L14 Intro/overview Circulation Flashcards
Components of cardiovascular system
Muscular pump = heart (cardio)
Fluid = blood
Conduits = blood vessels
Together = cardiovascular system
What’s blood?
Plasma (55%)
Buffy coat (<1%)
Leukocytes
Platelets
Erythrocytes (45%)
RBCs
Main functions cardiovascular system
- Gas transport: deliver O2 to tissues and return CO2 to lungs
- Deliver nutrients to active cells or storage sites
- Transport hormones
- Help reg body temp
- Stabilize pH
- Contain cells that fight infection
Why constant need to transport gases around body?
Constant need for energy around body
ATP not stored, must be produced in cells continuously by oxidation of metabolic fuels
Glucose to ATP, use O2
Remove CO2 because it generate H+ and can influence pH
Arterial blood pH
7.45
Cannot survive long w/ pH <6.8 or >8.0
CV, respiratory, and renal systems work together to maintain pH
Acidosis
Denature metabolic enzymes and ion channels
Decrease CNS function can lead to coma, death
Alkalosis
Neurons to hyperexcitable
Tingling, fasciculation, paralysis of respiratory muscles
Heart double pump systems
Serves two circuits / vascular loops
Pulmonary circulation
Systemic circulation
Pulmonary circulation
Right side (RV) pumps deoxygenated blood to the lungs and back to the heart
Right
Deoxygenated
Systemic circulation
Left side (LV) pumps oxygenated blood to the periphery and back to right side
Left
Oxygenated
Cardiac input (CO) =
Venous return (VR)
Heart rate (HR) x stroke volume (SV)
Heart chambers
Right atrium (RA) : receives blood from vena cava
Left atrium (LA) : receives from lungs
Right ventricle (RV) : ejects blood into pulmonary circuit
Left ventricle (LV) : ejects blood into the systemic circuit
Heart valves
Tricuspid and mitral valves: btw atrium and ventricles, prevent backflow into atria when ventricles contract
Pulmonary and aortic valves: btw ventricle and blood vessels, prevent backflow into ventricles when ventricles relax
Tricuspid valve
Right AV valve
Three flaps
Mitral bicuspid valve
Left AV valve
Two flaps
Pulmonary semilunar valve
Btw right ventricular and pulmonary artery
Semilunar flap
Aortic semilunar valve
Btw left ventricle and aorta
Semilunar flap
Systole
Heart muscles contract
Dyastole
Heart muscle relax
Dilation goes to relaxation (to remember)
How does the heart get it’s own blood supply?
Right coronary artery
Left coronary artery
Coronary sinus
Coronary arteries
Supply blood to the myocardium and other components of the heart
Originate from left side of the heart at the beginning (root) of aorta
Most myocardial perfusion occurs during
Diastole
Heart regulates coronary vasodilation or vasoconstriction based upon the hearts oxygen demand
Coronary circulation possesses unique pharmacological characteristics and reactivity to adrenergic stimulation
Blood vessel features
Arteries contain more smooth muscle and elastic fibers (radius proportional to flow, recoil and descent- absorb pressure)
Veins contain valves to prevent backflow which enhances venous return (less elasticity, more collagen for holding volume)
Diameter of blood vessels
Largest - aorta
Smallest- capillaries (1 layer of epithelium for O2 exchange)
