Renal Physiology (1B)

Question 1

Diffusion

Answer 1

• movement within short distances
• crosses membrane barriers

Movement from one location to another due to random thermal motion

Question 2

What dictates the rate of diffusion?

Answer 2

1. chemical properties of the cell membrane
2. nature of the molecules (polar or unpolar)

Question 3

Polar molecules

Answer 3

generally unable to diffuse across bilayer (amino acids, glucose, water)

Question 4

Non- polar molecules

Answer 4

diffuse rapidly (CO2, fatty acids, steroids)

Question 5

Overtime what happens to solute molecules in a solvent?

Answer 5

Evenly distribute themselves

Question 6

What happens after a while to solute in a solvent?

Answer 6

Reaches diffusional equilibrium

Question 7

Water molecules are

Answer 7

polar and depends of aquaporins

Question 8

What are aquaporins?

Answer 8

water channels

Question 9

Is the rate of water diffusion through a membrane set?

Answer 9

It is variable

Question 10

WHAT IS WATER DIFFUSION GUIDED BY? ***

Answer 10

water concentration

Question 11

Water concentration is measured by*

Answer 11

osmoles which is equal to 1 mole of solute particles)

Question 12

Osmolarity (mol/L)

Answer 12

number of solutes per unit volume of solution

Question 13

Pure water concentration means that the osmolarity is ____ and water concentration is ____.

Answer 13

low, high

Question 14

A solution of solute means that the osmolarity is ___ and the water concentration is ____.

Answer 14

high, low

Question 15

Solvent + solute is =

Answer 15

solution

Question 16

Addition of more solute would ___ solute concentration and ___ water concentration

Answer 16

increase, reduce

Question 17

After diffusional equilibrium has occured,

Answer 17

equalized solute and water concentrations on both sides

Question 18

Osmosis

Answer 18

net movement of water across a selectively permeable membrane from region of high water –> low water concentration

Question 19

Pressure to prevent solvent movement (osmosis) is

Answer 19

osmotic pressure of solution

Question 20

The opposing pressure required to stop osmosis completely is equal to the

Answer 20

osmotic pressure

Question 21

In osmosis, the partition is permeable only to

Answer 21

water

Question 22

Tonicity

Answer 22

[non-penetrating solutes] of extracellular solution relative to intracellular environment

Question 23

What will the solute concentrations in relation to tonicity influence?

Answer 23

cell volumes changes

Question 24

Non-penetrating solutes are like

Answer 24

Na+ and K+

Question 25

Penetrating solutes are like

Answer 25

Urea

Question 26

Isotonic (isoosmotic)

Answer 26

1. same concentration of NPS outside and in the cell 2. no change to cell volume and shape will remain the same

Question 27

Hypertonic (hyperosmotic)

Answer 27

1. higher [ ] of NPS outside than inside cell 2. cells will shrink

Question 28

Hypotonic (hypoosmotic)

Answer 28

1. lower [ ] of NPS outside the cell than inside 2. cells will swell

Question 29

Water flows from an area of ____ osmolarity to _____ osmolarity

Answer 29

lower, higher

Question 30

Normal osmolarity inside a cell**

Answer 30

300 mOsm/L

Question 31

If the mOsm goes up inside a cell that means the cell is

Answer 31

hypertonic (b/c the movement of water is out and thus more solute inside)

Question 32

If the mOsm goes down inside a cell that means that the cell is

Answer 32

hypotonic (b/c the movement of water is in and thus less solute inside)

Question 33

Movement of water/solute out of the blood (plasma) is called

Answer 33

filtration

Question 34

Movemement of water/solute into the blood (plasma) is called

Answer 34

absorption

Question 35

Plasma is found in the

Answer 35

capillaries

Question 36

The movement of solutes between the plasma and interstitial fluid occurs at the

Answer 36

systemic capillaries

Question 37

The systemic capillaries are highly permeable to

Answer 37

1. water 2. most solutes

Question 38

At the arterial end, filtration is at its ____ and pressure is _____.

Answer 38

greatest, high

Question 39

At the venous end, filtration _____ and absorption ___. The pressure ultimately ____.

Answer 39

decreases, increases, drops

Question 40

What are the two arrows that are exiting the blood capillaries (filtration)

Answer 40

1. capillary hydrostatic pressure (Pc) 2. osmotic force due to interstitial fluid protein concentration (piIF)

Question 41

What are the two arrows that are entering the blood capillaries (absorption)

Answer 41

1. interstitial fluid hydrostatic pressure (Pif) 2. osmotic force due to plasma protein concentration (pic)

Question 42

Hydrostatic pressure occurs when

Answer 42

blood pushes against the wall of the capillaries from inside and or outside

Question 43

Blood flows from the ___ end to the ___ end.

Answer 43

arterial to venous

Question 44

IMPORTANT: what is the formula to determine net filtration pressure

Answer 44

Pc + piIF - Pif - pic (forces moving outwards) - (forces moving inwards)

Question 45

What ultimately is the main factor that determines fluid movement along the capillaries

Answer 45

The Starling Law

Question 46

What is the ultimate goal of the renal system?

Answer 46

to achieve homeostasis

Question 47

What is homeostasis?

Answer 47

Total body balance of any substance (ie. water, BV and BP, solutes)

Question 48

Photographically, what is balance of homeostasis?**

Answer 48

Gain (ingestion or product of metabolism) balanced with losss (excretion or get metabolized)

Question 49

What factor (arrow) has the most pressure effect on capillaries

Answer 49

capillary hydrostatic pressure that is directed out of the capillaries