Lecture 18 Flashcards
Micronutrients?
- Substances that are required in very small quantities in order to maintain life and growth (mg’s per day)
Include:
- Minerals
- Water soluble vitamins
- Fat soluble vitamins
Minerals/vitamins involved in cardiac function?
Vitamin B1 (Thiamin), Selenium, K, Ca, Mg
Vitamin B1 (Thiamin) role in cardiac function?
- Release of energy supplied to heart
- Deficiency leads to: cardiac enlargement, oedema, build up of lactate and pyruvate, vasodilation and ultimately increase workload on the heart
Selenium role in cardiac function?
- Acts as an anti-oxidant
- Component of glutathione peroxidase involved in protecting cells against reactive oxygen species
- Deficiency can lead to: cardiomyopathy (weakening of the heart)
K, Ca, Mg?
- Involved in electrical signalling
- Deficiencies can lead to: arrhythmias (irregular heart beats)
Minerals involved in BP?
Na, K, Ca, Mg
Role of Na in BP?
- Plays major role in regulation of body fluids including blood pressure and even acid base balance through Na/K pump systems
- Main cationic electrolyte of blood
- Excessive sodium intake can lead to hypertension
Role of K in BP?
- Exchange ion with sodium concentrated primarily inside the cell
- Higher potassium intake can reduce blood pressure (promotes natriuresis…loss of Na through urine)
Role of Ca in BP?
Can reduce blood pressure
Role of Mg in BP?
Involved in smooth muscle function and implicated in control of blood pressure
Vitamin k’s role in blood clotting?
- Vitamin K is involved in the synthesis of gamma-carboxyglutamic acid from glutamic acid
- 4 of the factors involved in the clotting cascade contain
gamma-carboxyglutamates: prothrombin and factors VII, IX and X - Therefore vitamin k is required for the synthesis of clotting factors
Which drug prevents the regeneration of vitamin k?
Warfarin (thins blood to prevents clots)
Roles of iron in the body?
- Key in the oxygen carrying and storage proteins within the body (haemoglobin)
- Essential to energy producing reactions such as electron transfer chains (phosphorlaytion)
Intake/absorption of iron in the body?
- Haem (ring haem structure. comes from fish, liver, meat, etc)
- Non-haem (no ring. comes from green veggies, nuts)
- Absorption tightly controlled as iron is toxic. Excess ingested iron is stored in enterocytes and shed at the end of their life cycle.
Disease associated with an iron deficiency?
Anaemia
- can lead to: reduced work capacity, compromised immune system (white blood cells function affected) and eventually heart failure
Where is iron found in the body?
60% is found in the RBC’s as part of haemoglobin and the remained is in the bone marrow (site of RBC synthesis) and liver (in Ferritin)
What are the minerals/vitamins that work with iron?
Cu, vitamin B2, vitamin B6, and vitamin B12/9, vitamin A
Cu and it’s role with iron?
- Found in red blood cells and as a component of caeruloplasmin which in blood plasma converts Fe2+ to Fe3+
- Cu deficiency leads to hypochromic anaemia (less ion in RBC, paler)
Vitamin B2 and it’s role with iron?
Deficiency leads to hypochromic anaemia due to impaired Fe absorption
Vitamin B6 and it’s role with iron?
Involved in incorporation of Fe into haem and therefore has a role in RBC formation
Vitamin B12/9 and it’s role with iron?
- Vitamin B12 (cobalamins) and Vitamin B9 (folate) are used in the formation of purines and pyrimidines for the synthesis of DNA and RNA - therefore needed for cell division
- Deficiencies results in reduced DNA synthesis in developing RBCs prior to division resulting in large dilute cells with low oxygen carrying capacity
Vitamin A and it’s role with iron?
- Unsaturated hydrocarbons involved in utilising iron from ferritin, which stores iron in the liver
