Side ASide B
What affects the amount and distribution of body fluids?
Age, gender, and amount of fat
How much water does a fat cell contain?
Almost NO water.
Water in all spaces is exchanged ____ while maintaing constant fluid volume.
What triggers the sensation of thirst?
A rising blood osmolarity or a decreasing blood volume.
What are sensations are felt by a human that trigger thirst?
Dry mouth, or thought of not having a drink for a while
Of all the water loss pathways, which is the most important and most sensitive?
The kidneys ____ and ____ water loss.
What is the minimum amount of urine per day needed to excrete toxic waste products?
What is the minimum volume of urine called?
obligatory urine output
If 24-hr urine output falls below the obligatory output amount wastes are retained and could cause?
lethal electrolyte imbalances, acidosis, and a toxic buildup of nitrogen.
insensible water loss
water loss from the skin, lungs, and stool
What is the amount of sweating controlled by?
Anotomic Nervous System, body temp, and blood flow in the skin
What does the endocrine system help control?
fluid and electrolyte imbalances
Three hormones that help control critical fluid and electrolyte imbalances are
aldosterone, Antidiuretic hormone (ADH) and natriuretic peptide (NP)
The hormone secreted by the adrenal cortex whenever sodium level in the extracellular fluid (ECF) is decreased.
prevents both water and sodium loss
prevents excessive kidney excretion of sodium and prevents blood potassium levels from becoming too high.
vasopressin, produced in the brain and stored in the posterior pituitary gland
ADH antidiuretic hormone
Releases from the posterior pituitary gland, controlled by the hypothalamus in response to change in the blood osmolarity.
Secreted in repsonse to increased blood volume and BP because it is stretching the heart tissue.
natriuretic peptide (NP)
creates effects that are opoposite of aldosterone