Set 2 Flashcards
What is the number of rib pairs in domestic animals and how does rib size relate to number?
18 (19) ribs in the horse 13 ribs in cows, dogs, and cats 15 ribs in pigs 12 ribs pairs in humans and camelids More ribs mean narrower ribs that are more mobile
How do the ribs move in respiration? Relate this to artificial respiration and the gallop.
Cranial/lateral movement on inspiration and caudal/medial movement on expiration.
Since the abdominal viscera acts like a plunger on the diaphragm facilitating expiration, the horse synchronizes its breathing with its gait. When the forelimbs hit the ground the body slows momentarily and the abdominal plunger causes expiration; as the body leaps forward inspiration occurs.
What is the major inspiratory muscle and what is its “antagonist”?
Diaphragm, serratus dorsalis cranialis and abdominal muscles.
While the external abdominal oblique m. is most important, all 4 abdominal muscles (2 obliques, transversus and rectus) act in expiration by means of the "abdominal press" because they all put presure on the abdominal visceral "plunger" and thereby force the diaphragm forward. The serratus dorsalis caudalis was hard to see in the dog but shows well in the horse. However, it is of minor significance compared with the abdominal muscles.
What synovial structure is the basis of fistulous withers? Where is it located?
Fistulous withers is inflammatory disease of the supraspinous bursa caused by either infection or parasites. Supraspinous bursa located between the funicular portion of the nuchal ligament and the dorsal spinous process of the 2nd through 5th thoracic vertebrae.
Compare the depth of the chest in dog, horse and ruminants? Why the difference?
Ruminant > Horse > Dog. The sternum is lower in the horse (than the dog) and more so in the ox, because the deeper the abdomen the deeper the chest. There is a deeper chest in the ruminant to accommodate the massive abdominal viscera.
Where do the intercostal veins drain to?
Azygos vein. It drains the thoracic wall passes cranially around the root of lung. It is only on the right side on the dog, cat, horse and camelid. In the ruminant the right and left azygos are present but the left is larger. In swine there is only a left azygos vein and it drains to the cardiac vein making it good for myocardial sampling.
Define (or locate): mitral valve, tricuspid valve, bicuspid valve, semilunar valves, tracheal bronchus. What is the significance of RAT and LAMB?
The mitral valve is the same thing as the bicuspid valve and it is in the left side of heart. The tricuspid valve is the A-V valve on the right. Your semilunar valves are in your aorta and pulmonary trunk openings. The tracheal bronchus is only in ruminants and pigs. It is a separate bronchus off the trachea that ventilates the right cranial lung lobe.
RAT stands for: Right Atrioventricular Valve is Tricuspid
LAMB stands for: Left Atrioventricular Valve is Mitral/Bicuspid
If you had a choice as a veterinary surgeon of which side to put down in lateral recumbency, what side would you choose with regard to pulmonary function? What side would you choose to correct a PDA (patent ductus arteriosus)? [right lateral recumbency means the right side is down].
Put the right side down ( right lateral recumbency) so there wasn’t so much of the lung weight bearing down on the heart, since the right lung is more extensive and large compared to the left. This is what you would do to correct a patent ductus arteriosus.
The subsinuosal and paraconal interventricular grooves of the heart take their names from what adjacent structures . In other words, what sinus and what cone? Differentiate between; atrium and auricle, pectinate and papillary mm., ductus arteriosus and venosus.
The subsinuosal interventricular groove gets its name from the coronary sinus that is nearby. The paraconal interventrcular groove gets its name from the conus arteriosus: the funneling portion of the right ventricle that leads up into the pulmonary trunk.
Atrium: region of the heart that receives blood and drive it into the ventricle.
Auricle: the small conical pouch that projects from the upper anterior part of each atrium of the heart.
Pectinate muscle: specialized intracardiac muscle mainly in the right atrium that helps the right atrium dilate without much wall stress.
Papillary muscle: the muscle that anchors the heart valves.
Ductus arteriosus: shunts blood from the pulmonary trunk to the aorta.
Ductus venosus: shunt that diverts blood from the sinusoids and toward the systemic veins.
Research veterinarians are often asked to suggest the best species for use as an animal model to study various human health issues. Coronary artery disease is a huge subject for physicians. In that regard, what is the origin of the subsinusoidal artery in dog, ruminant, horse and pig? How does this affect the relative size of the coronary arteries in these species
Origin of subsinusoidal artery in dog and ruminant: Left coronary artery
Origin of subsinusoidal artery in horse and pig: Right coronary artery
How are the flaps of the AV valves named? What prevents prolapse of these valves?
Right AV: septal, parietal, and angular valves.
Left AV: septal and parietal cusps.
The chordae tendinae and papillary muscles prevent the AV valves from prolapsing.
How many veins empty into the sinus venerum of dog, horse, pig and ruminants? What is the crista terminalis and why is it so named?
Sinus venerum is a smooth walled area of the right atrium where blood is received from the vena cava and coronary sinus.
Great and middle cardiac veins in the dog empty into the sinus venerum. Can’t find how many veins empty in for horse, pig, or ruminant.
Crista terminalis: junction between sinus venosus and heart in developing embryo. Also, the vertical crest of the interior wall of the right atrium that lies to the right of the sinus of the vena cava and separates this from the remainder of the right atrium. It is the termination of the cranial vena cava
Sampling of metabolites from the myocardium is a useful tool for study of heart disease. As a lab animal veterinarian, how would you advise a researcher interested in doing this? Which animal model and what route for venous sampling would be most easy to use and why?
The easiest sampling would be in the pig, since their azygous vein on the left drains into the cardiac vein making it useful for myocardial sampling.
What are the meanings of the terms: pluck, sweetbreads, brisket, withers, hilus, carina and os cordis? What is the significance of each?
Pluck: slaughterhouse term for thoracic viscera.
Sweetbreads: thymus and sometimes pancreas
Brisket: enlarged cranial part of ox sternum that holds most of the weight when the ox is in sternal recumbency.
Withers: top of shoulders, highest part of thorax
Hilus: where vessels enter and exit the lung
Carina: where trachea bifurcates into bronchii
Os Cordis: bones caudal to aortic valve in the ox.
What is the significance of the line of pleural reflection?
When doing thoracocentesis the needle tip must be above this line to get fluid out of the pleural cavity. This line of pleural reflection has the boundaries of the 8th or 9th costal chondral junction to middle of the last rib. In the horse this line is less steep due to longer thorax and in the ox the line is steep due to a deeper chest of shorter length.
