junction

junction

 [jungk´shun]

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.

junc·tion

(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

(jŭngk'shŭn) [TA]

The point, line, or surface of union of two parts, mainly bones or cartilages.
Synonym(s): junctio.

junction

(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

Synapse.

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.

MYONEURAL JUNCTION

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.

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.

junc·tion

(jŭngk'shŭn) [TA]

The point, line, or surface of union of two parts, mainly bones or cartilages.