Linked Life Data

6056014

Source:http://linkedlifedata.com/resource/pubmed/id/6056014

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1968-1-4
pubmed:abstractText
The tubular heart of tunicates is composed of a single layer of myoendothelial cells. The direction of contraction reverses every few minutes. The conduction times in both directions are the same. Conduction velocity was greatest in the middle of the arms of the V-shaped heart and slowest in the apex. The greater the heart length, the greater was the conduction velocity. The Q(10) of conduction velocity was 2-2.3. Removal of the raphe which attaches the heart to the pericardium and removal of a line of undifferentiated cells opposite the raphe did not change the conduction velocity or prevent the heart from reversing the direction of conduction. The median resting potential of 42 cells was -71 mv and the median action potential was 75 mv. At 20 degrees C the duration of the action potential was 1.2 sec and the maximal rate of depolarization was 3-10 v/sec. An increase in the beat frequency produced by electrically stimulating the heart decreased the resting potential, rate of rise, the duration, and the overshoot of the action potential. The shape of the action potential was sometimes different in the two directions of conduction. The electrophysiological evidence indicates only one cell type and suggests that the mode of the spread of excitation is by local current flow from cell to cell.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-1295
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2097-107
pubmed:dateRevised
2010-6-22
pubmed:meshHeading
pubmed:year
1967
pubmed:articleTitle
Conduction velocity and intracellular action potentials of the tunicate heart.
pubmed:publicationType
Journal Article