Medical terminology is heavily built on combining forms that refer to specific organs, tissues, and body systems. The cardiovascular and blood-related systems begin with "cardio-" (heart, from Greek kardia), supported by "angio-" (vessel, usually blood or lymph, as in angiography), "arterio-" (artery, as in arteriosclerosis), "phlebo-" (vein, as in phlebitis and phlebotomy), and "vaso-" (vessel, especially a blood vessel, as in vasoconstriction and vasodilation). Blood itself is referenced by "hemato-" or "hemo-" (as in hematology, hemoglobin, hemorrhage), with color-specific forms "erythro-" (red, especially red blood cells, as in erythrocyte) and "leuko-" (white, especially white blood cells, as in leukocyte and leukemia). Clotting is described by "thrombo-" (as in thrombosis, thrombocyte, thrombocytopenia), lymph and the lymphatic system by "lympho-" (as in lymphocyte and lymphoma), and the spleen by "spleno-" (as in splenectomy and splenomegaly).
The respiratory and upper-airway systems use "pulmono-" for the lungs, "broncho-" for the bronchus (as in bronchitis and bronchoscopy), "pneumo-" for the lungs, air, or gas (as in pneumonia and pneumothorax), "laryngo-" for the larynx (as in laryngitis and laryngoscopy), "pharyngo-" for the pharynx or throat (as in pharyngitis), and "rhino-" for the nose (as in rhinitis and rhinoplasty). The chest cavity is described by "thoraco-" (as in thoracotomy). The digestive system relies on "gastro-" (stomach, as in gastritis and gastroenterology), "hepato-" (liver, as in hepatitis and hepatomegaly), "chole-" (bile or gallbladder, as in cholecystectomy and cholecystitis), "entero-" (intestine, as in enteritis and gastroenteritis), "colo-" (colon, as in colostomy and colonoscopy), "procto-" (rectum or anus, as in proctoscopy), and "stomato-" (mouth, as in stomatitis). The abdominal wall is referenced by "laparo-" (as in laparoscopy and laparotomy), and stones by "litho-" (as in lithotripsy).
The urinary and reproductive systems share several combining forms. "Nephro-" and "reno-" both refer to the kidney (nephrology, renal artery), "uro-" means urine or the urinary tract (urology, polyuria), "cysto-" can mean the bladder or a fluid-filled sac (cystoscopy, cholecystitis), and "vesico-" refers specifically to the urinary bladder (vesicostomy, vesicoureteral). The female reproductive system uses "oophoro-" for the ovary (oophorectomy, oophoritis), while the male system uses "orchio-" or "orchido-" for the testicle (orchitis, orchiectomy). Glands in general are described by "adeno-" (adenoma, adenocarcinoma), with "thyro-" used for the thyroid gland (thyroidectomy, thyrotoxicosis) and "pancreato-" for the pancreas (pancreatitis, pancreatectomy).
The nervous system and special senses employ "neuro-" (nerves and nervous system), "encephalo-" (brain, as in encephalitis and encephalogram), "meningo-" (the meninges covering the brain and spinal cord, as in meningitis), and "myelo-" (spinal cord or bone marrow, as in myelogram and myeloma). The eye is described by "ophthalmo-" (ophthalmology, ophthalmoscope) and the eyelid by "blepharo-" (blepharitis, blepharoplasty). The ear uses "oto-" (otitis, otoscope), and the head is described by "cephalo-" (cephalalgia, hydrocephalus). The musculoskeletal system combines "osteo-" (bone, as in osteoporosis and osteotomy), "chondro-" (cartilage, as in chondritis and chondromalacia), "arthro-" (joint, as in arthralgia and arthroscope), "myo-" (muscle, as in myalgia, myocardium, and myopathy), "teno-" (tendon, as in tenosynovitis and tenorrhaphy), and "fibro-" (fiber or fibrous tissue, as in fibromyalgia). The skin and soft tissues are covered by "dermato-" or "derma-" (skin, as in dermatitis and dermatology), "lipo-" (fat, as in lipoma and liposuction), "melano-" (black or melanin pigment, as in melanoma and melanocyte), "necro-" (death or dead tissue, as in necrosis and necropsy), "pyo-" (pus, as in pyorrhea and pyogenic), and "sclero-" (hard or hardening, as in scleroderma and atherosclerosis). General body and cellular terms include "somato-" (body, as in psychosomatic and somatic), "tropho-" (nourishment or development, as in atrophy and hypertrophy), "glyco-" (sugar, as in glucose, glycogen, and glycolysis), "hydro-" (water, as in hydrocephalus and dehydration), "histo-" (tissue, as in histology), "cyto-" (cell, as in cytology and cytoplasm), "karyo-" (nucleus of a cell, as in karyotype and prokaryote), and "onco-" (tumor or mass, as in oncology).