Cardiac Cycle, Tissue Fluid and Oxygen Dissociation Curve

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SUMMARY

The discussion focuses on the cardiac cycle, specifically the pressure differences between the left ventricle and the aorta, the impact of temperature on the oxygen dissociation curve of hemoglobin, and the formation and reabsorption of tissue fluid in capillaries. It is established that the left ventricle's lower pressure is due to its larger volume compared to the aorta's smaller diameter. Additionally, the optimal temperature for hemoglobin's oxygen dissociation is around 37°C, which benefits mammals in oxygen transport. The discussion also confirms that approximately 85% of tissue fluid is reabsorbed at the venous end of capillaries, with the remainder being drained into the lymphatic system.

PREREQUISITES
  • Understanding of the cardiac cycle and heart anatomy
  • Knowledge of hemoglobin's oxygen dissociation curve
  • Familiarity with capillary structure and function
  • Basic concepts of the lymphatic system
NEXT STEPS
  • Study the mechanics of the cardiac cycle and pressure variations in heart chambers
  • Research the effects of temperature on hemoglobin's oxygen affinity
  • Examine the role of proteins in tissue fluid formation and reabsorption
  • Explore the functions of the lymphatic system in fluid balance
USEFUL FOR

Students preparing for AS biology exams, educators teaching cardiovascular physiology, and anyone interested in understanding the physiological processes related to blood circulation and tissue fluid dynamics.

garytse86
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Hello people I am currently having problems doing my AS exam paper. Can you please help?

The question is:

During the cardiac cycle, the pressure in the left ventricle falls to a much lower level than in the aorta. Give an explanation for this difference?

I have no idea about this because we were not taught about this.

The second question was:

How the effect of temperature on the oxygen dissociation curve of haemoglobin might be advantageous to mammals?

The third question was:

State two features of capillaries that enable tissue fluid to be formed:

I only can think of one: Basement membrane is permeable so plasma can escape from the blood.

The third question was:

It is estimated that 85% of tissue fluid is reabsorbed at the venous end of a capillary. Describe what happens to the remaining tissue fluid.

It is a three-mark question: but I put:
The rest of tissue fluid is drained into the lymphatic system through he lymph capillaries. And some fluid bathe the cells.

I really appreciate your help. Thanks a lot.
 
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Originally posted by garytse86
The question is:

During the cardiac cycle, the pressure in the left ventricle falls to a much lower level than in the aorta. Give an explanation for this difference?
Well, what is the volume of the left ventricle and what is the diameter of the aorta? The aorta is smaller, thus the pressure will be higher.

The second question was:

How the effect of temperature on the oxygen dissociation curve of haemoglobin might be advantageous to mammals?
The dissociation must have the best value for take-up and give-off of oxygen at 37oC?

The third question was:

State two features of capillaries that enable tissue fluid to be formed:

I only can think of one: Basement membrane is permeable so plasma can escape from the blood.
Uhm, let me think. This was way back.. there is something to do with proteins.. First plasma can escape from the blood, but it has to be resorbed to the blood later. Proteins are essential in this process, that is what causes those swollen hunger-bellies.

The third question was:

It is estimated that 85% of tissue fluid is reabsorbed at the venous end of a capillary. Describe what happens to the remaining tissue fluid.
The lymphatic system takes care of it, you are right.
 
Thanks a lot for your help, it was very useful!:smile: