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Biomedical subjects

K Floyd

Publications and source records attributed to K Floyd.

At least 55 records · Page 3Linked to original sources
PubMed1977

Effects of bradykinin mediated by autonomic efferent nerves.

Intra-arterial injections of bradykinin cause increases in blood pressure and increased impulse rates in single sympathetic efferent fibres. The peptide also causes one or more large bladder contractions, which are associated with increased impulse rates in pelvic nerve efferent fibres whose spontaneous discharges are temporally associated with increases in intravesical pressure. These induced increases in pelvic nerve discharge and intravesical pressure could be abolished or greatly reduced by interference with conduction in pathways which mediate reflex bladder contractions. It is concluded that bradykinin has little direct action on the bladder, and that the large contractions which result from its administration are mediated by the central nervous system.

Action Potentials↗
PubMed1977

The effects of bradykinin on afferent units in intra-abdominal sympathetic nerve trunks.

The effects of intra-arterial injections of bradykinin on afferent discharges in the splanchnic and hypogastric nerves have been studied. All units which were excited by the peptide were mechanosensitive. Following i.a. bradykinin, the slowly adapting mechanoreceptors associated with the bladder showed increased discharge rates which appear to be related to changes in intravesical pressure. When the effects of bradykinin on the bladder were blocked by cord cooling, the afferents were not excited. It is concluded that bradykinin causes discharges in the slowly adapting mechanoreceptors around the bladder because it causes bladder contractions, and not because of any chemosensitivity of the nerve ending.

Action Potentials↗
PubMed1976

Mechanosensitive afferent units in the hypogastric nerve of the cat.

1. Recordings have been made from ninety single afferent units in the hypogastric and lumbar splanchnic nerves of the cat. 2. The majority of units examined had properties similar to those previously described in the splanchnic nerve: they were slowly adapting mechanoreceptors with one to six punctate mechanosensitive sites distributed mainly along blood vessels as they approached the viscera in peritoneal ligaments; they had a wide range of mechanical thresholds and conduction velocities in the range 0.5-24 m s-1. 3. Receptive fields were found over the bladder base or its peritoneal ligaments or both, on the uterus or broad ligament or both, on the colon or mesocolon or both, and in association with the ureter, vas deferens, prostate or pelvic fat pads. 4. Discharges from afferent units associated with the bladder were investigated during spontaneous (or reflex) bladder contractions, passive distensions, and tetanic contractions induced by electrical stimulation of the sacral spinal cord. The mean spike rates of the adapted (tonic) discharges, observed during distensions and induced tetani, differed over part of the range of intravesical pressures examined. Their behaviour is discussed in relation to the concept of 'in series' tension receptors within the bladder wall.

Action Potentials↗
PubMed1975

The mechanical properties of oesophageal striated muscle in the cat and sheep.

1. A study has been made of the mechanical behaviour of isolated strips of cat and sheep oesophageal muscle. 2. At 37 degrees C, time to peak tension in an isometric twitch was about 80 ms in both muscles. Tetanic fusion frequency was 30 s-minus 1, twitch: tetanus ratio 0.4-0.47, and maximum velocity of shortening was 3 lengths. s-minus1. 3. The results are compared with the prperties of other muscles.

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