Cells and the internal environment Flashcards Preview

Human Physiology (1) > Cells and the internal environment > Flashcards

Flashcards in Cells and the internal environment Deck (29)
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1
Q

What are the 3 major fluid compartments in the body?

A

Blood plasma, interstitial fluid, intracellular fluid

2
Q

What is the body weight % of blood plasma?

A

5%

3
Q

What is the body weight % of interstitial fluid?

A

15%

4
Q

What is the body weight % of intracellular fluid?

A

40%

5
Q

What is the body weight % of extracellular fluid?

A

20%

6
Q

What are the 3 internal environments that we absorb water from?

A

Blood vessels, stomach, intestine

7
Q

From the internal environment, where does the fluid pass through first?

A

Blood plasma

8
Q

From the blood plasma, where does the fluid pass too?

A

Lungs, kidneys, interstitial fluid

9
Q

What separates the blood plasma and interstitial fluid?

A

Two compartment capillary wall

10
Q

What separates the interstitial fluid and intracellular fluid?

A

Cell membrane

11
Q

What does the process of having a cell membrane achieve?

A

Osmotic equilibrium

12
Q

What is the general trend in extra vs intra fluids ion concentrations?

A

Extracellular has high concentrations of Na and Cl but low concentrations of K and protein. Intracellular has low concentrations of Na and Cl but a high concentration of K and protein.

13
Q

Why does intracellular fluid have a high protein concentration?

A

Enzyme reactions

14
Q

What is the composition of intra vs extra cellular fluids called?

A

Chemical disequilibrium

15
Q

Why does a chemical disequilibrium occur?

A

Differences in the composition and cell membranes permeability to molecules

16
Q

What molecule properties makes it hard to cross a membrane?

A

Large size, low lipid solubility, high charge

17
Q

What is the most important factor that affects permeability?

A

Charge

18
Q

What is a membrane impermeable to?

A

Sugars, amino acids, peptides, proteins and inorganic ions

19
Q

What is diffusion?

A

Diffusion is the process of random collisions causing molecules to move down a gradient from a high to low concentration to make an equilibrium

20
Q

What is filtration?

A

Filtration occurs under a high pressure and a porous membrane which will only allow molecules of a certain size through

21
Q

What is an example of filtration?

A

Kidney

22
Q

What is osmosis?

A

Osmosis is the movement of water across a membrane in response to a solute concentration gradient. It moves from low to high solute gradient

23
Q

What is osmotic pressure?

A

Pressure which would prevent water moving

24
Q

What is protein mediated transport?

A

PMT is where proteins act as carriers and channels to facilitate the flow of substances that cannot permeate through the lipid bilayer

25
Q

What are 2 examples of molecules which us PMT?

A

Ions and large unionised molecules

26
Q

What process happens to allow PMT

A

Facilitated diffusion down a concentration gradient. No energy is required. Active transport against a concentration gradient, ATP is used

27
Q

Describe endocytosis:

A

Endocytosis is the process of a molecule being engulfed by the cell membrane into the cell

28
Q

What 2 ways are there for endocytosis:

A

Pinocytosis - pinches off pockets

Phagocytosis - engulfing

29
Q

What is exocytosis?

A

The process of hormones and neurotransmitters leaving the cell