Thyroid Function

Question 1

Why is the Thyroid Gland brown?

Answer 1

Becuase of the obsorbed iodine

Question 2

What is the name of the ajoing part between the two lobes of the thyroid?

Answer 2

Isthmus

Question 3

What are the bumps on the Thyroid?

Answer 3

The bumps are called lobules abd contain follicles which is where the hormone is made

Question 4

What is the order of organisation of the thyroid gland?

Answer 4

Lobules - Tyroid Follicles - collid and follicular cells and C-Cells

Question 5

What do you find within the Collid and what does it do?

Answer 5

Thyroglobulin molecules, that carry the T3 and T4

Question 6

What is a free T3 and T4?

Answer 6

These are hormones that have been released by the Throid globuline molecule. These are now active.

Question 7

What are the basic ingredients of Throid Hormones?

Answer 7

Tyrosine and Iodine

Question 8

How is T4 and T3 made?

Answer 8

T4 = 2 x DIT molecules
T3 = 1 x MIT and 1 x DIT

Question 9

What is the differences between T3 and T4?

Answer 9

T4 is the primary molecule but is usless, it need to be reduced to T3 so that it can complete its role

Question 10

There are 3 globulines that T3 and T4 bind to, what are there names?

Answer 10

TBG = Thyroid Binding Globuline
TBPA = Thyroid Binding Pre Albumine
TBA = Thyroid Binding Albumine

Question 11

Explaine how steriod work?

Answer 11

Steroids are lipid soluable so slide through the membrane.
Then bind to receptors in the cytoplasm.
The get carried into cell to act on DNA

Question 12

Explaine the two ways Thyrodi hormones work?

Answer 12

They bind to a receptor in the cytoplasm and get carried to the DNA (just like a steroid) or they bind to the mitrocondria and make ATP. So can effect the genome (pathway 1) or no genome effect (pathway 2)

Question 13

How does Adrenaline and noradrenaline work?

Answer 13

They use sencond messangers. Bind onto external receptors on the membrane, which activates the G - Protein linked receptor. This second receptor then leaves and causes the cell response.

Question 14

List some of the actions caused by increased T3 and T4.

Answer 14

Increased oxygen consumption
increased cardiac output
Increase Basal Metabolic Rate
Increase ATP

Question 15

What effect does T3 and T4 have physically on the body systems?

Answer 15

Increased HR and Systolic and Diastolic BP, increased blood flow
Increase of ventalation rate
Increase appitites, increase digestive juice

Question 16

What is the pathway between the hypothalamus and the target response?

Answer 16

Hypothalamus releases Thyroid releasing hormone (TRH) which goes to the Anterior pituitory via portal system. It releases Thyroid Stimulating Hormone (TSH), which travels to the Thyroid gland. It releases T3 and T4 and BMR is increased, protein synthesis is increased etc etc

Question 17

What effect does the TSH hormone, released by the pituitory gland, have on the Thyroid Gland?

Answer 17

Increase of Iodine absorbtion
Stimulates T3 and T4 creation
Increase in thyroglobulin secreation into colloid
Increase in colloid endocytosis
Increase in follicular cells
Increase of blood flow

Question 18

What is hyper and hypo thyrodisum?

Answer 18

Over production and underproduction of Thyroid homones.
Primary - problem at Throid gland
Secondary - problem at Pituitory gland
Tertiary - problem at the hypothalamus

Question 19

Explaine Hypothyroidisum?

Answer 19

This is when the Thyroid dosent produce enough T3 and T4. Causes an increase level of TSH and reduced negative feedback from Tyroid gland, defincency in iodine (Goiter)

Question 20

What are the common effects of Hyperthyroidisum?

Answer 20

Increased BMR
Weight loss, appitites increase
Anxity, mental excitability
Hair loss
Increased heart rate
Sweatiness
Diarrhoea
Graves disease (toxicity of T3 and T4)

Question 21

What are the common effects of Hypothyroidsium?

Answer 21

weight gain
Depression
Dry skin, brittle hair
Bradycardia
Dry cold skin
Constipation

Question 22

Are thyroid hormones lipophydic?

Answer 22

Yes - fat loving water hating. as are steroids.