40. Circulatory System

In which animal does the circulatory system include a heart and a system of closed vessels?

An individual suffering from __________ has irregularly shaped erythrocytes and may suffer from severe pain and organ swelling.

A patient with which of the following conditions would probably benefit by injections of purified stem cells?

In a fish, blood circulates through __________, whereas in a mammal, it circulates through __________.