Functions of the Internal Organs

Heart

          Pump oxygenated blood to cells

          Pump deoxygenated blood to lungs

          Maintain blood pressure

Lungs

          Oxygenate Blood

          Expire Carbon Dioxide

          Aid in acid base balance

          Involved in beat to beat variability of Heart

          Converts Angiotensin I to Angiotensin II, responsible for regulate blood pressure

Kidney

          Removes waste products from blood

          Regulates fluid volume, reabsorbtion and excretion

          Involved in Blood pressure regulation

          Secretes erythropoietin which stimulated marrow to make RBC

          Secretes rennin which regulates blood pressure

          Secretes active form of Vit D which helps maintain calcium balance for bones

          Regulates acid base balance

          Involved in inorganic electrolyte balance

Spleen

          Acts like a large lymph node involved in immunological functions , like the production of antibodies and the maturation of B- and T-lymphocytes, and Macrophages

          Acts as a blood filter to remove waste, including damaged red blood cells, platelets, and bacteria, through phagocytosis by macrophages and neutrophils

          Removes hemoglobin from RBC and recirculates it

          Acts as a reservoir for various other white blood cells and platelets

          Acts as a filter against foreign organisms that infect the bloodstream

          Creates new blood cells especially during fetal debelopment

Liver

Endocrine functions

          Secretes insulin-like growth factor 1 (IGF-1) in response to growth hormone, this encourages growth by inducing mitosis in many tissues, especially bone.

          Involved in the production of vitamin D.

          Converts triiodothyronine (T3) from thyroxine (T4).

          Secretes angiotensinogen, which is acted upon by renin in the kidney to form angiotensin.

          Metabolizes and transforms hormones

Clotting functions

          Produces many of the plasma clotting factors, especially prothrombin and fibrinogen.

          Makes bile salts, important for the absorption of vitamin K, necessary for production of the clotting factors.

Plasma proteins: Creates and secretes albumin in the plasma, acute phase proteins , binding proteins for steroid hormones, lipoproteins, and trace elements, and other proteins

Digestive functions through bile production and secretion

          Creates and secretes bile acids, important for digestion and absorption of fats.

          Neutralizes acid in the duodenum by secreting into the bile a bicarbonate-rich solution of inorganic ions, that neutralizes acid in the duodenum.

Organic metabolism

          Changes plasma glucose into glycogen and triacylylycerols in the absorptive phase.

          Produces triacylylycerols and secretes it as lipoproteins in the absorptive phase.

          Changes glucose from glycogen and other precursors gluconeogenesis- during the postabsorptive phase and lets the glucose into the blood.

          Changes fatty acids into ketones when fasting.

          Manufactures urea, the waste product of amino acid and protein catabolism, and discharges it into the blood to be dealt with be the kidneys.

Cholesterol Metabolism

          Manufactures cholesterol and discharges it into the blood.

          Secretes plasma cholesterol into bile.

          Changes plasma cholesterol into bile acids.

Excretory, Detoxification, and Degradative Functions

          Releases bilirubin and bile pigments into the bile

          Excretes many foreign and endogenous organic molecules through the bile.

          Biotransforms many foreign and endogenous organic molecules into other usable substrates or some improved way of excreting the metabolite.