Mod 10: Fluid, electrolytes, and acid-base balance

Question 1

What’s the difference between intracellular fluid and extracellular fluid

Answer 1

Most of the bodys water resides inside cells – intracellular fluid
The remaining 35% of the body is water reside outside cells – extracellular fluid

Question 2

Extracellular fluid includes

Answer 2

The fluid between the cells inside tissue, called interstitial fluid, as well as the fluid within vessels as blood plasma and lymph
- Cerebrospinal fluid, synovial fluid in the joints, vitreous and aqueous humors of the eye, and digestive secretions – are called transcellular fluid

Question 3

If the concentration of electrolytes (And therefore the osmolarity) Of tissue fluid rises, water moves…

Answer 3

Out of the cells into tissues

Question 4

If the osmolarity of tissue fluid falls, water moves…

Answer 4

Out of the tissues and into the cells.

Question 5

Mechanisms to increase fluid intake

Answer 5

Physical changes stimulate the thirst centre in the hypothalamus – salivation decreases, causing a dry mouth and the sensation of thirst – consumption of water leads to a rise in total water volume

Question 6

Mechanisms to decrease urine output

Answer 6

Physical changes didn’t like the hypothalamus which stimulates the posterior pituitary to secrete antidiuretic hormone - ADH prompts the collecting ducts of the kidneys to reabsorb more water and produce less urine - The rate of fluid loss slows until waters ingested

Question 7

What is the main electrolyte in extracellular fluid

Answer 7

Sodium – accounting for 90% of its osmolarity

Question 8

The role of sodium in extracellular fluid

Answer 8

• Determines the volume of total body water
• Influences how body water is distributed
• Plays a key role in depolarization, making it crucial for proper nerve and muscle function

Question 9

Main electrolyte in intracellular fluid?

Answer 9

Potassium

Question 10

Functions of potassium

Answer 10

• potassium is crucial for proper nerve and muscle function (which also depends upon adequate levels of sodium)
• Aldosterone regulates serum levels of potassium, just as it does sodium
• Rising potassium levels - Aldosterone Causes the kidneys to excrete potassium as they reabsorb sodium

Question 11

What does hyperkalemia do?

Answer 11

Makes nerve and muscle cells irritable, leading to potentially fatal cardiac arrhythmias

Question 12

hypokalemia Results in

Answer 12

Muscle weakness, depressed reflexes, and cardiac arrhythmias

Question 13

Besides strengthening bones, calcium plays a key role in

Answer 13

Muscle contraction, nerve transmission, and blood clotting

Question 14

Hypercalcemia Inhibits depolarization of

Answer 14

Nerve and muscle cells, leading to muscle weakness, depressed reflexes, and cardiac arrhythmia

Question 15

Hypocalcemia increases excitation of

Answer 15

Nerves and muscles, leading to muscle spasms and tetany

Increase muscle contraction