Cardiovascular pt. 1 Flashcards
Blood flow depends on a _____ ______ sufficient to fill vessels and a ______ that moves blood forward
Blood volume
Pressure
Protection for the heart from infections; consists of parietal and visceral layers - pericarditis
Pericardium
Muscle of heart; myocardial infarction; myocarditis
Myocardium
Consists of 3 layers which are continuous with the heart valves; endocarditis
Endocardium
Atrioventricular Valves:
Tricuspid
Mitral
-supported by the chordae tendineae
Semilunar Valves:
Pulmonic
Aortic
Valves must open and close properly or _____ or ___________ will occur
Stenosis or regurgitation
______ are abnormal heart sounds caused by the flow of blood across a diseased valve. The narrowing (stenosis) of the valve produces turbulence and rapid blood flow. Also, decreased viscosity of blood increases blood flow e.g severe anemia
Murmurs
_____ are sounds emitted by the valves when opening is impaired
Clicks
Vegetative lesions form on the valves, release bacteria into bloodstream or the lesion itself breaks off forming an obstruction; the lesions grow larger causing valvular dysfunction e.g. regurgitation
Infective Endocarditis
Etiology: Streptococcal with childhood strep and congenital disorders; Staph infections in drug abusers, other bacteria, fungi
Upon occasion, pumping activity of the heart fails but electrical activity continues
PEA (Pulselessness electrical activity)
Electrical Activity ______ mechanical events of the cardiac cycle
Precedes
P Wave: Atrial depolarization
QRS: Ventricular depolarization
T Wave: Ventricular repolarization
The exchange of sodium, potassium, and calcium ions in the cardiac cells of the myocardium causes a _________ _________ of the heart.
Electrical depolarization
Atria contract just before systole and add __ to volume in ventricles
30%
Venous return is affected by amount of _____ available to come into the heart e.g shock, not enough or too much fluid postop, RAP increases if lung pressure increases
blood
_______ is the volume of blood coming into the left ventricle causing muscle stretch. Represents WORKLOAD for the heart
Preload
The more muscles are stretched in diastole, the greater the contraction in systole
Frank-Sterling Law
Stretch is 2 and 1/2 times resting length
about 70 ml of blood to be released with each contraction (stroke volume)
Cardiac Output:
CO = SV x HR
Cardiac output increases with physical activity in the healthy person and decreases with rest and sleep
Cardiac output can be clinically measured with the pulmonary artery catheter using the ____ _______ method
Fick Temperature
_______ is the pressure that the heart must contract against in order to move blood out of Left ventricle into the aorta
Afterload
- Arterial blood pressure is main source of afterload for LV
- Pulmonary pressure is main source of afterload for RV
- Aortic stenosis would also increase afterload
The ability of the heart to change the force of its contraction without changing the length of diastole
Cardiac Contractility
Ability of certain cells in the conduction system to repeatedly beat or conduct
Automaticity
Both a tachycardic and bradycardic rate will ______ cardiac output
Decrease
B/P =
B/P = CO x Total Peripheral Resistance (TPR)
BP is the amount of pressure exerted against the walls of the blood vessels
(BP cuff - indirect; A-line and Swans-Gantz line is direct)
Are sensitive to changes in O2, CO2, and H+ ion content of blood
Located in carotids and aorta
Induce vasoconstriction and regulate ventilation since they are stimulated by a buildup of CO2 and H ions
Chemoreceptors
_______ __ is a strong vasoconstrictor and stimulate aldosterone by increasing salt and water retentiion
(RAAS)
Angiotensin II
Renin-Angiotensin-Aldosterone System (HUMORAL MECHANISM)
Released from the posterior pituitary in response to decreases in blood volume and blood pressure, an increase in osmolality of body fluids and other stimuli.
Vasopressin (ADH) (HUMORAL MECHANISM)
Long term regulation of blood pressure is in the ____-____ ____ system which regulates extracellular fluid volume and sodium level
Renal-Body Fluid System
Endothelium produces ____ ____. _______, and similar enzymes
- Nitric oxide (inhibits platelet aggregation and causes vasodilation)
- Prostacyclin (inhibits platelet aggregation and causes vasodilation)
Platelets produce a prostacyclin, Thromboxane A2, which causes vasoconstriction and increases aggregation - _____ blocks this response
Aspirin
Hypertension
Actual cause unknown
Age-related changes, family history, hyperinsulinemia and insulin resistance
- More prevalent and severe in blacks
- High salt intake
- Obesity
- Stress/excess alcohol consumption
- Oral contraceptive Drugs
A standard drink is equal to
14.0 grams of pure alcohol
Normal BP
Less than 120,
Less than 80
Elevated
120-129
Less than 80
HTN Stage 1
130-139
80-89
HTN Stage 2
140 or higher
90 or higher
Hypertensive Crisis
Higher than 180
Higher than 120
S/Sx of Hypertension
Typically Asymptomatic
- Headache
- Other symptoms relate to target organ damage
Main complication is stroke
Formation of plaque build up on the inside of blood vessel walls
- makes the inner lining rough
- easy for cholesterol stick to it
- causes formation of plaque
Atherosclerosis
Chronic disease of the arteries
Abnormal thickening & hardening of artery walls
Can worsen BP:
-may develop w/ age, people with diabetes & high fat diets
Arteriosclerosis
