[FMS] NAM - metals Flashcards
Where is sodium found and excreted?
- Mostly found in blood and in ECF (extracellular fluid)
- Mostly excreted in urine
What is a sodium-associated disease?
Osteoporosis
What is too low Na in serum known as?
Too low Na in serum = Hyponatremia
- Electrolyte abnormality
- cells swell
- decrease in total body water
What is too high Na in serum known as?
Too high Na in serum= Hypernatremia
-cause: limited access to water or impaired thirst mechanism
-decrease in total body water relative to electrolytes
-water problem
-water leaves cells and enters blood aiming to dilute it and lowering Na levels
What does too much Na in the diet lead to?
-too much Na= facial puffiness, high bp, heart disease and stroke
-can cause Ca loss- increase in Ca excretion some can be from bone
Where is potassium found and excreted?
- Mostly inside the cells than outside; present in all body tissues
- Mostly excreted in urine, 10% in sweat and stool
- K has a strong relationship with Na
What is low levels of K in the blood known as?
Hypokalemia
- Cause 1: excessive K loss in urine (due to medications that increase urination)
- These medications are often prescribed for high blood pressure or heart disease
- Cause 2: Low K intake; associated with increased blood pressure and higher risk stroke
- If you have low K levels, you may have a heart problem, such as an irregular heartbeat
What is high levels of K in the blood known as?
Hyperkalemia
- Can be life-threatening
- Heart muscle activity may be reduced, weakness, paralysis in feet or respiratory
Where is magnesium found?
- 50% of body’s magnesium is in bone
- Very little in blood
What are the physiological functions of magnesium?
- Cofactor
- Protein synthesis
- muscle and nerve function
- blood pressure regulation
- oxidative phosphorylation, and glycolysis, and DNA, RNA and glutathione
- Regulates insulin secretion
- Contributes to formation of bone and teeth
What is too low levels of magnesium known as?
Hypomagnesemia
- Low Mg impairs the Mg-dependent adenyl cyclase generation of cAMP
- This decreases release of parathyroid hormone (PTH)
- Since PTH regulates Ca levels, Ca levels are decreased
^ Hypomagnesemia patients are at risk of cardiac arrhythmias
What is too high levels of magnesium known as?
- Major cause is renal failure
- Cardiovascular and neurological complications
Where is calcium found?
- About 99% of body’s calcium is stored in bones and teeth
- Cells (muscle cells) and blood also contain ca (bound to albumin or exist as ionised Ca).
What are the physiological functions of calcium?
- Formation of bone and teeth
- Small fraction of Ca in blood, ECF, and other tissues -
- mediates blood vessel contraction/dilation
- muscle contraction
- blood clotting
- nerve transmission, and hormonal secretion.
What are diseases associated with calcium?
- osteoporosis
- dental changes
- cataracts
- Familial hypocalciuric hypercalcemia (FHH): inherited disorder - FHH-usually do not show symptoms
How is iron regulated at high systemic levels by hepcidin?
-If you have high systemic/tissue iron levels, your liver hepatocytes sense this and they produce the hormone, hepcidin.
- This hepcidin binds on to the ferroportin molecules.
- Ferroportin is a transmembrane ion exporter which is uni-directional.
- If that is degraded then iron cannot come out into the circulation.
- And so by iron levels not coming out into the circulation, iron levels are maintained under normal physiological conditions.
- The body also has high levels of systemic ion present, we don’t want more iron to come out from the cells into the circulation.
How is iron regulated at low levels and by what molecule?
REGULATED BY HEPCIDIN
When iron levels iron levels are low, hepcidin secretion decreases.
- Less hepcidin is able to bind to ferroportin.
- These ferroportin molecules are functional and not degraded.
- Therefore they allow the exist of iron from inside the cells to the outside of the cell which isn’t part of the systemic circulation.
- So it brings an iron into the circulation to prevent anaemia.
What is the role of zinc in the human body?
