The circulatory system

Name the three blood components that carry out transport, defence, and clotting functions, and state what each of them does.

Explain what blood plasma is, what blood looks like when its components are separated, and cite two types of substances that travel dissolved in it.

Explain what white blood cells are and reason why their number in the blood increases when we have an infection.

Look at the cross-sectional image of the heart. State which numbers point to the two atria and which point to the two ventricles, and explain one difference between their walls.

Name the four chambers of the heart and state through which one oxygen-poor blood from the body enters and from which one oxygen-rich blood leaves towards the whole organism.

The heart is said to actually be "two pumps in one". Explain what this expression means, which internal wall separates the two halves, and what problem there would be if the blood from both sides mixed.

Complete the sentence with the correct terms: "$\dots$ carry blood from the heart to the organs, $\dots$ return it from the organs to the heart, and $\dots$ are very thin vessels where the exchange of substances with tissues takes place."

State whether these statements are true or false and justify your answer: a) all the blood flowing through the arteries is rich in oxygen; b) capillaries connect arteries with veins; c) the heart valves prevent blood from flowing backwards.

Arteries have thick, elastic walls, and veins have thinner walls. Relate this difference to the pressure at which blood travels in each type of vessel, and explain what would happen if a vein had to withstand the pressure of an artery.

Describe the complete pathway of blood through the two circuits of the circulatory system: the pulmonary circuit (or minor circuit), indicating which heart chamber it begins in, which vessel carries it out, what happens to it in the lungs, and through which vessel and to which chamber it returns; and the systemic circuit (or major circuit), indicating which chamber it leaves from, through which major artery, to which parts of the body it carries blood, and through which major vein it returns to the heart.

Follow the path of a glucose molecule from the moment it is absorbed in the small intestine until it reaches a cell in the thigh, indicating which vessels it travels through, which heart chambers it passes through, and what compulsory "detour" it makes before reaching its destination.

A patient goes to the doctor and is diagnosed with severe pulmonary hypertension (the resistance of the vessels leading to the lungs is abnormally high), while the pressure in the rest of the body is normal. Two years later, an ultrasound reveals that the muscular wall of one of their two ventricles has doubled in thickness to compensate for this extra workload.

1. a) Reasonably justify which of the two ventricles will have increased in thickness.
2. b) Predict what consequences it would have for gas exchange in the alveoli and for the body if that ventricle were to eventually fail due to muscular exhaustion.