The raptorial siphonal apparatus of the carnivorous septibranch Cardiomya planetica Dall (Mollusca:Bivalvia), with notes on feeding and digestion

1980 ◽  
Vol 58 (4) ◽  
pp. 670-679 ◽  
Author(s):  
Robert G. B. Reid ◽  
Suzin Porteous Crosby
Keyword(s):  
Blood Pressure ◽  
Sensory Input ◽  
Inhalant Siphon ◽  
Sensory Mechanism

Cardiomya planetica Dall is a carnivorous septibranch bivalve. The food-capturing organ is the inhalant siphon, which can be rapidly extended by a surge of blood. The increase in blood pressure is brought about by the contraction of the septum. The sensory mechanism is constituted by seven siphonal tentacles with mechanoreceptors at their tips. The mechanoreceptors are composed of clumps of clubbed cilia in apical pits lined with microvilli. The activity of the septum, inhalant siphon, and pallial valve is coordinated with the sensory input through a large siphonal ganglion. Food consists largely of ostracods and digestion appears to be periodic.

Convergence of sympathetic, vagal, and other sensory inputs onto neurons in feline ventrolateral medulla

1991 ◽  
Vol 260 (6) ◽  
pp. H1918-H1928 ◽  
Author(s):  
R. W. Blair
Keyword(s):  
Blood Pressure ◽  
Reticular Formation ◽  
Sensory Input ◽  
Vagal Stimulation ◽  
Stellate Ganglion ◽  
Ventrolateral Medulla ◽  
Multiple Sources ◽  
Pressure Sensitive ◽  
Alpha Chloralose ◽  
Stimulation Of

Responses of 80 neurons in rostral and caudal ventrolateral medulla to multiple sources of sensory input were assessed in cats anesthetized with alpha-chloralose. Sixty-one of eighty-one neurons (76%) were excited by stimulation of the stellate ganglion, and one neuron exhibited inhibition followed by excitation. In response to vagal stimulation, 12% of the neurons were excited and 29% inhibited. Vagal stimulation reduced the responses of 13 of 39 (33%) neurons to sympathetic stimulation. Overall, one-third of the neurons responded to both sympathetic and vagal stimulation. There was no difference in proportion of responsive neurons in rostral versus caudal ventrolateral reticular formation. Cells were also tested for auditory, visual, and natural somatic stimuli. Ten percent of the neurons responded to all five stimuli, and another 25% responded to four stimuli. Twelve percent of neurons were unresponsive to any stimulus. Twenty cells were tested for responses to changes in blood pressure elicited with phenylephrine and nitroglycerin. Seven neurons were inhibited by increases or excited by decreases in pressure, four had the opposite responses, and nine were unresponsive. In general, blood pressure-sensitive cells exhibited comparable convergence of other inputs as the overall cell population. However, three times as many pressure-insensitive neurons received vagal input as did pressure sensitive neurons. In conclusion, neurons in the ventrolateral medulla, including the vasopressor and vasodepressor regions, receive and integrate convergent input from multiple sensory origins. Since the regions of the reticular formation studied are functionally heterogeneous, the precise functions of these neurons are not known.

Sensory denervation of the kidney attenuates renovascular hypertension in the rat

1986 ◽  
Vol 250 (1) ◽  
pp. H82-H86 ◽  
Author(s):  
J. M. Wyss ◽  
N. Aboukarsh ◽  
S. Oparil
Keyword(s):  
Blood Pressure ◽  
Renovascular Hypertension ◽  
Sensory Input ◽  
Sham Group ◽  
Left Renal Artery ◽  
Dorsal Rhizotomy ◽  
Afferent Nerves ◽  
Lower Blood ◽  
Sensory Denervation

To determine the role of the renal afferent nerves in the pathogenesis of one-kidney, one-clip renovascular hypertension, the renal afferent nerves were selectively lesioned by dorsal rhizotomy, a procedure that eliminates renal sensory input to the spinal cord but does not directly damage the sympathomotor innervation of the kidney. One week after denervation, the proximal left renal artery was clipped in denervated and sham control rats. Blood pressure of the sham group rose progressively over the next 5 wk, to 185 mmHg (systolic). In contrast, blood pressure of the denervated rats leveled off in the borderline hypertensive range, a level significantly lower than that of the sham group but significantly higher than that of non-clipped rats. In two further experiments the specificity of this effect was demonstrated. Lesion of the dorsal root nerves on the side of nephrectomy did not significantly lower blood pressure of non-clipped rats, and contralateral dorsal rhizotomy did not lower the blood pressure of clipped rats. These results demonstrate that the renal afferent nerves significantly contribute to one-kidney, one-clip renovascular hypertension in the rat.

The distribution and density of ciliary tufts on the siphons of Anodonta cygnea (Mollusca: Bivalvia)

1990 ◽  
Vol 48 (3) ◽  
pp. 518-519
Author(s):  
Wen-lung Wu
Keyword(s):  
Osmium Tetroxide ◽  
Internal Surface ◽  
Mechanical Stimuli ◽  
Type Ii ◽  
Sensory Receptors ◽  
Anodonta Cygnea ◽  
Type Iv ◽  
Sem Study ◽  
Inhalant Siphon ◽  
Type V

The mantle of bivalves has come entirely to enclose the laterally compressed body and the mantle margin has assumed a variety of functions, one of the pricipal ones being sensory. Ciliary tufts, which are probably sensory, have been reported from the mantle and siphons of several bivalves1∽4. Certain regions of the mantle margin are likely to be more or less, sensitive to certain stimuli than others. The inhalant siphon is likely to be particularly sensitive to both chemical and mechanical stimuli, whereas the exhalant siphon will be less sensitive to both. The distribution and density of putative sensory receptors on the in-and ex-halant siphon is compared in this paper.The excised siphons were fixed in glutaraldehyde and osmium tetroxide, the whole procedure of SEM study is recorded in Wu's thesis.Type II cilia cover the tips of tentacles, 6.13um. Type IV and type V cilia are found on the surface of tentacles. Type IV cilia are occasionally present at the tips of tentacles, 8 um long. They are the commonest type on the surface of tentacles. Type VI cilia occor in the internal surface of the inhalant siphon, but are not found on the surface of tentacles, 6.7-10um long.

Evaluation of two methods of teaching blood pressure measurement

1988 ◽  
Vol 52 (9) ◽  
pp. 519-521
Author(s):  
NK Nordstrom ◽  
S Longenecker ◽  
HL Whitacre ◽  
FM Beck
Keyword(s):  
Blood Pressure ◽  
Pressure Measurement ◽  
Blood Pressure Measurement

Long- and short-term blood pressure andRR-interval variability and psychosomatic distress in chronic fatigue syndrome: authors’ reply 1

1999 ◽  
Vol 97 (3) ◽  
pp. 319 ◽  
Author(s):  
D.A. DUPREZ ◽  
M.L. DE BUYZERE ◽  
B. DRIEGHE ◽  
F. VANHAVERBEKE ◽  
Y. TAES ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Chronic Fatigue Syndrome ◽  
Chronic Fatigue ◽  
Short Term ◽  
Fatigue Syndrome
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