The body constantly makes new cells for the purposes of growth or the replacement of old, damaged, or recently dead cells.
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:
Organs of excretion make up the excretory system.
They include the :
kidneys-Blood by-products are filtered out by the kidneys and leave the body in urine form. They are part of the urinary system, which also includes the ureters, bladder, and urethra
large intestine-By-products enter the intestine and leave the body in the form of feces
liver- breaks down harmful substances. It's by-products are excreted into bile or blood.
skin-Sweating eliminates excess water and salts, as well as a small amount of urea, a byproduct of protein catabolism
lungs- oxygen is exchanged for a waste gas called carbon dioxide. Your bloodstream then carries this waste gas back to the lungs where it is removed from the bloodstream and then exhaled
Hope this helps!!!!!!
Forever friend and helper,
Cammie :)
