CMB1004/L25 Endocrinology

Question 1

Describe hormonal control of body systems/tissues.

Answer 1

Hormones are secreted by specialised cells into the blood and act on specific receptors in target tissues

Question 2

Describe gap junctions specificity.

Answer 2

Dependent on anatomical location.

Question 3

Describe synaptic transmission specificity.

Answer 3

Dependent on anatomical location and receptors

Question 4

Describe paracrine and autocrine specificity.

Answer 4

Dependent on receptors

Question 5

Describe endocrine specificity.

Answer 5

Dependent on receptors

Question 6

Define classically the endocrine system.

Answer 6

Endocrine cells within endocrine glands release hormones which are conveyed by the blood stream and act on distant cells

Question 7

Why isn’t the classical definition of the endocrine system fully correct?

Answer 7

Hormones can have local and distant effects

Question 8

Give 3 examples of non-classical endocrine tissues.

Answer 8

Kidney
Heart muscle
Endothelium
Platelets
Adipocytes
White blood cells

Question 9

Define a hormone.

Answer 9

Chemical messenger, synthesised by specialised cells, secreted into the blood in small amounts which act on a specific receptor in target organs to regulate cellular function

Question 10

Give 3 features of hormones.

Answer 10

High affinity
Synergistic
Permissive
Antagonistic
Competitive

Question 11

What is a synergistic hormone? Give an example.

Answer 11

The effect of two hormones is greater than one alone
Thyroid and norepinephrine on heart rate

Question 12

What is a permissive hormone? Give an example.

Answer 12

The presence of one hormone is necessary for another to have an effect
Thyroid and aldosterone on Na/K pumps in kidney

Question 13

Give an example of antagonistic hormones.

Answer 13

Insulin and glucagon

Question 14

Give an example of competitive hormones.

Answer 14

Epinephrine and norepinephrine

Question 15

Give the 3 classes of hormones.

Answer 15

Steroids
Peptides
Amino acids

Question 16

What are steroid hormones synthesised from?

Answer 16

Cholestrol

Question 17

What is the most commonly produced type of hormone in the body?

Answer 17

Peptide hormones

Question 18

What are amino acid hormones synthesised from? (which amino acid specifically?)

Answer 18

Tyrosine

Question 19

When are steroid hormones released?

Answer 19

Immediately following synthesis

Question 20

Describe the structure of steroid hormones.

Answer 20

Small hydrophobic/lipophilic

Question 21

What kind of receptors do steroid hormones act on?

Answer 21

Intracellular receptors which bind to DNA

Question 22

Describe the effects of steroid hormones. (2)

Answer 22

Slow and long-lasting

Question 23

In which form are peptide hormones stored?

Answer 23

Preprohormones (inactive)

Question 24

What kind of receptors do peptide hormones bind to?

Answer 24

Cell surface receptors then via 2nd messenger systems

Question 25

When are amino acids hormones released?

Answer 25

Instantly following synthesis

Question 26

What kind of receptors do amino acid hormones bind to?

Answer 26

Intracellular receptors Cell surface receptors

Question 27

Give 3 examples of 2nd messengers.

Answer 27

cAMP cGMP Ca2+ Diacylglycerol IP3

Question 28

Give an example of a rapid hormone response.

Answer 28

Transporter protein activation/inhibition

Question 29

Give an example of short-term hormone response.

Answer 29

General metabolism Neurotransmitter synthesis/release Receptor sensitivity

Question 30

Give an example of long-term hormone response.

Answer 30

Regulation of gene expression

Question 31

Give an example of a 3rd messenger.

Answer 31

Dephosphoprotein Phosphoprotein Via protein phosphatase/kinase

Question 32

What kind of receptors cause muscle relaxation?

Answer 32

Beta-2 adrenergic receptors (cAMP pathway)

Question 33

Give the 4 mechanisms of hormone release.

Answer 33

Continuous Pulsatile Circadian Exocytosis on stimulus

Question 34

Give the one mechanism of steroid hormone activation.

Answer 34

Post-release modification

Question 35

Give 3 mechanisms of hormonal control effects.

Answer 35

Modification Degradation Receptor down-regulation Termination of intracellular effects Negative feedback

Question 36

Give 3 substances which regulate negative feedback loops.

Answer 36

Metabolites Hormone itself Tropic hormone released by pituitary