Co2 in blood

Question 1

Carbon dioxide is an essential part of the buffer systems which controls the pH of extra cellular fluid.

where can ufind Co2?

Answer 1

Although CO2 is transported in venous blood,

there is a substantial amount of CO2 in arterial blood which has a vital role in acid base balance!

COOOL

Question 2

when carbon Dioxide is in Plasma it may form hydrogen ions and (bicarbonate) ions.

But The reaction is slow…why?

Answer 2

The reaction is slow because there is little carbonic anhydrase in the plasma.

Question 3

how does Co2 determine the pH of plasma, and therefore extra cellular fluid?

Answer 3

it depends on the extent of dissociation,

he equilibrium is driven towards dissociation by rises in dissolved CO2.

Question 4

Remember…..The amount of CO2 which dissolves is directly proportional to pCO2.

Answer 4

ok

Question 5

how is bicarbonate formed?

Answer 5

come from a reaction of CO2 in the rbc

Question 6

pH therefore _____ if pCO2 rises
pH therefore_____ if [HCO3-] rises

Answer 6

pH therefore falls if pCO2 rises
pH therefore rises if [HCO3-] rises

Question 7

Henderson - Hasselbalch equation

Question 8

In plasma the ratio of [HCO3-] to dissolved CO2 is _____

Answer 8

20:1

Question 9

In body fluids with few or no other buffer systems (e.g. plasma alone, CSF),

how is the concentration of HCO3, affected by pCo2?

Answer 9

it is not affected by changes in pCO2, and remains effectively constant over all physiological values of pCO2 unless changed by other mechanisms.

Question 10

Describe Carbon Dioxide reaction in the Red Cell.

Answer 10

Question 11

function of Carbonic Anahydrase?

Answer 11

accelerates the time Co2 reacts with water!

Question 12

what do the H ions produced in the reaction do?

Answer 12

binds to globin chains of Hb, this decreases the affinity of Hb to Oxygen! O2 is released!

BOHR shift TO RIGHT

facilitates O2 to be delivered to tissues!

Question 13

The hydrogen ions bound to Haemoglobin has a large buffering capacity,

IT is enhanced further when it is Hb is __________

Answer 13

de-oxygenated.

Question 14

The reaction is therefore ‘drawn’ towards production of HCO3-. The amount produced depends primarily upon the buffering effects of haemoglobin, with only minor effects of changes in pCO2.

Question 15

what happens to the HCO 3- formed in the RBC

Answer 15

HCO3 concentratio in RBC is MORE than in plsma>> so it moves out!

BUTT.. if too much HCO3 leaves, it’ll make the inside of RBC positive!

we dont want all this change in charges and shit happening…..

so HCO3- is exchanged with Cl-!

Question 16

why r RBC slighty swollen in venous side?

Answer 16

bc when Cl was entering the cell and HCO#- was leaving,

CL coming in causes water to follow it,,, causing a slight swelling!

Question 17

The pH of the body fluids is therefore determined by the relationship between:

Answer 17

• the amount of CO₂ dissolved in plasma, and
• 􏰀the amount of HCO_3^- formed from CO2 in the RBC by a reaction involving Hb

Question 18

where is [HCO3-] in plasma also controlled?

Answer 18

is also controlled by the kidney

Question 19

The critical feature is that so long as there is 20x as much HCO 3- as dissolved CO2 in plasma then the pH will be 7.4.

Answer 19

got it

Question 20

how is Co2 transported to lungs? it what forms?

Answer 20

Question 21

The amount of CO2 transported by the blood is determined by what?

Answer 21

difference between the venous and arterial CO2 content.

Question 22

Does CO₂ travel from tissues to lungs as carbamino compounds more or as dissolved CO_{<strong>2</strong> more} ?

Answer 22

as carbaaminno more!

Question 23

Describe the function of carbamino compounds.

Question 24

State the factors influencing the Hco3 concentration of plasma.

Question 25

what happens when RBC reach lungs?

Answer 25

Question 26

List in order methods of Co2 transport from greatest to least

Answer 26

80% as (bicarbonate).

12% as carbamino compounds

8% of transported CO2 travels as dissolved CO2,

Question 27

difference in Co2 and O2 in blood

and effects of hyperventilation

Answer 27

Question 28

alaa look at workbook noted for this session ok?