ch10-12
Aldosterone
Hormone that stimulates the kidney to retain sodium ions and water It is essential for sodium conservation in the kidney, salivary glands, sweat glands and colon.
How does antidiuretic hormone function?
It stimulates water reabsorption by the kidneys.
Describe how minerals and other dietarycomponents affect mineral bioavailability
Minerals can compete with each other at the absorption and transport level Acid and meat enhance absorption Phytate, oxalate, tannins decrease absorption
Hemoglobin
Oxygen carrying protein in red blood cells
Keshan's Disease is a result of _____________ deficiency.
Selenium deficiency
Regulation of water balance
Signals from the brain (hypothalamus) •Dry mouth motivate the consumption of fluid
D.A.S.H
-A Dietary Approaches to Stop Hypertension -A diet high in fruits &vegetables, low in fat
Describe the functions of phosphorus and magnesium in the body.
-Bone health -Magnesium also impt for water balance, nerve and muscle functions
iron deficiency
-Fatigue -Cannot maintain body temperature -Prone to infection -Adverse pregnancy outcomes and impair development -Pica eating ice or metal
regulation of blood calcium
-The parathyroid hormone (PTH), secreted by the parathyroid glands, is responsible for regulating blood calcium levels; it is released whenever blood calcium levels are low. 1.PTH increases blood calcium levels by stimulating osteoclasts, which break down bone to release calcium into the blood stream. 2.PTH increases blood calcium levels by increasing the amount of calcium resorbed by the kidneys before it can be excreted in the urine. 3.PTH increases blood calcium levels by triggering the formation of calcitriol, which increases absorption of dietary calcium through the intestines. -Calcitonin, a hormone produced by the thyroid, acts in opposition to PTH by inhibiting osteoclasts, stimulating osteoblasts, and increasing excretion of calcium into the urine by the kidneys.
order of iron deficiency
1. ferritin 2.transterrin 3.hemoglobin
3 functions of electrolytes
1.Fluid balance: affects water distribution 2.Nerve functions 3.Muscle contractions
A person's bone density is highest at around age
30 years
Regulation of iron
A. Absorbed iron is (1) bound to storage protein ferritin or (2) picked up by the transport protein transferrin B. Transferrin-‐iron complex deliver iron to cells(1) hemoglobin -carries oxygen in blood(2) myoglobin -carries oxygen in muscle C. Iron losses(1) Blood loss (2) Shedding of cells from intestine, skin, urinary tract
What is the function of renin?
Activates angiotensin
Describe how high intakes of zinc affect copper absorption
Copper and zinc interact with one another. High intakes of one can decrease the absorption of the other.
In general, mineral binders __________ the bioavailability of nutrients.
decrease
groiter
forms from lack of iodine; thyroid tries to produce thyroxine to compensate and it enlarges
renin
hormone secreted by the kidney; it raises blood pressure by influencing vasoconstriction (narrowing of blood vessels)
In general, estrogen, weight bearing activities and being overweight are factors that __________ bone density
increase
dietary and life style factors that reduce the risk of osteoporosis
increase vit D and calcium
Cretinism is due to ___________ deficiency
iodine
Ferritin
iron storage protein
transferrin
iron transport protein
food enrichment
nutrients added back after loss from food processing
Food fortification
process of adding vitamins and minerals to food staples; one of the most cost-effective ways to save lives
Homeostasis
relatively constant internal physical and chemical conditions that organisms maintain Homeostasis is regulated by the intake of both water and salt
growth, sperm production and antioxidant
zinc
Sodium & blood pressure
Water follows salt•Salt intake > blood volume increases > blood pressure increases
Regulation of blood pressure
When blood pressure is low (blood loss, salt imbalance), our body will respond to increase blood pressure. When blood pressure is low, the kidneys will be able to sense it. The kidneys will release rennin. Renin converts angiotensin (inactive) to angiotensin II (active). Active angiotenin II will do result in two major reponses. One, angiotensin II will constrict the blood vessels to increase blood pressure. Secondly, angiotensin II will trigger the adrenal gland to release aldosterone. Aldosterone will stimulate the kidneys to retain sodium, which will retain water. Increase in water retention will increase blood pressure. Water follows salt. Water àsalt àincrease water/ blood plasma àblood pressure.
Copper deficiency
anemia Copper is needed to incorporate iron into transferring and also into hemoglobin. Deficiency in copper can lead to secondary iron deficiency.
Pica
compulsive eating of nonnutritive substances such as clay or ice
myoglobin
An oxygen-storing, pigmented protein in muscle cells.
In general, which type of iron source has a higher bioavailability?
heme iron