physiology and blood Flashcards
What does the heartbeat depend on?
The nervous system.
Where does the heartbeat start?
The Sinoatrial (SA) node (pacemaker)
What is tachycardia?
A rapid heart rate, over 100 beats per minute.
What is bradycardia
A slow heart rate, less than 60 beats per minute.
What is the opposite of epinephrine?
Norepinephrine
What is the average heart rate?
75 beats per minute
What happens during atrial diastole?
The atrium relaxes, opening valves and allowing blood to flow into the ventricles.
What happens during atrial systole?
The atria contract, forcing blood into the ventricles.
What is isovolumetric contraction?
The preparation stage for the next step in the cardiac cycle, with no activity occurring.
What happens during ventricular systole?
The ventricles contract, forcing blood out of the heart.
What is isovolumetric systole
phase with no activity in the chambers; blood pressure decreases
What does the “Lub” heart sound indicate
The closing of the atrioventricular (AV) valves.
What does the “Dub” heart sound indicate?
The closing of the semilunar valves at the end of ventricular systole.
What does Starling’s Law of the Heart state
The critical factor controlling stroke volume (SV) is how much cardiac muscle is stretched.
What does the tunica intima consist of?
Endothelium, loose connective tissue, and internal elastic lamina
What does the tunica media consist of?
Smooth muscle, elastic fibers, and external elastic lamina.
What does the tunica externa consist of?
Collagen fibers.
what is the process of the heart pumping blood
1
Blood pumps into the inferior vena cava
2
It goes through the superior vena cava
3
The blood then drains straight into the right atrium
4
Next, it goes to the right ventricle, passing through the tricuspid valve
5
The,n towards the pulmonary valve to go to the pulmonary artery (for the lungs)
6
Directly goes to the lungs for gas exchange (CO2 -> O2)
7
The blood then returns to the pulmonary vein
8
It travels to the left atrium
9
After, it then transports to the left ventricle, passing through the mitral valve
10
This then goes to the ascending aorta, passing the aortic valve
11
Following the descending aorta
12
Finally, spreads out to the other organs
What happens during centrifugation of blood?
The formed elements separate from the plasma.
What percentage of blood is erythrocytes
45% of blood, known as hematocrit.
What is the buffy coat?
A thin, whitish layer between the erythrocytes and plasma, containing leukocytes and platelets.
An iron-bearing protein that binds oxygen in red blood cells
hemoglobin
A decrease in the oxygen-carrying ability of blood due to low RBC count or deficient hemoglobin
anemia
A genetic disorder where hemoglobin is abnormally shaped.
sickle cell anemia
