✎✎✎ Biological Characteristics Of Hawksbill Birds

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Biological Characteristics Of Hawksbill Birds

A notch occurs in each side of the upper jaw and Biological Characteristics Of Hawksbill Birds limbs lack claws. The settlement of Australia by Indigenous Biological Characteristics Of Hawksbill Birds between 48, and 70, years ago Biological Characteristics Of Hawksbill Birds [4] and by Europeans fromhas significantly affected the fauna. Part of the atlas ventral Biological Characteristics Of Hawksbill Birds vertebra 1 is resting on the occipital part Biological Characteristics Of Hawksbill Birds the skull, posterior to The Importance Of Captive Whales hyoid apparatus. The lungs are located dorsally and are attached Biological Characteristics Of Hawksbill Birds the carapace and vertebral column Fig. Dear Reader, please register to read gulfnews. It is a complex environment with Biological Characteristics Of Hawksbill Birds biodiversity Steroid In Baseball Biological Characteristics Of Hawksbill Birds various primitive horseshoe Middle School Leader to Biological Characteristics Of Hawksbill Birds advanced organisms dolphins.

What is a Hawksbill Turtle?

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This website stores cookies on your computer. These cookies are used to improve your experience and provide more personalized service to you. Both on your website and other media. To find out more about the cookies and data we use, please check out our Privacy Policy. Share on Facebook. Share on Twitter. The distal parts of the flippers are cut off by the field of view in this CT image. The plastron is composed of 9 bones that are separate in hatchlings but become fused in older turtles. The distinct shape of the entoplastron bones may serve as a key characteristic to distinguish some cheloniid species.

The bone is roughly Tshaped in hawksbills and the shaft narrows abruptly. It is arrow-shaped in green turtles; wide anteriorly with a shaft that narrows gradually. The overall shape isalmost dagger-like in the Kemp's ridley as the shaft narrows gradually. The bone is cruciform in loggerheads; the lateral processes are distinct and the shaft tapers along its posterior half. The entoplastron has not been described diagnostically for the olive ridley. Entoplastron bones change shape during ontogeny, hence it is recommended that this characteristic be used only in adults.

In Dermochelys there is no hypertrophy of bone between the ribs of the carapace. The bony carapace remains composed solely of an expanded nuchal, ribs, and vertebrae. Ventrally, the plastron is composed of aring of reduced plastron bones. No entoplastron is present. The anterior appendicular skeleton includes the flippers and pectoral girdles. The pectoral girdle, left to right in ventral, posterior, and anterior views, is composed of two bones and 3 parts that serve as a major site for attachment of the swimming musculature. The acromion process extends medially from the ventral part of the scapula. The coracoid a ventral bone, is flat and wide distally. The shoulder joint glenoid fossa , is formed by the coracoid and the scapula.

After Wyneken, Skeletons of flippers left and right shown in dorsal view. Note the flat wide wrist and the elongated digits that form the flipper blade. Ventrolaterally it forms part of the shoulder joint, the glenoid fossa Fig. The acromion processes extend medially from each scapula to articulate with the entoplastron via ligaments. The coracoids form the remainder of the glenoid fossa and then extend posterior medially. Each terminates in a crescentshaped coracoid cartilage. The acromialcoracoid ligament extends from the acromion to the coracoid. The majority of the flipper retractor and abductor muscles attach to the coracoid processes and the acromialcoracoid ligaments. The forelimb is composed of the humerus radius and ulna, carpals, metacarpals, and 5 phalanges Figs.

The flipper blade is formed by widening and flattening of the wrist bones and elongation of the digits Fig. There is a large bony medial process extending beyond the humeral head to which flipper abductor and extensor muscles attach Fig. Distal to the head and almost diagonally opposite is the lateral process or deltoid crest to which attach flipper protractor muscles Figs. In Dermochelys, the humerus is extremely flattened.

It is composed primarily of cancellous bone, relatively little cortical lamellar bone, and with thick vascular cartilage on its articular surfaces Figs. In prepared skeletons, the cartilage is often lost. The extensive vascular channels in the cartilage are indicative of chondro-osseus bone formation Fig. This is unlike the cheloniid bone, which is formed by deposition of relatively thick layers lamellae of cortical bone around a cellular bony core cancellous bone; Fig.

The flipper Fig. The radius and ulna are short in sea turtles and, in adults, functionally fused by fibrous connective tissue. Dorsal view of a leatherback flipper. The cheloniid humerus is distinctive in its form with a slightly offset head and enlarged medial process. Almost opposite the medial process and just distal to the head is a U-shaped lateral process deltoid crest to which attaches the major ventral swimming muscles. Ventral view of the leatherback flipper. The articulated forelimbs of this leatherback shows some of the extensive cartilages at the bone ends and the extreme elongation of the digits.

The large humerus has an almost primitive form with its flattened profile and extended medial process. The head and distal articulations to the radius and ulna are largely cartilaginous. The two ilia are oriented dorsoventrally, articulate with the sacral vertebrae, and attach the pelvis to the carapace via ligaments. All 3 bones form the acetabulum hip socket on each side. They are separate bones joined by cartilage in hatchlings but quickly ossify and fuse to form a single structure in older turtles.

The pelvic bones of the leatherback, however, remain connected by cartilage throughout life Fig. This loggerhead pelvis, dorsal view, shows the 3 bones fused pubis, ischium, and ilium that form each side. The epipubic cartilages that would form the anterior edge of the pelvis in life are missing from this preparation. The ilia articulate with the sacral vertebrae and carapace. Anterior is toward the bottom of the picture. Chondro-osseus bone formation. Vascular channels are seen in this cut end of a leatherback humerus. Longitudinal sections through humerii. The loggerhead humerus top has relatively more lamellar bone light color than in the leatherback humerus bottom. The lamellar bone is deposited in layers in some cheloniid species and populations; in others, layers are not distinct.

The femur has a relatively straight shaft with a strongly offset head. There are major and minor trochanters distal to the head Fig. The distal femur articulates with the tibia and fibula. The short ankle consists of the calcaneum, astragalus, and distal tarsals There are five digits. The 1st and 5th metatarsals are wide and flat and the phalanges are extended adding breadth to the distal hind limb area Figs.

Left and right femurs anterior view left immature turtle, posterior view right mature turtle. The femur, an hour glass-shaped bone, has an offset head. The trochanters become more pronounced as the turtles age. The pelvis of the leatherback is composed of both bone and cartilage throughout life. Hence, skeletal preparations of the pelvis usually result in 3 pairs of bones which do not retain their spatial relationships.

Dorsal view of a leatherback hind limb. The articulated hind limb shows the extensive cartilages between bones that are typical of the leatherback skeleton. The hind foot is wide and the digits somewhat elongated. Digits are designated by numbers, with I being the digit on the tibial side and V on the fibular side. Ventral view of the leatherback hind limb. The femur is the bony element of the thigh, the tibia and fibula are the bony elements of the shank. The ends of these bones are cartilaginous. The ankle is somewhat flattened and laterally expanded, resulting in wide placement of the digits. This architecture contributes to the rudder-shape of the hind limb. Muscles originate and insert via tendons. The origin of a muscle is its fixed point while the insertion is typically the point that it moves.

Muscles can attach via their tendons to bones, muscles, skin or eyes. Where known, the innervations of the muscles are reported. For reading ease, the designation of M. Names and key concepts are given in bold the first time the muscle is discussed. Muscle functions are described with each figure. As they apply to sea turtles, these functions are as follows. Flexion bends one part relative to another at a joint; extension straightens those parts. Protraction moves one part usually a limb out and forward; retraction moves that part in and back.

Abduction moves a part away from the ventral surface; adduction brings the part toward the body's ventral surface. Rotation turns a structure. Depressor muscles open a special form of abduction a structure, jaws in this case, while levators close jaws a kind of adduction. Muscle groups. The muscles described here are the major or large muscles detailed discussion of most muscles can be found in the primary literature. For convenience, muscles are grouped by region; axial muscles, include the head muscles; ventral muscles include both proximal pectoral and pelvic muscles that are associated with the plastron; forelimb and respiratory muscles are those found on the flippers, carapace, and scapula involved in flipper movements and breathing.

Posterior muscles are the large muscles of the hip, thigh, and lower leg. Muscles of the flipper blade and hind foot are not discussed or illustrated in detail here because they are obscured by extensive connective tissue and are difficult for most to identify, even with special dissection equipment and techniques. Ventral Muscles. The massive ventral musculature is found after removing the plastron Fig. This musculature is dominated by a superficial muscle, the pectoralis major which originates on the plastron and inserts on the lateral process and shaft of the humerus.

Anterior to the pectoralis and ventral to the acromion processes are two muscles: the deltoideus ventral part , which originates on the ventral scapula, acromion, and anterior plastron bones and the supracoracoideus, which has several subdivisions. Its anterior part originates on the acromion Figs. Both the deltoideus and the anterior part of the supracoracoideus insert on the lateral process of the humerus. These 3 ventral muscles function in swimming and respiration by movement of the shoulders and plastron. Their innervations are via the supracoracoid nerve from the ventral portion of the brachial plexus see Nervous System, Figs.

After removing the pectoralis major, deep locomotor muscles are found associated with the pectoral girdle Figs. The biceps brachii has several subdivisions, or heads, in sea turtles. The superficial head Figs. Innervation is via the inferior brachial flexor and median nerves. The coracobrachialis magnus originates on the dorsal side of coracoid process and inserts on the medial process of the humerus. The posterior part of the supracoracoideus Fig. These muscles are innervated by the supracoracoid nerve. There is an extensive series of arteries and veins running within and between these very active muscles Fig. A pair of superficial posterior muscles, the left and right rectus abdominis Fig. Each originates on the lateral pubis and inserts on the plastron.

They stabilize the pelvis and may function in compressing the plastron during breathing. Superficial ventral muscles of the pectoral and pelvic girdles. The large pectoralis major is a forelimb retractor and adductor. Both the deltoideus and the supracoracoideus protract and abduct the humerus. The rectus abdominus is a pelvic stabilizer. The deep pectoral muscles are exposed after removal of the pectoralis major. These forelimb retractors, separated on the animal's left right in picture , are the biceps brachii superficialis and coracobrachialis magnus. The posterior part of the supracoracoideus both adducts and retracts the flipper. Diagrams of cheloniid right shoulder muscles including locomotor and respiratory muscles. Superficial ventral muscles top left , deep ventral muscles bottom left , posterior muscles bottom right , and lateral muscles top right.

The extensor digitorum, extensor radialis intermedius, tractor radii, and flexor carpi all control the extension and flexion of the flipper blade. After Wyneken, brachialis inf. The deep pectoral muscles of the animal's right side are shown in detail. The supracoracoideus has two parts: posterior, which protracts and anterior, which retracts the forelimb. The latissimus dorsi and teres major together originate on the scapula and the carapace from the attachment point of the scapula, along the first pleural bone to the anterior peripheral bones.

They insert via a common tendon just distal to the head of the humerus. The scapular head of the deltoideus arises from the anterior scapula and inserts on the lateral process and shaft of the humerus. The subscapularis muscle is very large, originates on the medial and posterior scapula, and inserts on the large medial process and the shaft of the humerus. These muscles are innervated by the deltoid nerve a branch of the brachial plexus. There are two sheet-like respiratory muscles located dorsally, which are often destroyed when removing the pectoral girdles Figs.

These are the testocoracoideus origin: carapace near the anterior inframarginals; insertion: dorsal coracoid and testoscapularis origin: carapace posterior to the latissimus dorsi; insertion: dorsal scapula and the scapular attachment to the carapace. They are innervated by cervical spinal nerves. The humeral head arises from the humerus, and the scapular head arises from the scapula.

Both converge to form a common tendon inserting on the proximal ulna. This muscle may have only a humeral head in Dermochelys The triceps is innervated by the superficial radial nerve a branch from the superior brachial nerve of the brachial plexus. Ventral pectoral muscles with arteries and veins. The pectoral artery is found running along the deep muscles of the shoulder. The testoscapularis, a respiratory muscle, is deep to the pectoralis. Other pectoral muscles originating on the coracoid are reflected medially to the right in this picture.

Superficial dorsal forelimb muscles right. The two heads of the triceps brachii, triceps scapular head and triceps humeral head are forelimb adductors, which twist the flipper. The more medial biceps and flexor carpi ulnaris muscles flex the flipper blade. The extensor digitorum muscle becomes diffuse in adults as fibrous connective tissue stiffens the flipper blade. Young turtles can extend the digits, somewhat mature turtles cannot. Ventral forelimb muscles right. Most of the ventral muscles flex the flipper blade relative to the upper arm. The extensor radialis extends the flipper.

The scapular head of the triceps may twist the flipper blade along its axis, or abduct the forearm. Dorsal forelimb muscles of an immature hawksbill. In young animals, the muscle divisions of the forearm and the flipper, particularly, are more obvious than in older animals. Less connective tissue is present and the digits can flex and extend to a limited extent. Dorsal view of the pectoral musculature. The carapace, skin and fat have been removed from left. The head, cut cervical vertebra, and scapular ends provide landmarks for orientation. The latissimus dorsi, a large sheet-like muscle, is shown intact animal's right and cut animal's left.

It, plus the teres major and deltoideus scapular head, not shown , abduct and sometimes protract the flipper. The large subscapularis is a strong flipper protractor. The coracobrachialis, a ventral muscle, is seen extending from the shoulder posteriorly, toward its origin, the coracoid. When two heads are present, the biceps superficialis arises from the coracoid and inserts on the pisiform of the wrist. The muscle has two bellies in series, with a short tendon in the middle. The second and most prominent head, the biceps profundus also originates on the posterior coracoid, but ventral to the biceps superficialis and inserts via a tendon with the brachialis on the ulna Fig.

In Dermochelys and Lepidochelys often there is just a single head inserting on the radius and ulna. The pectoral muscles of the left shoulder, arm and flipper. The large subscapularis covers most of the scapula. The large coracobrachialis is seen ventrally, covering much of the coracoid. The biceps muscle has one or two heads varying among species and among individuals. The biceps superficialis extends from the shoulder mostly the coracoid to the pisiform bone of the wrist, and probably helps control the twist or rotation of the flipper blade.

The biceps profundus seen only as a partial separation here acts as a flipper retractor and a flexor of the flipper blade at the elbow. Most axial muscles are associated with the neck and tail of sea turtles. The majority of the neck muscles are illustrated with the neck circulation Figs. These include the transverse cervical muscles, and the biventer cervical muscle. Here, the superficial muscles of the throat and the jaw muscles are described. The tail musculature is not discussed because it has not been studied in any detail. The major deep muscles of the neck are the longus colli and retrahens colli The longus colli muscles are short, segmentally arranged, and travel obliquely between successive cervical vertebrae; they serve to extend the neck.

The retrahens colli originate on the cervical vertebrae and extend posteriorly to insert on the dorsal vertebral elements of the carapace. They are neck flexors and retractors, to the extent that marine turtles extend and retract the neck. Head Muscles. Just beneath the skin of the throat is a thin layer of muscle, the intermandibularis which has fibers running between the two dentary bones. It inserts on a flat midline tendon raphe that runs the length of the throat Fig. The intermandibularis becomes the constrictor colli posterior to the jaw joint Fig. Just deep to the intermandibularis are muscles running obliquely between the jaws and inserting on the hyoid, the geniohyoideus Posterior to the geniohyoideus is a pair of strap-like muscles, the coracohyoideus that extend to the hyoid apparatus from the coracoid Figs.

These muscles assist in depressing the jaw, swallowing, and pumping the throat gular flutter. They are innervated by the facial nerve. Muscles of the tongue, innervated by the hypoglossal nerve, and the glossopharyngeal nerve are not described here. The jaw muscles of turtles are mostly located inside the skull. Because of these deep positions, most are described but not illustrated. Unlike mammals, turtles lack a mandibularis muscle; instead they have an adductor mandibulae with several heads. The heads originate on the parietal, supraoccipital, quadrate, prootic, and opisthotic bones Fig.

Medial to the adductor mandibulae complex is a pair of connected muscles. The intermandibularismuscle runs from the lower jaw to the tendon of the pseudotemporalis muscle which itself continues to the parietal bone. These jaw closing muscles are all innervated by the trigeminal nerve The jaws Fig. Ventral and superficial neck muscles. The constrictor colli muscle of the ventral neck is exposed lateral to and overlying the trachea. The midline raphe tendon is visible along the anterior half of the muscle. Dissection of the ventral neck muscles, showing the deep muscles right in picture and superficial muscles left. The parallel fibers of the intermandibularis arise from the lower jaw, and terminate in the cut raphe found overlying the hyoid body and anterior trachea.

The coracohyoideus travels along the trachea to the hyoid. The carotid artery lies deep to these muscles. The depressor mandibulae arises from the quadrate, quadratojugal, and squamosal bones and inserts on the articular of the lower jaw; in Dermochelys a portion also inserts on the auditory tube. These parts are innervated by the facial nerve. This oblique axial section through the neck of a hawksbill, is just posterior to the jaw joint ventrally and supraoccipital crest dorsally.

The muscles, major blood vessels, trachea, and esophagus can be identified. Their relative positions and extent are seen in this dissection. The major posterior muscles can be identified after removing the rectus abdominus and the skin covering the hind legs and tail. Ventrally, these are the puboischiofemoralis externus and internus the pubotibialis ,the flexor tibialis complex and the ambiens Figs. The puboischiofemoralis externus, a thigh adductor, covers much of the ventral pelvis, and arises from the ventral pubis, ischium, and membrane covering the thyroid fenestrae Fig. Different parts of this muscle can either protract or retract the leg. The puboishiofemoralis internus is large in cheloniids and has both superficial and deep components.

It may be absent in Dermochelys and replaced in function and position by the iliofemoralis When present, it originates on the dorsolateral pubis, ilium, and the sacral vertebrae. It inserts on the femur's major trochanter. The pubotibialis part of the flexor tibialis complex, is found in cheloniids but is absent in Dermochelys This muscle originates on the pubic symphysis and lateral pubis; it inserts on the tibia with the flexor tibialis internus The flexor tibialis internus, a Yshaped muscle, originates on the sacral and postsacral vertebrae dorsally, and ventrally on the pelvic symphysis and lateral pubis.

It passes distally and wraps around the gastrocnemius muscle to insert on the tibia. The flexor tibialis externus has two heads Figs. The dorsal head arises from the ilium and the ventral head from the posterior ischium. Both converge to insert, via a single tendon, on the tibia and the gastrocnemius muscle of the shank; some fibers insert on the skin and connective tissues of the shank. The adductor femoris Fig. The ischiotrochantericus not shown , a leg retractor, originates on the anterior pubis and pubic symphysis. It inserts on the major trochanter of the femur. The dorsal hip and thigh muscles illustrated in Circulatory Anatomy; Figs.

The iliotibialis originates on the dorsal ilium and inserts with the ambiens on the patellar tendon. Deep to these two muscles, the femorotibialis see Nervous System, Fig. The peroneal and femoral nerves of the sacral plexus innervate most of these dorsal hip muscles. The hind foot extensors Fig. They flex the lower leg or extend the digits. Anterior and dorsal foot extensors of a loggerhead right hind limb. The leg is abducted and flexed at the knee. The foot extensors flex the lower leg or extend and spread the digits. The superficial ventral hip muscles. The puboischiofemoralis externus is an adductor of the leg. The puboishiofemoralis internus the anterior ventral portion is seen here is a protractor and abductor of the leg.

The flexor tibialis complex, including the pubotibialis, flexes and retracts the leg and controls the shape of the trailing edge of the foot, perhaps during steering. More anteriorly, the ambiens is a weak adductor and protractor of the hind leg and can extend the shank. The deeper ventral hip muscles are shown after removing the superficial limb retractors. The adductor femoris and puboishiofemoralis internus are antagonistic muscles, with the former adducting the thigh and the later abducting it.

The heart is multichambered and serves as the main pump. Arteries have thick walls of muscles and elastic fibers; they carry blood away from the heart. Veins carry blood to the heart; they have thinner layers of muscle and elastic tissues and tend to collapse in dead animals. Most veins contain valves. The lymphatic vessels transport tissue fluid from outside the circulatory system back to the blood.

The lymphatic vessels are very thin walled and difficult to photograph. They surround the arteries and veins like sheaths. The heart is located within the pericardium and bordered ventrally by the acromion and coracoid processes Figs. Dorsally it is bordered by the lungs and laterally by the lobes of the liver. Within the pericardial sac, the heart is bathed with clear, colorless to slightly yellow pericardial fluid. All turtle hearts have four parts or chambers Fig. These three ventricular compartments are separated only partially from one another.

The posterior part of the pericardium and ventricle apex are attached to the peritoneum by the gubernaculum cordis Fig. This structure anchors the heart during ventricular contraction. Ventral heart. The heart is exposed after removing the pericardium. The more dorsal sinus venosus is not visible. Both aortas turn dorsally and are obscured partially by the brachiocephalic trunk. The pulmonary arteries arise from a common base, the pulmonary trunk. The abdominal veins from the posterior muscles are exposed posterior to the heart.

Landmarks for location of the heart after removal of the plastron. The two acromion processes and acromialcoracoid ligaments frame the pericardium ventrally. When the plastron is removed carefully, the paired abdominal veins are preserved. They drain the ventral pelvic muscles; blood flows anteriorly returning toward the two lobes of the liver. View c shows a close-up of the heart after removal of the ventral pericardium. Arising from the anterior and ventral part of the heart are the great vessels: two aortas and a pulmonary trunk Fig.

The right aorta supplies blood to the head, limbs, and lower body, the left aorta to the viscera. The pulmonary trunk divides into the right and left pulmonary arteries taking the blood to the right and left lungs, respectively. The branches of the major vessels are good landmarks for locating organs and hence can serve like a map to locate specific structures. The right aorta gives off a branch right away called the brachiocephalic trunk and then continues posteriorly to the lower body where it joins the left aorta.

The brachiocephalic trunk bifurcates; each branch produces a small thyroid artery to the thyroid gland anteromedially Fig. The branches of the brachiocephalic continue laterally as subclavian arteries Figs. The brachiocephalic trunk acts as a landmark for locating the thyroid and thymus glands Glands; Figs. The four chambers of the heart can be identified in this ventral view. The ventral pericardium has been trimmed away to show both the heart and its great vessels. The apex of the ventricle is anchored to the pericardium and peritoneum posteriorly. The venous drainage from the anterior body to the precaval veins can just be seen lateral and anterior to the left atrium.

Anterodorsal view of the heart and its major arteries. The great vessels emerge as three large vessels. The right aorta gives rise to the brachiocephalic trunk before it bends posteriorly. The thyroid arteries arise from the brachiocephalic trunk shortly after it bifurcates, or, in this case, from the carotid arteries. It then gives rise to the left and right subclavian arteries. The right carotid is not dissected free of its connective tissue. The carotid arteries Figs. The carotids often termed common carotids supply blood to the head. They bifurcate near the skull to form the external and internal carotid arteries. The ventral cervical arteries travel anteriorly then bifurcate to supply branches to the esophagus.

The subclavian arteries continue laterally towards the flippers; near the junction of the scapula and coracoid they become the axillary arteries. There, branches to the scapular musculature arise anterior subscapular artery. The axillary artery gives off both a branch to the carapace just prior to entering the forelimb, the marginocostal artery which travels posteriorly along the lateral aspect of the shell, and a branch to the ventral pectoral muscles, the pectoral artery Fig. As the axillary artery crosses the humerus, it becomes the brachial artery supplying radial, ulnar, then distally the digital arteries of the flipper. Major arteries, ventral view. The major arteries are shown diagrammatically. Some subdivisions are not labeled for diagram clarity. These include the ventral cervical, axillary, anterior scapular, pectoral, anterior pancreaticoduodenal, and haemorrhoidal arteries.

The major arterial and venous paths are summarized diagrammatically in Figs. These diagrams show the most common routes taken by vessels. However, the circulatory system is among the most variable of all organ systems and hence, sometimes vessels branch in unique and unexpected manners. Major veins, ventral view. Note that all branches are not shown or labeled to minimize diagram complexity. These include the azygos, transverse and central vertebral, eosophageal, hepatic, pectoral, pericardial, vesicular, pelvic, lipoidal, hypogastric, gastric, anterior and posterior pancreatic, mesenteric, common mesenteric, and inferior mesenteric.

This lateral view of a green turtle has all superficial neck muscles cut and reflected dorsally. The arteries and veins were injected with latex to provide contrast. The carotid artery at arrow is deep and lies adjacent to the longus colli muscles of the cervical vertebrae. The left aorta, the middle of the three great vessels, turns dorsolaterally and passes the level of the stomach before producing three branches: the gastric artery the coeliac artery and the superior mesenteric artery The gastric artery bifurcates quickly and sends branches to the greater lateral aspect and lesser medial aspect curvatures of the stomach Figs.

The coeliac artery branches shortly after leaving the left aorta and forms the anterior pancreaticoduodenal artery to the pancreas, duodenum and stomach and the posterior pancreaticoduodenal artery to the distal pancreas, duodenum, liver, and gallbladder Fig. The superior or anterior mesenteric artery gives off many branches that fan out through the intestinal mesenteries and supply the small intestines. After giving off the superior mesenteric artery, the left aorta continues posteriorly where it joins the right aorta typically to form a single dorsal aorta. The position where the two join is variable, but generally is within the middle third of the body. The ventral view of the left aorta and its major branches in a loggerhead after removal of the heart and viscera.

The right aorta joins the left aorta very early in this loggerhead, just posterior to the origin of the superior mesenteric artery. Circulation of the stomach. The ventral gastric artery drains to the lesser curvature of the stomach. It becomes the pyloric artery at the level of the pyloric sphincter. Arteries and veins of the stomach, pancreas, and duodenum. The dorsal gastric artery drains to the greater curvature of the stomach.

The coeliac artery, the second artery arising from the left aorta, supplies these branches to the duodenum, the stomach near the pyloris, and to the pancreas. A pair of epigastric arteries branches off the dorsal aorta at the level of the kidneys; they travel laterally to join the marginocostal artery of the carapace. Right external jugular vein with vertebral branches scapula esophagus caudal artery renal arteries right kidney left kidney adrenals dorsal aorta costal artery left lung right lung right aorta left aorta Figs. The carapace has been removed from this green turtle and the arteries injected with latex. The right and left aortas join along the middle third of the body.

Costal intercostal branches extend anteriorly and across the body. Branches to the gonads, adrenals, kidneys, and hind limbs arise, then the caudal artery continues posteriorly along the midline to the tail and cloaca. This animal was missing its right hind limb. The carapace has been removed from this green turtle. The arteries are injected with latex to show the arterial branches to the gonads, adrenal glands, and kidneys.

Variability is common in the circulatory system and is shown here. In this animal, the right gonadal artery is long and crosses dorsal and to the right adrenal gland, rather than extending lateral or anterior to it. There are 3 asymmetric rather than symmetric pairs of renal arteries supplying the kidneys. The epigastric arteries do not arise in the typical manner from the dorsal aorta, but instead from the left common iliac. The common iliacs continue as the external iliacs then divide to form the femoral and sciatic arteries. The internal iliacs arise directly from the dorsal aorta, in this case, turn ventrally, and supply blood to the bladder and large intestine.

The caudal vertebral artery continues posteriorly along the midline. The external iliac supplies the femoral and sciatic arteries to the hind leg Fig. The internal iliac provides branches to the bladder and gonadal ducts, and the haemorrhoidal artery to the large intestine. The dorsal aorta then extends to the tail as the vertebral caudal artery Figs. Dating Tips. Register Login Language: English en. Register to contact people from your country living in Germany just like you! Dating site for Expats in Germany Finding love is a challenging quest even in your home country. Online dating guide for expats Living in Germany is an incredible opportunity to rediscover and reinvent yourself, including the romantic side of your life.

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There is just one dermochelyid species, the leatherback, Dermochelys coriacea Figs. Lateral view of the cervical vertebrae from an Biological Characteristics Of Hawksbill Birds green turtle. These protected areas include national parks and other Biological Characteristics Of Hawksbill Birds, as well as 64 wetlands registered Essay On Friendship In John Steinbecks Of Mice And Men the Biological Characteristics Of Hawksbill Birds Convention and 16 Biological Characteristics Of Hawksbill Birds Heritage Sites. Parkville, Vic. The carotids often termed common carotids supply Biological Characteristics Of Hawksbill Birds to the head. Credit: Trout Unlimited. Ventral Muscles.