hearts Flashcards
What are the layers of the pericardial cavity and heart?
The heart is enclosed in a sac of serous membranes, the layers are:
-Parietal pericardium: outer layer of the sac
-Pericardial cavity: the potentail space between the inner and
outer layers of the sac
-Visceral pericardium: the inner layer of the sac
What are the layers of the heart:
-Epicardium: thin, outer layer of the heart
-Myocardium: thicker, middle layer composed of cardiac
muscle tissue
-Endocardium: thin, layer lining the cavities, its continuous with
Endothelium of blood vessels
Whats the structure of the fish heart, how does blood flow through and the state of oxygenation of the blood?
There’s two official chambers, but also a sinus venosus and conus arteriosus.
Sinus venosus recieves deoxygenated blood from common cardinal veins
-thin walled
Then into the single atrium through SA valve.
-thicker than the sinus venosus
Then into ventricles through the AV valve
-thickest wall, main pump
Out the ventricles through the conus arteriosus and the semilunar valves.
All deoxygenated, gets oxygenated by the aortic arches at the gill slits.
What’s the structure of the amphibian heart? How does blood flow through it? Where is the oxygenated blood?
Three chambered heart
Completely divided atrium
-right atrium: deoxygenated blood from systemic
-left atrium: oxygenated blood from pulmonary vein
-trabecular. Folds
Ventricle: single
-thick muscular wall, deoxygenated blood from right and
oxygenated blood from left
-trabecular arrangements of the wall keeps the blood
seperated
Conus/truncus arteriosus
-spiral valve also helps keep blood serperate
-right side: pulmonary arteries
-left side: to body
Whats the difference between the general reptillian heart and the heart of crocodiles?
The ventricle is completely divided in crocadiles
How is the turtle heart set up?
Completely divided atrium
Incompletely divided ventricle, interventricular canal/foramen
Right atrium: deoxygenated blood.
left atrium: oxygenated blood
Ventricle
-left side = cavmun arteriosus
-right side: cavmun venosum and cavum pulmonale
How does blood flow through the turtle heart?
Oxygenated blood comes through the pulmonary veins into the left atrium
Through left AV valve and into cavum arteriosum and through the interventricular canal to the cavum venosum.
Then through the semilunar valves and into the left and right aortae.
Systemic deoxygenated blood from the vena cava goes into the right atrium.
Through the right AV valve and into the cavum venosum
Into the cavum pulmonale through the semilunar valve and into the pulmonary artery to the lungs.
During atrial contraction the AV open and have what effect on the interventricular canal?
Occluded which keeps oxygenated and deoxygenated blood separated
What’s the purpose of the Foramen of Pinizza and what vessels do they connect?
An adaption for diving so circulation can continue when the animal is submerged and not using the lungs.
Foramen of Panizzae is the whole between the crossing of left and right aorta. (Systemic trunk)
Crocodiles
how does the mammialian heart develop?
First stage, arises from the splanchnic mesoderm. Paired double-walled tubes, out layer of epimyocardium and inner later of endocardium
Conus arteriosus Ventricle Atrium Sinus venosus (Backwards from adult heart, tube fused then fold in on themselves)
Fusion begins at cranial end, conus arteriosus. Pulsates first. slowest pulsation
Sinus venosus is the last to fuse and the last to pulsate
In heart development of a mammal if which two structures do not meet results in the hole in the heart, a interventricular defect.
Endocardinal cushion and IVS (interventricular septum)
How does blood flow through the fetal heart?
Oxygented blood from the placenta and into the right atrium. Foramen oval into the left atrium
Through left AV valve into the left ventricle
Then through the aortic trunk and through aortic semilunar valve
And out the aortic arch and body.
Blood that enters the right ventricular from the right AV vavle into the right ventricule. Goes through the right semilunar vavle and into the pulmonary trunk down through the ductus arteriosus and into the aortic arch and body.
What the function of the papillary muscles and chordae tendinae in the ventricule of the mammialian heart?
The chordae tendinae attaches to the flaps of the AV valve. On the other end they are attched to the papillary mucsles .
