Revision from Textbook (Cv System) Flashcards
What is the pulmonary circuit?
Blood vessels that carry blood to and from lungs.
Which side of the heart receives oxygen poor blood?
Right side.
What is the systemic circuit?
Blood vessels that carry blood to and from all body tissues.
Which side of the heart receives oxygenated blood returning from the lungs?
Left side.
What are the two receiving chambers?
Right and left atrium.
What does the right atrium receive.
Blood returning from systemic
What does the left atrium receive?
Blood returning from pulmonary circuit.
What are the two pumping chambers?
Right and left ventricle.
What does the right ventricle pump?
Pumps blood to pulmonary circuit.
What does the left ventricle pump?
Blood into the systemic circuit.
How many lobes does left lung have?
2
How many lobes does right lung have?
3
What are the layers of the pericardium?
Fibrous and serous
What are the 2 layers of the serous pericardium?
Parietal and visceral.
What is the pericardial cavity?
Between parietal and visceral layer, filled with serous fluid (no friction)
What is the visceral layer of serous pericardium known as?
Epicardium.
What is the endocardium made up of?
Sheet of endothelium, continuous with endothelial lining of blood vessels leaving and entering heart.
What is the interatrial septum?
Divides the heart longitudinally (separates the atria).
What is the interventricular septum?
Divides heart longitudinally to separate ventricles.
What is the coronary sulcus?
Groove encircling junction of atria and ventricles like crown.
Where is the anterior interventricular sulcus?
Cradles anterior interventricular artery, marks anterior part of septum separating ventricles.
What are the 2 basic parts of the right atrium internally?
Smooth walled posterior, anterior portion of pectinate muscles.
What are pectinate muscles?
Bundles of muscle tissues forming ridges in the walls of heart.
What is the crista terminalis?
C shaped ridge that separates the posterior and anterior regions of the right atrium.
What is the fossa ovalis?
Shallow depression in interatrial septum in left atrium.
What are the 3 veins that blood enters the right atrium via?
Superior vena cava, inferior vena cava, coronary sinus.
What does the coronary sinus do?
Collects blood draining from myocardium.
How many pulmonary veins enter left atrium?
4
Which ventricle forms most of anterior surface of heart?
Right ventricle
Where does the right ventricle pump blood into?
Pulmonary trunk (routes blood to lungs for gas exchange).
Where does the left ventricle eject blood into?
Aorta.
How many pulmonary arteries are there?
2
What are trabeculae carneae?
Irregular ridges of muscle that line walls of ventricular chambers
What are papillary muscles?
Play role in valve function, project into ventricular cavity.
What are the AV valves?
Tricuspid and mitral.
How many cusps does tricuspid have?
3
How many cusps does mitral valve have?
2
What are chordinae tendinae?
Small chords that anchor valves to papillary muscles
What happens to AV valves when ventricles contract?
Intraventricular pressure rises, forcing blood superiority against valves, therefore they close.
What are the semilunar valves?
Aortic and pulmonary valves.
How many cusps do pulmonary and aortic have?
3
How many coronary arteries are there?
2
Where are the coronary arteries?
Arise from base of aorta and encircle heart in coronary sinus.
Where is the left coronary artery?
Runs towards left side of heart and divides into two branches.
What are the two branches of the left coronary artery?
Anterior interventricular artery and circumflex artery.
Where does the anterior interventricular artery supply blood to?
Interventricular septum and anterior walls of both ventricles.
Where does the circumflex artery supply blood to?
Left atrium and posterior walls of left ventricle,
What are the two branches of the right coronary artery?
Right marginal artery and posterior interventricular artery.
What does right marginal artery supply blood to?
Myocardium of lateral right side of heart.
What does posterior interventricular artery supply blood to?
Posterior ventricular walls.
What is venous blood?
Deoxygenated blood that travels through venous system into right atrium.
What are the cardiac veins?
Collects venous blood, oath roughly follows coronary arteries.
What do the cardiac veins join together to form?
Coronary sinus.
What is a tributary?
Vein that empties into a larger vein
What are the main 3 tributaries of coronary sinus?
Great cardiac vein, middle cardiac vein and small cardiac vein.
Where is great cardiac vein?
Anterior interventricular sulcus.
Where is the middle cardiac vein?
Posterior interventricular sulcus.
Where is the small cardiac vein?
Runs along hearts right inferior margin.
What are features of cardiac muscle?
Striated and contracts by sliding filament mechanism.
How is cardiac different to skeletal muscle?
Cardiac is short, fat, branched and interconnected.
What is cardiac muscle cell called?
Cardiac myocyte.
What are gap junctions?
Electrically connect myocytes (allow ions to pass from cell to cell).
What are desmosomes?
Keep myocytes from pulling apart during contraction.
What do sarcomeres contain?
Z discs, A bands and I bands (reflects arrangement of actin and myosin)
What is a functional syncytium?
Single coordinated unit.
What is the first phase of the cardiac cycle?
Ventricular filling- pressure in heart low, blood comes in from circulation, AV open and SL valves closed. Atrial systole means they contract and the rest of the blood into the ventricles, ventricles now have end diastolic volume.
What is the second phase of the cardiac cycle?
Isovolumetric contraction- as atria relax, ventricles contract and pressure rises closing the AV valves. This phase is the very short period of time when the ventricles are completely closed chambers. As pressure keeps rising, exceeds pressure in arteries and then this phase ends when SL forced open.
What is the third phase of the cardiac cycle?
Ventricular ejection- blood rushes from ventricles to aorta and pulmonary trunk.
What is the fourth phase of the cardiac cycle?
Isovolumetric relaxation- ventricles relaxed (blood no longer compressed). Blood from aorta and pulmonary trunk flow back to the heart so SL valves forced closed. Ventricles are completely closed chambers again
What is the lub sound?
Av valves closing (ventricular pressure rises above atrial pressure).
What is the dub sound?
When SL valves close at ventricular relaxation.
What is cardiac output?
Amount of blood pumped out of each ventricle in 1 minute.
How do you calculate cardiac output?
Heart rate x stroke volume
What is stroke volume?
Volume of blood pumped out by one ventricle with each beat. (Correlates with force of ventricular contraction).
What is cardiac reserve?
The difference between resting and maximal CO.
In terms of blood, what does stroke volume represent?
End diastolic volume (amount of blood collects in the ventricle during diastole) minus the end systolic volume (amount of blood left in ventricle after it contracts).
What is preload?
Degree that cardiac muscles are stretched just before they contract.
What is the connection between preload and stroke volume?
The higher the preload, the higher the stroke volume (frank starling law of the heart).
What is the difference between optimal lengths of skeletal and cardiac muscle lengths?
Resting skeletal muscles are kept near optimal length (maximal extension), cardiac are shorter than optimal (can produce dramatic increases in contractile force).
What is venous return?
The amount of blood returning to the heart and distending its ventricles.
Relationship between venous return and stroke volume?
Anything that increases venous return, increases SV, EDV, CO.
What is contractility?
Contractile strength achieved at a given muscle length.
What is afterload?
Pressure that the ventricle must overcome to eject blood (back pressure arterial blood exerts on aorta and pulmonary valve).
What is the link for hypertension and afterload?
Reduces ability to eject blood. More blood remains in the heart after systole (reducing stroke volume).
Why does heart rate increase when adrenaline and noradrenaline released?
Noradrenaline binds to receptors, threshold is reached quicker and so SA node fires more rapidly and increases HR.
