Final Exam 4 Flashcards
What are the three basic parts of the circulatory system?
The heart, blood, and pipes (arteries and veins)
What are the two pumps of the heart and which one is the main?
Right and Left (main)
What is the pericardium?
The thin layer covering the surface of the heart
What is the myocardium?
Muscle; majority of the heart wall thickness
What is the endocardium?
The thin layer covering the surface of the heart, inner layer
Where do arteries carry blood?
Away from the heart
What are arteries?
Thick muscular walls that deal with high pressure
What do capillaries do?
connect arteries and veins
What are capillaries (structure)?
Microscopic vessel network through tissue; permeable to allow gas/nutrient exchange between blood and interstitial fluid
Where do veins carry blood?
To the heart
What are veins?
More thin-walled, easily distensible and deal with low presure
How do veins prevent backflow?
They have valves
How does deoxygenated blood become oxygenated?
oxygen diffuses from the alveolus into the lungs into RBCs, which binds to hemoglobin and 1 hemoglobin molecule binds to 4 oxygen molecules
What is the function of the right atrium?
Receives deoxygenated blood from the vena cava
What is the function of the left atrium?
Receives oxygenated blood from the pulmonary vein
How does the blood get from the atriums to the ventricles?
The atria contact and force the blood into the ventricles
What prevents multidirectional flow?
AV valves
What is systole?
When the ventricles are contracting
What is diastole?
When the ventricles are relaxing
At rest what is systole and diastole?
systole is about 1/3 time, diastole is 2/3 time
At exercise, which is more prominent: systole or diastole?
Systole
What does blood pressure depend on?
Cardiac output (CO) and venous return to the heart (preload)
What is cardiac output?
total blood flow; Volume of blood ejected from the heart every minute
What is venous return?
Flow of blood delivered by the heart, contributes to blood pressure
Where do the right and left coronary arteries originate from?
at the root of the aorta
What do the right and left coronary arteries supply?
the myocardium
What happens during diastole?
there is myocardial relaxation and the coronary arteries are filled with blood to perfuse the heart
True/False: Cardiac muscle cells do not have chemical synapses.
False; Cardiac muscle cells also have chemical synapses
What is the function of the chemical synapses in cardiac muscle cells?
Sympathetic and parasympathetic branches of the autonomic nervous system use these to MODULATE (not initiate) cardiac muscle function
True/False: Sympathetic and parasympathetic branches of the autonomic nervous system use chemical synapse to initiate cardiac muscle function
False: Sympathetic and parasympathetic branches of the autonomic nervous system use these to MODULATE (not initiate) cardiac muscle function
What is another name for the sympathetic nervous system?
Fight-or-flight
What is another name for the parasympathetic nervous system?
Rest-and-Digest
What is released during fight or flight (sympathetic)?
Epinephrine
What is released during rest or digest (parasympathetic)?
Acetylcholine
What is stroke volume?
Amount of blood ejected (Output) during a single heartbeat (from either left or right ventricle)
How do you calculate CO?
CO= Heart rate x Stroke volume
What does preload affect?
The end-systolic volume
What does the afterload affect?
ESV
What can change stroke volume?
Contraction and afterload
Explain what a strong/weak heart means in relation to the aorta.
Strong heart = more blood ejected into Aorta
Weak heart = less blood ejected into Aorta
What is afterload?
The resistance after the blood is ejected from the ventricle
What affect does plaque have?
It narrows the diameter of the arteries and increases after load, increases resistance therefore decreases stroke volume
