Unit 3 Flashcards
(142 cards)
How much of a healthy adults body weight is fluid?
50-70%
2/3 of body fluid is ___________ fluid
Intracellular
1/3 of body fluid is ___________ fluid
Extracellular
Lean tissues (muscle) is made up of ____% fluid
70%
Fat tissue is made up of ___ % fluid
10-20
What are electrolytes?
Mineral salts that dissolve in water and separate to form ions
T/F: There is a slight difference in electrical charge on either side of the cells membrane that is needed for the cell to perform normal functions
True
What are the predominant intracellular ions?
Potassium and phosphate
What are the predominant extracellular ions?
Sodium and chloride
Water has ______ capacity for heat.
High. It takes a lot of energy to raise it’s temperature and because the body has a lot of water, only prolonged exposure to heat can increase body temp
T/F: Cell membranes are freely permeable to electrolytes so they generally go where they want.
False
Cell membranes are NOT freely permeable to electrolytes so they generally stay where they are unless actively transported.
What is a side effect of severe diarrhea/vomiting, in regards to fluid balance?
The body loses a lot of both water and electrolytes
What is the result of water/electrolyte loss with severe diarrhea/vomiting in regards to solute concentration?
Sometimes the water loss is much greater than the electrolyte loss. Therefore the extracellular electrolyte concentration becomes very high which pushes fluid out of the cell. Dehydration.
What is the result of water/electrolyte loss with severe diarrhea/vomiting in regards to the heart?
These changes in fluid and electrolytes can change the flow of electrical impulses through the heart –> irregular heart rate –> fatal if untreated
Which two electrolytes play a big role in nerve impulse conduction?
Sodium and potassium
What happens during depolarization re: sodium?
Stimuli (ex: hand on burner) prompts changes in membrane allowing influx of sodium into nerve cell and causing it to be slightly less negatively charges. If enough sodium enters, an electrical impulse is generated along the membrane.
What happens during repolarization re: potassium?
Returns to normal electrical state by releasing potassium to ECF
What happens during muscle contraction, re: calcium?
Occurs in response to stimulation of nerve cells
Increase flow of calcium from storage site in muscle cell triggers muscle contraction.
What happens to calcium as the muscle cell relaxes post-contraction?
Muscle cell can relax once electrical signal is complete and calcium pumped back into storage.
What part of the body regulates thirst?
The hypothalamus
Name 3 situations in which the body is triggered to increase thirst
- Increased salt concentration
- Reduced blood volume and pressure
- Dry tissues in mouth/throat
What happens when ADH is released from the pituitary?
Kidneys reabsorb more water and return it to blood. Decreased urine output.
What is metabolic water?
Water formed from body’s metabolic reactions
How much water is produced from metabolic water/day?
10-14% of water needs per day