Cardiovascular Flashcards
Location and position of the heart
- left of midline, at an angle
- rotated so the right border sits more anteriorly while the left border is posterior
- apex projects inferiorly toward left side of the body
What is the heart in and what surrounds it?
- mediastinum and it is surrounded by the lungs
Right border of the heart is formed by what?
- Right atrium
Left border is formed by what?
- Left atrium and left ventricle
Inferior border
- slopes causally and to the left through
- formed mainly by right ventricle
Superior border
- the beginning of the ascending aorta
Apex is formed by what?
- left ventricle
Posterior border of the heart is formed by what?
- mainly by the left atrium
Pericardial sac
- double-layered membrane the heart occupies
- outer fibrous membrane
- inner serous membrane
- pericardial cavity is filled with pericardial fluid — prevents friction
- visceral pericardium: immediately covers the surface of the heart
Myocardium
- thick layer of cardiac muscle
- all cardiac muscle found here
Endocardium
- thin layer of simple squamous epithelium (endothelium) and areolar CT
Epicardium
- AKA visceral pericardium is the outer layer of heart
Myocardium: Cardiac Muscle
- cardiac muscle is striated muscle with intercalated discs
Desmosomes
- connect the two myocardial cells and keeps them tgthr so when the heart contracts, they don’t separate
Gap junctions
- create electrical connection btw muscle cells thru heart contractions
Ventricles
- pumping chambers thick-walled
- thicker muscle cells bc they’re the ones that pump the blood out of the heart
- right ventricle - pumps blood out to the lungs
- left ventricle - pumps blood out onto the body
Atria
- receiving chambers thin-walled (low pressure)
- receive blood from the great vessels
- right atrium: receives blood from the vena cava
- left atrium: receives blood from the pulmonary veins
Coronary sulcus
- separates atria and ventricles
- also called atrioventricular sulcus
- pic: anterior view
Interventricular sulci
- separates right and left ventricles
- pic: anterior view
How blood flows through the heart
• Superior and inferior vena cava will bring deoxygenated blood into the right atrium
• That deoxygenated blood will then pass through the tricuspid valve from the right atrium to the right ventricle
• Deoxygenated blood will then travel out of the right ventricle into the pulmonary truck via pulmonary semilunar valve
• This blood will then go to the lungs via pulmonary arteries
• Blood gets oxygenated
• Comes back in from the left atria via pulmonary veins
• Oxygenated blood will then travel through the bicuspid/mitral valve (in between the left atrium and left ventricle) so it can enter the left ventricle
• Oxygenated blood will then travel from the left ventricle into the aorta through the aortic semilunar valve
• Blood will go back out to the body to supply everything else in the body
Left AV valve
- aka bicuspid/mitral valve
- sits btw left atrium and left ventricle
Right AV valve
- aka tricuspid valve
- sits btw right atrium and right ventricle
Pulmonary semilunar valve
- sits btw right ventricle and pulmonary trunk
Aortic semilunar valve
- sits btw left ventricle and ascending aorta
Atrioventricular valves
- cusps of atrioventricular valves attach to papillary muscles via chordae tendinae “heart strings”
- prevents prolapse of the valve into the atrium (blood going back into the atrium = bad!)
Trabeculae carnae
- are large, irregular muscular ridges on inside of ventricular walls only
- prevents backflow of blood
Receives and features of right atrium
- receives: venous (low-oxygen) blood from inferior vena cava, superior vena cava, coronary sinus
- features: prominent auricle, pectinate muscles (only found in the atria of the heart
Receives and features of right ventricles
- receives: venous (low-oxygen) blood from right atrium
- features: tricuspid valve, moderator band, pulmonic semilunar valve
- right bundle branch: w/in moderator
Venous blood is pumped through the right ventricle through the pulmonary artery, then to the lungs, where it gets
Oxygenated
Receives and features of left atrium
- receives: arterial (high-oxygen) blood from right pulmonary veins and left pulmonary veins
- features: prominent auricle
Receives and features of left ventricle
- receives: arterial (high-oxygen) blood from left atrium
- features: thick myocardium, left atrioventricular valve (2 cusps, also known as bicuspid of mitral valve), aortic semilunar valve with sinus (openings for right and left coronary arteries)
- blood will exit left ventricle and head up to the ascending aorta thru the aortic semi-lunar valve
- once it exits it goes thru the aorta into the systemic circulation
Coronary circulation
- right coronary artery: travels along the AV sulcus (or coronary)
- left coronary artery: travels behind pulmonary trunk and then it’ll give off its branches
Left coronary artery circulation
- supplies anterior aspect of left ventricle, left atrium, and the interventricular septum
- left coronary artery
- left circumflex artery: travel along coronary sulcus btw left atrium and left ventricle and curve around of the posterior aspect of the heart
- anterior interventricular artery/left anterior descending: passes obliquely down the anterior surface of the heart in the interventricular sulcus
Right coronary artery circulation: anterior view
- supplies right atrium, right ventricle, and back of left ventricle
- SA nodal artery
- marginal artery: runs along acute margin
Right coronary artery circulation: posterior view
- right coronary
- AV nodal branch
- posterior interventricular artery: runs in the posterior interventricular sulcus
Coronary circulation: venous drainage
- small cardiac vein = also drains into coronary sinus
- typically runs w/ right coronary artery
- great cardiac vein: travels with anterior interventricular artery (wrap around the heart and then drain into the coronary sinus)
- coronary sinus: receives middle and great veins (also receives drainage from the middle cardiac vein. Travels btw left atrium and left and right ventricle)
- middle cardiac vein: travels with posterior interventricular artery (drains into coronary sinus)
- goes to coronary sinus then drains into the atrium
Coronary circulation: venous drainage Pt. 2
SA node
- has specialized pacemaker myocytes that generate impulse
- impulse propagated through atrial myocardium
AV node
- slows impulse, allowing atria to contract and ventricles to fill with blood
Bundle of his
- impulse is propagated from atria to ventricles only through bundle of his
Left bundle branch and right bundle branch
- travel through interventricular septum
What supplies our heart with oxygenated blood so that our heart can effectively pump oxygen to our body?
- coronary circulation: right and left coronary artery
