Endocrine Flashcards
where does the PP arise from
floor of the 3rd ventricle
what link does the PP have to the hypothalamus
neural link
what link does the AP have to the hypothalamus
vascular link
what does the PP secrete
2 hormones: oxytocin and ADH
- synthesised in hypothalamus
what does the AP release?
- ACTH (adrenocorticotropic hormone)
- GH
- prolactin
- TSH
- FSH
- LH
what does ACTH stand for
adenocorticotropic hormone
what stimulates ACTH release?
CRH (corticotropin releasing hormone) by the hypothalamus
what 3 hormones does the thyroid gland produce
- fT3 –> triiodothyronine
- T4 –> thyroxine
- calcitonin
what is fT3
triiodothyronine
what does the production T3 and T4
iodine and tyrosine
which is more abundant T3 or T4?
T4 > T3
fT3 is also known as the ____ which is most abundant near ____
- active thyroid hormone
- the target organs
when is the purpose of T3 and when do T3 levels decrease?
- purpose: nutrient metabolism
- sickness and fasting
what does fT3 bind to
fT3 binds to nuclear receptor
= regulates gene transcription
what is the purpose of T4?
what is the medication that causes both hypo and hyper thyrodism?
what blood tests to test for graves
- Thyroid Stimulating Immunoglobin (TSI)
- anti thyroid antibody
what is the negative feedback loop?
secondary: elevated fT4, T3, TSH
how to manage graves disease?
medical:
1. thioamides
2. potassium iodine
3. radioactive iodine 131 (second line definitive treatment) –> will likely cause hypothyrodisim
surgical: total thyroidectomy
what is jod-basedows phenomenon?
large doses of exogenous iodine cause hyperthyrodism
(how is agranulocytosis linked to thyroid)
agranulocytosis
= low neutrophil count
= NEED to come to A&E to check blood works if get a fever/ sick/ etc.
how are hormones transported?
free (T3/fT4) or protein bound (not bioactive or bioavailable)
what are the 2 main types of cell surface receptors?
- GPCR
- RTK
full names for T3 and T4
T3: tri|iodo|thyroNine
T4: thyroXine
what do parafollicular C cells secrete?
calcitonin
= inhibit bone resorption
= decrease plasma Ca2+
**effect of calcitonin is weaker than PTH effect
what are the 2 states that Ca2+ exists in, and which one is active?
ionised (active)
unionised (inactive)
what is the cofactor to PTH?
magnesium
which terminus of PTH binds to the PTH receptor?
N terminus
