7

How does the solubility of a hormone affect how it is transported? Give examples.

Answer 7

Lipophilic hormones are transported whilst bound to a carrier
eg. Thyroxine (T3) bound to thyroxine binding globulin
Cortisol to transcortin

Question 8

how does the solubility of a hormone affect how and where it binds to its target receptor?

Answer 8

soluble hormones cannot pass through the cell membrane so binds to receptors of membrane–> So acts through a secondary messenger

Insoluble hormones diffuse through the cell membrane and act on intracellular receptors

Question 9

Examples of positive feedback?

Answer 9

Oestrogen levels high–>Increased LH

Also blood clotting whereby clotting factors tend to stimulate other substances

Question 10

Describe the negative feedback loop of cortisol

Answer 10

Stress–>CRH production from the hypothalamus
CRH acts on the pit gland to produce ACTH
ACTH acts on the adrenal cortex to secrete cortisol

Cortisol has a negative feedback effect on the pit gland (Stops secreting ACTH) and the hypothalamus (Stops secreting CRH)
So decreases cortisol production

Question 11

Why are some hormonal effects faster than others?

Answer 11

If effect is altering the activity of enzymes or proteins, response is rapid

If its altering gene expression, can take longer

Question 12

Where is the appetite control centre?

Answer 12

Arcuate nucleus

Question 13

Name four chemicals responsible for appetite

Answer 13

PYY
Ghrelin
Leptin
Insulin

Question 14

Describe the effect (Promote hunger or inhibit hunger) of the four chemicals responsible for appetite

Answer 14

PYY- inhibit hunger
Ghrelin- Stimulate hunger
Leptin- Inhibits hunger
Insulin- Inhibits hunger

Question 15

Explain how we get the feeling of euphoria and tiredness after eating

Answer 15

Full stomch–>release of POMC–>Broken down into products including β endorphins–>euphoria and tiredness