Cardiovascular System Flashcards
Systemic Flow
Blood pumped from aorta to rest of body. Carries oxygen, nutrients, hormones; removes metabolic waste
Pulmonary Flow
Deoxygenated blood from right ventricle pumped to the lungs. CO2 is removed and O2 is replenished
Pathway of Blood Flow (Cycle)
Veins-vena cava-right atrium-right venticle-pulmonary artery-lungs-pulmonary vein-left atrium-left ventricle-aorta-arteries-arterioles-capillaries-venules-veins
Delivery of Oxygen
- Diffuses into blood in alveolar capillaries (lungs)
- Binds to hemoglobin in Red Blood Cells
- Gets transported to tissues
- Used in cellular respiration
Removal of Carbon Dioxide
- Cellular respiration produces CO2
- Carbonic anhydrase converts to bicarbonate (bc CO2 is nonpolar and not very soluble in blood)
- Dissolved bicarbonate and CO2 transported in blood
- Diffuses out of alveolar capillaries & exhaled out
Blood Pressure
Pressure blood exerts on the walls of blood vessels
Systolic Pressure
Blood pressure when blood is being pumped (ventricles contracting)
Diastolic pressure
blood pressure when blood is not being pumped (ventricles relaxing)
Arteriole
Controls blood flow to capillaries. Allows body to control which tissues get more blood. Important for vasoconstriction.
Capillaries
Site of blood-tissue solute exchange
Atrioventricular valves
Separate atria from ventricles. Prevent blood from flowing back into atria; promote forward flow. Includes tricuspid valve and mitral/bicuspid valve
Semilunar valves
Separate ventricles from vasculature. Prevent blood from flowing back into heart. Includes pulmonary valve and aortic valve
Tricuspid valve
between right atrium and right ventricle
Mitral/bicuspid valve
between left atrium and left ventricle
Pulmonary valve
separates right ventricle from pulmonary circulation
Aortic valve
separates left ventricle from aorta
Electrical conduction of heart
Contraction of cardiac muscle originates from electrical impulses that start at SA node in right atrium. Contraction causes increase in pressure that pushes more blood into ventricles (atrial kick). Signal spreads to AV node, between atria and ventricles
Systole
Ventricles contract, AV valves close, blood pumped out of ventricles
diastole
Ventricles relax, semilunar valves close, blood from atria fills ventricles
Cardiac Output (CO)
total blood pumped by ventricle per minute.
CO=HR *SV
HR= heart rate, beats per min
SV=stroke volume, volume of blood pumped per beat
Erythrocytes
Red blood cells.
Designed for O2 transport. Contain hemoglobin molecules, which each bind four molecules O2. Biconcave shape: helps travel through capillaries and increased surface area for gas exchange. Lack organelles. (no cell. resp.)
Leukocytes
White blood cells.
Crucial for immune system.
2 Classes: Granulocytes and agranulocytes
Granulocytes
3 kinds: neutrophils, eosinophils,basophils.
contain granules toxic to invading microbes, released via exocytosis. involved in inflammatory rxns, allergies, fighting parasites
Agranulocytes
2 kinds: lymphocytes and thrombocytes
Lymphocytes
important for specific immune response. targeted fight against pathogens. primary response and long term pathogen recognition. exposure to weakened pathogen caused creation of memory cels (vaccines). Include B cells and T cells and monocytes
Thrombocytes
Platelets.
cells fragments released from bone marrow cells. assist in blood clotting
ABO blood types
A and B are codominant (both expressed). i is recessive. O blood (ii) does not have A or B proteins. if given blood transfusion, would produce antibodies to A, B, or AB blood
Rh factor
+ if D allele present. - if D allele absent. autosomal dominant inheritance. If - would produce antibodies when receive transfusion with + blood type
Blood pressure measurement
expressed as a ratio, systolic/diastolic. P=CO *TPR
P=pressure differential, CO=cardiac output, TPR=total peripheral resistance
Resistance of blood flow
capillaries and arterioles act as resistors, limit blood flow. resistance based on length and cross section of blood vessel. longer-more resistance. larger cross section-less resistance
Baroreceptors
detect change in force. decreased b.p. stimulates vasoconstiction, which increases b.p.
Chemoreceptors
sense when osmolarity of blood is too high (indicates dehydration). promotes release of antidiuretic hormone (ADH or vasopressin). increases reabsorption of water which increases blood volume & pressure
aldosterone
increases reabsorption of sodium which increases reabsorption of water
Exchange of oxygen
carried primarily by hemoglobin. O2 diffuses into alveolar capillaries in lungs. cooperative binding: once first O2 binds, hemoglobin has conformational shift, increases affinity to O2. more O2 released to tissues during exercise, rather than taken to lungs.
Exchange of carbon dioxide
waste product, must be removed from blood. nonpolar so most is converted to bicarbonate (HCO3-) by carbonic anhydrase. Production of H+ ions decreases pH. H+ binds hemoglobin and decrease affinity for binding O2
Hydrostatic pressure
force blood exerts against walls of blood vessel. generated by contraction of heart. pushes fluid out of bloodstream, into interstitium through capillary walls
Osmotic pressure
pressure from solutes drawing fluid into bloodstream. also called oncotic pressure
Coagulation
platelets protect vascular system by forming clots to prevent blood loss when injured. injuries damage endothelium of vessel and expose collagen. platelets sense collagen, triggering clumping of platelets. coag.factors activate prothrombin to form thrombin which produces fibrin. fibrin contributes to stable clot.
Plasmin
breaks down blood clots after healing process
fibrin
forms net of fibers after being activated by thrombin, initiated by coagulation factors. produces stable blood clot
