What's the difference between pessulus and ventral?
Pessulus
Definition:
(n.) A delicate bar of cartilage connecting the dorsal and ventral extremities of the first pair of bronchial cartilages in the syrinx of birds.
Example Sentences:
(1) While at level of the proximal and distal third of the tympanic membrane the morphological and structural aspects of the cells resemble that of the adjacent structures (pessulus and primary bronchi), the middle part of the epithelium layer becomes gradually flattered; the epithelium is made up of oblique or horizontal cells which touch each other by means of many lateral interdigitations.
(2) M. sternotrachealis relaxes the membranes by drawing the drum of the trachea caudad, or, via the syringeal ligament, by rotating the pessulus cranioventrad, or both.
Ventral
Definition:
(a.) Of or pertaining to that surface of a carpel, petal, etc., which faces toward the center of a flower.
(a.) Of, pertaining to, or situated near, the belly, or ventral side, of an animal or of one of its parts; hemal; abdominal; as, the ventral fin of a fish; the ventral root of a spinal nerve; -- opposed to dorsal.
(a.) Of or pertaining to the lower side or surface of a creeping moss or other low flowerless plant. Opposed to dorsal.
Example Sentences:
(1) The possibility that the ventral nerve photoreceptor cells serve a neurosecretory function in the adult Limulus is discussed.
(2) While the heaviest anterogradely labeled ascending projections were observed to the contralateral ventral posterolateral nucleus of the thalamus, pars oralis (VPLo), efferent projections were also observed to the contralateral ventrolateral thalamic nucleus (VLc) and central lateral (CL) nucleus of the thalamic intralaminar complex, magnocellular (and to a lesser extent parvicellular) red nucleus, nucleus of Darkschewitsch, zona incerta, nucleus of the posterior commissure, lateral intermediate layer and deep layer of the superior colliculus, dorsolateral periaqueductal gray, contralateral nucleus reticularis tegmenti pontis and basilar pontine nuclei (especially dorsal and peduncular), and dorsal (DAO) and medial (MAO) accessory olivary nuclei, ipsilateral lateral (external) cuneate nucleus (LCN) and lateral reticular nucleus (LRN), and to a lesser extent the caudal medial vestibular nucleus (MVN) and caudal nucleus prepositus hypoglossi (NPH), and dorsal medullary raphe.
(3) By 3 d in the chick embryo, the first neurons detected by antibodies to Ng-CAM are located in the ventral neural tube; these precursors of motor neurons emit well-stained fibers to the periphery.
(4) Following injections of HRP into the apex of the heart, the sinoatrial (SA) nodal region and the ventral wall of the right ventricle, we observed that HRP-labeled sympathetic neurons were localized predominantly in the right stellate ganglia, and to a lesser extent, in the right superior and middle cervical ganglia, and left stellate ganglia.
(5) The effects of clozapine on the spontaneous firing rate of noradrenergic (NE, locus coeruleus), dopaminergic (DA, zona compacta, ventral tegmental area) and non-dopaminergic (zona reticulata) neurons was studied in chloral hydrate anesthetized rats.
(6) Differences between parental and nonparental birds in VIP profiles were detected in the ventral portion of the infundibular region.
(7) The dominance of XBMP-4 over activin may account for the ability of injected XBMP-4 RNA to 'ventralize' whole Xenopus embryos.
(8) This column is located ventral and lateral to the dorsolateral division of the trigeminal motor nucleus, and just medial to the descending trigeminal nerve rootlets.
(9) Lumbosacral spine films revealed only minimal degenerative changes, while lumbar myelogram showed L4-L5 and L5-S1 ventral extradural defects.
(10) The ventral root dissection technique was used to obtain contractile and electromyogram (e.m.g.)
(11) The ventral tract ends almost entirely in the anterior lobe with the majority of fibres terminating contralateral to the side of the hemisection.
(12) Descending neurons have opposite structural polarity, arising in the brain and terminating in segmental regions of the fused ventral ganglia.
(13) It was found that within the dorsal part of the well known pressor area there is a narrow strip, 2.5 mm lateral from the mid line, starting ventral to the inferior colliculus and ending in the medulla close to the floor of the IV ventricle, from which vasodilatation in skeletal muscles is selectively obtained.
(14) Injection of the tracer substance wheat germ agglutinin-horseradish peroxidase (WGA-HRP) directly into the basilar pontine nuclei using a ventral surgical approach resulted in the labeling of somata in many areas both rostral and caudal to the basilar pons.
(15) Contact guidance has been suggested to direct NC cells ventrally in the trunk, but this has been subject to doubt (see Newgreen and Erickson, 1986, Int.
(16) These additional projections were interpreted as entering the CN by a ventral route.
(17) Cytochrome oxidase histochemistry revealed patchy patterns of the enzyme activity in transverse sections through the caudal part of the ventral subnucleus of the principal sensory trigeminal nucleus, interpolar spinal trigeminal nucleus, and layer IV of the caudal spinal trigeminal nucleus in the cat.
(18) Zebrin II-negative Purkinje cells are present in a continuous region encompassing the rostromedial part of the valvula, the lobus transitorius, lobe C1 and the ventral part of lobe C2, and in a small, lateral zone of the posterior part of the caudal lobe.
(19) To test whether congenital nemaline myopathy (NM) might have a neurogenic basis, we evaluated the number and frequency distribution of L5 motoneuron cell bodies and their myelinated ventral root (VSR) axons in a typical case.
(20) Fractionation of the supernatant from ventral or dorsal hypothalamic homogenates resulted in a bimodal distribution of IR-TSH.