Lecture 3- Principles Of Hormone Action

Question 1

Endocrine

Answer 1

Act on cells distant from the site of secretion

Question 2

How are endocrine hormones released?

Answer 2

Into the blood stream by ductless endocrine glands

Question 3

What are the 2 major forms of diabetes mellitus?

Answer 3

1. Insulin dependent diabetes mellitus

2. Non insulin dependent diabetes mellitus

Question 4

Which of the 2 types of diabetes mellitus is commonly referred to as type 1?

Answer 4

Insulin dependent diabetes mellitus

Question 5

When does type 1 diabetes normally occur?

Answer 5

Childhood

Question 6

When does type 2 diabetes usually occur?

Answer 6

After the age of 40

Question 7

Where is insulin secreted from?

Answer 7

Beta cells of the islet of Langerhans

Question 8

What is the first thing that happens after insulin binds to the receptor?

Answer 8

Endocytosis

Question 9

What does endocytosis of the insulin receptor complex lead to?

Answer 9

Degradation of the hormone and regulation of the receptor numbers

Question 10

When is the number of insulin receptors down-regulated?

Answer 10

When the insulin plasma concentration is high

Question 11

Why is the insulin receptor down regulated at high insulin plasma concentrations?

Answer 11

Because of the accelerated rate of endocytosis and degradation

Question 12

Why does the target cell lose sensitivity to insulin?

Answer 12

Synthesis of new receptors is slower than the degradation of those bound to insulin

Question 13

Paracrine

Answer 13

Act on cells close to the cell that released the hormone

Question 14

How do local mediators differ from neurotransmitters?

Answer 14

Local mediators are releases in a non directional manner into the extracellular space, instead of synaptic cleft

Question 15

Prostaglandins, histamines and peptide growth factors are examples of which hormone class?

Answer 15

Paracrine hormones

Question 16

Which cells release histamine?

Answer 16

Mast cells

Question 17

When do mast cells release histamine?

Answer 17

When activated at the site of injury or infection

Question 18

What is the major effect of histamine?

Answer 18

Causes blood vessels to be leaky

Question 19

What are the cardinal signs of inflammation that occur due to histamine actions?

Answer 19

Redness, swelling, pain

Question 20

What is the benefit of the effects of histamine?

Answer 20

The ‘leaky’ blood vessels allow immune system cells to gain access to the site of infection

Question 21

Autocrine

Answer 21

Act on the same cell that released the hormone

Question 22

What hormone is released by T-cells which then stimulates T cell proliferation?

Answer 22

interleukin-2

Question 23

T cell binding to a macrophage with an antigen induces what process in the T cell?

Answer 23

Clonal selection

Question 24

What T cell secretion enhances clonal selection?

Answer 24

Interleukin-2

Question 25

When do T cells express IL-2 receptors?

Answer 25

While bound to a macrophage

Question 26

What is the effect of human growth hormone on fat cells?

Answer 26

Breaks down triglycerides and inhibition of lipid uptake

Question 27

What hormone is secreted from the liver in response to human growth hormone?

Answer 27

Insulin like growth factor (IGF-1)

Question 28

What is the name of insulin’s precursor?

Answer 28

Proinsulin

Question 29

What part of proinsulin is cleaved to form active insulin?

Answer 29

C chain

Question 30

Steroid hormones are all derived from what molecule?

Answer 30

Cholesterol

Question 31

Where is progesterone synthesised?

Answer 31

Corpus luteum

Question 32

What glucose related process do glucocorticoids stimulate?

Answer 32

Gluconeogenesis

Question 33

What process do mineralcorticoids stimulate in the kidney?

Answer 33

Sodium re-uptake

Question 34

Which hormone type is lipid soluble?

Answer 34

Steroid hormones

Question 35

Where are the receptors for lipid soluble hormones?

Answer 35

Within the target cell

Question 36

What are the receptor molecules for steroid hormones?

Answer 36

Transcription factors