Ch 18: Cardiovascular System Flashcards
What is the difference between the right and left sides of the heart?
Right: receives oxygen-poor blood from tissues
Left: receives oxygenated blood from lungs
Where does the right side of the heart pump to?
Pumps to lungs to get rid of CO2, pick up O2 via pulmonary circuit
Where does the left side of the heart pump to?
Pumps to body tissues via systematic circuit
What are the receiving chambers of the heart?
- Right atrium
2. Left atrium
What is the difference between right and left atrium?`
Right: receives blood returning from systematic circuit
Left: receives blood returning from pulmonary circuit
What are the pumping chambers of heart?
Right and left ventricles
What is the difference between the right and left ventricles?
Right: pumps blood through pulmonary circuit
Left: pumps blood through systemic circuit
Where is the heart located?
Mediastinum
2/3 of heart is left of the midsternal
Compare the base and apex of the heart
Base: leans toward right shoulder
Apex points toward left hip
What is the approximate size of the heart?
Size of fist
What are the 2 pericardium of the heart?
- Superficial fibrous pericardium
2. Deep 2-layered serous pericardium
What is the purpose for superficial fibrous pericardium?
Protects, anchors to surrounding structures and prevents overfilling
What are the 2 layers of serous pericardium?
- Parietal
2. Visceral
What portion of the heart does the parental layer line?
Internal surfaces of fibrous pericardium
What portion of the heart does the visceral layer (epicardium) line?
External surface of the heart
What separates the 2 serous pericardium layers?
Pericardial cavity
What is the purpose of the pericardial cavity?
Decreases friction
What is pericarditis?
Inflammation of pericardium
What is cardiac tamponade?
Excess fluid sometimes compresses heart that limits pumping ability
What does pericarditis cause?
Roughens membrane surfaces increasing pericardial friction and rubbing
What are the 3 layers of the heart wall?
- Epicardium
- Myocardium
- Endocardium
What is the epicardium?
Visceral layer of serous pericardium
What is myocardium?
Spiral bundles of contractile cardiac muscle cells
What is the endocardium?
Lines heart chambers that covers valves, consists of endothelial lining of blood vessels
Describe the characteristics of the cardiac skeleton
Crisscrossing interlacing layer of connective tissue
What is the purpose of the cardiac skeleton?
- Anchors cardia muscle fibers
- Supports great vessels and valves
- Limits spread of action potentials to specific paths
Where are the locations of four chambers?
2 superior atria
2 inferior ventricles
What separates the atria?
Interatrial septum
What separates the ventricles?
Interventricular septum
What is an auricle?
Appendages that increase atrial volume
Where are the auricles located?
Left and right atrium
What is the purpose for auricles?
Contribute to propulsion of blood
What are the 3 veins that empty into the right atrium?
Superior vena cava, inferior vena cave, coronary sinus
How many pulmonary veins go into the left atrium?
4
What is the purpose for the papillary muscles?
Anchors chordae tendinae to prevent inversion or prolapse of mitral and tricuspid valves on systole
Where does the right ventricle pump blood?
Pulmonary trunk
Where does the left ventricle pump blood?
Aorta
What is the purpose of atrioventricular valves?
Prevents back flow into atria when ventricles contract
What are 2 AV valves?
Tricuspid valve (right) Mitral valve (left)
What are the purposes for chordae tendineae?
- Anchors cusps to papillary muscles
- Hold valve flaps in closed position
- Ensure undirectional blood flow through heart
- Open and close in response to pressure changes
What is the purpose for semilunar valves?
Prevents back flow into ventricles when ventricles relax by opening and close in response to pressure changes
What are the 2 SL valves?
- Aortic semilunar valve
2. Pulmonary semilunar valve
What is incompetent valve?
When blood backflows so heart re-pumps blood over and over
What occurs during vavular stenosis?
Stiffs flaps that constrict opening to where the hear must exert more force to pump blood
Why would the left ventricle of the heart have a thicker cell wall than the right?
Pumping with great pressure do to greater after load
How are valves replaced?
Mechanical, animal, cadaver valves
Describe the route of the pulmonary circuit
Right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary trunk → pulmonary arteries → lungs → pulmonary veins → left atrium
Describe the route of the systemic circuit
Left atrium → mitral valve → left ventricle → aortic semilunar valve → aorta → systemic circulation
What is the difference between pulmonary and systemic circuit?
P: short-low pressure circulation
S: long, high-friction circulation
Compare the anatomy of the 2 ventricles
Left ventricle wall is 3x thicker than right
Compare the volumes of blood that are pumped to the pulmonary and systematic circuit
Equal volumes fo blood is pumped
When would blood supply be pumped to the heart?
- Delivered when heart is relaxed
2. Left ventricle receives most blood supply
What is the purpose of the anastomoses?
- Provide additional routes for blood delivery
2. Cannot compensate for coronary artery occulusion
Identify the difference between left and right coronary artery
Left: supply left atrium and left ventricle
Right: supply right and most of right ventricle
What are the cardiac veins?
Collect blood from capillary beds
What is the coronary sinus?
Empties into right atrium formed by merging cardiac viens
What cardiac veins the coronary sinus empties into?
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
What is angina pectoris?
Thoracic pain caused by fleeting deficiency in blood delivery to myocardium causing cells to weaken
What is myocardial infarction?
Caused by prolonged coronary blockage where areas of cell death repaired with non contractile scar tissue
What are the junctions between cardiac cells?
Intercalated discs
What is purpose of desmosomes in the cardiac muscle?
Prevent cells from separating during contraction
What is the purpose of gap junctions in the cardiac muscle?
Allows ions to pass from cell to cell electrically couple adjacent cell allowing the heart to function as a single unit?
What is the term for behaving as a single coordinated unit?
Functional syncytium
Describe the structure of cardiomyocytes
Striated, short, branched, fat interconnected containing a central nuclei