Lesson 9 Flashcards
how many liters of water does an adult body contain ?
40 L
what percentage of water found inside of cells ?
2/3
muscle cells and epithelial cells contain what % water ?
70-80%
fat cells and bone cells contain what % water
20% or less
the water that is not inside of cells is outside of cells (extracellular fluid). what does it contribute to?
cardiovascular system and lymphatic system
what does the extracellular fluid include ? (7)
lymph, blood, sweat, tears, gastric juices, spinal fluid, fluid between joints
where does water move towards ?
the highest concentration of SOLUTES
what is osmosis ?
mvmt of water across a membrane towards the side with a larger concentration of solutes
what is a selectively permeable membrane going to do w the same amount of solute on both sides ?
if both sides are with equal amount of solute, the tendency for water to move in either direction is the same
what is a selectively permeable membrane going to do if there is a bit more solute on side B - where will the solute flow?
the solute cannot flow across the divider (membrane)
what is a selectively permeable membrane going to do if there is a lot more solute on side B - what will happen to the water ?
although solute cannot flow across the divider, water can, so the volume of water becomes greater on side B in order for the concentration on side A and B to be equal
what are electrolytes ?
salts that dissolve in water and dissociate into ions
what is the role of electrolytes ?
help to control the volume of water within the fluid compartments
what are cations ?
positively charged ions
what are anions ?
negatively charged ions
what percentage of blood plasma is water ?
92% of blood plasma is water
what is metabolic water ?
water that is the byproduct of energy metabolism
how much water is produced by sedentary people
300 mL/day
how much water is produced by active people
500 mL/day
how does water regulate body temp
sweat which evaporates and cools skin and blood at skin surface
what needs to happen for water to be pulled up to the surface ?
water molecules at surface must evaporate
what are the 3 factors in % of water in body
age, sex, body composition
how does age affect % body water
newborn 75% water
elderly 45% water
why does sex and body composition affect % water in body
males have less fat, therefore more muscle tissue and more water
how much % water in fat
20%
how much % water in muscle
75%
everytime the heart contracts, how much blood output goes to the kidneys directly ? why?
21% to compensate for water losses
what is cardiac output ?
volume of blood pumped into circulation / minute
what does urine travel to the bladder through ?
ureter
how much urine produced per minute
1 mL
what is the relationship between BP and blood volume
increasing blood volume increases BP
kidneys are controlled by which two hormones from which two glands ?
ADH (posterior pituitary)
aldosterone (adrenal gland)
what does ADH do ?
retains water
therefore retains sodium and excretes potassium
what does aldosterone do?
retains sodium
therefore retains water and excretes potassium
what is the main effect of both ADH and aldosterone ?
increase BP and blood volume
what are three dietary mineral ways to manage BP
increase potassium and magnesium intake
reduce salt intake
what are DASH diets ?
Dietary Approaches to Stop Hypertension
what can treat dehydration ?
water intake
in some cases electrolytes
what is hyponatremia ?
low sodium in blood
what are three symptoms of hyponatremia ?
severe headache, confusion, seizures
what is water intoxication ?
body water contents too high in all body fluid compartments
it can cause hyponatremia
what happen to water flow in hyponatremia ?
water leaves interstitial fluid and goes into cells
what is the drug that may cause hyponatremia ?
MDMA bc it causes dehydration and ppl may drink a lot
what is the UL for water
none
what is metabolism
the sum total of all the chemical reactions on in living cells
what reactions require energy ?
anabolic
what are anabolic reactions ? (3)
glycogen production, TG production,
protein production
what is the most energetically expensive organ ? why?
kidneys
need 5 cups of blood per minute to make urine
what is the main role of kidneys ?
convert inactive vitamin D into the active form
what is the energy currency of the cell ?
ATP
what are 3 examples of catabolic reactions ?
glycolysis, protein and TG breakdown
where are gases and nutrients and waste exhanged between cells and the blood
capillaries
rank the amount of mitochondria per cell in fat, muscle, and liver
muscle> liver> fat
what happens with the chemical energy in the C-H bonds of glucose ?
ATP 40%
heat lost 60%
how is the Na+/K+ pump activated by ATP?
it is phosphorylated, and ATP becomes ADP
food gives mitochondria fuel to make ATP: true or false
true
how many kcal/day does the liver require
380
which fat does the liver make ?
VLDL and cholesterol
which vitamins is the liver responsible for
vit A and D
what is the AMDR fat
20-35%
what is the AMDR protein
10-35%
what is the AMDR CHO
45-65%
what are the three ways the energy is used in our body ?
thermic effect of food
physical activity
basal metabolism
what is the % of our diet that goes to basal metabolism ?
50-65%
what is basal metabolism ?
the energy needed to maintain life when body is at rest
how is basal metabolic rate measured ?
fasting and resting 12 hrs
what does basal metabolic rate not include ?
energy spend for physical activity, food digestion, absorption of nutrients
rank the following by BMR from high to low : liver, muscle, heart, kidney, brain
liver brain muscle kidney heart
what is the thermic effect of food ?
estimation of energy required to process food (digestion, absorption, transport, metabolization)
what is the least expensive PA?
running
can running help cognitive function ?
yes
what are the 5 factors that influence BMR?
body composition (the higher the muscle/fat ratio, the higher the BMR) sex (men>women) BSA (taller people >) age (growing kids >>) genes
describe the sweat gland maturation ?
sweat glands are non function when born
mature over first year
who will have more sweat glands : someone in hot or cold environment ?
hot
when does BMR setting start ?
in fetus
what is the connection between birth weight and risk of disease ? why
low birth weight means higher risk of disease, since in utero these fetuses lowered their BMR to conserve energy
what is thrifty gene theory?
low birth weight means higher risk of disease, since in utero these fetuses lowered their BMR to conserve energy and then they predict an environment of food scarcity
what is epigenetics ?
the study of how environment (like nutrients) can affect gene expression
what are nutrigenomics ?
study how food can affect gene expression
what are nutrigenetics ?
study how genes influence how nutrients are metabolized
