aortic nerve(redirected from Cyon nerve)
a branch of the vagus that ends in the aortic arch and base of the heart; composed entirely of afferent fibers; its stimulation elicits a brainstem reflex that slows the heart, dilates the peripheral vessels, and lowers blood pressure.
Cyon,Elie de, Russian physiologist, 1843-1912.
Cyon nerve - a branch of the vagus that ends in the aortic arch and base of the heart. Synonym(s): aortic nerve
Ludwig,Karl F.W., German anatomist and physiologist, 1816-1895.
depressor nerve of Ludwig - Synonym(s): Ludwig nerve
Ludwig ganglion - a small collection of parasympathetic nerve cells in the interatrial septum.
Ludwig labyrinth - proximal and distal convoluted tubules and the associated renal corpuscles supplied by branches of the interlobular arteries. Synonym(s): convoluted part of kidney lobule
Ludwig nerve - a branch of the vagus which ends in the aortic arch and base of the heart. Synonym(s): aortic nerve; depressor nerve of Ludwig
Ludwig stromuhr - one of the first devices for measuring flow in blood vessels.
pertaining to or emanating from the aorta. See also aortic arch.
occurs most often in dogs, where it is caused by Spirocerca lupi larvae, turkeys and primates, causing dyspnea, cyanosis and coughing. May be congenital affecting the aortic trunk and the arch sometimes associated with aneurysm of an aortic sinus. See also copper nutritional deficiency.
aortic aneurysm, inherited
see inherited aortic aneurysm.
aortic annulus fibrosus
the fibrous ring in the wall of the root of the aorta. In the bovine heart the ring carries the ossa cordis (see os2 cordis).
aortic base rupture
rupture of the vessel just above the semilunar valves.
small neurovascular structures on either side of the aorta in the region of the aortic arch. The left body is located at the angle between the left subclavian artery and the aorta, and the right at the junction of the right subclavian and right common carotid arteries. They contain chemical receptors which send impulses through the afferent branches of the vagus nerve and are involved in regulating respiration so as to ensure an appropriate partial pressure of oxygen in the arterial blood.
aortic body tumors
single or multiple nodules within the pericardial sac near the base of the heart. Malignant tumors may invade the anterior mediastinum. Called also heart base tumor.
the dilated part of the aorta at its origin, caused by the swellings of the aortic sinuses.
constriction of the aorta at the site of entry of the ductus arteriosus causing a syndrome similar to that of stenosis of the aortic valve.
aortic cystic medionecrosis
pools of ground substance within the elastic media of the aorta. May predispose to arterial aneurysm but this material is present in the aortas of normal horses.
aortic depressor nerve
pressure receptors in the aortic arch and thoracic aorta which assist in maintaining circulatory equilibrium by communicating pressure changes through the aortic depressor nerve, an afferent branch of the vagus nerve; stimulation causes heart slowing and vasodilation.
the aorta receives blood from the right ventricle. There are a number of variations of the basic defect. The common one is the aorta overriding the septum, which is defective, so that the aorta receives blood from both ventricles. The clinical syndrome includes dyspnea and cyanosis from birth, usually with a loud systolic murmur. Affected animals are not viable.
occurs in cats in association with feline cardiomyopathy and rarely in dogs. Acute pain with paresis to paralysis in the hindlegs, cold, cyanotic feet and no femoral pulse are signs of the condition.
an opening in the diaphragm through which the aorta, thoracic duct, the right and/or left azygos veins pass.
see iliac artery thrombosis.
is one of the early lesions in poisoning by plants that induce mineralization of tissues, e.g. solanummalacoxylon. In combination with lesions in the myocardium causes a syndrome of congestive heart failure.
see cardiac depressor nerve.
the aorta is easily palpable per rectum in cattle and horses; valuable as a clinical sign only in cases of thrombosis at the bifurcation; incision at this point has been used as a means of euthanasia in an emergency.
an anomaly of the aorta in which there is an opening between the ascending portion of the aorta and the pulmonary artery; clinical signs are similar to those of patent ductus arteriosus, but surgical correction is much more difficult.
see valvular regurgitation.
the part of the aorta attached to the atrioventricular fibrous rings and myocardium.
1. in horses is caused by weakening of the wall of the aorta by migrating strongyle larvae. In cattle the cause may be onchocerciasis, in pigs experimental diets deficient in copper. Sudden death results from cardiac tamponade or dissecting aneurysm into the ventricular muscle.
2. sudden death in growing turkeys due to dissecting aneurysmal rupture of the aorta and death due to internal hemorrhage; the cause is unknown. Copper deficiency is suspected as a cause in several animal species.
the merged ventral aortae of the embryo which supplies blood to the aortic arches.
aortic septal defect
a congenital anomaly in which there is abnormal communication between the ascending aorta and the pulmonary artery just above the semilunar valves.
the three pouch-like dilatations of the aortic bulb which carry the cusps of the aortic valve. The coronary arteries arise from the left caudal and the cranial sinuses.
aortic subvalvular stenosis
in dogs and pigs is possibly an inherited defect. Characterized by stenosis of the aorta just below the semilunar valves. In pigs, it causes congestive heart failure in the newborn, but in affected dogs severity increases with age so that clinical effects may not be apparent until the patients are older.
the valve at the entrance to the aorta from the left ventricle made up of three semilunar leaflets or valvulae.
aortic valve rupture
rupture of the medial cusp is recorded as a cause of sudden death in horses usually as a sequel to endocarditis.
aortic valvular disease
stenosis is rarely an acquired disorder, but may be an inherited defect in several species. In cats and rarely dogs, restrictive cardiomyopathy may be a cause of subvalvular aortic obstruction. Valvular incompetence may be congenital or acquired and results in diastolic overloading of the left ventricle with a characteristic water-hammer pulse and diastolic murmur. See also aortic stenosis, aortic subvalvular stenosis (above).
the cranial part of the left ventricular cavity leading to the root of the aorta in the avian heart.