vitamins 4 Flashcards
what is the calcium level that needs to be maintained in the blood
9-11mg/dl
what is the importance of calcium
- extracellular fluid - CA2+ essential
- nerve cells
- muscle cells - too high cardiac arrest, too low respiratory arrest
where is the major store of calcium
99% bones
what happens to osteoblast and osteoclast activity at different calcium levels
too low - osteoclast activity releases calcium
too high - osteoblast activity stores calcium
what is the uncalcified bone matrix called
osteoid
what is the characteristics of a osteoclast cell
- release calcium
- multinucleate cell
- secretes acid - dissolves bone marrow
what is the characteristics of a osteoblast cell
- store calcium
- line bone surface
- secrete bone matrix - osteoid
- embedded as osteocytes
what does the parathyroid hormone do - PTH
- 84 aa peptide hormone
- low calcium - parathyroid hormone secreted, acts on calcium sensing receptor and cAMP
promotes: - osteoclast activity - release calcium
- kidneys - decrease calcium loss and calcitriol formation
what is the function of calcitriol
- made in kidney by vitamin D
promotes: - uptake of calcium from gut
- decreases calcium loss by kidneys
- osteoclast activity to release calcium
what does calcitonin do
- secreated from thyroid gland at high calcium levels
- inhibits osteoclasts
- inhibits kidney calcium reabsorption
what are the % of calcium absorbed in the kidney
proximal tubule - 70%
distil tubule - - 9%
thick ascending limb - 20%
collecting duct - 1%
what is the bmi formula
BMI = weight (kg) / hight (m2)
what is the increased risks associated with obesity
- type 2 diabetes
- coronary heart disease
- some cancers - breast and bowel
- strokes
- reduced quality of life - psychological problems
what are the causes of obesity
- consuming calories - increases the well fed state, fatty and sugary foods, cheap and high calorie food
- lack of exercise
- hormonal/ genetic
what does lipoprotein lipase secretion do
- lipolysis of chylomicron —> free fatty acids and chylomicron remnant
what does triglycerides contain in the digestive pathway
perilipins
what does excess fat lead to
- enlarged adipose
- cell proliferation - de novo adipogenesis
what is the evolution of adipose tissue
- store for times of need
- reduce heat loss
- immune response
- buoyancy
what is the characteristics of healthy adipose tissue
- insulin sensitive
- functional mitochondria
- beige fat biogenesis - cold exposure
- angiogenesis
- anti-inflammatory
what happens to malfunctioning adipose tissue
- decreased insulin sensitivity
- decreased mitochondrial function
- decreased fat biogenesis
- decreased angiogenesis
- increased inflammation
- increased fibrosis
- altered lipid profile - increase
what happens in the under fed state
- metabolism decreases and huger increases
- eat and reach homeostasis
- if you over eat you may reach nutrient overload state - well fed state
what happens in the well fed state
- metabolism increases and hunger decreases
- body then reaches homeostasis
- body then begins to reach a nutrient deprived state - under fed state
what is the afferent system
carries signals towards the central nervous system
what is the efferent system
carries signals from the central nervous system
