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.
Report Abuse. Veins carry blood towards the heart...Arteries carry blood away from the heart and Capillaries are the smallest form of Arteries. Basically if you poke your finger, you are bleeding from a Capillary...if you stab yourself high in the front of the thigh, you are probably bleeding from the Femoral Artery.eport Abuse. Veins carry blood towards the heart...Arteries carry blood away from the heart and Capillaries are the smallest form of Arteries. Basically if you poke your finger, you are bleeding from a Capillary...if you stab yourself high in the front of the thigh, you are probably bleeding from the Femoral Artery.