Organization of Respiratory Reflexes in the Caudal Region of the Nucleus of the Tractus Solitarius

Author(s):  
G. D. Housley ◽  
S. Brew ◽  
D. de Castro ◽  
J. D. Sinclair
2004 ◽  
Vol 47 (4) ◽  
pp. 784-801 ◽  
Author(s):  
David J. Zajac ◽  
Mark C. Weissler

Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults produced syllable trains of /pʌ/ using a mouthpiece coupled to a computer-controlled perturbator. The device randomly created bleed apertures that ranged from 0 to 40 mm 2 during production of the 2nd or 4th syllable of an utterance. Although peak oral air pressure dropped in a linear manner across bleed apertures, it averaged 2 to 3 cm H 2 O at the largest bleed. While slope of oral pressure also decreased in a linear trend, duration of the oral pressure pulse remained relatively constant. The patterns suggest that respiratory reflexes, if present, have little effect on oral air pressure levels. In Study 2, both oral and subglottal air pressure responses were monitored in 2 adults while bleed apertures of 20 and 40 mm 2 were randomly created. For 1 participant, peak oral air pressure dropped across bleed apertures, as in Study 1. Subglottal air pressure and slope, however, remained relatively stable. These patterns provide some support for the occurrence of respiratory reflexes to regulate subglottal air pressure. Overall, the studies indicate that the inherent physiologic processes of the respiratory system, which may involve reflexes, and passive aeromechanical resistance of the upper airway are capable of developing oral air pressure in the face of substantial pressure bleeds. Implications for understanding speech production and the characteristics of individuals with velopharyngeal dysfunction are discussed. KEY WORDS: stop consonants, oral air pressure, subglottal air pressure, respiratory reflexes, velopharyngeal dysfunction


Nematology ◽  
2009 ◽  
Vol 11 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Il-Kweon Yeon ◽  
Gaurav Singh ◽  
Irfan Ahmad ◽  
Chung-Don Choi

AbstractThe type species of the genus Butlerius, viz., B. butleri Goodey, 1929, is redescribed and illustrated from specimens collected in South Korea. Additional information is provided for the cuticle, stoma structure, female reproductive system and the male caudal region. The Korean population is 1336-1857 μm long, a = 33.9-43.5, b = 5.41-6.34, c = 3.38-4.20, c′ = 14.13-19.0 and V = 40-45%. Males have spicules 39-49 μm long and a gubernaculum 25-33 μm long. There are nine pairs of genital papillae, three pairs precloacal and six pairs postcloacal. The v5,6,7 clusters are widely separated, one group situated just posterior to the phasmids and the other group at level of pd. Although there are some differences in morphometrics as compared with the type population, the species is easily identified by the similarities in the structure of the stoma, pharynx, spicules and gubernaculum. Butlerius singularis and B. filicaudatus are proposed as synonyms of the type species.


2013 ◽  
Vol 151 (1) ◽  
pp. 21-28 ◽  
Author(s):  
JUDY A. MASSARE ◽  
DEAN R. LOMAX

AbstractAn ichthyosaur in the collections of the Sedgwick Museum, Cambridge (CAMSMX.50187) was collected in the nineteenth century by the renowned fossil collector Mary Anning, but has never been adequately described in the literature. As an Anning specimen, it is certainly from the Lower Jurassic of Lyme Regis, west Dorset. The near complete presacral skeleton is lying on its left side and includes a complete skull, one complete and one partial forefin, pectoral bones, all six elements of the pelvic girdle, and both hindfins. The centra in the anterior caudal region, however, are from another individual and may have replaced the original ones. The specimen is identified as Ichthyosaurus based on the morphology of the humerus and forefin. It is assigned to I. breviceps on the basis of the relatively short snout, large eye, and tall neural spines. This is the only known specimen of I. breviceps to preserve a complete pelvis. Notably, the ilium is longer than the pubis and ischium, and the pubis is longer than the ischium. This individual is the largest I. breviceps reported in the literature, with jaw length of 33.5 cm and estimated length from snout to tail bend of 1.6 m.


Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 159-168
Author(s):  
Th. Lender ◽  
C. Briançon

Induction of sexual maturity in a fissiparous Planarian, Dugesia gonocephala The planarian Dugesia gonocephala reproduces either sexually, or asexually by fission, according to the presence or absence of a genital apparatus. The experimental induction of sexual maturity in a fissiparous planarian can be obtained by grafting a piece of a planarian with a genital pore containing mature testes, whether they are testes existing in the graft before the operation (grafts of testes) or testes differentiated in the piece after grafting (grafts of ovaries). Grafts of cephalic or caudal region, and pieces of a planarian without genital pore, cannot induce this maturation and cannot differentiate testes. The induction of testicular structures seems to be dependent on hormones. The development of a genital apparatus in a planarian without genital pore is accompanied by the disappearance of fission.


Zootaxa ◽  
2021 ◽  
Vol 4970 (1) ◽  
pp. 189-194
Author(s):  
THI ANH DUONG NGUYEN ◽  
REYES PEÑA-SANTIAGO

Crassolabium unicum sp. n., collected from a natural habitat in Vietnam, is described and illustrated. The new species is characterized by its 0.77–0.94 mm long body, three-layered cuticle, lip region offset by depression and 12–13.5 µm broad, odontostyle 13.5–15 µm long with wide aperture occupying 36–46% of its length, neck 235–260 µm long, pharyngeal expansion 117–131 µm long or occupying 47–52% of total neck length, anterior part of intestine presenting very distinct folds, female genital system didelphic-amphidelphic, uterus simple and 28–43 µm or 0.7–0.9 body diameters, vulva transverse (V = 45–52), prerectum bearing a blind postrectal sac, caudal region short and rounded (21–25 µm, c = 45–61, c’ = 0.6–0.8) with two (dorsal and ventral) lacunae between outer and intermediate cuticle layers, and male unknown. It is compared with the similar representatives of the genus. 


2018 ◽  
Vol 46 (2) ◽  
pp. 177-184
Author(s):  
Sumon Debnath ◽  
Gulshan Ara Latifa ◽  
Mohajira Begum ◽  
Md Abu Obaida

Present study was conducted to evaluate nutritional values of smoked hilsa fish (Tenualosa ilisha; Hamilton, 1882) in relation to its raw condition. Smoking is one of the processes of fish preservation from ancient period of our country. The nutrients values of the hilsa from two different regions were significantly (p < 0.05) varied. The nutritional values were different before and after processing of hilsa. Riverine hilsa contains relatively more moisture (56.45 ± 0.51%) and protein (15.98 ± 0.50%) than marine hilsa. Fat (16.18 ± 0.45%) and salt (1.92 ± 0.18%) contents are higher in marine hilsa; whereas ash (8.34 ± 0.35%) content was higher in riverine hilsa. Minerals like iron (4.72 ± 0.08 mg/100 g) and calcium (481.77 ± 6.20 mg/100g) remain in large amount on marine hilsa but phosphorus (115.73 ± 4.36 mg/100 g) content remain high level in riverine hilsa. In addition, the protein (raw condition, 19.54 ± 0.47%, riverine; 17.12 ± 0.42%, marine and smoked condition, 29.64 ± 0.41%, riverine; 28.51 ± 0.51%, marine) and fat (raw condition, 16.41 ± 0.46%, riverine; 20.07 ± 0.39%, marine and smoked condition, 20.71 ± 0.47%, riverine; 23.31 ± 0.47%, marine) content were higher in abdominal region of riverine and marine hilsa both raw and smoked condition than head region (protein in raw condition, 11.21 ± 0.51%, riverine; 10.51 ± 0.53%, marine and smoked condition, 17.14 ± 0.42%, riverine; 15.69 ± 0.4%, marine; fat in raw condition, 9.04 ± 0.45%, riverine; 11.21 ± 0.51%, marine and smoked condition, 12.32 ± 0.44%, riverine; 14.56 ± 0.47%, marine) and caudal region (protein in raw condition17.21 ± 0.52%, riverine; 15.22 ± 0.66%, marine and smoked condition, 27.68 ± 0.44%, riverine; 26.73 ± 0.46%, marine; fat in raw condition, 14.05 ± 0.5%, riverine; 17.28 ± 0.47%, marine and smoked condition, 17.35 ± 0.43%, riverine; 19.18 ± 0.51%, marine). Bangladesh J. Zool. 46(2): 177-184, 2018


1983 ◽  
pp. 108-156 ◽  
Author(s):  
Andrzej Trzebski
Keyword(s):  

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