Week 1: Cardiovascular System Flashcards
T or F
The pulmonary vascular bed has less resistance than the systemic bed
T
Sympathetic neural activation of the heart will increase which of the following?
a. heart rate
b. PR interval
c. metabolic demands
d. coronary flow rate
e. cardiac contractility
f. sleep
a, c, d and e
What does “venous capacitance” mean?
The measure of a BLOOD VESSEL’’s ability to increase the volume of BLOOD it holds without a large increase in BLOOD PRESSURE.
T or F
Thrombophlebitis never causes oedema
F
Thrombophlebitis is inflammation of the veins and will cause swelling but might cause oedema, especially if long standing.
T or F
Lymphatic blockage favours oedema formation
T
T or F
Decreased plasma protein concentrations doesn’t increase the chances of oedema formation
F
T or F
Greatly increased capillary pore size increases the chances of oedema formation
T
What separates the two atrium in the heart?
interatrial septum
What separates the two ventricular in the heart?
interventricular septum
The right atrium and right ventricle are connected via what valve?
The tricuspid valve
The left atrium and left ventricle are connected via what valve?
The bicuspid valve
The bicuspid valve is also called…
the mitral valve
The leaflets of the hearts atrioventricular valves are connected to fibrous tissue called…
chordae tendinae.
What are chordae tendinae attached to?
papillary muscles
Contraction and relaxation of what muscles cause a hearts valves to open and close?
papillary muscles
Contraction and relaxation of what muscles cause a hearts valves to open and close?
T or F
Like the atriums and ventricles of the heart, the aorta and pulmonary trunk also have valves.
T
The pulmonary and aortic valves are also called…
semilunar valves
The characteristic “double up” sound of the heartbeat is produced during…
the closing of the heart valves.
T or F
The walls of the atrium are thicker than those of the ventricles.
F
They are thinner
Which ventricle pumps blood a greater distance at higher pressures?
the left ventricle
T or F
The walls of the left ventricle are comparatively thicker than those of the right ventricle.
T
What 4 sections/fibres of the heart are considered specialised cardiac tissue?
- Sino-atrial Node (SAN)
- Atrio-ventricular Node (AVN)
- Bundle of HIS
- Purkinje Fibres
T or F
All specialised cardiac tissue is auto-excitable
T
The wall of the heart is comprised of what three layers?
from inside out:
Endocardium
Myocardium
Epicardium
Which layer of the hearts walls contains cardiac myocytes?
The myocardium
A heart walls myocardium consists mainly of … cardiac muscle fibers arranged … around each heart chamber.
contractile
spirally
Which layer of the heart is continuous with the endothelial lining of the blood vessels?
endocardium
What is mesothelium?
the epithelium that lines the pleurae, peritoneum, and pericardium
Which layer of the heart walls can be described as a simple squamous mesothelium supported by a layer of loose connective tissue containing blood vessels and nerves.
the epicardium
What is the layer of loose fibrous tissue uniting the endocardium and myocardium called?
the subendocardial layer
What does the endocardium of the heart wall consist of?
- the lining endothelium
- the lining endotheliums supporting layer of fibroelastic connective tissue with scattered fibers of smooth muscle
- the subendocardial layer
The subendocardial layer of the heart walls is specialsed for what?
impulse induction
The subendocardial layer of connective tissue in the ventricles surrounds … fibres of the heart’s impulse conducting network.
Purkinje
What specialised heart fibre am I?
I am modified cardiac muscle fibers joined by intercalated disks but specialised for impulse conduction rather than contraction. I contain glycogen but relatively few organelles and peripheral myofibrils.
Purkinje fibres
T or F
Purkinje fibers typically are paler staining than contractile muscle fibers.
T
T or F
The thickness of the myocardium varies between chambers.
T
T or F
The thickness of the myocardium is NOT directly proportional to the work the chamber has to perform to pump blood.
F
What is the thickest layer of the heart walls?
The myocardium
T or F
The atria, serve as receiving chambers and perform little pumping action.
T
T or F
The blood flow through atria is passive.
T
When the ventricles contract, they must generate enough pressure to force open the … and push the blood into the …
semilunar valves
circulatory trees (systemic and pulmonary)
Under normal resting conditions, between heart beats, the pressure in the pulmonary artery is approximately … mmHg and pressure in the aorta is approximately … mmHg.
8
80
It is estimated that the left ventricular wall is … times thicker/thinner compared to the right ventricular wall.
3
thicker
What am I?
I am a cell type that covers and protects most of the internal organs of the body as well as adipose and connective tissue.
mesothelium
The aorta, the pulmonary trunk, the superior vena cava, and inferior vena cava of the heart are collectively referred to as…
great vessels
The S1 heart sound is caused by the closure of what valves?
The tricuspid and mitral valve
A split S1 sound is best heard in which auscultation area?
The tricuspid
T or F
In a typical heart the tricuspid and mitral valve will close simultaneously
T
Thus creating the S1 sound. A split S1 sound indicates that the tricuspid and mitral valves aren’t closing simultaneously.
T or F
A split S1 is medically concerning.
F
A split S1 is usually a normal finding that can be found in approximately 40%-70% of the population.
What does a right bundle branch block (RBBB) cause?
An RBBB causes the electrical impulse to reach the left ventricle before the right ventricle and makes the mitral and tricuspid valve close at different times. A split S1 is heard in RBBBs.
Match the term to the definition:
a. Cardiac output
b. Stroke volume
c. Heart rate
- The number of heart beats per minute
- The amount of blood pumped out of each ventricle/minute
- The volume of blood ejected per beat
a2
b3
c1
Diastole and systole are abbreviated as…
EDV and ESV
T or F
Stroke volume can only be changed by changes in EDV or ESV.
T
T or F
The phase of cardiac cycle during which the ventricles contract is called diastole
F
systole
Ventricle muscles
relaxing is called …
diastole
T or F
During systole, the blood is pumped out of the heart, and during diastole the heart is filled with blood.
T
What is meant when myocardium is said to be a “functional syncytium”?
That means the cells are not isolated from each other, and whenever one cell is excited, it leads to excitation spreading to all cardiac muscle cells.
T or F
Contrary to the cardiac muscle, the skeletal muscle cells show autorhythmicity.
F
vice versa
Excitation of the heart normally starts from the … node
sino-atrial (SA)
T or F
As we move down the conduction pathway
from the sinoatrial node to the AV node, the rate of firing increases
F
decreases
The normal firing rate of the heart is … to … beats per minute.
70 to 80
Frank Starling’s law states what?
that stroke volume of the left ventricle will increase
as the left ventricular volume increases. (This is due to myocardial stretch causing a more forceful systolic contraction.)
When a person stands up,
the cardiac output of that person falls, why?
because of a fall in central venous pressure.
The sympathetic nervous system exercises control over the heart via … fibres. Whilst the parasympathetic nervous system exercises control via … fibres.
adrenergic
cholinergic
T or F
While the parasympathetic nervous system reduces the force of atrial contraction,
it does not affect the ventricles.
T
… arteries are the only arteries in the body that carry deoxygenated blood.
Pulmonary
Increased tissue metabolic rate leads to … dilation and increased tissue …
arteriolar
blood flow
Which neural fibers provide the most important means of reflex
control of vascular resistance and organ blood flow?
sympathetic nerve fibers
AV valves close/open when atrial pressures are higher than ventricular pressures.
open
The heart is an efficient and durable pump that on average beats … times per day and ejects over … litres of blood per day.
100,000
7000
Blood vessels, measuring … Km in length when joined end-to-end, act as pipes that are connected to the heart allowing a constant flow of blood to all parts of the body.
160,000
T or F
The kidney receives more blood flow than its metabolic requirements mainly due to its excretory functions.
T
There are multiple variables that regulate the blood vessels which are critical to maintain their function. The most important ones are …, … and …
blood flow, blood pressure, and vessel resistance.
The heart starts beating at about … weeks in utero.
five
T or F
When we are resting blood flow to the skin is reduced.
T
The cardiovascular system includes what two separate circulatory sets?
pulmonary circulation and systemic circulation.
T or F
The right side of the heart is responsible for systemic circulation,
whereas the left side is responsible for pulmonary circulation.
F
vice versa
Normal pulmonary artery systolic pressure at rest is about … to … mmHg.
18 to 25
The low pressure in the pulmonary circuit is due to …., resulting in lower resistance.
the large cross-sectional area of the pulmonary circulation
The normal systolic pressure in systemic circulation is about …mmHg.
120
The high pressure in the systolic circuit is to overcome the …., in particular the arterioles.
resistance of systemic blood vessels
The septum that separates the right from the left atrium is known as the …, and the septum that separates the right from the left ventricle is known as …
interatrial septum
interventricular septum
T or F
Morphologically, the interatrial septum is very important because it holds the bundle of His and the right and left bundle branches.
F
the interventricular septum
The systemic circulation
is complemented by which two accessory systems?
The portal and azygos systems.
T or F
The blood within the azygos system is very low in oxygen, but very high in nutrition.
F
the portal system
Both the portal and azygos systems eventually drain into the … system.
caval
The … system helps drain venous blood from intercostal spaces and the posterior abdominal wall.
azygos
When the right side of the heart fails blood starts to pool in what locations?
The primary site would be the right atrium. Once the right atrium has reached capacity, the blood will start to pool in the superior and inferior vena cava.
What side of a patients heart is failing when there is jugular venous pressure?
The right side
Pooling of blood in the inferior vena cava results in a pulsatile …
liver.
T or F
Peripheral pooling results in oedema.
T
Heart failure in the left side of the heart results in a pooling of blood in the left atrium. Once the left atrium has reached its capacity, blood will start to pool in the …
pulmonary circuit
The coughing up of blood stained mucus indicates heart failure in which side of the heart?
left
Difficulty breathing, especially when lying down indicates heart failure in which side of the heart?
left
The percentage of blood that the heart can carry is
usually measured by a unit called …
ejection fraction.
Normal left ventricular ejection fraction
is about … to …%.
50 to 60%
What does HFREF stand for?
heart failure with reduced ejection fraction
When heart failure with reduced ejection fraction occurs the heart is pumping only …% of its blood into the systemic circulation.
40
T or F
In systolic heart failure, the hearts ejection fraction may be reserved.
F
In diastolic heart failure
T or F
Clinically, left heart failure eventuality leads to right heart failure.
T
T or F
The hearts valves are bidirectional
F
unidirectional
T or F
In the vascular system,
only veins have valves
T
Under normal conditions, average pressure in systemic arteries is approximately … mmHg whereas the average pressure in systemic veins approaches … mmHg.
100
0
Briefly describe Poiseuille’s Law.
Blood flows through a vessel within an organ only because of the pressure difference that exists between the blood in the arteries supplying the organ and the veins draining it
T or F
The sarcoplasmic reticulum of cardiac myocytes stores many calcium ions
F
They store few
T or F
Cardiac myocytes have few mitochondria
F
They have plentiful
T or F
The myocardium is comprised only of myocytes
F
Although myocytes make up 70% of the myocardium
… is used as a biomarker
for myocardial infarction.
Troponin
Within the cardiac myocytes, the fibres can be divided into … and … fibres
slow and fast
Within the SA node and AV node, the fast fibres can be converted into slow fibres by the effects of ….
hypoxia or certain toxins that block sodium channels.
T or F
The normal atrial and ventricular myocardial cells as well as specialised conducting tissue in the heart are all fast fibres.
T
T or F
Skeletal muscle action potentials are very rapid,
whereas cardiac muscle action potentials are spread over a considerable time.
T
This spread of action potential is primarily due to calcium ions.
…. are a component of the cardiac conducting system exhibiting the longest plateau phases
of any cardiac tissue.
Purkinje fibres
Sympathomimetic drugs not only increase the …,
but also increase the ….,
which helps increase the slope of phase four depolarisation.
heart rate
slow inward calcium current
The sympathetic nervous system causes a marked positive/negative inotropic effect due to an/a increase/decrease in the flux of calcium,
whereas parasympathetic nervous system causes
a positive/negative inotropic effect
by increasing/reducing the flux of calcium.
positive
an increase
negative
reducing
Small changes in … concentration can have a devastating effect on the heart.
potassium
Match the terms to the definitions:
a. Bathmotropy
b. Lusitropy
c. Inotropy
d. Dromotrophy
e. Chronotropy.
- contractility
- rate
- conduction at the AV node
- excitability
- relaxation
a4, b5, c1, d3, e2
Activation of the cardiac parasympathetic nerve activity will have a positive/negative chronotropic effect on the heart.
negative
Why would increased arterial pressure cause a reduction in stroke volume?
because it takes more force to overcome the resistance of the peripheral vasculature.
T or F
it is possible for a person
to have a heart attack yet a very normal ECG.
T
What does the P wave on an ECG represent?
atrial depolarisation
What does the Q wave on an ECG represent?
depolarisation of the interventricular septum.
What does the QRS wave on an ECG represent?
ventricular depolarisation.
What does the T wave on an ECG represent?
ventricular repolarisation.
In some ECGs, an additional positive
deflection may be noticed immediately after the T wave. This is known as the … wave and it is thought to represent the … of …
U
repolarisation
Purkinje fibres
On a standard EKG paper, or ECG paper, the speed is … millimeters per second.
25
T or F
The baroreceptor reflex is slow
F
it is a very fast reflex and occurs within minutes
after a change has occurred in the cardiovascular system.
T or F
Blood pressure is directly proportional to blood volume
T
What 3 things are responsible for the viscosity of the blood?
The composition of plasma
The total number of cells in the blood
The resistance of the cells to deformation and temperature
What 3 types of capillaries are present within the body?
continuous, sinusoidal, and fenestrated.
T or F
Capillaries are “naked” tubes of endothelium i.e. they are not surrounded by a layer of smooth muscle
T
What is the most abundant capillary type in the body?
continuous capillaries
T or F
Blood flow that bypasses the capillaries, as it passes from the arterial to the venous side of the circulation via metarterioles, has been termed nutritional flow, or shunting.
F
non-nutritional flow
Diffusion across a capillary wall is governed by … law.
Fick’s
What does Fick’s law state?
This law states that for adequate diffusion to occur concentration gradient of the solute and distance of diffusion play important roles.
T or F
Plasma proteins can generally cross the capillary wall
F
The only effective oncotic agent in capillaries is …
protein
capillary oncotic pressure, favours/opposes filtration out of the capillaries and is dependent on the … concentration in the blood.
opposes
protein
capillary hydrostatic pressure, favours/opposes movement out of the capillaries and is dependent on both … and ….
favours
arterial
venous blood pressures
Treatment for oedema includes…
medication, reducing intake of salt, wearing compression stockings, and keeping legs raised.
Common drug classes used to treat oedema include…
corticosteroids, loop diuretics, thiazide diuretics, potassium-sparing/thiazide diuretic combinations, thiazide-like diuretics, carbonic anhydrase inhibitors, and potassium-sparing diuretics.
What medications can cause oedema?
Pramipexole, clonidine, trazadone, MAO-inhibitors, NSAID’s, calcium channel blockers, beta-blockers, corticosteroids, gabapentin, pregabalin, pioglitazone, rosiglitazone and insulin.
Stimulation of the … nerve reduces heart rate.
vagus
