The medicine want advanced enough to fight off the sicknesses and doctors weren't very knowledgeable
The first one should be correct
Hope that helped
As blood glucose returns to its baseline level, the levels of insulin and glucagon in the blood will stabilize. As the blood glucose levels begin to drop below the base line, the concentration of glucagon hormone increases. while as the blood sugar levels increases above the baseline, the level of insulin hormones increases. Insulin and glucagon work antagonistically to maintain the normal level of glucose in the blood.
The lymphatic vessels are thin-walled valvular structures, composed of lymphangions, which carry the lymph from the tissues, via the lymph nodes, to the bloodstream. For this reason, they are analogous to veins and venules.
The lymphatic network is present throughout the body with the exception of the central nervous system and non-vascularized tissues.
It is separated in two circuits: one for the upper right quarter of the body, and one for the rest.
The lymphatic channels join together to form lymphatic vessels more and more voluminous.
Finally, The lymph is drained by two large collectors:
* The right lymphatic canal
* The thoracic duct.
All lymphatics thus end up in the upper vena cava system by two separate circuits.
I'm afraid none of those is correct. The correct option would be subspecies. Subspecies are different variations, one could say, of a same organism.
Hope it helped,
Happy homework/ study/ exam!