Heart and Fetal Circulation Flashcards
General characteristics of Heart
- equal amt of blood leaves right and left side
- approx size of fist
- rests on diaphragm
- 2/3 lies left of midline
What are general anatomical characteristics of the heart (6)
- apex
- base
- sup. r. point
- sup. l. point
- inf. r. point
- inf. l. point
What is the pericardium
Double layered membrane surrounding and protecting the heart
What are the 2 layers of the pericardium
- Fibrous layer (outer)
- prevents overstretching of heart - Serous layer (inner)
- outer parietal layer
- inner visceral layer: epicardium
What is pericardial cavity and pericardial fluid?
Cavity: btwn visceral and parietal layer of serous pericardium
Fluid: in pericardial cavity
What is pericarditis and cardiac tamponade?
Pericarditis: inflammation of pericardium
Tamponade: consequence of inflammation (compression of heart)
What are the layers of the heart wall?
- Epicardium: visceral layer of pericardium
- Myocardium: cardiac muscle tissue
- Endocardium: inner smooth lining of chambers, covers valves of heart, continuous w/ endothelial lining of large blood vessels
Which ventricular wall is thicker?
Left
From which major veins does the right atrium receive blood?
IVC, SVC, coronary sinus
What are the parts of the right atrium?
- right auricle
- pectinate muscle
- interatrial septum (fossa ovalis)
- tricuspid valve
What are the parts of the right ventricle?
- trabeculae carnae
- cordae tendinae
- papillary muscles
- interventricular septum
- pulmonary semilunar valve (3 cusps)
From where does the left atrium receive blood?
Pulmonary veins
What are the parts of the left atrium?
- left auricle
- pectinate muscle
- bicuspid “mitral” valve
What are the parts of the left ventricle?
- trabeculae carnae
- cordae tendinae
- papillary muscles
- aortic semi-lunar valve
What happens when the AV valves are open?
- pointed ends project into ventricles
- blood moves into ventricle
- papillary muscles are relaxed
- cordae tendinae are slack
How to the AV valves close?
- ventricles contract
- pressure drives cusps upward
- papillary muscles contract
- cordae tendinae are tightened and prevent cusps from opening into the atrium
What is the role of semilunar valves?
allow ejection of blood into vessels and prevent backflow into the ventricles
Describe semilunar valves.
- each consists of 3 cusps
- outer border is attached to artery wall
- valves are open when ventricular pressure exceeds arterial pressure
What is supplied by the systemic and pulmonary circulation?
Systemic: entire body except lungs
Pulmonary: lungs
Describe the coronary arteries
- R and L originate at the base of ascending aorta
- L coronary a: supplies both ventricles and left atrium
- R coronary artery: supplies both ventricles
- most parts of the heart receive from both arteries
List the coronary veins
- coronary sinus
- great cardiac vein
- middle cardiac vein
- small cardiac vein
- anterior cardiac vein
What are the 3 phases of the cardiac cycle?
- relaxation period
- ventricular filling
- ventricular systole
What is systole?
Phase of contraction
What is diastole?
Phase of relaxation
