Lecture 73 Flashcards
Many physiological processes depend on ____________ and ____________ availability
Ca and P
Regulatory system to maintain extracellular fluid levels of Ca and P include:
- Vit D
- Parathyroid hormone
- calcitonin
Processes in which Ca is involved
neurotransmission, Learning and memory, muscle contraction, mitosis, mobility, secretion, fertilization, blood clotting, structure of bones and teeth
Is Ca higher extracellularly or intracellularly
extracellularly
how much calcium is ionized (free form)
50 percent
Why is Ca conc higher extracellularly?
Membranes are very impermeable to Ca
How much calcium is bound (albumin, proteins) calcium?
40 percent
We need ionized Ca to remain in normal range (50%). This depends on pH. If pH is low acidosis can cause ____________ to Ca?
Increases ionized Ca channels
Complexed calcium (anions: phosphate and bicarb) is how much of calcium
10 percent
Intracellular Ca has a lower ?
Concentration
Cytosolic (intracellular) Ca can be increased as need-
fine balance of control
If Ca intake goes down, body adjust by increasing?
Percentage of Ca absorbed
Ca-sensing by Ca receptors on endocrine cells is involved in?
Ca homeostasis
____________ is hypocalcemia?
Low calcium levels
____________ is a common cause of hypocalcemia in animals?
- Lactation
- parathyroid and Vit D disorders
- gut metabolism
- renal failure
- ethylone glycol toxicity
Twitching/cramping of skeletal muscles and numbness/tingling, seizures can be due to?
Hypocalcemia
Low or high levels of plasma Ca is talking about?
Ionized Ca
Increased in plasma Ca (ionized Ca)
Hypercalcemia
constipation, polyuria, polydipsia, lethargy, coma and death can be caused due to?
Hypercalcemia
____________ can cause Hypercalcemia?
Parathyroid disorders and Vit D toxicity
Changes in plasma protein concentration can alter?
Ca in plasma
____________ can lead to altering Ca in plasma?
Changes in protein concentrations, complexing anion concentration and acid-base disturbances
Change the fraction of Ca bound to plasma albumin
Acid-base disturbance
Albumin can bind ____________ or ____________ ions
H+, Ca2+
more H ions in blood, more H ions bound to albumin, free ionized Ca increases. ____________ is this?
Acidemia
Acidemia can cause?
hypercalcemia
Less h ions in blood, more Ca bind to albumin, ionized Ca in blood decreases. ____________ is this?
Alkalemia
Alkalemia can lead to?
Hypocalcemia
interaction of bone, kidney, and intestines, plus parathyroid hormone, calcitonin and vit D
Calcium homeostasis
bone is constantly remodeled so Ca can be ____________ from blood
released or absorbed
____________ stimulates bone resorption of Ca
Parathyroid hormone and Vit D
____________ inhibits bone resorption of Ca?
Calcitonin
intestine will absorb Ca but the amount is regulated by?
Vitamin D
Absorption of Ca in the intestines decreases/increases with age
Decreases
Excess Ca in the diet is excreted where?
Shit
Kidneys reabsorb Ca- which is regulated by?
PTH
98% of filtered Ca is reabsorbed where?
Kidney
____________ is a component of ATP, various cofactors, lipids, RNA, DNA and bone
Phosphate
Percentage of phosphate absorbed from the diet is ____________
constant
Phosphate helps to balance many?
Cations