Flashcards in Physiology- Cardio Deck (102)
What are the 3 main plasma proteins?
What is the major blood electrolyte?
Where does erythropoiesis occur?
Cessation of bleeding is known as what?
What is the role of platelets in hemostasis?
they stick to the injured site causing a platelet plug
What do you call a clot that includes RBCs?
What makes up a clot?
platelet plug plus fibrin
Vitamin K is important for which clotting factors?
II, VII, IX, X
What initiates the intrinsic pathway of the blood coagulation cascade?
blood coming into contact with exposed collagen of the damaged tissues.
What mineral is needed for proper clotting?
What is the insoluble substance that precipitates out at an injury site?
Hemophilia is a genetic absence of what clotting factors?
Hemophilia A: Factor VIII
Hemophilia B: Factor IX
What substance dissolves clots?
What substance cleaves fibrinogen into fibrin?
Myocardial cells have more of this organelle due to its high oxidative capacity:
What cellular feature allows the heart to contract as a syncytium?
gap junctions between the muscle cells
How do T tubules differ between cardia and skeletal muscle?
Cardiac: T tubules contain extracellular fluid high in calcium
Skeletal: T- tubules contain extracellular fluid that is low in calcium
What structure brings depolarization inside the cardiac muscle and helps regulate cytoplasmic calcium?
What prevents tetanic contraction in cardiac muscle?
the long cardiac action potential
What aspect of the action potential prevents a second action potential from taking place?
long refractory period of plateau period
What is the originator of the cardiac action potential?
the SA node
What property allows the SA node to function as a primary pacemaker?
small cell size allows it to spontaneously depolarize
What acts as a delay station for the action potential?
The AV node
Why does the AV node delay the action potential?
to allow atrial muscle to depolarize before ventricular muscle, to allow for filling
What can act as a secondary pacemaker in pathological conditions?
the AV node
What allows for rapid conduction of the action potential?
Bundle of His
Bundle Branch fibers
What is the sequence of electrical impulse in the heart?
SA node--> specialized tracts--> AV node and atrial muscle--> Bundle of HIS--> bundle branches--> Purkinjie fibers--> ventricular muscle
What serves to depress the heart rate at rest by slowing down the SA node?
parasympathetic nervous system
How does the sympathetic nervous system affect conduction through the electrical system?
it speeds up conduction of the action potential and therefore increases heart rate