Calcium basics Flashcards
Where are hormones created
endocrine glands/cels
what stims the release of hormones
stimuli (metabolite, hormones, neurotransmitter)
3 main types of hormones
- peptide/protein (3+ AAs)
- steroid (from cholesterol)
- amine (single AA)
where in cell are peptide hormones created
DNA>mRNA>ER (translated)>golgi>secreted
how is cholesterol turned into steroid hormones
enzymes (in mitochondria and smooth ER)
2 things that determine the biological activity of hormones
- target cell - what is does
2. metabolism (liver, kidney)
where are Ca and P ions most concentrated
Ca - extracellular
P - intracellular
what happens to most Ca injested
feces
what % are the 2 bone types
80% compact
20% spongy
what % Ca turnover per year for adult and children
adult - 18%
child - 100%
what bone cell incr. Ca and how
osteoclast -creates acidic env,
what regulates osteoclast diff.
osteoblasts
what signal does blast use to tell clast to diff.
RANKL on blast to RANK on clast
what can be used to block RANKL ligand
OPG - no clast diff.
what are 2 main promoters of RANKL
- calcitriol
2. PTH
which 3 hormones control plasma Ca
- PTH
- Calcitriol
- Calcitonin
3 target sites of these hormones
- bones
- kidneys
- digestive tract
where is PTH produces
parathyroid
half life of PTH
10 mins
2 funstions of PTH
- nicrease plasma Ca
2. reduce plasma Ph
what is PTH stim
low Ca or high Ph
what does PTH do to bone
increase RANKL>more clast>bone resorbtion
what does PTH do to kidney
increase Ca reabsrb
- inrc. calcitriol
- lower Ph reabsrob
what are calcitriol effects in intestine
increase Ca transport into body
what are calcitriol effects in kidney
Ca reabsorb via TRPV5
what are calcitriol effects in bone
incr blast, but also RANKL so more clasts
where is calcitonin made and half life
thyroid and 10 mins
what are effects of calcitonin in bone and kidney
bone - inhibit clast
kidney - incr. Ca excretion
