Practical Two Flashcards
Interstitial fluid
water + dissolved substances eg vitamins
Active transport
cell uses energy to move substances across membrane eg NA/K ions
What are the three components of blood?
- Plasma 55%
- Buffycoat < 1%
- Erythrocytes 45%
What makes up plasma?
- water
- WBC
(least dense)
What makes up Buffycoat ?
- leukocytes
- platlets
What makes up Erthyrocytes ?
- RBC
most dense
Which layer of blood is haematocrit ?
erthrocytes
haemotcrit
anemic (oxygen deprivation)
haemotacrit
polysethemia
function of RBC in gas transport
combining oxygen gas with haemoglobin
What strucure is absent in RBC
a nucleus = increased surface area= haemoglobin to carry oxygen
what is the sape of a RBC and how does it facilitate transport
- Bioconcave discs = increased surface area = increased haemoglobin transported
- also allows to pass through small capillaries
diffusion
tendency of molecules/ions to move from an area of high concentration down a concentration gradient
Osmosis
Diffusion of a solvent (water) through a selectively permeable membrane passing through membrane when there is a different concentration on either sides
Tonicity
ability of a solution to cause a change in cell shape or tone by osmosis
Isotonic
Solution with a concentration of nonpenetrating solutes equal to that found in reference cell
Hypotonic
below normal tone or tension
more dilute than reference cell
Hypertonic
High concentration of non penetrating solutes than reference cell
greater osmotic pressure
how does RBC in an isotonic solution affect osmosis
no net water movement across cell membrane
how does RBC in hypotonic solution affect osmosis
net water movement into cell resulting lysis
what does a greater concentration gradient mean
the faster molecules will move
therefore faster in a 3% solution
