Physiology thyroid gland Flashcards
Cutting what can cause aphony
Non-recurrent laryngeal nerve
Cutting the vagus nerve causes
Respiratory problems
What is used to detect nodules
Thyroid ecography
% of people having a 5th thyroid gland
10%
% of T4 undergoing deoiodination to T3
90%
Inhibition of TSH
Dopamine
Somatostatin
Glucocorticoids
Histology: what is provided by capillaries
iodide
Home to thyroid hormone production
Colloid
Main secondary receptor
cAMP
Ab binding to same receptor as TSH causing hyper activity DISEASE
Grave’s disease
Symtransporter getting iodide from circulation to gland
DIS
Iodide to colloid through which transporter
PENDRINE
Iodination occurs through which enzyme
TPO
Oxidation will give rise to
MIT and DIT
T3 composition
MIT + DIT
T4 composition
DIT + DIT
% T4 and T3
93% T4
7% T3
Iodination and coupling done through which enzyme
TPO
What allows release of T3 and T4 into circulatory system
Degradation of colloid droplets through lysosomes
Which are recycled
Iodide and tyrosine
Chaikoff effect
Radioactive I- released during nuclear attacks
Intake of iodide tablets to saturate I- necessity for the body to not absorb the radioactive I-
Other use of iodide tablets
Treating hyperthyroidism
% thyroid hormone bound and unbound
99% bound
1% not bound
70% of thyroid hormone is bound to
TBG
15-20% of thyroid hormone bound to
Albumin
10-15% of thyroid hormone bound to
Transthyretin
Production of T4 in
Thyroid gland
T3 produced in
Periphery tissues
% of T3 produced from T4
75%
Half life of T3 and T4
T3 - 1 day
T4 - 6.2 days
Conversion of T4 into T3 through enzyme
Deiodinase (D)
Deosinases functioning in peripheral circulation
D1 and D2
Deodinase functioning in hypothalamus and pituitary
D2
Deosinase turning T4 into RT3 (inactive)
D3
When is the conversion into RT3 important
In situations of stress
Thyroid hormone and catechlamine are anabolic or catabolic
Catabolic
When will the body inhibit catabolic action
When in disease
Cathecolamine function
Prepare the body for exercise, increase HR
TBG enter cells through
Diffusion
T3 and T4 effect
Stimulate B adrenergic receptors –> production of cathecolamines