Cardiovascular System Flashcards
Where is the cardiovascular system derived from?
Mesoderm (middle germ layer)
Splachnopleura, by lateral plates
In what order is the heart created?
Blood islets in cephalic portion of embryo
Two endocardial tubes, migrates caudally
Tubes fuses forming primitive heart tube
Primitive heart tube forms into 5 chambers
Heart loop formation
Partitioning of the heart
Describe the heart looping
Primary heart tube grows, the pericardial sac doesn’t, forcing the heart tube to loop
Normal distribution of the heart chambers occurs
What are the five chambers created by the primitive heart tube?
Arterial trunk (aorta+pulmonary artery) Heart bulbs (right ventricle) Ventricle (left ventricle) Atrium (front parts of L+R atria) Venous sinus (posterior part of R atria, SAN and coronary sinus)
Describe the partitioning of the heart
Endocardial cushions grows inwards forming a trio-ventricular canal, fuses to become intermediate septum dividing atria+ventricle
Formation of atrioventricular valves
Mitral valve
Bicuspid
Between LEFT atria and ventricle
Tricuspid valve
Between RIGHT atria and ventricle
Primary foramen
Primary interatrial septum grows ventrally leaving the primary foramen
Secondary foramen
Secondary interatrial septum grows dorsally leaving secondary foramen and closing primary foramen
Foramen oval
Primary and secondary foramen runs parallel leaving foramen ovale
Remains open until after birth
Interventricular septum/foramen
Wall between ventricles, with foramen allowing blood to pass between the ventricles
Spiroid septum
Closes interventricular foramen, closes communication between ventricles
Embryonic network
Primitive aorta and cardiac veins
Vitelline network
Vitelline arteries and veins
Gives rise to arteries (digestive, celiac, mesentric)
After birth
What are the 5 aortic arches in the embryonic network giving rise to?
1+2- maxillary artery
3- carotid system
4- left=aorta right= subclavian artery
5- pulmonary artery
Umbilical network
Iliac arteries
Vesicular arteries (urinary bladder)
Forms round ligament of urinary bladder
Cardinal/cardiac veins
Vena cava
Azygous vein
Renal vein
Ovarian/testicle veins
Vitteline veins
Caudal vena cava
Liver sinusids
Umbilical vein forms
Round ligament of the liver
Port vein
Blood circulation of fetus
Oxygenated blood from mother via placenta in umbilical VEINS
through liver draining in to portal vein and mixes with deoxygenated blood
Vena cava to R atrium-60% to L atrium via foramen ovale-L ventricle through mitral valve- aorta- rest of organism
Umbellical ARTERIES collect deoxygenated blood and back to placenta/mother
Ductus arteriosus
Via ductus arteriosus blood goes to aorta since lungs are collapsed in fetus=too high resistance
Closes after birth forming arterial ligament (shut off by increased pressure when lungs inflate)
What modulation occur after birth?
Lungs inflate increases pressure causing the closing of ductus arteriosus, absorbs blood from pulmonary artery
Embryonic circulation stops
CO2 increases causing contraction of inspiratory muscles
Fusion of interatrial septum due to high speed of blood
Patent ductus arteriosus
Still communication between pulmonary artery and aorta
Mixing oxygenated and deoxygenated blood
Persistant 4th aortic arch
Pinches esophagus
Leading to megaesophagus
Mediastinum
Space between lungs where heart is situated (medial)
Cranial, medial and caudal part
Tetralogy of fallot
Pulmonary stenosis
Ventricular septal defect
R ventricular hypertrophy
Overriding aorta
Where do you perform ascultation of heart?
3-6th rib, 7th in dogs/cats
Cardiac notch
Base of heart
Atriums
Dorsal-cranial
Apex of heart
Ventricles (left)
Ventro-caudal
Cardiac notches
Area not covered by lungs
Where auscultation is made
Pericardium
Heart sac
Surrounds and protects heart
Fibrous pericardium
Most external layer
Fixed ventrally to sternum by periosternal ligament
Fixed causally to diafraghm by pericardiophrenic ligament
Serous pericardium
Most internal, 2 layers
Parietal- completely fused to fibrous pericardium, external
Visceral- internal, covers directly the heart, makes it look shiny
Coronary groove
Coronary vessels
Separates atriums from ventricles
Surrounding all except cranial surface (pulmonary artery)
Lingitudinally
Interventricular groove
Divides ventricles into Left (sinosidal) and Right (paraconial)
Sinus of vena cava
Right atrium
Where vena canvas meet
Coronary sinus
Sac on backside of right atria
Where coronary veins drain deoxygenated blood
Intervenous tubercle
Right atria
Between vena canvas
Helps pushing blood to ventricle
Outlet of azygous vein
Right atria
Alternative path if vena cava is blocked
Tricuspid valve
Between R atria and R ventricle
SAN
Sino-atrial node
Right atrium
Pacemaker of the heart
Oval fossa
Right atria
Remnants of foramen ovale
Auricle/atrial appendage
Cavity/inner surface of atrium
Pulmonary veins
Left atrium
Leading oxygenated blood from lungs
Mitral valve
Bicuspid
Between L atrium and ventricle
Pulmonary valve
Semilunar/sigmoid valve
Tricuspid
Between left atria and pulmonary arteries
Septomarginal traneculae
From septum to lateral wall of R ventricle
Holds right branch of bundle of HIS
Aortic valve
Semilunar/sigmoid valve
Tricuspid
Between left atria and aorta
Endocardium
Innermost layer of heart
Looks shiny
Myocardium
Cardiac muscle
Epicardium
Visceral serous pericardium
Looks shiny
Sinus of vena cava
R atrium
Where cranial and caudal vena cava meet
Coronary sinus
R atrium
Sac on the “back side” where coronary veins drains deoxygenated blood into atria
Intervenous tubercle
R atria
Btw vena cavas
Helps pushing blood into ventricle
Outlet of azygous vein
R atria
Alternative path if vena cava is blocked
Tricuspid valve
Between R atria and R ventricle
Sinoatrial node/SAN
R atria
Pacemaker of the heart
Oval fossa
R atria
Remnants of foramen ovale
Auricle/atrial appendage
Cavity/inner surface of atrium
Pulmonary veins
L atria
Brings oxygenated blood from lungs
Mitral valve
L atria, separates atria and ventricle
Pulmonary arteries
Brings deoxygenated blood from R ventricle to lungs through pulmonary valve
Septomarginal trabeculae
From septum to lateral wall of ventricles
Holds parts of bundle of HIS
most visible in right ventricle
Aorta
Brings oxygenated blood from left ventricle out to the body
Endocardium
Internal layer of heart
Looks shiny
Myocardium
Cardiac muscle
Middle layer
Epicardium
Outermost layer
Visceral serous pericardium
Looks shiny
Fibrous rings
Surrounding the valves on base of heart
Fibrous Trigons
Hard area around the valves
At base of heart
