Heart Structure Flashcards
What are the components of the fish circulation
Dorsal and ventral aorta External and internal carotids Swim bladder, lungs Gills 6 gill arches (wipe out 2,2,5 arches and dorsal 3-4 branch to get same system as mammals)
What are the schematic cross sectional shapes of the RV and LV
Right ventricle is crescent shaped and contracts going centrally
Left ventricle is spherical and contracts inwards
Which species does the aorta have high contractility
Rabbit
What are the features of the RIGHT chambers of the heart
Atrium has 3 veins (cranial, caudal and azygous)
There are 2 crests - terminal and inter venous which divert flow to prevent turbulent mixing
Autricles are cranially left and are the embryonic reminance of the atrium
Coronary sinus
Pectinate muscles
Ventricles
Trabecular carnae muscles
CUSPS : right atrioventricular cusp = tricuspid
Chorda tendinae attached to papillary muscles
What role do cusps have
Prevent back flow by helping to keep valves open/shut but also help squeezing blood out of vessels in the heart
What’s the difference between the atria and auricle
Atria have smooth internal surface but auricles have ridged internal surface due to pectinate muscles
What are the features of the left chambers of the heart
Pulmonary vein
Aorta
Left pulmonary artery
Coronary vessels in coronary groove
Cusp = left atrioventricular bicuspid mitral
VENTRICLES
Moderato bands bridge ventricles to wall of the heart for support
What are the features of the fibrous skeleton of the heart
Left coronary artery goes around LAV and beneath PA and right coronary artery goes around RAV
Ossa cordis caudal to the aorta on either side are bones of the heart
Great coronary vein runs around the LAV also called coronary sinus
Features of coronary sinus
No valves, little tone
What is the role of the azygous vein
Drains dorsal thorax
What is the old connection between the aorta and pulmonary artery
Ligamentum arteriosum which is the remnants of the ductus arteriosus shunt in the fetus
What is the coronary circulation
Including 2 circumflex branches and 2 descending branches and one vein
Circumflex branch of right coronary artery comes out from the aortic valve cranially arching around to the right side
Left one comes out on the left, the circumflex branches out bends around to the caudal side to eventually be on the right side of the heart
Branches get sent down in the groove between the ventricles
Give septal branch and L descending branch in interventricular groove (formed from L circumflex branch)
Coronary vein forms on the left, arcs around caudally to become the coronary sinus > dumps stuff into right atria
What are the features of the coronary circulation - miscellary
Major vessels lie outside the myocardium because they would be damaged by the pressure inside, some venous drainage into atria/ventricles but most drains via coronary vein
Describe the electrical conductivity in the heart
Sinuatrial node is located near intervenous crest in right atria, which sends signals to the AVN near to where the coronary sinus enters.
The AVN splits into the right and left crura of bundle of his which follow down to the apex, splitting into moderator bands = bypasses for the impulse to leave from the septum out to the wall
There are insulating fibrous skeletons that separate the atria and ventricles
What is the parasympathetic innervation
Comes from the 10th vagus nerve. Comes down neck in vagus sympathetic trunk alongside common carotid artery.
Through the thoracic inlet and over top of heart
Branches off into SAN and AVN as PS only affects HR
Cardiovagal fibres reduce HR
