Flashcards in Cardiac Objectives Deck (28):
List the functions of the Cv System
Transport of materials, nutrients, cell to cell communication, waste from tissue
What is the main homeostatic variable controlled by the CV system?
What two factors control MAP
Cardiac Output, and Total Peripheral Resistance
How does CO and TPR affect MAP?
TPR-Affects the resistance of the system to flow. More resistance=more pressure.
CO- affects how much blood is flowing into the arteries. More blood=more pressure.
How is CV system organized?
Left Atrium, Left Ventricle, Aorta, Descending Arteries, Capillaries, Ascending Veins, Vena Cava, Right Atrium, Right Ventricle, Pulmonary Arteries, Pulmonary Veins.
What is the Cardiac Conduction System? And what are the parts of it?
The system of modified myocytes that action potentials travel down. Starting with the SA node, to the Internodal pathways, Av Node, Av Bundle, Bundle Branches, Purkinje Fibers.
Describe the 5 phases of the Cardiac Action Potential
0: Na permability High, cell depolarizes.
1: Na channels close at 20mv, K leaks out repolarizing the cell.
2:Decrease in K permabiltiy, increase in CA permability, ap flattens.
3: CA channels close, K permability increases. Cell repolarizes rapidly
4:Resting Membrane Potential.
Why do cardiac cells have long refractory periods?
To avoid tetanus
What is EC coupling?
What is EC coupling initiated by?
What are some differences between cardiac EC coupling and Skeletal muscle?
Ca induces Ca to be released from SR. Ca is pumped out of the cell using secondary active transport.
What ekg wave represents ventrical repolarization?
What does the p wave represent?
What does the QRS complex represent?
What factors affect cardiac output?
Stroke Volume, and Heart Rate
Which autonomic system has the greatest affect on heart rate?
What does epinephrine affect in stroke volume?
force and rate of contraction, venous resistance.
Which blood vessel controls the resistance to flow?
Which blood vessel is known as pressure resovoirs?
Which blood vessel is known as volum reservoir?
What are the two types of pressures in blood pressure?
Systolic Pressure, Diastolic Pressure.
What is the importance of pressure gradients?
Blood flows down pressure gradients
Where is the lowest blood pressure found?
Where is the highest blood pressure found?
Why does blood pressure fall as blood travels through the system?
Due to friction with the wall or the resistance to flow.
How is the perfusion of tissues regulated?
By changing the resistance of the arterioles that lead to cappillaries near tissues.
How is arteriolar diameter regulated?
Through tonic control, using norepinephrine.