How can flatworms, simple animals with a flat body shape, survive without a circulatory system?
In flatworms, all cells are located near central body branches or near the body surface, so diffusion alone can transport important nutrients.
Blood pressure tends to fall with increasing distance from the heart. On the bias of the information, which of the following lists the types of blood vessel, in order, from highest blood pressure to lowest?
Arteries, Capallaries, Veins
The heartbeat in a vertabrate:
Is initiated by modified muscle tissue, the sinoatrial (SA) node, that contracts without nerve stilulation.
How are the blood-curculation system and the lymbic system related to each other?
Blood carries nutrients and oxygen to cells and removes their watse. The lymphatic system removes bacteria and debris from the blood.
The polygraph, or 'lie detector' test, functions by monitoring all of the following except:
Changes in oxygen content of the blood
Carbon dioxide transport differs from oxygen transport in the circulatory systems of mammals, because:
CO2 is transported mostly in the plasma, while O2 is transported mostly in the red blood cells.
Breathing in birds is more like 'breathing' in fishes than in mammals because:
Oxygen never runs into a dead end.
Under regular metabolic conditions, what percentage of oxygen is released from the blood to the tissues?
Why is carbon monoxide (CO) so dangerous?
CO prevents hemoglobin from binding to and transporting O2 to the body tissues, resulting in oxygen starvation and death.
Why does llama hemoglobin have a higher oxygen-binding affinity than human hemoglobin?
Llamas live at higher elevations than most humans and require a means to bind O2 when oxygen is at a lower concentration in the air.