Module 4: Physiology of the Cardiovascular System Flashcards
Blood flow through the heart basics (2)
1) Four internal valves assure one-way flow of blood
2) Double pump with two circuits
a) Pulmonary circuit (right)
b) Systemic circuit (left)
Pulmonary circuit in the heart (3)
1) Goal: Send deoxygenated blood to the lungs for oxygenation
2) Right atrium through tricuspid valve into right ventricle
3) Exits right ventricle through pulmonary valve
Pulmonary circuit to the lungs (3)
1) Pulmonary trunk to pulmonary arteries
a) Only arteries in heart carrying de-oxygenated blood
2) Lungs for exchange of gases
3) Pulmonary veins (now oxygenated) to left atrium
Systemic circuit in the heart (6)
1) Goal: send oxygenated blood to the body tissues
2) Left atrium
3) Bicuspid/Mitral valve
4) Left ventricle
6) Aortic Valve to Aorta
Systemic Circuit to the tissues (4)
1) Systemic Arteries
2) Systemic Veins (Parallel those of arteries)
3) Back to heart via Inferior/Superior Vena Cava
4) Right Atrium
Blood Flow Through the Heart Summarized (6)
1) Right atrium through tricuspid valve
2) Right ventricle through pulmonary valve
3) Pulmonary trunk to pulmonary arteries
4) Lungs to pulmonary veins to left atrium
5) Bicuspid valve to left ventricle
5) Aortic valve to the aorta
Bloodflow through the heart visual (memorize)
Heartbeat basic facts (3)
1) Each heartbeat lasts about 0.85 seconds
2) Heart beats about 70x per minute
3) Must contract and relax in a cyclical pattern to act as a pump
Two components of heartbeat (2)
1) Systole
a) Contraction of chambers
2) Diastole
b) Relaxation of chambers
Phase 1 of cardiac cycle (4)
1) Lasts about 0.15 seconds
2) Atrial Systole: Atria Contract
3) Ventricular diastole: Ventricles are relaxed
4) Allows for maximum filling of the ventricles
Phase 2 of cardiac cycle (4)
1) Lasts about 0.30 seconds
2) Ventricular systole: Ventricles Contract
3) Atrial diastole: Atria are relaxed
4) Allows for pumping of blood into pulmonic and systemic circuits
Phase 3 of cardiac cycle (3)
1) Lasts about 0.40 seconds
2) All chambers relax
3) Passive filling of the atria
Heart sounds (4)
1) Sounds as the valves of the heart close
2) Lub sound
a) Atrioventricular valves close
b) Bicuspid/tricuspid valves
3) Dub sound
a) Semilunar valves close
b) Aortic/pulmonic valves
4) Can be heard using a stethoscope
Blood pressure (2)
1) Systolic pressure
a) Pressure in the arteries when blood is forced into the the arteries during ventricular systole
b) “Top number”
2) Diastolic pressure
a) Pressure in arteries during ventricular diastole
b) “Bottom number”
Sphygmomanometer (2)
1) Medical equipment used to measure blood pressure
2) Measures the amount of pressure required to stop the flow of blood through the artery
a) Usual the brachial artery (in the arm)
Sphygmomanometer picture (memorize)
Sphygmomanometer components (6)
1) Bulb
2) Bladder
a) fills with air
3) Cuff
a) Wraps around arm, holds bladder in place over the artery
4) Valve
a) Releases pressure to allow blood to flow
5) Manometer
a) Displays the pressure in mmHG (millimeters mercury)
Stethoscope (for blood pressure)
Used to listen to first and last sounds of the blood flow
Blood pressure final reading (2)
1) Top/bottom
a) Systolic/Diastolic
2) 120/80 is considered healthy
Systemic blood pressures (5)
1) Highest in the aorta
2) Falls within the arteries and arterioles
3) Difference in systolic vs. diastolic gradually diminishes
4) Capillaries:
a) Slow, even flow
b) Allows for diffusion of gasses and wastes
5) Veins
a) Very low, can even approach zero
How can Veins return Blood to the Heart (3)
1) Low resistance in the venous walls
a) Ability to stretch to accommodate larger volume
2) Valves
a) One way
3) Assistance of muscular contraction
a) Contractions squeeze blood through veins, one-way due to valves
Intrinsic Electrical Rhythm (2)
1) Electrical impulses enable the heart’s rhythmic pumping
a) Contracts the heart muscle tissue
2) Nervous and Endocrine systems help to regulate the heart rate
a) Number of beats per minute
b) Changes with emotional and physical stressors
Sinoatrial node (5)
1) Small mass of specialized cardiac tissue
a) Contains both cardiac and nervous tissue characteristics
2) Electrical impulse that controls cardiac cycle begins here
3) Found in the right atrium
4) Pacemaker of the heart
5) Spreads through atria, causing left and right atrial systole
Three other components of electrical impulse system (after sinoatrial node) (3)
1) Atrioventricular node
2) Bundle of His
3) Purkinje fibers
a) Right and left ventricular contraction
Visual of conduction system of heart
Electrocardiogram (EKG or ECG) (3)
1) Device used to measure electrical impulses in the heart
2) Corresponds to the mechanical events happening
3) Used to monitor and diagnose patient conditions
P-wave (ECG) (2)
1) Atrial depolarization
2) Atrial systole
QRS complex (ECG) (3)
1) Ventricular depolarization
2) Ventricular systole
3) Largest wave as the ventricles are the largest with the most mass
T-wave (ECG) (2)
1) Ventricular repolarization
a) Returning to rest
b) Ventricular diastole
2) Atrial repolarization is hidden within the QRS complex
