Copy of `Dorland's Medical Dictionary`

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Dorland's Medical Dictionary Category: Health and Medicine > Medical Dictionary Date & country: 31/12/2010, USA Words: 39128

Porto-Vac
(por´to-vak) trademark for a portable wound suction device that is compressed to create a gentle suction; as the unit expands a negative pressure is created, allowing fluids and debris to be evacuated.

portoenterostomy
(por″to-en″tәr-os´tә-me) surgical anastomosis of the jejunum to a decapsulated area of liver in the porta hepatis region, and to the duodenum; done to establish a conduit from the intrahepatic bile ducts to the intestine in biliary atresia.

portogram
(por´to-gram) the film obtained by portography.

portography
(por-tog´rә-fe) radiography of the portal vein after injection of opaque material. portal portography portography after injection of opaque material into the superior mesenteric vein or one of its branches, the abdomen being opened. splenic portography ...

portosystemic
(por″to-sis-tem´ik) connecting the portal and systemic venous circulation.

portosystemic shunt
a surgically created shunt that connects the portal and systemic circulations, such as a mesocaval, portacaval, or splenorenal shunt.

Portuguese-Azorean disease
Machado-Joseph disease.

porus
(por´әs) Latin word meaning pore. porus acusticus externus the outer end of the external acoustic meatus. porus acusticus internus the opening of the internal acoustic meatus in the cranial cavity. porus opticus the ope...

Posadas disease
(po-sah´dahs) Posadas-Wernicke disease (po-sah´dahs ver´nĭ-ke) coccidioidomycosis.

position
(pә-zish´әn) a bodily posture or attitude. the relationship of a given point on the presenting part of the fetus to a designated point of the maternal pelvis; see presentation.

position effect
in genetics, the change in expression of a gene as a function of a change in its position relative to that of other genes.

position sense
posture sense a variety of muscular sense by which the position or attitude of the body or its parts is perceived.

positional nystagmus
that which occurs, or is altered in form or intensity, on assumption of certain positions of the head.

positional vertigo
that associated with a specific position of the head in space or with changes in position of the head in space.

positive
(poz´ĭ-tiv) having a value greater than zero. indicating existence or presence, as chromatin-positive. characterized by affirmation or cooperation.

positive accommodation
adjustment of the eye for short distances by contraction of the ciliary muscle.

positive balance
a state in which the amount of water or an electrolyte excreted from the body is less than that ingested.

positive end-expiratory pressure
(PEEP) a method of control mode ventilation in which positive pressure is maintained during expiration to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange. A PEEP higher than the critical closing press...

positive pressure
pressure greater than that of the atmosphere.

positive pressure ventilation
any of numerous types of mechanical ventilation in which gas is delivered into the airways and lungs under positive pressure, producing positive airway pressure during inspiration; it may be done via either an endotracheal tube or a nasal mask. See also ventilator.

positive scotoma
one that appears as a dark spot in the visual field.

positive sharp wave
a short burst of biphasic electrical activity recorded from a muscle fiber, usually evoked by stimulation or injury by electrode insertion or other electrode movement; spontaneous occurrence of such waves at other times may be a sign of a myopathic disorder or a denervated muscle.

positron
(poz´ĭ-tron) the antiparticle of the electron. When a positron is emitted by a radionuclide it combines with an electron and both undergo annihilation, producing two 511-keV gamma rays traveling in opposite directions. This effect is used in positron emission tomography.

positron emission tomography
(PET) a combination of computed tomography and scintillation scanning. Natural biochemical substances or drugs tagged with a positron-emitting radioisotope are administered to the subject by injection; the tagged substance (tracer) then becomes localized in specific tissues the same way its natural analogue does. When t...

posology
(po-sol´ә-je) the science of dosage or a system of dosage. adj., posolog´ic., adj.

post mortem
(pōst mor´tәm) Latin phrase meaning after death.

post partum
(pōst pahr´tәm) Latin phrase meaning after childbirth.

post–cardiac injury syndrome
fever, chest pain, pleuritis, and pericarditis occurring several weeks to months after injury to the heart, including that inflicted by surgery (often called postpericardiotomy syndrome) or myocardial infarction (often called post–myocardial infarction syndrome).

post–lumbar puncture syndrome
headache in the erect posture, sometimes with nuchal pain, nausea, vomiting, diaphoresis, and malaise, all relieved by recumbency, occurring several hours after lumbar puncture and lasting a few days; it is due to lowering of intracranial pressure by leakage of cerebrospinal fluid through the needle tract.

postanesthesia
(pōst″an-es-the´zhah) following anesthesia.

postanesthesia care unit
(PACU) a specialty unit in a hospital for the care of patients recovering from anesthesia and intravenous sedation; formerly called recovery room.

postanesthesia nurse
a nurse who cares from patients recovering from anesthesia.

postauricular
(pōst″aw-rik´u-lәr) located or performed behind the auricle of the ear.

postaxial
(pōst-ak´se-әl) behind an axis; in anatomy, referring to the medial (ulnar) aspect of the upper limb, and the lateral (fibular) aspect of the lower limb.

postbrachial
(pōst-bra´ke-әl) on the posterior part of the upper limb.

postbranchial bodies
ultimobranchial bodies.

postcapillary
(pōst-kap´ĭ-lar´e) located just to the venous side of a capillary. venous capillary.

postcardinal veins
paired vessels in the early embryo that return blood from regions caudal to the heart.

postcardiotomy
(pōst″kahr-de-ot´ә-me) occurring after open-heart surgery.

postcardiotomy pericarditis
pericarditis occurring as a complication after cardiac surgery, characterized by effusion and occasionally by constriction.

postcardiotomy psychosis syndrome
anxiety, confusion, and perceptual disturbances occurring three or more days after open heart surgery.

postcardiotomy syndrome
postpericardiotomy syndrome.

postcava
(pōst-ka´vә) inferior vena cava. adj., postca´val., adj.

postcaval shunt
portacaval shunt.

postcentral area
postrolandic area an area just posterior to the central sulcus of the cerebral hemisphere that is the primary receiving area for general sensations.

postcentral gyrus
the convolution of the frontal lobe immediately behind the central sulcus; the primary sensory area of the cerebral cortex; called also posterior central gyrus.

postcholecystectomy syndrome
a type of dysfunction of the sphincter of Oddi, seen after cholecystectomy.

postcibal
(pōst-si´bәl) postprandial.

postcoital
(post-koi´tәl) after coitus.

postcoital contraceptive
one that blocks or terminates pregnancy after sexual intercourse; called also emergency contraceptive.

postcoital test
(for infertility) examination of secretions aspirated from the vaginal fornix and endocervical canal after coitus, to determine the number and condition of spermatozoa present and the extent to which they have penetrated the cervical mucus. Called also Huhner test and Sims test.

postcommissurotomy syndrome
(pōst-kom″ĭ-sher-ot´ah-me) postpericardiotomy syndrome.

postconcussional syndrome
(pōst-kon-kush´ah-nal) physical and personality changes that may occur following head injury; they may include amnesia, headache, dizziness, difficulty concentrating, restlessness, depression, irritability, sweating, heart palpitations, and insomnia.

postdiastolic
(pōst″di-әs-tol´ik) after diastole.

postdicrotic
(pōst″di-krot´ik) after the dicrotic wave of the sphygmogram.

postdiphtheritic paralysis
diphtheritic paralysis.

postdormital paralysis
sleep paralysis occurring upon waking.

postepileptic paralysis
Todd paralysis.

posterior
(pos-tēr´e-әr) directed toward or situated at the back; opposite of anterior. Called also dorsal.

posterior ampullary nerve
the branch of the vestibular nerve that innervates the ampulla of the posterior semicircular duct, ending around the hair cells of the ampullary crest.

posterior auricular artery
origin, external carotid artery; branches, auricular and occipital branches, stylomastoid artery; distribution, middle ear, mastoid cells, auricle, parotid gland, digastric and other muscles.

posterior auricular muscle
origin, mastoid process; insertion, cartilage of ear; innervation, facial nerve; action, draws auricle backward.

posterior auricular nerve
origin, facial nerve; branches, occipital branch; distribution, posterior auricular and occipitofrontalis muscles and skin of external acoustic meatus; modality, motor and general sensory.

posterior auricular vein
a vein that begins in a plexus on the side of the head, passes down behind the pinna, and joins with the retromandibular vein to form the external jugular vein.

posterior border position
the most posterior position of the mandible at any specific vertical relation to the maxillae.

posterior cecal artery
origin, ileocolic artery; branches, none; distribution, cecum.

posterior central gyrus
postcentral gyrus.

posterior cerebral artery
origin, terminal branching of basilar artery; branches,(first or precommunical part)posteromedial central, short circumferential, thalamoperforating, and collicular arteries; (second or postcommunical part) posterolateral central and thalamogeniculate arteries, and medial and lateral posterior choroidal, and peduncular branches; ...

posterior chamber of eye
that part of the aqueous humor–containing space of the eyeball between the iris and the lens.

posterior circumflex humeral artery
origin, axillary artery; branches; none; distribution, deltoid, shoulder joint, teres minor and triceps muscles.

posterior column of spinal cord
the posterior portion of the gray matter of the spinal cord; in transverse section it is seen as a horn.

posterior column syndrome
posterior cord syndrome sensory deficits and ataxic phenomena derived from a lesion of the posterior columns of the spinal cord.

posterior communicating artery
an artery that establishes a connection between the internal carotid and posterior cerebral arteries; branches, posteromedial central, thalamotuberal, and mammillary arteries, artery of tuber cinereum, and branches to the optic chiasm, oculomotor nerve, and hypothalamus.

posterior condyloid foramen
condylar canal.

posterior conjunctival arteries
origin,medial palpebral arteries; branches, none; distribution, lacrimal caruncle, conjunctiva.

posterior cricoarytenoid muscle
one of the intrinsic muscles of the larynx; origin, back of cricoid cartilage; insertion, muscular process of arytenoid cartilage; innervation, recurrent laryngeal nerve; action, separates vocal folds.

posterior cruciate ligament
(PCL) see cruciate ligaments of knee.

posterior cutaneous nerve of arm
origin, radial nerve in the axilla; distribution, skin on back of arm; modality, general sensory.

posterior cutaneous nerve of thigh
origin, sacral plexus—S1–S3; branches, inferior cluneal nerves and perineal branches; distribution, skin of buttock, external genitalia, and back of thigh and calf; modality, general sensory.

posterior deep temporal artery
origin, maxillary artery; branches, none; distribution, temporalis muscle, and anastomoses with middle temporal artery.

posterior drawer sign
posterior drawer test see drawer tests.

posterior ethmoidal artery
origin,ophthalmic artery; branches, meningeal and septal and lateral nasal branches; distribution, posterior ethmoidal air cells, dura mater, nose.

posterior ethmoidal nerve
origin, nasociliary nerve, from ophthalmic nerve; distribution, mucosa of posterior ethmoid cells and of sphenoidal sinus; modality, general sensory.

posterior facial vein
retromandibular vein.

posterior fascicular block
left posterior hemiblock; see hemiblock. See also fascicular block.

posterior fontanelle
occipital fontanelle. a triangular fontanelle at the junction of the occipital and parietal bones; it usually closes by the third or fourth month of life. Called also occipital or triangular fontanelle.

posterior funiculus of spinal cord
the white substance of the spinal cord lying on either side between the posterior median sulcus and the dorsal root. Called also dorsal funiculus.

posterior gastric artery
origin, splenic artery; branches, none; distribution, posterior gastric wall.

posterior horn of spinal cord
the horn-shaped configuration presented by the posterior column of the spinal cord in transverse section; called also dorsal horn of spinal cord.

posterior intercostal arteries
for the first (highest) two pairs, see first posterior intercostal artery and second posterior intercostal artery; there are nine other pairs (III–XI): origin,thoracic aorta; branches, dorsal, collateral, muscular, and lateral cutaneous branches; distribution, thoracic wall.

posterior intercostal veins
the veins that accompany the posterior intercostal arteries and drain the intercostal spaces posteriorly; the first ends in the brachiocephalic or the vertebral vein, the second and third join the superior intercostal vein, and the fourth to eleventh join the azygos vein on the right and the hemiazygos or accessory hemiaz...

posterior interosseous artery
origin, common interosseous artery; branches, recurrent interosseous artery; distribution, deep parts of back of forearm.

posterior interosseous veins
the veins accompanying the posterior interosseous artery, which join the ulnar veins near the elbow.

posterior interventricular vein
middle cardiac vein.

posterior labial hernia
enterocele (def. 2).

posterior labial nerves
origin, perineal nerves; distribution, labia majora; modality, general sensory.

posterior labial veins
small venous branches from the labia which open into the vesical venous plexus; they are counterparts of the posterior scrotal veins in the male.

posterior lacerate foramen
jugular foramen.

posterior lateral nasal arteries
origin, sphenopalatine artery; branches, none; distribution, frontal, maxillary, ethmoidal, and sphenoidal sinuses.

posterior lobe of hypophysis
posterior lobe of pituitary gland neurohypophysis.