Kidneys are two bean shaped organs found on the left and right side of the body in vertebrates. They are located in the back of the abdominal cavity. Kidney processes the blood supplies to it via filtration, reabsorption, secretion and, excretion; the consequences of those processes is the production of urine.
The kidney secretes two hormones namely,
It is a glycoprotein. It acts on the bone marrow to increase the production of red blood cells. Stimuli such as bleeding or moving to high altitude trigger the release of EPO.
Calcitriol is 1,25(OH2) Vitamin D3, the active form of vitamin D. Calcitriol acts on the cells of intestine to promote the absorption of calcium and phosphate from food.
Atrium is the upper chamber in which blood enters the heart. There are two main atria in heart, which receive blood- the left atrium from lungs and the right atrium from the venous circulation.
The atrium secretes Atrial natriuretic peptide (ANP). ANP is peptide hormone which reduces an expanded extracellular fluid (ECF) volume by increasing renal sodium excretion. These cells contain volume receptors.
Thymus gland is located behind your sternum and between your lungs. The thymus gland will not function throughout a full lifetime, but it has a big responsibility when its active- helping the body to protect itself against autoimmunity, which occurs when the immune system turns against itself. Therefore, thymus gland plays vital role.
The thymus gland secretes thymosin, it is mainly important because it stimulates the development of T lymphocytes, also known as killer cells. Its function in the immune system is to recognize foreign antigens on the surface of invading cells.