Gross Anatomy of the Brachial Plexus in the Giant Anteater (Myrmecophaga tridactyla)

Ten forelimbs of five Myrmecophaga tridactyla were examined to study the anatomy of the brachial plexus. The brachial plexuses of the M. tridactyla observed in the present study were formed by the ventral rami of the last four cervical spinal nerves, C5 through C8, and the first thoracic spinal nerve, T1. These primary roots joined to form two trunks: a cranial trunk comprising ventral rami from C5‐C7 and a caudal trunk receiving ventral rami from C8‐T1. The nerves originated from these trunks and their most constant arrangement were as follows: suprascapular (C5‐C7), subscapular (C5‐C7), cranial pectoral (C5‐C8), caudal pectoral (C8‐T1), axillary (C5‐C7), musculocutaneous (C5‐C7), radial (C5‐T1), median (C5‐T1), ulnar (C5‐T1), thoracodorsal (C5‐C8), lateral thoracic (C7‐T1) and long thoracic (C6‐C7). In general, the brachial plexus in the M. tridactyla is similar to the plexuses in mammals, but the number of rami contributing to the formation of each nerve in the M. tridactyla was found to be larger than those of most mammals. This feature may be related to the very distinctive anatomical specializations of the forelimb of the anteaters.     

Der M. cucullaris beim Amerikanischen Tapir (Tapirus terrestris, L. 1758)

The reexamination of the branchiogenic muscles of the shoulder shows also in the Lowland Tapir, that the dorsal branch of the Ramus ext. of the N. accessorius innervates the three parts of the M. trapezius (Pars clavicularis, cervicalis and thoracalis), and the ventral branch innervates the two parts of the M. sternocleidomastoideus (Pars sternomandibularis and sternomastoidea). There is no Pars cleidomastoidea in the latter muscle. As common name for all muscles innervated by the Ramus ext. of the N. accessorius, the term M. cucullaris is proposed again.     

Mm. Intertransversarii eervicis of the ox (Bos taurus L.)

The cervical intertransverse muscles and their nerve supply are described and illustrated in the ox. The literature is reviewed and the principles of subdividing these muscles are discussed. They are divided into dorsal and ventral intertransversarii according to their innervation. The Mm. intertransversarii dorsales cervicis arise from the articular processes of C7-C3, follow a craniolateral course and insert by means of 1–4 fascicles on the transverse processes of preceding vertebrate including the atlas. They are innervated by the dorsal rami of cervical spinal nerves. The Mm. intertransversarii ventrales cervicis are grouped into medial and lateral parts. The medial part consists of short fascicles which extend between contiguous transverse processes from C7-C2. They are pierced by the emerging ventral branches of the spinal nerves and are innervated by them. The lateral part consists of longer fascicles which follow a dorsocranial course and attach to the ventral tubercles of preceding vertebrae as well as to the wing of the atlas. All ventral intertransverse muscles are innervated by the ventral rami of cervical spinal nerves.     

Anatomical Structure of the Brachial Plexus in the Merlin (Falco columbarius)

This study aimed to document the detailed features of the morphological structure and the innervation areas of the brachial plexus in Merlin (Falco columbarius). The skin and muscles of five adult male Merlins were dissected under the stereo microscope. The Merlin had two plexus trunks. The accessory brachial plexus consisted of ventral rami C10 and C11. C11 was divided into two branches: the cranial and caudal. The brachial plexus was composed of a rather complex network involving the ventral rami of C11‐C13, T1 and T2. In addition, a thin branch from the last two cervical sympathetic nerves participated in the plexus formation. C12, C13 and T1 had rather thick trunk. C12, C13 and T1 were also involved in the formation of the brachial plexus emerging after 1 cm from the foramen inter‐vertebrale as three trunk roots.     

Anatomical Evaluation of the Thoracolumbar Nerves Related to the Transversus Abdominis Plane Block Technique in the Dog

Transversus abdominis plane (TAP) is a fascial plane containing the thoracolumbar nerve branches that innervate the abdominal wall. Limited information is available on the anatomical organization of these nerve branches in the dog, which is of great importance for the success of the TAP block anaesthetic technique. The aim of this study was to describe the origin and conformation of thoracolumbar nerves running through the TAP in 20 hemi‐abdominal walls of 10 adult mongrel dog cadavers with an average body weight of 12.6 kg (range: 9.6‐15.6). The abdominal walls were dissected from superficial to deep direction, the skin and both obliquus externus abdominis and obliquus internus abdominis muscles were dissected and reflected dorsally to expose the transversus abdominis muscle and the thoracolumbar nerve branches located in this plane. The anatomical features of ventral nerve branches were described. The thoracic nerve branches: T7–T12 and costoabdominalis; and the lumbar nerve branches: iliohypogastricus cranialis, iliohypogastricus caudalis, ilioinguinalis and cutaneus femoris lateralis were identified in all the cadavers. Anatomical variations related to the presence or absence within the TAP of the T7, T8 and T9 nerve branches were found. These variations should be taken into account when planning the TAP block technique in dogs.     

Anatomical study of the ventral rami of thoracic spinal nerves in Sapajus apella (Primates: Cebidae)

This study aimed to describe the gross anatomy of the ventral rami of the thoracic spinal nerves in capuchin monkey (Sapajus apella) and compare with humans and other primate species. Eight specimens, prepared in 10% formalin solution and dissected following routine standard techniques, were used. The animals presented 13–14 pairs of thoracic spinal nerves emerging from the intervertebral foramen and divided into dorsal and ventral rami. The ventral rami of the first 12 or 13 pairs represented intercostal nerves and the latter referred to the subcostal nerve. The intercostal and subcostal nerves gave off muscular and cutaneous branches (lateral and ventral), which promote innervation of muscles and skin associated with the chest and abdominal wall. Atypical anatomy was verified for the 1st, 2nd and 7th to 13th intercostal nerves as well as for the subcostal nerve. The morphological characteristics were similar to those observed in humans and some non‐human primates, especially in the absence of collateral branches.     

Spinal Root Origin of the Radial Nerve and Nerves Innervating Shoulder Muscles of the Dog

The ventral spinal root origin of the radial nerve, its muscle branches, and brachial plexus nerves which supply shoulder and thoracic musculature was determined in the dog. Electrophysiological signal averaging techniques measured evoked potential from specific ventral spinal roots to individual muscle nerves. The entire radial nerve received input from the sixth cervical (C6) through the second thoracic (T2) spinal roots. The most significant (p less than .05) input to triceps brachii came from C8 while the deep ramus of the radial nerve received its largest input from C7. The brachiocephalicus, suprascapular, and subscapular nerves all received their most significant (p less than .05) innervation from C6. Approximately 90% of the evoked potential to the axillary nerve originated from C7. The thoracodorsal nerve received most of its innervation from ventral roots C7 and C8. The lateral thoracic nerve which innervates the cutaneous trunci muscle was supplied by ventral roots C8-T2. Examination of innervation patterns suggests that only modest variation of spinal root input to specific nerves occurred between individual dogs.     

The Arterial Supply to the Eye of the Bactrian Camel (Camelus bactrianus)

The arterial supply to the eye of the bactrian camel (Camelus bactrianus) was studied by gross dissection. The supply came from the external ophthalmic, external ethmoidal and malar and maxillary tubercular arteries, ophthalmic rete mirabile, and the rostral epidural rete mirabile. The external ophthalmic artery gave rise to branches to supply the dorsal oblique muscle, lacrimal gland, superior and inferior eyelids, and the lateral angle of the eye, and to take part in the formation of the rostral epidural rete and the ophthalmic rete mirabile. The external ethmoidal artery detached off some branches to supply the ventral and medial dorsal rectus oblique muscles, the conjunctiva of the superior eyelid and the fat body of the orbit. The branches of the malar artery supplied the inferior, superior and third eyelids, ventral oblique muscle, and the medial angle of the eye. The ophthalmic rete mirabile gave off many branches to supply the rectus muscles of the eye, dorsal oblique and retractor oculi muscles, levator muscle of the superior eyelid, and the choroid.     

Die Mm. omotransversarius und sternocleidomastoideus des Esels

The omotransversarius and sternocleidomastoideus muscles in the donkey The donkey has like the horse a M. omotransversarius and a tripartite M. trapezius. Unlike the horse it has both parts of the M. sternocleidomastoideus, i. e. the Pars sternomandibularis and the Pars cleidomastoidea. The latter part is lacking in the horse.     

Ultrasound‐guided approach for axillary brachial plexus,femoral nerve,and sciatic nerve blocks in dogs

Objective To describe an ultrasound‐guided technique and the anatomical basis for three clinically useful nerve blocks in dogs. Study design Prospective experimental trial. Animals Four hound‐cross dogs aged 2 ± 0 years (mean ± SD) weighing 30 ± 5 kg and four Beagles aged 2 ± 0 years and weighing 8.5 ± 0.5 kg. Methods Axillary brachial plexus, femoral, and sciatic combined ultrasound/electrolocation‐guided nerve blocks were performed sequentially and bilaterally using a lidocaine solution mixed with methylene blue. Sciatic nerve blocks were not performed in the hounds. After the blocks, the dogs were euthanatized and each relevant site dissected. Results Axillary brachial plexus block Landmark blood vessels and the roots of the brachial plexus were identified by ultrasound in all eight dogs. Anatomical examination confirmed the relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels. Three roots (C7, C8, and T1) were adequately stained bilaterally in all dogs. Femoral nerve block Landmark blood vessels (femoral artery and femoral vein), the femoral and saphenous nerves and the medial portion of the rectus femoris muscle were identified by ultrasound in all dogs. Anatomical examination confirmed the relationship between the femoral vessels, femoral nerve, and the rectus femoris muscle. The femoral nerves were adequately stained bilaterally in all dogs. Sciatic nerve block. Ultrasound landmarks (semimembranosus muscle, the fascia of the biceps femoris muscle and the sciatic nerve) could be identified in all of the dogs. In the four Beagles, anatomical examination confirmed the relationship between the biceps femoris muscle, the semimembranosus muscle, and the sciatic nerve. In the Beagles, all but one of the sciatic nerves were stained adequately. Conclusions and clinical relevance Ultrasound‐guided needle insertion is an accurate method for depositing local anesthetic for axillary brachial plexus, femoral, and sciatic nerve blocks.     

Respiratory muscle perfusion in ponies during prolonged submaximal exercise in thermoneutral environment.

Distribution of blood flow among various respiratory muscles was examined in 8 healthy ponies during submaximal exercise lasting 30 minutes, using radionuclide labeled 15-microns diameter microspheres injected into the left ventricle. From the resting values (40 +/- 2 beats/min; 37.3 +/- 0.2 C), heart rate and pulmonary arterial blood temperature increased significantly at 5 (152 +/- 8 beats/min; 38.6 +/- 0.2 C), 15 (169 +/- 6 beats/min; 39.8 +/- 0.2 C), and 26 (186 +/- 8 beats/min; 40.8 +/- 0.2 C) minutes of exertion, and the ponies sweated profusely. Mean aortic pressure also increased progressively as exercise duration increased. Blood flow increased significantly with exercise in all respiratory muscles. Among inspiratory muscles, perfusion was greatest in the diaphragm and ventral serratus, compared with external intercostal, dorsal serratus, and scalenus muscles. Among expiratory muscles, blood flow in the internal abdominal oblique muscle was greatest, followed by that in internal intercostal and transverse thoracic muscles, in which the flow values remained similar. The remaining 3 abdominal muscles had similar blood flow, but these values were less than that in the internal intercostal, transverse thoracic, and internal abdominal oblique muscles. Blood flow values for all inspiratory and expiratory muscles remained similar for the 5 and 15 minutes of exertion. However, at 26 minutes, blood flow had increased further in the diaphragm, external intercostal, internal intercostal, transverse thoracic, and the external abdominal oblique muscle as vascular resistance decreased. On the basis of our findings, all respiratory muscles were activated during submaximal exercise and their perfusion had marked heterogeneity.(ABSTRACT TRUNCATED AT 250 WORDS)     

青海高原牦牛肩胛上、下神经和腋神经解剖

本文报道了生活在高寒低氧环境下的青海高原牦牛的肩胛上、下神经和腋神经的起源、位置、行程、分支和分布情况。其主要特征是肩胛上神经、肩胛下神经纤维都来自第６、第７颈神经的腹侧支、其神经的分支支配与牛、水牛、马的基本相同。腋神经纤维来自第７、第８颈神经和第１胸神经,其分支支配三角肌、小圆肌、冈下肌、臂头肌锁臂部以及前臂的筋膜和皮肤     

Microclimate and Animal Life in the Equatorial Mountains

The venom apparatus in both species of Dendroaspis shows great similarity to that described in other proteroglyphs. There is a posterior bulbous portion or main gland and an anterior narrower portion, the accessory gland, that surrounds the secretory duct. The gland is enclosed in a very tough connective tissue capsule. Fibres from the m. adductor externus superficialis insert on the connective tissue capsule on the dorsal aspect of the venom gland. They serve to compress the gland and expel the venom when the snake strikes. Ventrally, fibres of the m. pterygoideus are also inserted on the investing sheath. This muscle supports the gland ventrally and also appears to play some role in venom ejection. The arrangement of the jaw musculature is similar in both species of Dendroaspis. Since the m. adductor externus superficialis is closely associated with the venom gland it has become highly specialized and exhibits great variation among snakes. This muscle in Dendroaspis differs from that in other proteroglyphs in the extension of its origin in a ventral direction over the postorbital bone to the maxilla. As in other elapids, the m. levator anguli oris is absent in both species of Dendroaspis.     

CT measures of osseous cervicothoracic intervertebral foramina are repeatable and associated with CT measures of adjacent articular processes in horses

Narrowing of the equine cervicothoracic intervertebral foramina (IF) has the potential to cause forelimb lameness and/or neck pain although limited information is available on CT of the IF. The aims of this retrospective, analytical study were to describe a protocol for quantifying CT cervicothoracic IF size; evaluate the repeatability of IF size measures; test associations between IF size and adjacent articular process (AP) size, ventral extent, and anatomic location; and determine the proportion of IF with narrowing. Computed tomographic images were acquired in 20 Warmblood horses that presented with forelimb lameness and/or neck pain. All IF between C5 and T2 (n = 160) were evaluated. IF cross-sectional area (CSA), APCSA, and AP ventral extent were measured. The repeatability of IFCSA measurement was calculated. Possible associations between IFCSA and: APCSA, ventral extent, side, or location were assessed. IF narrowing was defined as more than 50% of reduction in IF height when compared with its widest part(s). The repeatability of IFCSA measurement was excellent. There was a significant association between IFCSA and: APCSA (P < 0.001; R² = 0.859; slope = −0.106), ventral extent (P = 0.022; R² = 0.161; slope = −0.0617), and location (P < 0.001; higher values between C7 and T2). The association between IFCSA and ventral extent was small. Narrowing was identified in 61 (38.1%) IF. Maximum degree of narrowing was most common at the cranial (26.3%) and middle (68.8%) third of the IF. Narrowing was not identified at T1-T2. In conclusion, CT cervicothoracic IF size can be measured with excellent repeatability, and associations were found between IF size and: AP size, ventral extent, and location.     

Spinal Nerve Root Origin of the Median, Ulnar and Musculocutaneous Nerves and their Muscle Nerve Branches to the Canine Forelimb

The contribution individual ventral spinal nerve roots made to the canine median nerve, ulnar nerve, musculocutaneous nerve, and their muscle nerve branches was determined electrophysiologically. Each spinal nerve root was sequentially stimulated. Utilizing quantitative signal averaging techniques, the evoked potential was measured at each tested peripheral nerve. Evoked potential to the median nerve originated from the seventh cervical spinal root (C7) through the second thoracic spinal root (T2) with most input from C8 and T1. The ulnar nerve received evoked potential from C7-T2. Although T1 provided the major input to both the median and ulnar nerves, the relative contribution of T1 was greater in the ulnar nerve. The musculocutaneous nerve received input from ventral spinal roots C6-T1 with C6 and C7 providing most of the evoked potential. The ventral spinal roots which supplied the bulk of the evoked potential to a particular muscle nerve were consistent between individual dogs. Variation of evoked potential input was greatest from spinal roots which supplied less than 10% of the total potential.     

Innervation of the wing membrane in the bent-winged bat Miniopterus fuliginosus

The nerves that innervate the fingertips and wing membrane from the upper arm of the bent-winged bat Miniopterus fuliginosus were examined under a stereomicroscope. The radial, median, ulnar and musculocutaneous nerves were formed by the brachial plexus, which ran to the wing membrane. The two suspected axillary nerves ran to the wing membrane. The radial nerve ran to the end of the first digit, while the median nerve ran along the forearm and subsequently branched-off to run along the second to fifth digits up to the end of the phalanges. The ulnar nerve ran to the plagiopatagium on the extensor side of the elbow joint. Finally, the musculocutaneous nerve passed through the ventral side of the humerus and branched out at the elbow joint to run radially to the propatagium area. In this study, the visible nerves that were distributed from the upper arm to the fingertips of Miniopterus fuliginosus were formed by C6–T1.