Cardiovascular System Part 1 Flashcards
Which circuit has the greatest drop in pressure
Systemic
Which circuit has a medium pressure and resistance
Pulmonary
Which circuit has a higher pressure and resistance
Systemic
In which circuit do veins carry deoxygenated blood
Systemic
In which circuit do arteries carry deoxygenated blood
Pulmonary
In which circuit do veins carry oxygenated blood
Pulmonary
In which circuit do arteries carry oxygenated blood
Systemic
Blood volume found in systemic veins
84%
Total blood volume
5L
Total blood output
5L/min
Ventricular pump: Filling phase
Ventricle fills from the venous end (vein)
Ventricular pump: Ejection phase
Contraction, the volume goes down, inlet valve closed and outlet valve open
Ventricular pump: Improvement #1
The atrium accumulates venous blood during the ejection phase
Ventricular pump: Imporvement #2
Adding auricle, increase the capacity of the atrium
How outlet valves work
- Ventricular ejection
- Ventricular relaxation
- Ventricular pressure decreases
- Pressure in great arteries is larger
- Blood flows to ventricles
- Filling semilunar valves of the ventricles
- Valve flaps forced together to make a seal
What is the inner and outer wall of pericardium made of?
Single-layer of squamous mesothelium
Layers of pericardium from inside out
- Visceral pericardium
- Pericardial space (serous fluid)
- parietal pericardium
- fibrous pericardium
Where does the apex of the heart point
Points inferiorly, anteriorly to the left
The right border of the heart is formed mainly by the _______
Right atrium
The left border of the heart is formed mainly by the ____
The left ventricle and partially left atrium
The inferior border of the heart is formed mainly by the _______
Right ventricle
Which valve is not supported by a fibrous ring?
The pulmonary valve
Pathway of AP
SA node -> AV node -> atrioventricular bundle -> bundle branches -> Purkinje fibres
Elastic artery: Systole
Blood flows into the artery faster than it can flow out, it stretches the artery causing it to store kinetic energy
Elastic artery: Diastole
Pushes blood out into arterial tree by elastic recoil
Elastic artery: structure
many thin sheets of elastin
Conduction system of heart: speed of SA node -> atrial muscle
Slow 0.5m/s
Conduction system of heart: speed atrioventricular node
Very slow 0.05m/s
Conduction system of heart: speed of AV bundle -> Purkinje fibers
Fast 5m/s
Conduction system of heart: Result of SA node -> atrial muscle
Atrial contraction
Conduction system of heart: Result of Atrioventricular node
100ms second delay, allows atria to top up ventricle with blood
Conduction system of heart: Result of AV bundle -> Purkinje fibers
Complete even ventricular contraction = systole
Which blood vessel is responsible for the bulk distribution of blood around the body
Muscular artery
Muscular artery: blood is proportional to the _th power of the _______
4th power of the radius
Muscular artery: Structure
Many layers of circular smooth muscle wrapped around the vessel in the middle tunic
Which blood vessel controls blood flow?
Arteriole
Which vessel has the greatest pressure drop?
Arteriole: occurs where the greatest resistance to flow is
The degree of constriction of arterioles determines
- Total peripheral resistance, which affects:
- mean arterial blood pressure
Arteriole: structure
Between one and three layers of circular smooth muscle wrapped around the vessel in the middle tunic
Which blood vessel allows for the exchange of gases, nutrients, and wastes between blood and surrounding tissue fluid?
Capillary
The capillary
- Tiny thin-walled structures
- Blood flow is slow
- Both allow for the exchange
Capillary: structure
- Only wide enough for one blood cell
- Capillary wall is a single layer of endothelium
Which blood vessel carries white blood cells around the body to infections?
Venules
Venules
- Low-pressure vessels
- Carry WBC around the body to infection
- Small venules = endothelium + CT
- Large venules also have a single layer of smooth muscle
Veins: overview
- Thin-walled, low-pressure vessels
- drain blood back to atria
- walls are easily stretched
Veins: structure
- Similar to muscular artery but walls are much thinner for their size (less muscle and CT)
- Larger veins, like those in legs, have valves to prevent backflow
Coronary arteries: Overview
- The valve immediately upstream is the aortic valve
- The coronary arteries supply the tissue with oxygenated blood
- The chamber into which the cardiac veins drain is the right atrium
With regard to resistance in the cardiovascular system, the parameter with the largest effect is:
Radius
An increase in cardiac sympathetic activity would most likely and immediately:
increase stroke volume
The component of the conduction system providing the only electrical connection between the atria and the ventricles is the:
Atrioventricular bundle
With regards to the Frank-Starling law of the heart, an increase in venous return to the heart will result in:
An increase in end-diastolic volume
Electrical stimulation of the vagus nerve would result in:
Bradycardia - Bradycardia means your heart rate is slow. This can be completely normal and desirable, but sometimes it can be an abnormal heart rhythm (arrhythmia). If you have bradycardia and you have certain symptoms along with the slow heart rate, then it means your heartbeat is too slow
A decrease in arterial blood pressure would most likely and immediately lead to:
Decreased afterload
Cardiac output
The volume of blood ejected into the aorta from the left ventricle per minute
Stroke volume
The volume of blood pumped out from one ventricle in one cardiac cycle
Venous return
Rate of blood returning back to the heart every minute (flow)
Cardiac reserve
- The difference between cardiac output when the heart is working as hard as it can and when it is at rest
- = maximum cardiac output - minimum cardiac output
Preload
The stretch on the heart before it contracts (EDV)
Contractility
The strength/force of contraction at any given preload
- Can be increased by positive inotropic agents (promote Ca2+ entry/influx during cardiac APs)
- Can be decreased by negative inotropic agents (increase K+ entry or decrease Ca2+ entry)
Afterload
The pressure required for the blood to be pushed out of the ventricles and into the arteries (the pressure that needs to be overcome to open the semilunar outlet valves)
Increased afterload = decreased stroke volume
Frank-Starling law of the heat
More preload = greater force of contractility/inotrophy
(More blood pumped in during diastole = more blood pumped out in systole = increase in SV)
The more the heart is filled is diastole, the greater the force of contraction during systole
Blood flows from the pulmonary veins into the:
left atrium
During the cardiac cycle, the volume of blood in the ventricles:
Decreases most rapidly in the phase of ventricular ejection
The function of the Chordae tendineae is to:
Prevent eversion of the AV valves during ventricular systole
The part of the heart’s conduction system which conducts most slowly is the
Fibers of the AV node
Closest CSF producing structure to the midbrain
Cerebral aqueduct
The semilunar valve is between the:
the right ventricle and the pulmonary trunk
Atrioventricular valves close when the:
ventricles contract
Atrioventricular valves open when the:
Ventricular pressure falls below atrial pressure
The function of the Chordae tendineae is to:
Prevent eversion of the AV valves during ventricular systole
What occurs when the aortic and mitral valves are both closed?
Pressure in the left ventricle is either rapidly increasing or decreasing
Which structures, seen in a coronal section of the brain, are all white matter?
Corpus callosum
Cerebral peduncles
Internal capsule
Blood flows into the coronary arteries from the:
Ascending aorta
Coronary arteries are classified as:
Muscular arteries
The SA node is located in the:
the right atrial wall near the opening of the superior vena cava
During the cardiac cycle the papillary muscles contract when:
the mitral and tricuspid valves are closing
What are the four landmarks visible on the lateral side of the human brain, that define the lobes?
- Lateral fissure
- Preoccipital notch
- End of parieto-occipital sulcus
- Central sulcus
The Frank-starling law states that
a greater force of contraction can occur if the heart muscle is stretched first
The second heart sound (dupp) is created by the:
turbulence generated as a result of the closing of the semilunar valves
The fibrous skeleton of the human heart:
- It provides attachment for the ventricular inlet and outlet valve cusps
- It acts as an electrical insulator between the atrial muscle and ventricular muscle
- It acts to prevent distortion of the ventricular inlet and outlet valves
- It is penetrated by the atrioventricular bundle of the heart’s conduction system
Baroreceptors are located in the:
walls of the aorta and carotid arteries
A fall in blood pressure results in:
a decrease in afferent baroreceptor nerve firing
Blood flows most slowly through the:
capillaries because their total cross-sectional area is the largest
During the cardiac cycle the papillary muscles contract when:
the mitral and tricuspid valves are closing
Blood pressure is highest in which blood vessel?
Brachiocephalic trunk
Net filtration equation
NFP = (BHP + IFOP) - (BCOP + IFHP)
The pulmonary and aortic valves lack Chordae tendineae because:
when the valves close the cusps remain stable because of their cup-shape
An increase in venous return most directly affects
stroke volume
Stimulation of the heart by autonomic nerve fibers traveling with the vagus nerve causes:
decreased heart rate and no change in ventricular contractility
If Ach is applied to the heart, but the cardiac output is to remain constant, which of the following would have to happen?
stroke volume must increase
An increase in the preload on the heart is most likely to result from:
an increase in blood volume
A decrease in arterial blood pressure would most likely and immediately lead to
decreased afterload
Deoxygenated blood leaves the ___ side of the heart towards the lungs to receive oxygen
right
Oxygenated blood from the lungs enters the ___ side of the heart
left
Oxygenated blood leaves the ___ side of the heart towards to rest of the body to provide oxygen for body systems
left
Superior vena cava
Vein that carries deoxygenated blood from the upper half of the body (head and upper limbs) to the right atrium of the heart
Inferior vena cava
Vein that carries deoxygenated blood from the lower half of the body to the right atrium of the heart
Pulmonary trunk
blood vessel that divides to form the right and left pulmonary arteries
Pulmonary artery
Blood vessel that transports deoxygenated blood from the right ventricle of the heart to the lungs
Pulmonary vein
Blood vessel that transport oxygenated blood from the lungs to the atrium of the heart
Outlet valves of the heart are the ___ and ___ valves
aortic and pulmonary
Inlet valves of the heart are the ___ and ___ valves
triscuspid and mitral
Outlet valves are sometimes described as ___, due to their shape
semilunar
Both aortic and pulmonary valves have ___ cusps and ___ cords
three
lack
The peak pressure in the left atrium is __ mmHg
5
The peak pressure in the left ventricle is __ mmHg
120
The peak pressure in the right atrium is ___mmHg
2-3
The peak pressure in the right ventricle is __ mmHg
25
The fibrous skeleton:
fibrous rings that support the mitral, aortic, and tricuspid valves
The fibrous skeleton strengthens the ___ and ___ valves the most due to their high pressure
Aortic and mitral
Dilated cardiomyopathy
dilation of the muscle wall of the heart
Mitral regurgitation
an abnormal reversal of blood flow from the left ventricle to the left atrium cause by disruption of mitral valve function
Dilated cardiomyopathy causes the ____ ____ supporting the ___ valve to stretch
Fibrous skeleton
Mitral
Dilated cardiomyopathy affects which ventricle the most and why?
Left, high pressure
During mitral regurgitation, the left ___ pressure slightly increases
atrial
