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Medical Dictionary


haustra (haw′stra)
Plural of haustrum. [L.]

haustral (hos′tral)
Relating to a haustrum.

haustration (hos′tra′shun)
1. The process of formation of a haustrum. 2. An increase in prominence of the haustra. haustrations of colon SYN: haustra of colon, under haustrum.

haustrum, pl .haustra (hos′trum, haw′stra) [TA]
One of a series of saccules or pouches, so called because of a fancied resemblance to the buckets on a water wheel. [L. a machine for drawing water, fr. haurio, pp. haustus, to draw up, drink up] haustra coli [TA] SYN: haustra of colon. haustra of colon [TA] the sacculations of the colon, caused by the teniae, or longitudinal bands, which are slightly shorter than the gut so that the latter is thrown into tucks or pouches. SYN: haustra coli [TA] , cellulae coli, haustrations of colon, sacculation of colon.

haustus (haws′tus)
A potion or medicinal draft. [L. a drink, draft]

Abbreviation for hepatitis A virus.

Haverhillia multiformis (ha-ver-hil′e-a mul-ti-for′mis)
See Streptobacillus moniliformis.

Clopton, British anatomist, 1650–1702. See haversian canals, under canal, haversian lamella, haversian spaces, under space, haversian system.

haversian (ha-ver′shan)
Relating to Clopton Havers and the various osseous structures described by him.

C.A., U.S. orthodontist. See H. appliance, H. retainer.

Sir Walter Norman, British chemist and Nobel laureate, 1883–1950. See H. conformational formulas of cyclic sugars, H. perspective formulas of cyclic sugars.

Georges, French physician, 1841–1933. See H. hematoblast, H. solution, H.-Widal syndrome.

Leonard, U.S. microbiologist, *1928. See H. limit.

John, English physician, 1740–1827. See H. nodes, under node.

hazelwort (ha′zel-wort)
SYN: Asarum europaeum.

Abbreviation for hemoglobin.

Abbreviation for hemoglobin Chesapeake.

Abbreviation for antibody to the hepatitis B e antigen.

Abbreviation for antibody to the hepatitis B surface antigen.

Abbreviation for antibody to the hepatitis B core antigen.

Abbreviation for hepatitis B surface antigen.

Abbreviation for hepatitis B core antigen.

Abbreviation for carboxyhemoglobin.

Abbreviation for His bundle electrogram.

HBe, HBeAg
Abbreviation for hepatitis B e antigen.

Abbreviation for oxyhemoglobin.

Hb S
Abbreviation for sickle cell hemoglobin.

Abbreviation for hepatitis B virus.

Abbreviation for 25-hydroxycholecalciferol.

Abbreviation for Health Care Financing Administration.

Abbreviation for human chorionic gonadotropin.

H chain
SYN: heavy chain.

Abbreviation for human chorionic somatomammotropic hormone; human chorionic somatomammotropin.

Abbreviation for hematocrit.

Abbreviation for hepatitis C virus.

Abbreviation for homocysteine.

Abbreviation for mustard gas.

Abbreviation for L. hora decubitus, at bedtime.

Abbreviation for human diploid cell vaccine; human diploid cell rabies vaccine.

Abbreviation for high density lipoprotein. See lipoprotein.

Abbreviation for hepatitis delta virus.

Symbol for helium.

3He, 4He
Symbols for helium-3 and helium-4, respectively.

Sir Henry, English neurologist, 1861–1940. See H. areas, under area, H. lines, under line, H. zones, under zone.

head (hed) [TA]
1. [TA] The upper or anterior extremity of the animal body, containing the brain and the organs of sight, hearing, taste, and smell. 2. [TA] The upper, anterior, or larger extremity, expanded or rounded, of any body, organ, or other anatomic structure. 3. The rounded extremity of a bone. 4. That end of a muscle that is attached to the less movable part of the skeleton. SYN: caput [TA] . [A.S. heafod] bulldog h. the broad h. with high vault occurring in achondroplasia. h. of caudate nucleus [TA] the h. or anterior extremity of the caudate nucleus projecting into the anterior horn of the lateral ventricle. SYN: caput nuclei caudati [TA] , anterior extremity of caudate nucleus. clavicular h. of pectoralis major muscle [TA] See pectoralis major (muscle). SYN: pars clavicularis musculi pectoralis majoris [TA] , clavicular part of pectoralis major (muscle). deep h. of flexor pollicis brevis [TA] the h. of short flexor of the thumb that arises from the trapezoid and capitate bones and transverse carpal ligaments. It is innervated by the deep ulnar nerve, and considered by many to be the first palmar interosseous muscle. SYN: caput profundum musculi flexoris pollicis brevis [TA] . h. of epididymis [TA] the upper and larger extremity of the epididymis. SYN: caput epididymidis [TA] , caput epididymis, globus major. h. of femur [TA] the hemispheric articular surface at the upper extremity of the thigh bone. SYN: caput femoris [TA] , caput ossis femoris, h. of thigh bone. h. of fibula [TA] the superior extremity of the fibula, which articulates by a facet with the undersurface of the lateral condyle of the tibia. SYN: caput fibulae [TA] , upper extremity of fibula. hourglass h. in congenital syphilis, a skull with depressed coronal suture. humeral h. [TA] the name applied to the heads of forearm muscles that attach to the humerus. Terminologia Anatomica lists humeral heads (caput humerale ...) of the following: 1) flexor carpli ulnaris (... musculi flexoris carpi ulnaris [TA]); 2) pronator teres (... musculi pronatoris teretis [TA]); and 3) extensor carpi ulnaris (...musculi extensoris carpi ulnaris [TA]). SYN: caput humerale [TA] . humeroulnar h. of flexor digitorum superficialis muscle [TA] the h. of the superficial flexor of the digits that attaches to both the humerus and the ulna. SYN: caput humeroulnare musculi flexoris digitorum superificialis [TA] . h. of humerus [TA] the upper rounded extremity fitting into the glenoid cavity of the scapula. SYN: caput humeri [TA] . lateral h. [TA] h. of origin farthest from the midline. Terminologia Anatomica lists lateral heads (caput laterale ...) of the following: 1) triceps brachii (... musculi tricipitis brachii [TA]); 2) gastrocnemius (... musculi gastrocnemii [TA]); and 3) flexor hallucis brevis (...musculi flexoris hallucis brevis [TA]). SYN: caput laterale [TA] . little h. of humerus SYN: capitulum of humerus. long h. [TA] the h. that has the more proximal origin. Terminologia Anatomica lists long heads (caput longum ...) of the following: 1) biceps brachii (... musculi bicipitis brachii [TA]); 2) biceps femoris (... musculi bicipitis femoris [TA]); and 3) triceps brachii (... musculi tricipitis brachii [TA]). SYN: caput longum [TA] . h. of malleus [TA] the rounded portion of the malleus articulating with the body of the incus. SYN: caput mallei [TA] . h. of mandible [TA] the expanded articular portion of the condylar process of the mandible. SYN: caput mandibulae [TA] . medial h. [TA] the h. of origin closest to the midline. Terminologia Anatomica lists medial h. (caput mediale) of the following: 1) triceps brachii (... musculi tricipitis brachii [TA]); 2) gastrocnemius (... musculi gastrocnemii [TA]); and 3) flexor hallucis brevis (... musculi flexoris hallucis brevis [TA]). SYN: caput mediale [TA] . Medusa h. SYN: caput medusae. h. of metacarpal [TA] the expanded distal end of a metacarpal that articulates with the proximal phalanx of the same digit. SYN: caput ossis metacarpalis [TA] . h. of metatarsal [TA] the expanded distal end of a metatarsal bone that articulates with the proximal phalanx of the same digit. SYN: caput ossis metatarsalis [TA] . oblique h. [TA] h. of origin which is diagonally situated. Terminologia Anatomica lists oblique heads (caput obliquum ...) of the following: 1) adductor hallucis (... musculi adductoris hallucis [TA]); and 2) adductor pollicis (... musculi adductoris pollicis [TA]). SYN: caput obliquum [TA] . optic nerve h. SYN: optic disk. h. of pancreas [TA] that portion of the pancreas lying in the concavity of the duodenum. SYN: caput pancreatis [TA] . h. of phalanx (of hand or foot) [TA] the rounded articular surface at the distal end of the proximal and middle phalanx of each finger and toe. SYN: caput phalangis (manus et pedis) [TA] . h. of radius [TA] the disk-shaped upper extremity articulating with the capitulum of the humerus. SYN: caput radii [TA] . h. of rib [TA] the rounded medial extremity of a rib that, except for ribs 1, 10, 11, and 12, articulates by two facets with the bodies of two contiguous vertebrae. SYN: caput costae [TA] . saddle h. SYN: clinocephaly. short h. [TA] for a muscle with two heads of origin (a “biceps” muscle), the h. originating nearest the insertion. See short h. of biceps brachii, short h. of biceps femoris. SYN: caput breve [TA] . short h. of biceps brachii [TA] h. of biceps brachii originating from coracoid process of scapula. SYN: caput breve musculi bicipitis brachii [TA] . short h. of biceps femoris [TA] part of biceps femoris originating from linea aspera of distal half of femur. SYN: caput breve musculi bicipitis femoris [TA] . h. of stapes [TA] the portion of the stapes that articulates with the lenticular process of the incus. SYN: caput stapedis [TA] . sternocostal h. of pectoralis major (muscle) [TA] portion of pectoralis major (muscle) originating from the sternum and ribs; acting alone the ternocostal part extends the arm at the shoulder joint; acting with the clavicular h. it adducts the arm. See pectoralis major (muscle). SYN: pars sternocostalis musculi pectoralis majoris [TA] , sternocostal part of pectoralis major muscle. superficial h. of flexor pollicis brevis [TA] the h. of the short flexor of the thumb that arises from the transverse carpal ligament (flexor retinaculum) and the trapezium. It is innervated by the recurrent branch of the median nerve. SYN: caput superficiale musculi flexoris pollicis brevis [TA] . h. of talus [TA] the rounded anterior portion of the talus articulating with the navicular bone. SYN: caput tali [TA] . h. of thigh bone SYN: h. of femur. transverse h. [TA] h. of origin of a muscle that is transversely situated. Terminologia Anatomica lists transverse heads (caput transversum ...) of the following: 1) adductor hallucis (... musculi adductoris hallucis [TA]); and 2) adductor pollicis (... musculi adductoris pollicis [TA]). SYN: caput transversum [TA] . h. of ulna [TA] the small rounded distal extremity of the ulna articulating with the ulnar notch of the radius and the articular disk. SYN: caput ulnae [TA] . ulnar h. [TA] the name applied to a h. of origin of a forearm muscle arising from the ulna. Terminologia Antomica lists ulnar heads (caput ulnare ...) of the following: 1) flexor carpi ulnaris (... musculi flexoris carpi ulnaris [TA]); 2) pronator teres (... musculi pronatoris teritis [TA]); and 3) extensor carpi ulnaris (... musculi extensoris carpi ulnaris [TA]). SYN: caput ulnare [TA] .

headache (hed′ak)
Pain in various parts of the head, not confined to the area of distribution of any nerve. SEE ALSO: cephalodynia. SYN: cephalalgia, encephalalgia, encephalodynia. benign exertional h. h. occurring with exertion or straining in the absence of any intracranial disease. bilious h. SYN: migraine. blind h. SYN: migraine. cluster h. possibly due to a hypersensitivity to histamine; characterized by recurrent, severe, unilateral orbitotemporal headaches associated with ipsilateral photophobia, lacrimation, and nasal congestion. SYN: histaminic cephalalgia, histaminic h., Horton cephalalgia, Horton h.. coital h. a form of benign exertional h. occurring during sexual activity. SYN: benign coital cephalalgia. fibrositic h. h. centered in the occipital region due to fibrositis of the occipital muscles; tender areas are present and, commonly, tender nodules are found in the scalp in the lower occipital region. histaminic h. SYN: cluster h.. Horton h. SYN: cluster h.. ice pick h. SYN: idiopathic stabbing h.. idiopathic stabbing h. brief repetitive sharp pains in the temporal-parietal area of the head. SYN: ice pick h.. migraine h. migraine. muscle contraction h. SYN: tension h.. nodular h. radiating pain in the head accompanied by nodular swellings in the splenius, frontalis, trapezius, and other muscles. organic h. h. due to intracranial disease. posttraumatic h. h. following trauma to the head or neck. reflex h. SYN: symptomatic h.. sick h. SYN: migraine. spinal h. h., usually frontal or occipital, that follows lumbar puncture; precipitated by patient's sitting or standing, and relieved by lying down; due to leakage of cerebrospinal (CSF) fluid through the puncture site, with resulting reduction in CSF pressure and traction on the dural and cerebral vessels. SYN: post–lumbar puncture syndrome. symptomatic h. a h. secondary to another organic condition. SYN: reflex h.. tension h. h. associated with nervous tension, anxiety, etc., often related to chronic contraction of the scalp muscles. SEE ALSO: posttraumatic neck syndrome. SYN: muscle contraction h., tension-type h.. tension-type h. SYN: tension h.. thunderclap h. sudden severe nonlocalizing head pain not associated with any abnormal neurological findings; of varied etiology, including subarachnoid hemorrhage, migraine, carotid or vertebral artery dissection, cavernous sinus thrombosis, and idiopathic. vacuum h. h. due to closure of the frontal sinus. vascular h. SYN: migraine.

headgear (hed′ger)
A removable extraoral appliance used as a source of traction to apply force to the teeth and jaws.

headgut (hed′gut)
SYN: foregut.

head-nodding (hed′nod-ing)
Head movements associated with congenital nystagmus, spasmus nutans, and miner's nystagmus. SYN: head tremors.

head-tilt (hed′tilt)
An abnormal position of the head adopted to prevent double vision resulting from underaction of the vertical ocular muscles.

heal (hel)
1. To restore to health, especially to cause an ulcer or wound to cicatrize or unite. 2. To become well, to be cured; to cicatrize or close, said of an ulcer or wound. [A.S. healan]

healer (he′ler)
1. A physician; one who heals or cures. 2. One who claims to cure by prayer, mysticism, new thought, or other form of suggestion.

healing (hel′ing)
1. Restoring to health; promoting the closure of wounds and ulcers. 2. The process of a return to health. 3. Closing of a wound. SEE ALSO: union. faith h. a treatment utilized since antiquity based upon prayer and a profound belief in divine intervention in human affairs. h. by first intention h. by fibrous adhesion, without suppuration or granulation tissue formation. SYN: primary adhesion, primary union. h. by second intention delayed closure of two granulating surfaces. SYN: secondary adhesion, secondary union. h. by third intention the slow filling of a wound cavity or ulcer by granulations, with subsequent cicatrization.

health (helth)
1. The state of the organism when it functions optimally without evidence of disease or abnormality. 2. A state of dynamic balance in which an individual's or a group's capacity to cope with all the circumstances of living is at an optimum level. 3. A state characterized by anatomic, physiologic, and psychologic integrity, ability to perform personally valued family, work, and community roles; ability to deal with physical, biologic, psychologic, and social stress; a feeling of well-being; and freedom from the risk of disease and untimely death. [A.S. haelth] behavioral h. an interdisciplinary field dedicated to promoting a philosophy of h. that stresses individual responsibility in the application of behavioral and biomedical science knowledge and techniques to the maintenance of h. and prevention of illness and dysfunction by a variety of self-initiated individual and shared activities. h. education process by which individuals and groups learn to behave in a manner conducive to promotion, maintenance, or restoration of h.. mental h. emotional, behavioral, and social maturity or normality; the absence of a mental or behavioral disorder; a state of psychological well-being in which one has achieved a satisfactory integration of one's instinctual drives acceptable to both oneself and one's social milieu; an appropriate balance of love, work, and leisure pursuits. public h. the art and science of community h., concerned with statistics, epidemiology, hygiene, and the prevention and eradication of epidemic diseases; an effort organized by society to promote, protect, and restore the people's h.; public h. is a social institution, a service, and a practice.

Health Care Financing Administration (HCFA)
The federal agency that determines reimbursement for federal programs.

health center
An institution or group of institutions providing all types of medical care and preventive services to a population.

Health Resources and Services Administration (HRSA)
A federal agency responsible for managing national data banks, such as the National Practitioner Data Bank, as well as other health care programs.

healthy (helth′e)
Well; in a state of normal functioning; free from disease.

Noble Sproat, U.S. gynecological surgeon and obstetrician, 1880–1955. See H. operation.

hear (her)
To perceive sounds; denoting the function of the ear. [A.S. heran]

hearing (her′ing)
The ability to perceive sound; the sensation of sound as opposed to vibration. SYN: audition. color h. a subjective perception of color produced by certain sounds. SEE ALSO: pseudochromesthesia. SYN: chromatic audition. normal h. SYN: acusis.

hearing aid (her′ing ad)
An electronic amplifying device designed to bring sound into the ear; it consists of a microphone, amplifier, and receiver. SYN: hearing instrument. behind-the-ear h. h. that rests on the medial aspect of the pinna. completely in the canal h. (CIC) a h. that fits entirely in the external auditory canal and is not visible at the surface of the body. digital h. programmable h. that can be customized to the extent of the user's hearing loss. in-the-canal h. h. that is placed in the external auditory canal but is still visible. in-the-ear h. h. that fits into the shell of the ear.

hearing impairment, hearing loss
A reduction in the ability to perceive sound; may range from slight inability to complete deafness. SEE ALSO: deafness, threshold shift. acoustic trauma hearing loss sensory hearing loss due to exposure to high-intensity noise. Alexander h. [MIM*203500] high frequency deafness due to membranous cochlear dysplasia. boilermaker's hearing loss SYN: noise-induced hearing loss. conductive h. a form of h. due to a lesion in the external auditory canal or middle ear. functional h. SYN: psychogenic h.. hereditary h. h. occurring in syndromic forms (in which there are other anomalies in addition to the h.) and nonsyndromic forms (in which h. is the only unusual finding) with autosomal dominant and recessive, X-linked, and mitochondrial modes of transmission; may be congenital, of early onset in childhood, or late onset in mid-life and advanced age. high-frequency h. selective loss of hearing for high frequencies, usually associated with sensory damage; common in acoustic trauma and noise-induced hearing loss. hysterical h. SYN: psychogenic h.. industrial hearing loss SYN: noise-induced hearing loss. low-tone hearing loss inability to hear low notes or frequencies. mixed hearing loss combination of conductive and sensorineural hearing loss. Mondini h. the h. resulting from the structural aberration of Mondini dysplasia. neural hearing loss form of sensorineural hearing loss due to a lesion in the auditory division of the 8th cranial nerve. noise-induced hearing loss sensory hearing loss due to exposure to intense impulse or continuous sound. SYN: boilermaker's hearing loss, industrial hearing loss, occupational hearing loss. occupational hearing loss SYN: noise-induced hearing loss. organic h. deafness due to a pathologic process or an organic cause, as opposed to psychogenic h.. perceptive h. former term for sensorineural deafness. psychogenic h. h. without evidence of organic cause; often follows severe psychic shock. SYN: functional h., hysterical h.. retrocochlear hearing loss term for sensorineural h.; suggesting a lesion proximal to the cochlea. Scheibe h. h. due to cochleosaccular dysplasia; usually autosomal recessive inheritance. sensorineural hearing loss a form of hearing loss due to a lesion of the auditory division of the 8th cranial nerve or the inner ear. sensory h. form of sensorineural h. caused by a lesion in the inner ear.

heart (hart) [TA]
A hollow muscular organ that receives the blood from the veins and propels it into the arteries. In mammals it is divided by a musculomembranous septum into two halves—right or venous and left or arterial—each of which consists of a receiving chamber (atrium) and an ejecting chamber (ventricle). SYN: cor [TA] , coeur. [A.S. heorte] armor h. extensive to complete calcification (rarely ossification) of the pericardium usually producing constrictive pericarditis. armored h. calcareous deposits in the pericardium due to subacute or chronic pericarditis. SYN: panzerherz. artificial h. a mechanical pump used to replace the function of a damaged h., either temporarily or as a permanent prosthesis. athlete's h. a more or less loose designation for cardiac findings in healthy athletes that would be or could be abnormal in patients with disease, including atrioventricular blocks, left ventricular hypertrophy and, sometimes, benign arrhythmias and atrioventricular blocks. athletic h. hypertrophy of the h. supposedly due to systematic athletic conditioning. beer h. SYN: alcoholic cardiomyopathy. beriberi h. h. disease due to thiamine deficiency that may be epidemic or sporadic as characterized by cardiac metabolic damage and myocardial failure, often of the “high output” type, with edema (except in “dry” shoshin beriberi) and polyneuritis. The term is derived from Singhalese, “I am unable.” bony h. the presence of extensive calcareous patches in the pericardium and walls of the h., some of which chronically develop bony changes. chaotic h. apparently totally uncoordinated cardiac action or rhythm. crisscross h. an anomaly in which the ventricular relationships are not as expected for the given atrioventricular connection. drop h. SYN: cardioptosia. fatty h. 1. fatty degeneration of the myocardium; 2. accumulation of adipose tissue on the external surface of the h. with occasional infiltration of fat between the muscle bundles of the h. wall. SYN: cor adiposum. frosted h. hyaloserositis involving the pericardium. SYN: icing h.. globular h. SYN: round h.. hairy h. SYN: fibrinous pericarditis. Holmes h. a variant of double inlet left ventricle where the ventricular-arterial connection is concordant and the right ventricle is rudimentary. horizontal h. description of the hearts electrical position; recognized in the electrocardiogram when the QRS in lead aVL resembles that in V6 and QRS in aVF resembles that in V1; also, loosely, when the electrical axis lies between −30° and +30°. hyperthyroid h. response of the h. to hyperthyroidism, essentially the result of sympathetic stimulation producing rapid h. rates and ultimately cardiac failure and atrial fibrillation if untreated. hypoplastic h. a small h., as seen in Addison disease. icing h. SYN: frosted h.. intermediate h. loosely, description of the hearts electrical axis when this is directed at approximately between +30° and +60°. For cardiac position, recognized in the electrocardiogram when the QRS complexes in both lead aVL and aVF resemble that in V6. Jarvik artificial h. a pneumatic artificial h.. left h. the left atrium and left ventricle. mechanical h. term loosely applied to any mechanical circulatory assist device. movable h. SYN: cor mobile. myxedema h. the enlarged h. associated with untreated severe hypothyroidism, often accompanied by pericardial effusion; rare in modern medicine. ox h. a very large h., due to chronic hypertension or, more often, to aortic valve disease, especially regurgitation. SYN: bucardia, cor bovinum. parchment h. a congenital or acquired condition in which there is thinning of the right ventricular myocardium. See Uhl anomaly. SYN: right ventricular hypoplasia. pendulous h. SYN: cor pendulum. pulmonary h. the right atrium and ventricle, receiving the venous blood and propelling it to the lungs. SEE ALSO: cor pulmonale. right h. the right atrium and right ventricle. round h. abnormally smooth arcuate contours of the h. on imaging due either to disease of the ventricles or to a false cardiac appearance produced by excessive pericardial fluid. SYN: globular h.. sabot h. SYN: coeur en sabot. semihorizontal h. loosely refers to the hearts electrical axis when this is directed at approximately 0°. As a cardiac electrical position, recognized in the electrocardiogram when the QRS complex in lead aVL resembles V6 while that in aVF is small algebraically or absolutely. semivertical h. loosely descriptive of the hearts electrical axis when this is directed at approximately +60°. As a cardiac electrical position, recognized in the electrocardiogram when the QRS complex in lead aVF resembles V6 while that in aVL is small algebraically or absolutely. stone h. SYN: ischemic contracture of the left ventricle. systemic h. the left atrium and ventricle, receiving the aerated blood from the lungs and propelling it throughout the body. three-chambered h. congenital abnormality in which there may be a single atrium with two ventricles or a single ventricle with two atria. Rudimentary parts of the atrial and ventricular septa may be present but are incompetent to prevent a virtual single chamber in either case. tiger h. a fatty degenerated h. in which the fat is disposed in the form of broken stripes in the subendocardial myocardium. tobacco h. cardiac irritability marked by irregular action, palpitation, and sometimes pain, believed to occur as a result of the heavy use of tobacco. univentricular h. an anomaly in which all blood flows through one ventricle or in which the arterioventricular valves are committed to empty into only one chamber in the ventricular mass. venous h. the right side, including both the atrium and ventricle, of the h.. vertical h. loosely descriptive of the hearts electrical axis when this is directed at approximately +90°. As a cardiac electrical position, recognized in the electrocardiogram when the QRS complex in lead aVL resembles V1 while that in aVF resembles V6. wooden-shoe h. SYN: coeur en sabot.

heartbeat (hart′bet)
A single complete cycle of contraction and dilation of heart muscle.


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