Exam 4 - Chapter 26 Deck Flashcards
(49 cards)
How much (%) of fluid makes up the adult body mass? *For both females and males
Fluid are a large part of adult body mass
55% of female body mass (have more adipose tissue)
60% of male body mass (have more muscle mass, muscles retain more water)
What are the main compartments fluids can be found in?
Inside cells (2/3) - Intracellular is called cytosol (cell juice)
Outside of cells (1/3) - Extracellular fluid (80% of interstitial fluid) OR blood plasma (20% of extracellular fluid)
Exchange of water and ions in the plasma membrane?
Separates intracellular fluid from interstitial fluid
Keeps intracellular cytosol fluid inside the cell
Keeps interstitial extracellular fluid outside of the cell (in space)
Exchange of water and ions in the blood vessel walls?
Divide the extracellular components (interstitial fluid from blood plasma)
Keeps blood plasma in the blood vessels
Keeps interstitial fluid outside of the blood vessels
Exchange of water and ions in the capillary walls?
Super thin to allow for exchange of water and solutes between blood plasma and interstitial fluid of extracellular fluid
Site of capillary exchange
Composed of endothelium/one layer of squamous
What are the four methods of continuous exchange among body fluid compartments?
Filtration, reabsorption, diffusion, and osmosis
Filtration
Leaving blood, going into the drop off cells
Reabsorption
Leaving cells, going back into the blood
Diffusion
Solute exchange
Osmosis
Water exchange (passive transport)
What are the main drivers of reabsorption and filtration? *Pressure
Hydrostatic and osmotic pressure
What are the main factors that determine body fluid volume?
The amount of urinary salt loss and osmolarity
What are the two main solutes in urine?
Na+ and Cl-
Wherever solutes go, water follows
Discuss ways water enters the body
Ingestion
Metabolic synthesis - when substances are broken down (we gain water as a product)
Discuss ways water exits the body
Urination - elimination of excess body water
Perspiration - most of water is lost through the skin through perspiration
Exhalation - breathe out water molecules
Feces
Why is it important that water in must be equal to the water out to remain hydrated/maintain homeostasis
Too much water loss can lead to dehydration
Too much water in body can lead to hypovolemia
When extracellular fluid is isotonic to the cells of the body, they do NOT shrink or swell (normal condition)
Changes in osmolarity such as dehydration or hypovolemia can cause the cells of the body to shrink or swell
Functions of ions formed when electrolytes dissociate and dissolve
Control osmosis of water between fluid compartments
Helps maintain acid-base balance
Carry electrical currents
Serves as cofactors
Discuss the differences in concentration
The concentration of ions is expressed in units of milliequivalents per liter (mEq/liter)
Blood plasma, interstitial fluid, and intracellular fluid have different concentrations of electrocytes and protein ions
Blood plasma contains many proteins ions; interstitial fluid contains only a few
Sodium and potassium ion concentrations are nearly opposite in extracellular (interstitial and plasma) and intracellular fluid
^This is because the ATP-dependent sodium-potassium pump keeps intracellular Na+ concentrations low and K+ concentration high
Proteins and nonelectrocyte concentration in the plasma, interstitial fluid, and intracellular fluid
Plasma = 90%
Interstitial fluid = 60%
Intracellular fluid = 97%
Sodium
Most abundant cation in extracellular fluid
Used for impulse transmission, muscle contraction, fluid, and electrolyte balance
Its level is controlled by aldosterone, ADH (retains sodium), and ANP (excretes sodium)
Chloride
The major extracellular anion
Helps to regulate osmotic pressure between compartments (electrochemical gradient)
Forms HCl in stomach (hydrochloric acid)
Regulation is controlled by aldosterone
Potassium
Most abundant cation in intracellular fluid in cytosol
Involved in fluid volume, impulse conduction, muscle contraction, and regulating pH
Mineralcorticoids (mainly aldosterone) regulate the plasma level
Bicarbonate
Important plasma ion
Major member of the plasma acid-base buffer system
Kidneys reabsorb or secrete it for final acid-base balance
Calcium
Most abundant mineral in the body
Structural component of bones and teeth
Used for blood coagulation, neurotransmitter release, muscle tone, excitability of nerves and muscles
Level in plasma regulated by parathyroid hormone which activates osteoclast and removal of calcium from bone tissue and increases calcium blood concentration
PTH is released in response to hypocalcemia (low blood calcium concentration) and stimulates activation of vitamin D and calcium in GI tract
