Cardio Review Flashcards
When are the AV valves closed?
Systole; during the isovolumetric contraction, reduced ejection, and isovolumetric relaxation
When are the AV valves open?
Diastole; during rapid ventricular filling, diastasis, and atrial systole
What event within the heart causes the AV valves to open? close?
- When atrial pressure is greater than ventricular pressure. Atrial filling leads up to the opening of AV valves
- ventricular pressure is greater than atrial pressure
When are the semilunar valves closed?
Diastole; during the period of isometric relaxation, rapid ventricular filling, diastasis, atrial systole, and isometric contraction
When are the semilunar valves open?
Systole; during the period of rapid and reduced ejection
What event causes the semilunar valves to open? close?
- Increase in ventricular pressure
- Increase in pulmonic and aortic pressure that is greater than ventricular pressure
Are both sets of valves closed during any part of the cycle? If so, when?
Both open? when?
- Yes, during isovolumetric contraction and isometric relaxation
- no
At what point in the cardiac cycle is the pressure in the heart highest? lowest?
- Rapid ejection
- Rapid ventricular filling
What is cardiac output?
The amount of blood pumped per unit of time
What is ejection fraction?
Stroke volume / diastolic volume
What are the phases of the cardiac cycle?
- Atrial systole (systole)
- Isovolumetric contractraction (systole)
- Rapid Ejection (systole)
- Reduced Ejection (systole)
- Isovolumetric Relaxation (diastole)
- Rapid ventricular filling (diastole)
- Diastesis (diastole)
Volume in the lungs at max inflation; sum of VC and RV
Total Lung Capacity (TLC)
TV + IRV + ERV + RV
Volume of air moved into or out of the lugs during quiet breathing
Tidal Volume (VT)
Volume of air remaining in the lungs after maximal exhalation
Residual Volume (RV)
Max volume of air that can be exhaled from the normal end-expiratory position
Expiratory Reserve Volume (ERV)
Max volume that can be inhaled from the normal end-inspiratory position
Inspiratory Reserve Volume (IRV)
Sum of IRV and TV
Inspiratory capacity (IC)
Max volume of air inhaled from the point of max expiration
Inspiratory Vital Capacity (IVC)
Volume of air breathed out after the deepest inhalation; IRV + TV + ERV
Vital Capacity (VC)
Volume in the lungs at the end-expiratory position
Functional residual capacity (FRC)
ERV + RV
What are central chemoreceptors sensitive to that will cause breathing?
pH, specifically H+ ions that cross the BBB
What is the normal partial pressures of O2, CO2, in gas exchange at the alveolar-capillary membrane?
- O2 = 104 mmHg
- CO2 = 40 mmHg
What are the factors that cause a right shift in the oxyhemoglobin saturation curve?
- increased CO2
- Increased DPG 2,3
- Increased exercise
- Decreased pH
- Increased altitude
- increased temperature
how readily the elastic forces accept a volume of inspired air
Lung compliance
C = change in volume/ change in pressure
ability to respond directly to force and return to its original resting position or shape after the external force no longer exists
elastance
E = change in pressure/ change in volume
This respiratory pattern is characterized by periods of respiration during which the VT starts shallow and gets progressively deeper, and then gets progressively shallower. This shallow-deep-shallow pattern is followed by periods of significant apnea that can last up to 30s or longer, then the cycle starts over. each cycle can take anywhere btwn 30 and 2 minutes or longer.
Cheyne-Stokes respirations
Seen in:
- strokes
- TBI
- Brain tumor
- carbon monoxide poisoning
- metabolic encephalopathy
A type of labored or hyperventilation characterized by a consistently deep and rapid respiratory pattern
Kussmaul’s respirations
Seen in:
a severe metabolic acidosis such as diabetic ketoacidosis
Respiratory pattern that has a prolonged inspiration phase followed by a prolonged expiratory phase
Apneustic respirations
- long expiratory phase commonly believed to be apneic phases
Seen in:
damage sustained to the upper pons
abnormally prolonged and deep breathing
hyperventilation
reduction in the amount of air entering the pulmonary alveoli which causes an increase in arterial CO2 level
hypoventilation
Which portion of the electrocardiogram (ECG) represents a small deflection sometimes seen just after the T wave, representing the final phase of ventricular repolarization?
U wave
Name the five traditionally designated auscultatory areas and their corresponding intercostal space
- Aortic valve area – 2nd R intercostal space
- Pulmonic area – 2nd L intercostal space
- Second pulmonic area – 3rd L intercostal space
- Tricuspid area – 4th L intercostal space
- Mitral area – 5th L intercostal space, midclavicular line
What are the parts of the EKG and what do they represent?
P - Spread of a stimulus through Atria (Atrial depolarization)
PR interval - time from initial stimulus of atria to initial stimulus of ventricles (.12-.2s)
QRS - the spread of a stimulant through the ventricles (Ventricular depolarization)
ST seg and T - the return of stimulated ventricular muscle to a resting state (Ventricular repolarization)
U - small deflection sometimes after T
QT interval - the time elapsed from the onset of ventricular depolarization until the completion of ventricular depolarization, with the interval varying with the cardiac rate
irregular breaths varying in depth and interrupted by intervals of apnea but lacking repetitive pattern, associated with increased intracranial pressure
Biot respirations
a narrowing or constriction that prevents the valve from opening fully and may be caused by scars or abnormal deposits on the leaflets; causes obstruction to blood flow and the chamber behind the narrow valve must produce extra work to sustain cardiac output
stenosis
occurs when the valve does not close properly and causes blood to flow back into the heart chamber; the heart gradually dilates in response to the increased volume work
Insufficiency (regurgitation)
Name this part of the cardiac cycle: Ventricular contraction causes the AV valves to close from contraction of papillary muscles; All valves closed
Isovolumetric contraction
- S1 happens here
Name this part of the cardiac cycle: intraventricular pressure falls sufficiently causing semilunar valves to close; all valves are closed
Isovolumetric relaxation
- S2 happens here
- dicrotic notch happens here (associated with a small back flow of blood into the ventricles resulting in aortic and pulm a. pressure tracings)
List the events of conduction through the heart
- SA node generates impulse
- Impulses pause (.1s) at the AV node
- AV bundle connects the atria to the ventricle
- Bundle branches conduct the impulses through the inter ventricular septum
- Purkinje fibers depolarize the contractile cells of both ventricles
What are the steps of oxygen transport?
- inspired oxygen and quality of ambient air
- Airways
- Lungs and chest wall
- diffusion
- Myocardial function
- perfusion
- peripheral circulation
- tissue extraction and use of oxygen
- Return of partially desaturated blood and CO2 to the lungs
