Thyroid gland

Question 1

main roles of the thyriod gland

Answer 1

regulates metabolism

makes T3 and T4

Question 2

min thyroid disorders

Answer 2

goiters
thyperthryoidism
hypothyroidism

Question 3

anatomy of thyroid

Answer 3

butterfly shaped
in neck
made of two lobes

Question 4

what hormones are involved with the thyroid

Answer 4

T3 and T4

calcitonin

Question 5

how are thryoid hormones stimulated to be made

Answer 5

parvocellular neurones from hypothalamus secrete TRH

this drives the ant.pt it make TSH which in turn stimuates the follcular cells of thyroid to make T3 and T4

Question 6

how does TSH work

Answer 6

binds to GPCR on thyrid follicle cells, cAMP is made, PKA involved

Question 7

how are T3 and T4 produced

Answer 7

• thyroglobulin synthesied by follicular cells of thyroid and exocytosed into lumen
• iodine also taken up by cell and coverted using peroxidase to free iodine
• the iodine incorportaed into thyrosin residues in thryglobulin
• this makes T3 and T4 now

Question 8

what is iogenation

Answer 8

the adding of iodine to the thryroglobulin

Question 9

what is T3

Answer 9

MIT and DIT

Question 10

what is T4

Answer 10

DIT and DIT

Question 11

properties of T3 and T4`

Answer 11

lipophillc
insoluble in water
needs a binding partner
inracellular receptor

Question 12

why is more T4 made

Answer 12

T3 is more potent
but T4 can be made active to T3 at the site of tissues by the removal of one iodine
T3 binds with higher affinities

Question 13

metabolic role of thyroid hormones

Answer 13

increased basal metabolic rate
increased HR
increased activity of sympathetic nerves
growth and maturation

Question 14

what is hypothyroidism

Answer 14

lack of thyroid hormones

Question 15

hypothyroidism in aduts

Answer 15

slow metabolisms, weight gain

quite common but can be undetected

Question 16

hypothyroidism in children

Answer 16

cretanism
brain damage which can be irreversible
routune screening now to prevent this

Question 17

causes of hypothyroidism in adults

Answer 17

1. inflamation of thyroid leaving cells damged
2. autoimmune- Hashitomotis
3. primary failure of glad
4. chronic dietary lack

Question 18

IDD

Answer 18

Iodine deficiency disorder
very prevalent disease
can cause goiters

Question 19

how is hypothyroidism treated

Answer 19

lifelong replacement of T4

or dietary iodine if required

Question 20

what is hyperthyroidism

Answer 20

too much thyroid hormones

Question 21

features of hyperthroidism

Answer 21

weightloss, fast metabolism
sensitive to heat
hyperactive
eat lots
eyeball extrusions

Question 22

causes of hyperthryoidism

Answer 22

• autoimmune, graves disease
• thyroid tumour
• secondary hypthalamus thour

Question 23

what is graves disase

Answer 23

autoimune disease that destroys thyroid tissue

produces antibodies that mimic TSH over stimulating receptors

Question 24

how can tumours lead to hyperthyoidism

Answer 24

primary: of the thyroid, it can hypersencrete
secondary: of hypothalamus over secreting TRH

Question 25

treatments for hyperthyroidism

Answer 25

• antithryoid drugs stopping synthesis

- surgically remove tumour

Question 26

descibe the thryoid axis secretion

Answer 26

1. low blood T3/T4 or low metbolic rate stimulates TRH production
2. TRH carried by hypophyseal portal system to stimulate Ant.pit thyrotrophs
3. TSH released into blood and stimulates thyroid follicles
4. T3 and T4 released into blood
5. elevated T3 inhibites release of TRH and TSH, neg feedback look