Answer:
Those capillaries that have endothelial cells tightly attached have an increase in cell-to-cell junctions, such as desmosomal junctions that are poorly permeable to substances.
These capillaries generally function as conductors or collectors and not as permeabilizers like the pulmonary capillaries that are fenestrated and allow a high passage of substances and gases.
The capillaries are waterproof and prevent the passage of substances or fluids such as in the blood-brain barrier that is very selective
Explanation:
The blood-brain barrier is too selective since it is not favorable for the organism that many fluids, drugs, substances or chemical compounds enter the brain space.
This is the reason why the vessels are waterproof and why pharmacology was challenged to invent drugs that could cross this barrier since it was considered impossible.
An example is dopamine, which in parkynson's disease the levo group is added to dopamine, thus forming levodopamine as a product, this is the only way that the drug crosses the blood-brain barrier and can pass the impermeable barrier generated by capillaries with endothelial cells that are close to each other or closely linked
Answer: It is the key to blocking infections
Explanation: I hope this is right :)
Answer:
In photosynthesis carbon dioxide is fixed and oxygen is released. In breathing, oxygen is consumed and carbon dioxide is released, releasing energy.
Explanation:
C is the answer. Due to the current state of the world economy; people, if left to their own devices, would fish as much as possible so they can sell their fish to make money. Current technology means we can catch as many fish as we want (trawlers etc.). The problem with this is that there is only a finite amount of fish in the sea. If we were to fish them without limits in place, we could cause them to go extinct.