HGH (Human Growth Hormone) is a protein hormone which is produced by the endocrine system in the human body. It is made from 190 individual amino acid molecules, and is secreted by the pituitary gland.
However, in pulmonary circulation, the arteries carry deoxygenated blood from the heart to the lungs, and veins return blood from the lungs to the heart. The difference between veins and arteries is their direction of flow (out of the heart by arteries, returning to the heart for veins), not their oxygen content.he pulmonary veins carry relatively oxygenated blood from the lungs to the heart. The superior and inferior venae cavae carry relatively deoxygenated blood from the upper and lower systemic circulations, respectively. The portal venous system is a series of veins or venules that directly connect two capillary beds.
In veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues of the body, back to the lungs; exceptions are the pulmonar â¦ y and umbilical veins, both of which carry oxygenated blood. 1  The Five Major Parts of the Brain At its most basic, the brain controls the body.ll other veins â¦ in the body carry  relatively de-oxygenated blood.   However in fetal circulation, the umbilical vein also carries  oxygenated blood.   Otherwise, arteries carry oxygenated blood to the body from  the aorta and heart. + 18 others found this useful.