scholarly journals Development of the Pectoral Lobed Fin in the Australian Lungfish Neoceratodus forsteri

2021 ◽  
Vol 9 ◽  
Author(s):  
Tatsuya Hirasawa ◽  
Camila Cupello ◽  
Paulo M. Brito ◽  
Yoshitaka Yabumoto ◽  
Sumio Isogai ◽  
...  

The evolutionary transition from paired fins to limbs involved the establishment of a set of limb muscles as an evolutionary novelty. In parallel, there was a change in the topography of the spinal nerves innervating appendicular muscles, so that distinct plexuses were formed at the bases of limbs. However, the key developmental changes that brought about this evolutionary novelty have remained elusive due to a lack of data on the development of lobed fins in sarcopterygian fishes. Here, we observed the development of the pectoral fin in the Australian lungfish Neoceratodus forsteri (Sarcopterygii) through synchrotron radiation X-ray microtomography. Neoceratodus forsteri is a key taxon for understanding the fin-to-limb transition due to its close phylogenetic relationships to tetrapods and well-developed lobed fins. At the onset of the fin bud in N. forsteri, there is no mesenchyme at the junction between the axial body wall and the fin bud, which corresponds to the embryonic position of the brachial plexus formed in the mesenchyme in tetrapods. Later, concurrent with the cartilage formation in the fin skeleton, the fin adductor and abductor muscles become differentiated within the surface ectoderm of the fin bud. Subsequently, the girdle muscle, which is homologous to the tetrapod serratus muscle, newly develops at the junction between the axial body wall and the fin. Our study suggests that the acquisition of embryonic mesenchyme at the junction between the axial body wall and the appendicular bud opened the door to the formation of the brachial plexus and the specialization of individual muscles in the lineage that gave rise to tetrapods.

2011 ◽  
Vol 56 (No. 8) ◽  
pp. 405-408 ◽  
Author(s):  
A. Aydin

The brachial plexus in adult red squirrels (Sciurus vulgaris) was found to be formed by the rami ventralis of C5, C6, C7, C8. A thin branch of C5 and C6 constituted the cranial trunk, and the caudal trunk was formed completely by the rami ventralis of C7 and C8. Thus, in squirrels, the spinal nerves which form the brachial plexus and the joining of these spinal nerves to each other differ from other rodents and mammals.


2019 ◽  
Vol 286 (1914) ◽  
pp. 20191571 ◽  
Author(s):  
Natalie Turner ◽  
Deimante Mikalauskaite ◽  
Krista Barone ◽  
Kathleen Flaherty ◽  
Gayani Senevirathne ◽  
...  

Appendage patterning and evolution have been active areas of inquiry for the past two centuries. While most work has centred on the skeleton, particularly that of amniotes, the evolutionary origins and molecular underpinnings of the neuromuscular diversity of fish appendages have remained enigmatic. The fundamental pattern of segmentation in amniotes, for example, is that all muscle precursors and spinal nerves enter either the paired appendages or body wall at the same spinal level. The condition in finned vertebrates is not understood. To address this gap in knowledge, we investigated the development of muscles and nerves in unpaired and paired fins of skates and compared them to those of chain catsharks. During skate and shark embryogenesis, cell populations of muscle precursors and associated spinal nerves at the same axial level contribute to both appendages and body wall, perhaps representing an ancestral condition of gnathostome appendicular neuromuscular systems. Remarkably in skates, this neuromuscular bifurcation as well as colinear Hox expression extend posteriorly to pattern a broad paired fin domain. In addition, we identified migratory muscle precursors (MMPs), which are known to develop into paired appendage muscles with Pax3 and Lbx1 gene expression, in the dorsal fins of skates. Our results suggest that muscles of paired fins have evolved via redeployment of the genetic programme of MMPs that were already involved in dorsal fin development. Appendicular neuromuscular systems most likely have emerged as side branches of body wall neuromusculature and have been modified to adapt to distinct aquatic and terrestrial habitats.


1985 ◽  
Vol 13 (01n04) ◽  
pp. 39-47 ◽  
Author(s):  
H.C. Dung

Typical spinal nerves have six cutaneous branches which reach to the skin of the body wall in the thorax and abdomen. Each of these six cutaneous branches correlates to an acupuncture point. This communication describes acupuncture points found in the thoracic and abdominal walls using anatomic nomenclature relating to cutaneous branches of the spinal nerves.


Author(s):  
A. Cevik-Demirkan ◽  
V. Ozdemir ◽  
I. Demirkan ◽  
I. Turkmenoglu

This study documents the detailed features of the morphological structure and the innervation areas of the plexus brachialis in the chinchilla (Chinchilla lanigera). The animals (5 female and 5 male) were euthanased with ketamine hydrocloride and xylazine hydrocloride combination, 60 mg/kg and 6 mg/kg, respectively. Skin, muscles and nerves were dissected under a stereo-microscope. The brachial plexus of the chinchilla is formed by rami ventrales of C5-C8, T1 and T2, and possesses a single truncus. The subscapular nerve is formed by the rami of the spinal nerves originating from C6 (one thin ramus) and C7 (one thick and 2 thin rami). These nerves innervate the subscapular and teres minor muscles. The long thoracic nerve, before joining with the brachial plexus, obtains branches from C6 and C7 in 5 cadavers (3 male, 2 female), from C7 in 4 cadavers (2 male, 2 female) and from C6-C8 in only 1 female cadaver. These nerves disperse in variable combinations to form the extrinsic and intrinstic named, nerves of the thoracic limb. An undefined nerve branch originates from the rami ventrales of C7, C8 and T1 spinal nerves enter the coracobrachial muscle.


2015 ◽  
Vol 4 ◽  
pp. 327-342 ◽  
Author(s):  
Paweł Reichert ◽  
Zdzisław Kiełbowicz ◽  
Piotr Dzięgiel ◽  
Bartosz Puła ◽  
Jan Kuryszko ◽  
...  

1979 ◽  
Vol 7 (4) ◽  
pp. 346-349 ◽  
Author(s):  
G. E. Knoblanche

A trial to ascertain the true incidence of inadvertent phrenic nerve block with brachial plexus block via the supraclavicular approach was carried out. Phrenic nerve block was monitored by x-ray screening of the diaphragm. There was an incidence of phrenic nerve block of 67% (10 cases of diaphragmatic paralysis in 15 brachial blocks). The possible causes of phrenic nerve block with brachial block are discussed. It is concluded that the phrenic nerve is blocked peripherally in front of the scalenus anterior.


2016 ◽  
Vol 19 (1) ◽  
pp. 213-215
Author(s):  
P. Reichert ◽  
Z. Kiełbowicz ◽  
J. Kuryszko ◽  
A. Bocheńska ◽  
B. Puła ◽  
...  

Abstract This study presents and evaluates side-to-side nerve repair techniques for their ability to induce collateral nerve sprouting. The coaptation of the ventral branches of spinal nerves C5 and C6 to C7 through an incision epineurium was used to repair the nerve. The number of myelinated fiber axons and G-ratio was evaluated. Preliminary results indicate the possibility of using side to side coaptation in brachial plexus nerve surgery.


1985 ◽  
Vol 13 (01n04) ◽  
pp. 133-143 ◽  
Author(s):  
H.C. Dung

This communication is the fifth in a series of six publications describing acupuncture points by anatomic nomenclature. This article describes acunpuncture points in the lumbar region of the posterior body wall, the inguinal and pelvic regins of the lower abdomen, and the medial surface of the thigh and leg. Acunpuncture points in these regions are generally established by anatomic features of the lumbar spinal nerves. Nerve branches of the posterior primary rami of the lumbar spinal nerves and the lumbar plexus provide the anatomic basis for acunpuncture points in these regions and are used to name the points accordingly.


2001 ◽  
Vol 26 (3) ◽  
pp. 183-191 ◽  
Author(s):  
A. TAVAKKOLIZADEH ◽  
A. SAIFUDDIN ◽  
R. BIRCH

Closed, high-energy transfer traction injuries of the adult brachial plexus lead to rupture or avulsion of the spinal nerves. Accurate preoperative diagnosis is crucial for surgical planning and reconstruction. Myelography, computerised tomographic myelography and magnetic resonance imaging are the main radiological methods for preoperative diagnosis of the lesion. This article reviews the current status of imaging of traction injuries of the adult brachial plexus.


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