| PIRS | plasma immunoreactive secretion |
|---|---|
| PS | pacemaker syndrome; paired stimulation; paradoxical sleep; paraspinal; parasympathetic; Parkinson sy... |
| PTHS | parathyroid hormone secretion [rate] |
| Se | secretion; selenium |
| SIADH | syndrome of inappropriate secretion of antidiuretic hormone |
| external fistula | A fistula between a hollow viscus and the skin. (05 Mar 2000) |
|---|---|
| external fixation | <orthopaedics> The use of a special metal orthopaedic device (external fixator) to stabilise regions of bone. The majority of this special metal hardware is placed outside of the skin. See: internal fixation. (27 Sep 1997) |
| external fixators | External devices which hold wires or pins that are placed through one or both cortices of bone in order to hold the position of a fracture in proper alignment. These devices allow easy access to wounds, adjustment during the course of healing, and more functional use of the limbs involved. (12 Dec 1998) |
| external genitalia | The vulva in the female, and the penis and scrotum in the male. (05 Mar 2000) |
| external haemorrhoid | Varicose dilatation of a vein of the external haemorrhoidal plexus, usually situated distal to the anal sphincter. (05 Mar 2000) |
| external haemorrhoids | Dilated veins forming tumours at the outer side of the external sphincter. (05 Mar 2000) |
| external hydrocephalus | Accumulation of fluid in the subarachnoid spaces of the brain, accumulation of fluid in the subdural space owing to a persistent communication between the subarachnoid and subdural spaces. (05 Mar 2000) |
| external iliac artery | <anatomy, artery> Origin, common iliac; branches, inferior epigastric, deep circumflex iliac; becomes the femoral at the inguinal ligament. Synonym: arteria iliaca externa. (05 Mar 2000) |
| external iliac lymph nodes | Nodes located in association with the external iliac vein; they are subdivided into three groups: intermediate external iliac lymph nodes, between the vein and the external iliac artery; lateral external iliac lymph nodes, and medial external iliac lymph nodes, medial to the vein; they all receive afferent vessels from the inguinal nodes, lower abdominal wall, and pelvic viscera, and send efferent vessels to the common iliac nodes. Synonym: nodi lymphatici iliaci externi. (05 Mar 2000) |
| external iliac plexus | A lymphatic plexus formed by the lymph nodes along the external iliac artery on either side, and their afferent and efferent vessels. Synonym: plexus iliacus externus. (05 Mar 2000) |
| external iliac vein | <anatomy, vein> A direct continuation of the femoral vein superior to the inguinal ligament, uniting with the internal iliac vein to form the common iliac vein. Synonym: vena iliaca externa. (05 Mar 2000) |
| external inguinal ring | The slit-like opening in the aponeurosis of the external oblique muscle of the abdominal wall through which the spermatic cord (round ligament in the female) and inguinal hernias emerge from the inguinal canal. See: aponeurosis of external abdominal oblique muscle. Synonym: annulus inguinalis superficialis, external inguinal ring, subcutaneous ring. (05 Mar 2000) |
| external intercostal membrane | The membrane that replaces the external intercostal muscle anteriorly between costal cartilages. Synonym: membrana intercostalis externa. (05 Mar 2000) |
| external intercostal muscles | Each arises from lower border of one rib and pass obliquely downward and forward to be inserted into the upper border of rib below; action, contract during inspiration, also maintain tension in the intercostal spaces to resist mediolateral movement; nerve supply, intercostal. Synonym: musculus intercostales externi. (05 Mar 2000) |
| external jugular vein | <anatomy, vein> Superficial vein formed inferior to the parotid gland by the junction of the posterior auricular vein and the retromandibular vein, and passes down the side of the neck crossing to the sternocleidomastoid muscle vertically to empty into the subclavian vein. Synonym: vena jugularis externa. (05 Mar 2000) |