Nagi,s 4th Lecture ENDOCRINOLOGY

Question 1

is the ionized iodide take into the thyroid active or not

Answer 1

Yes it is active because it is against electrical and constructional gradient

Question 2

What is the name of the ionized iodide pump

Answer 2

Na- ionized iodide symport

Question 3

What does stimuli Na- ionized iodide pump

Answer 3

Thyroid stimulating hormone TSH

Question 4

What are the inhibitors of the Na-I pump

Answer 4

Monovalentes ions 
Like
1-potassium perchlorate
2-thiocyanate 
Alao called antithyroid agents

Question 5

What are the other hormones that use iodide too

Answer 5

Salivary glands
Mammillary glands
Gastricry glands
Placenta

Question 6

What is the name of the enzyme the convert ionized iodide to elemental iodine

Answer 6

Thyroid peroxidase

Question 7

What is the name of the enzyme that carry the ionized iodide from the cells to the luman

Answer 7

Called pendrin

And it is iodide/chloride transporter

Question 8

What is the second name of the T4

Answer 8

Thyroxin

Question 9

What is the second name of the T3

Answer 9

Triiodothyronine

Question 10

What are the thyroid peroxidase anti drugs

Answer 10

Propyl thiouracil
Carbi mazole
Methi mazole

Question 11

What are the thyroid hormones carries in the blood

Answer 11

They are plasma proteins
70% is thyroid binding complex
15% albumin
15% prealbumin

Question 12

What is the chemical structure of thyroxin t4

Answer 12

3,5,3’,5’

Question 13

What is the chemical structure of the reversed triiodothyronine RT3

Answer 13

3,3’,5’

Question 14

How does the cell turn the T4 to T3 when it needs

Answer 14

بتشيل ال5’و برميها بالتراش ب انزايم اسمو

5’Deiodinase enzyme

Question 15

What is the half time of triiodothyronine T3

Answer 15

1 day

Question 16

What is the half time of the thyroxin T4

Answer 16

7 days

Question 17

In caes of any liver disease (less glubolins) or kidney disease (losing globulins) what happens to the thyroid hormones

Answer 17

The total hormones will decrease but the FREE part which is0.1% will stay constant due to the -ve FB mechanism

Question 18

What does the thyroid hormones do to the catechamines and why

Answer 18

They potentiate them because they are made if the same a.a tyrosine

Question 19

In the people who has hyperthyroidism what is more important to give more than antithyroid agents

Answer 19

Beta blockers because they potentiate the cachelamines work on adrenergic receptors too but the most important one is beta

Question 20

What are the receptors of the thyroid hormones

Answer 20

T4 take the 4 (alpha1,2-beta1,2)

T3 take 3 (all except alphat2)

Question 21

Are the thyroid hormones genomic or non genomics

Answer 21

Genomic

Question 22

At which age the blood brain barrier is developed

Answer 22

At the 2 year

Question 23

What are the functions of the thyroid hormones

Answer 23

Metabolism

Development in young

Question 24

What is the main effect of the metabolism function of the thyroid hormones

Answer 24

Increasing oxygen consumption by increasing the size and the number of the mitochondria almost in all tissues

Question 25

What are the the tissues that the thyroid hormones do not effect

Answer 25

1- adults brain because it cant pass the BBB 2- spleen and 3-lymphatic tissue 4-uterus and 5- testicles

Question 26

Which part of the body that the thyroid hormones do an inhibition effect on

Answer 26

Anterior pituitary as a negative feedback

Question 27

How does the thyroid hormones effect the mitochondria and the cell

Answer 27

Increased the size Increased the number Do (uncoupling oxidative phosphorylation) to use all the energy as a heat no only half heat and half ATP Increased the action of the na/k pump to use all ATP

Question 28

``` What are the secondary effects of the thyroid hormones on Cho Fat Protein Vit ```

Answer 28

Che: Increase glucose absorption Increase gluconeogenesis in liver Increase glycolysis in liver Fat: Increase lipolysis so increase FFA Increase receptors of LDL on the liver So DECREASE THEM IN BLOOD Proteins: Are normal in the normal rate but the EXCESS use them to make heat Vit: Due to all these reactions the demand on vitamins is increased

Question 29

What are the side effects of thr thyroid hormones on the body system

Answer 29

Cardiac sys: Increase heart output due to increase stroke volume and heart rate But NORMAL arterial blood pressure CNS: Nervousness Alertness Respiratory: Increase rate and depth GIT: Increase motility

Question 30

What is the effect of the thyroid on the mental growth in young

Answer 30

In utero and first few years | The source of the thyroid is the baby

Question 31

How does the thyroid hormones effects the physical development

Answer 31

Bones more than soft tissues

Question 32

What is the effect of the slightly hyperthyroidism on the excess hyperthyroidism on the muscles

Answer 32

In the slightly they will react powerfully Due the high level of glucose But In the sever it will be weak due to the proteins catabolism

Question 33

What does stimuli and inhibit | Thyroid release hormone

Answer 33

Stimuli cold | Inhibit stress because the sympathetic effect already increasing the heat

Question 34

What are the slow and fast effects of the thyroid stimuli hormone on the thyroid

Answer 34

Fast in 30 min the release the already prepared hormones And Increased endocytosis and proteolysis of thyroidglobulin Slow in hours days weeks Increased iodide trapping and synthesis of the hormones + increased blood flow to it so increase size

Question 35

What is the feedback of the thyroid hormones and to where

Answer 35

It is negative feedback to hypothalamus and anterior pituitary (most of it)

Question 36

What are the hormones that decrease thyroid stimuli hormone and why

Answer 36

Growth hormone inhibiting hormone Dopamine Because thyroid releasing hormone Increased the growth hormone releasing hormones And prolactin production

Question 37

What are the causes of the hypothyroidism

Answer 37

We have suprathyroidal And thyroidal The thyroidal mnemonic is CCCDE 1-Chronic thyroiditis (hashimito’s) autonomic 2-congenital 3-chronic low level of iodine diet (endemicيعني متمركز goitre) 4-Drugs antithyroidal agents or lethium(antipsychotic ) 5-excess removal

Question 38

What are the causes if the hyperthyroidism

Answer 38

Ectpic Thyroid tissue (non thyroidal tissue producing thyroidal hormones ) Suprathyroidal Thyroidal ``` 1-grave’s disease (autoimmune ) 2-acute thyroiditis 3-multinodular goitre( يعني حجمها كبير) 4-toxic adenoma 5- too much iodine deit ```

Question 39

What is the difference of the acute and chronic thyroiditis effect

Answer 39

The acute make irritation to the glad it self so it produces more hyperthyroidism The chronic it destroy the tissue leading to hypothyroidism

Question 40

Why in the endemic goitre the size of the thyroid enlarg

Answer 40

Because the body increases the size in the propose of getting more iodide

Question 41

What is the name of the artificial thyroxine

Answer 41

Levithyroxine

Question 42

What are the treatments that we can follow in the hypothyroidism

Answer 42

``` 1-Drugs: Antithyroid agents Beta-adrenergic blockers 2-radioactive iodine 3-subtotal thyroidectomy ```

Question 43

What is the sub clinical hypothyroidism

Answer 43

It is when the thyroid is producing low t3 and t4 which by -ve feedback the TSH increase and leads to over stimuli to thyroid and getting the t3,t4 to normal So in the test We will see increased TSH and normal T3,T4