CV Phy And Path 1 Flashcards
What is the effect of giant cell arteritis?
Inflammed vessel
Size of lumen is reduced
Can cause bitemporal vision loss
Describe the contents and purpose of plasma.
55% of blood fluid in humans
92% water
8% glucose, hormone, proteins, mineral salts, fats, vitamins
Describe RBC (erythrocytes). How does the shape aid in function?
Transport oxygen to and from lungs
Hemoglobin binds to oxygen
Shape increases surface area and allows them to fold to squeeze through small spaces
Describe WBC (leukocytes)
Vital defenses against disease and infection
What is the total volume of the blood?
4-5L
Describe platelets.
Interact with clotting proteins to prevent or stop bleeding
Describe the 3 methods by which CO2 is transported in the blood through capillaries.
CO2 carried in RBC
HCO3- (CO2 and H2O) dissolved in plasma as carbonic acid CO2 from tissues dissolved in plasma
Describe the function of the lymphatic system in the cardiovascular system.
Lymphatic system collects excess fluid that drains from cells and tissue throughout the body and returns it to the bloodstream
Recirculated though the body
Describe the overall arrangement of the cardiovascular system.
Heart is 2 pumps for 2 systems arranged in series
Systemic circulation and pulmonary circulation are arranged in series
Flow in all portions ranged in series must be the same
Subdivisions in each system arranged in parallel
Flow of portion in parallel must sum to equal flow in the system
What must be true regarding the flow in portions that are parallel in the cardiovascular system?
Incoming must equal outgoing (equal flow)
Define pressure.
Generated from myocardial contractions and stenosis of ventricles
Contract increases pressure
What is vascular resistance determined by?
Vessel diameter
Blood viscosity (high cholesterol, polycythemia increased RBC, anemia)
What effect does high cholesterol have on resistance? Polycythemia? Anemia?
Increases resistance , Decreases blood flow (clotting)
Increase resistance
Decrease resistance, decrease viscosity, decrease blood flow
What is the equation for determining blood flow rate? What are the determinants for blood flow?
P1-P2 (pressure gradient)/ Resistance
Pressure and resistance
Are pressure gradients necessary?
Yes needed for blood to flow
What are the layers of lumen in the heart?
Innermost- tunica intima
Tunic media (muscular)
Outermost- tunica adventitia
Describe the layers of histology in the heart. What are the coronary arteries?
Endocardium
Homologous with tunica intima
Dense fibroelastic CT, Continuous with valves
Myocardium
Homologous with tunica media
Epicardium
Homologous with adventitia
Pericardium
Coronary arteries
Homologous with vasa vasorum
(a network of small blood vessels that supply the walls of large blood vessels)
What are pace maker cells?
Non-contractile cardiac muscle
Rhythmic electric signals create action potential so heart can function on its own
Describe a cardiac myocyte.
Composed of bundles of myofibrils that contain myofilaments
Myofibrils have repeating microanatomical units
Mono or bi nucleated, frequent cell bifurcations
Describe sacromeres.
Basic contractile units of myocyte
Composed of thick and thin filaments, myosin and actin
Describe the cell junctions that exist between cardiac myocyte cells.
Intercalated discs: cell junctions
Mechanical coupling- desmosomes
Electrical coupling- gap junctions
Frequent cell bifurcations
These connections allow for the rapid travel of signals within the heart
What are transverse tubules (T-tubule) in the cardiac myocyte?
Invaginations of the cell membrane
Permit rapid transmission of the action potential into the cell
Regulate cellular calcium concentration