physio 1

What % of body weight = total body water

60%

What percent of total body water is intracellular fluid?

40%

What percent of total body water is extracellular fluid?

20%

What 2 things comprise extracellular fluid?

Plasma, interstitial fluid

If you have a dog that has 10% body fat and one that has 30% body fat, which dog would have a higher % of total body water?

10%

What % of total body water is plasma?

4%

What % of total body water is interstitial fluid?

16

Fill in the blank: __ mL/KG BW is average blood volume

70

What does osmole describe in fluid compartments?

Number of dissolved particles

_____ determines water movement between compartments

Osmolarity

If H+ ions increase, what happens to the pH?

Goes down

What does electroneutrality mean?

In each body fluid compartment, total positive charges must equal total negative charges

What is the major cation in ECF?

Na+

What is the major anion in ECF?

Cl- and HCO3 (bicarb)

What is the major cation in ICF?

K+

What are the major anions in ICF?

Proteins and organic phosphates (ATP)

What is responsible for preventing inappropriate cell signaling or muscle contractions?

Low ionized Ca2+ in ICF

What is ionized Ca2+?

Free calcium (unbound and free to interact)

When the osmolarity is the same in ECF and ICF what is maintained?

Electroneutrality

What is normal osmolarity?

290-300 mOsm/L

True or false: cell membranes are freely soluble to all solutes

False

True or false: cell membranes are selectively soluble

True

What is used to maintain selective permeability in cell membranes?

Transport mechanisms

Which transport mechanism that directly uses ATP is found on every cell?

Na+/K+ ATPase pump

Which way is Na+ pumped in the Na+/K+ ATPase pump?

Out

Which other transport mechanism directly uses ATP to help maintain selective permeability of membranes?

Ca2+/ATPase pump

What allows for nerve and muscle cells to have resting membrane potentials?

Ion concentration differences, K+ difference being high in ICF

What allows for absorption of nutrients in cells?

Na+ difference

Excitation-contraction coupling in muscle cells depends on what?

Ca2+ difference (high ECF, low ICF)

What are the 2 main components of cell membranes?

Lipids, proteins

The cell membrane being composed of lipids allows for what?

The cell membrane to be permeable to lipid substances such as CO2, O2, fatty acids, and steroid hormones

What does the phospholipid component of the cell membrane help to do?

Form lipid bilaer and allow the cell to exist in water environment

What do proteins function as in the cell membrane?

Transporters, receptors, enzymes, or channels

What kind of protein spans the membrane once or can be transmembrane proteins (span more than once)?

Integral proteins

What kind of protein is only on one side of the cell membrane?

Peripheral proteins

What kind of transport is NOT carrier mediates, does NOT require energy and depends on the concentration gradient (passive: downhill)?

Simple diffusion

What type of diffusion requires a carrier but does not require energy (passive:downhill)?

Facilitated diffusion

What are the 2 kinds of transport that can go against an electrochemical gradient?

Primary transport and secondary transport

What kind of transport uses direct input of energy and uses a carrier?

Primary transport

What kind of transport uses an indirect input of energy and uses a carrier?

Secondary transport

Select all that apply: What are the 5 variables that determine diffusion rate or non-electrolytes?

Concentration gradient, partition coefficient, diffusion coefficient, thickness of membrane, surface area

What 4 variables determine permeability?

Partition coefficient, diffusion coefficient, thickness of membrane, and surface area

In diffusion the concentration gradient says that the larger the concentration difference = ______

Larger the driving force

What is the partition coefficient?

Based on the lipid solubility of a solute, the higher the lipid solubility = higher partition coefficient = moves more easily

What is the diffusion coefficient based on?

Size of solute and viscosity of solution

True or false: the greater the surface area = higher diffusion rate

True

What is an example of particles that are lipid soluble, small, travel through non-viscous solution and thin membrane?

CO2 and O2

What is a diffusion potential/when is it created?

The potential difference that is created across a membrane bc of an ion concentration difference. It is created when a charged solute diffuses down its concentration gradient.

True or false: diffusion of a positively charged ion will slow down if diffusing into an area of positive charge

True

What two things make up the electrochemical gradient?

Electrical forces + concentration forces

This kind of diffusion uses a carrier protein but NO input of energy?

Facilitated diffusion

Why does facilitated diffusion move fast with low solute concentration?

Because a limited number of carriers, it will proceed faster at relatively low solute concentration

What is an example of facilitated diffusion in skeletal and adipose tissue that transports glucose into cells.

GLUT4 transporter because it requires insulin to move glucose bc glucose is water soluble

What are the 3 main features of carrier-mediated transport (facillitated diffusion)?

Saturation, stereospecificity, competition

In carrier mediated transport, saturation describes the phenomenon where the rate of transport ____ at lower solute concentrations.

Increases

What is the Tmax od carrier-mediated transport?

When you have saturated all carriers

True or false: carriers for D-glucose can transport L-glucose

False (stereospecific)

True or false: D-galactose can bind carriers for D-glucose

True (competition)

What kind of transport is used when one or more solutes is moved AGAINST a concentration gradient and uses ATP?

Primary active transport

This pump is present in membranes of ALL cells and uses 20-40% of cellular ATP in many tissues

Na+/K+ ATPase pump

How many Na+ is pumped into ECF?

3

How many K+ pumped into ICF?

2

The exchange of 3Na+ out/2 K+ in creates what?

Potential difference

What occurs in the plasma-membrane Ca2+ ATPase?

1 Ca 2+ is pumped out of the cell

What happens in the SERCA?

2 Ca2+ from ICF to sarcoplasmic reticulum

What does the H+/K+ ATPase pump do and where is it found?

Parietal cells of gastric mucosa that pumps H+ into lumen of stomach

What kind of transport indirectly uses energy by utilizing the Na+ gradient to transport solutes against their concentration gradient

Secondary active transport

What is co-transport (symport)?

All solutes transported in the same direction

What is counter-transport (antiport)?

Solutse move in opposite directions

What is counter-transport maintained by?

Na+/K+ pump

What kind of transport is the Ca2+/Na+ exchange that is typically also present on most cells?

Countertransport (antiport)