Test 3 (Cardiovascular system) Flashcards
What does plasma consist of?
90% water
Acts as fluid for transport
7-9% proteins
Erythrocytes
RBC
Leukocytes
WBC
Thrombocytes
Platelets
Contain no nucleus or organelles and have a disc shape
Erythrocytes
Oxygen carrying cell
Hemoglobin
What removes most of old RBC
Spleen
Refers to a below normal O2 carrying capacity of the blood
Anemia
What are some causes of anemia?
dietary deficiency pernicious anemia blood loss bone marrow failure hemolytic anemia
Colorless cell fragments that function for about 10 days
platelets
Hormone produced by liver increases number of megakaryocytic and therefore increases platelet production
Thrombopoienin
What are the 3 major steps involved in Hemostasis?
vascular spasm
formation of platelet plug
Blood clotting
Reduced blood flow through a damaged vessel
Vasculr spasm
Platelets aggregate on contact with exposed collagen in damaged wall of the vessel, which then release ADP which causes platelets to become sticky
Formation of platelet plug
Mobile units of bodys immune defense system
Leukocytes
What are the two circuits of the heart?
Pulmonary
Systemic
Takes deoxygenated blood from the heart to the lungs and releases CO2 and picks up O2
Pulmonary
Takes blood from left side of the heart to the body.. Releases O2 and picks up CO2
Systemic
What are the valves
atrioventricular
Semilunar
When are values open?
When pressure is greater behind the valve
When do valves close?
When pressure is greater in front of the valve
Allow blood to flow from atrium to ventricle only
Valves
Prevent valves from reverting during ventricular contraction
Chordae tendon attached to papillary muscles
Narrowing of the exit of the left ventricle, which causes heart murmur
Aortic stenosis
Defect in ventricular septum, which causes heart murmur
VSD
Cardiac
2 phases: Systole
Diastole
What happens in Systole phase?
Isovolumetric contraction
Ejection
Isovolumetric contaction
Ventricles contract but no blood ejected
BP rises above pressure in atria
Atriventricular valves shut
Ejection
look at pp
What happens in Diastole Cycle?
Isovolumetric Relaxation
Rapid filling
Atrial contraction
Pressure in ventricles drops below arterial pressure
Semilunar valves prevent back flow of blood
No change in ventricular volume
Isovolumetric Relaxation
Atria fail to contract regularly
Atrial fibrillation
What are the 3 specialized types of cardiac muscle cells
Auto rhythmic cells
Contractile cells
Sequence of Electrical Activity of Heart
SA node AV node Bundle of His Purkinje fibers Spread to non-conducting ventricular cells through gap junctions
Atrial depolarization
P wave
QRS wave
spread of depolarization
T wave
depolarization of ventricles
Provides blood supply to heart during diastole
Coronary vessels
Chest pain resulting from lack of oxygen to heart
angina
Caused by a weak left ventricle that is not pumping effectively
congestive heart failure
Volume of blood ejected by each ventricle each minute
cardiac output
Force exerted by blood
pressure
What are determinants of blood flow
blood viscosity
vessel length
vessel radius
Carry blood away from heart to tissues
Arteries
Smaller branches of arteries
aterioles
Smallest of vessels across which all exchanges are made with surrounding cells
Capillaries
Formed when capillaries rejoin and it returns blood to heart
Venules
Formed when venues merge
Veins
Maximal arterial pressure when the heart contracts
Systolic pressure (120)
Minimum pressure when blood is draining off into vessels downstream
Diastolic (70)
Average pressure driving blood forward into tissues throughout cardiac cycle
Mean arterial pressure
Restriciton in blood supply to tissues
ischemia
Blood pressure above 140/90
Hypertension
elevated bp due to age and treated with lifestyle modifications
Primary hypertension
Elevated bp due to preceding cause
secondary hypertension
Blood pressure below 100/60
hypotension
What factors enhance venous return
driving pressure from cardiac contraction
sympathetically induced vein vasconstricition
skeletal muscle activity
clots develop in the veins of lower limbs
Deep Vein Thrombosis
Occurs when the valves in the veins weaken and fail and blood pools in the veins
Varicose veins
Stretch receptors that sense bp and relay information to the brain
baroreceptors
Secreted in response to low blood pressure and low blood flow to kidneys
Aldosterone