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a place of meeting or coming together. adj., adj junc´tional.
atrioventricular junction in the conduction system of the heart, the junction between the atrioventricular node and the nonbranching portion of the bundle of His.
cementoenamel junction the line at which the cementum covering the root of a tooth meets the enamel covering the crown.
gap junction a narrowed portion of the intercellular space, containing channels linking adjacent cells and through which can pass ions, most sugars, amino acids, nucleotides, vitamins, hormones, and cyclic AMP. In electrically excitable tissues the gap junctions serve to transmit electrical impulses via ionic currents and are known as electrotonic synapses; they are present in such tissues as myocardial tissue.
myoneural junction (neuromuscular junction) the site of junction of a motor nerve fiber and a skeletal muscle fiber that it innervates. The discoid expansion of the terminal branch of the axon forms the motor end plate, the neurotransmitter that diffuses across the synapse is acetylcholine.
sclerocorneal junction limbus (def. 2).
ureteropelvic junction the area where the renal pelvis meets the ureter.


(jŭngk'shŭn), [TA]
The point, line, or surface of union of two parts, mainly bones or cartilages. Synonym(s): juncture (2)
Synonym(s): junctura (2) [TA], junctio


/junc·tion/ (-shun) the place of meeting or coming together.junc´tional
adherent junction  a type of intercellular junction that links cell membranes and cytoskeletal elements within and between cells, connecting adjacent cells mechanically.
amelodentinal junction  dentinoenamel j.
atrioventricular junction , AV junction part or all of the region comprising the atrioventricular node and the bundle of His, with the bundle branches sometimes specifically excluded.
cementoenamel junction  the line at which the cementum covering the root of a tooth and the enamel covering its crown meet, designated anatomically as the cervical line.
dentinocemental junction  the line of meeting of the dentin and cementum on the root of a tooth.
dentinoenamel junction  the plane of meeting between dentin and enamel on the crown of a tooth.
esophagogastric junction  the site of transition from the stratified squamous epithelium of the esophagus to the simple columnar epithelium of the cardia of the stomach.
gap junction  a narrowed portion of the intercellular space containing channels linking adjacent cells and through which pass ions, most sugars, amino acids, nucleotides, vitamins, hormones, and cyclic AMP. In electrically excitable tissues, these gap junctions transmit electrical impulses via ionic currents and are known as electrotonic synapses.
Enlarge picture
Gap junctions providing passageways between the interiors of adjacent cells.
gastroesophageal junction  esophagogastric j.
ileocecal junction  the junction of the ileum and cecum, located at the lower right side of the abdomen and fixed to the posterior abdominal wall.
intercellular junctions  specialized regions on the borders of cells that provide connections between adjacent cells.
mucocutaneous junction  the site of transition between skin and mucous membrane.
mucogingival junction  the histologically distinct line marking the separation of the gingival tissue from the oral mucosa.
myoneural junction , neuromuscular junction the site of apposition between a nerve fiber and the motor end plate of the skeletal muscle which it innervates.
occluding junction  tight j.
sclerocorneal junction  corneal limbus.
tight junction  an intercellular junction at which adjacent plasma membranes are joined tightly together by interlinked rows of integral membrane proteins, limiting or eliminating the intercellular passage of molecules.
ureteropelvic junction  the junction between the ureter and the renal pelvis.


Etymology: L, jungere, to join
an interface or meeting place for tissues or structures.


(jŭngk'shŭn) [TA]
The point, line, or surface of union of two parts, mainly bones or cartilages.
Synonym(s): junctio.


(junk'shun) [L. junctio, a joining]
The place of union or coming together of two parts or tissue layers.

amelodentinal junction

Dentinoenamel junction.

atrioventricular junction

The area of cardiac conduction pathway connecting the AV node with the atrioventricular bundle.

cementodentinal junction

The interface of dentin and cementum of the tooth. Synonym: dentinocemental junction

cementoenamel junction

The line around the tooth that marks the boundary between the crown and root of the tooth; the interface between enamel and cementum.

costochondral junction

The articulation or meeting place of the bony rib and its costal cartilage.

cervicomedullary junction

The nexus between the most superior part of the spinal cord and the medulla oblongata of the brainstem.

dentinocemental junction

Cementodentinal junction.

dentinoenamel junction

The plane or interface between the dentin of the tooth and the enamel crown; histological sections show it to be a scalloped boundary at the site of the basement membrane which separated the cell layers that formed the calcified enamel and dentin. Synonym: amelodentinal junction

dentogingival junction

The interface and zone of attachment between the gingiva and enamel or cementum of the tooth. It holds in place the junctional or attachment epithelium.

interneuronal junction


liquid junction

The point in a potentiometric reference electrode measurement system at which the reference solution makes contact with the test solution. An example is pH reference electrode.

mucocutaneous junction

The junction between the skin and a mucous membrane.

mucogingival junction

A scalloped, indistinct boundary between the gingiva and the oral mucosa on the alveolar process. The coral color of gingiva may be contrasted with the more vascular oral mucosa. Also called the mucogingival line.
Enlarge picture

myoneural junction

The axon terminal of a motor neuron, synaptic cleft, and sarcolemma of a muscle cell. Synonym: neuromuscular junction
See: illustration

neuromuscular junction

Myoneural junction.

saphenofemoral junction

The merging of the saphenous and femoral veins in the inguinal region.

sclerocorneal junction

The meeting point between the sclera and the cornea marked on the external surface of the eyeball by the outer scleral sulcus.
Enlarge picture
SQUAMOCOLUMNAR JUNCTION: Squamocolumnar junction of the distal esophagus (seen endoscopically)

squamocolumnar junction

1. The point in the cervical canal at which the squamous and columnar epithelia meet. As most cervical cancers begin in this area, it is important to obtain cells from this location for the Pap test.
2. The point above the lower esophageal sphincter where the squamous epithelium of the esophagus and the columnar epithelium of the stomach meet.
Synonym: transition zone. See: illustration

tight junction

A part of the junctional complex at the lateral interface between epithelial cells; also called zonula occludens.


(jŭngk'shŭn) [TA]
The point, line, or surface of union of two parts, mainly bones or cartilages.


the place of meeting or coming together.

cell junction
specialized regions of the cell surface where adjacent eukaryotic cell membranes are joined. Functionally, there are three types: tight junctions (impermeable), gap junctions (communicating) and adhering junctions (desmosomes).
corneoscleral junction
see corneoscleral junction.
costochondral junction
the joint between the bony dorsal part of a rib and the ventral cartilaginous part.
ileocecocolic junction
the T-junction between the ileum and the large intestine; in the cat the ileum and the colon merge end to end, the cecum enters from the side; in the horse the ileocecal and the cecocolic junctions are separated from each other.
mucocutaneous junction
see mucocutaneous margin.
neuromuscular junction
see neuromuscular junction.
sclerocorneal junction
see corneoscleral junction.
References in periodicals archive ?
7 miles from the junction with simple filling fare, while a little further at two miles away is Ridgeway Bar and Kitchen (2 Ridgeway Avenue, Newport NP20 5AJ).
Traffic using the M6 southbound heading for the north east via the M42 north, will be diverted via the M6 southbound at junction 4.
While acknowledging these shortcomings and challenges, Bandaru points out that the junctions tested so far provide merely a "proof of principle.
Harmon Meadow will also offer bus service to and from Secaucus Junction, beginning early next year.
Thompson, the drummer for The Second String, played at Java Junction Tuesday night to a crowd of about 100 people.
m57 junction 1 (tarbock island) to junction 7 (switch island),
M62 junction 28 Tingley: The eastbound side of the carriageway will be closed between the slip roads overnight on Tuesday, April 5, for technology works.
Its signatories included the family of businessman Roger Bowen, who died at the junction last March.
A191 Starting at the junction of Great Lime Road with the Whitley Road roundabout near Benton Square, North Tyneside, and ending at the junction of Jesmond Dene Roadwith the Great North Road junction in West Jesmond, Newcastle.
In Bromsgrove town centre, Church Street, from its junction with Market Street to the pedestrianised area, will be closed from 10.
and an independent team headed by Shinji Yuasa of the National Institute of Advanced Industrial Science and Technology Tsukuba, Japan, have tripled the key measure of performance of a memory component called a magnetic tunneling junction (SN: 4/3/99, p.