What are the critical functions of blood(3)?

1)To transport oxygen and nutrients throughout body and hormones from endocrine glands to tissue and cells 2)Regulated PH with buffers and helps to regulate body temperature due to bloods water content and controls water content of its cells as a result of dissolved sodium ions 3)Protects the body from infection by transporting leukocytes and antibodies to the site of infection and prevents blood loss using special clotting mechanisms