The cardiovascular system Flashcards
TRUE OR FALSE: The function of the AV valves is supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur
TRUE
What is required for cardiac muscle to contract?
An electrical signal from inside the heart
Blood returning to the heart from the systemic circuit first enters the
right atrium
Blood flowing into the heart from the venae cavae flows next through the ________ valve
The Tricuspid/right atrioventricular valve
Which valve prevents backward flow of blood into the left atrium ?
The Bicuspid/Mitral/Left atrioventricular valve
Regurgitation of blood into the atria is partly prevented by:
the action of connective tissue holding the atrioventricular valve
What is the normal pacemaker of the heart located?
The sinoatrial node
The P wave of the electrocardiogram represents the:
The atria contracting (depolarisation)
The electrical activation (depolarisation) of the ventricles is represented on an electrocardiogram by the:
QRS complex
The T wave on an ECG tracing represents:
ventricular deactivation (repolarisation)
Compared to arteries, veins have …. walls:
thinner
As blood travels from arteries to veins:
pressure drops
The main control of resistance to blood flow occurs in the:
arterioles
The baroreceptors in the aorta and carotid artery are sensitive to which stimuli?
arterial pressure
Which valve prevents backflow of blood into the right ventricle?
Pulmonary/Right semi-lunar valve
Which valve prevents backflow of blood into the left ventricle?
Aortic/Left semi-lunar valve
Which valve prevents backflow of blood from the right ventricle into the right atrium?
Tricuspid
Myocardial infarctions are the direct result of:
obstruction of blood flow to the heart muscle.
When we measure someone’s blood pressure, we are measuring their:
arterial pressure.
The arterial blood pressure is greatest:
when the ventricles are contracting.
At the arterial end of a capillary, water is forced out of the capillary by what?
the hydrostatic pressure of the blood in the capillary.
Which vessels have thin walls and require skeletal muscle contraction to keep blood moving?
Veins
Which of the following would result in an increase in blood pressure?
An increase in cardiac output
Which valve prevents backflow of blood from the left ventricle into the left atrium?
Mitral (bicuspid)
If a person’s blood pressure drops for some reason and remains lower than normal for some time, which hormone would you expect to be released in response to this drop in pressure?
Aldosterone
The left atrioventricular valve is closed:
by the contraction of the left ventricle
The blood supplying oxygen and nutrients to the myocardium would be flowing through which arteries?
coronary arteries
Which of the following is true about veins?
They are known as capacitance vessels
Which vessels have thin walls and require skeletal muscle contraction to keep blood moving?
Veins
Why are arterioles are known as resistance vessels?
Because they play a role in regulating blood pressure and blood flow by altering their diameter
The short-term response to low blood pressure would be:
increased heart rate and increased vascular resistance
Which of the following would be most likely in a patient with a leaking left atrioventricular (mitral) valve?
Blood flowing backwards into the left atrium and backing up in the pulmonary vessels –> fluid accumulation in the lungs
A patient suffers from an endocrine disorder in which her adrenal cortex is not secreting enough of its hormones. Which of the following would be one of the problems this patient would be likely to have?
Excessive amounts of sodium and water would be lost by the kidneys, leading to low blood pressure
A person whose ECG shows no P waves, but regular QRS and T complexes is likely to have:
an SA node that is not operating
Jenny has been told that she has a narrowed mitral valve, which means that when the valve is open, blood can only flow through slowly. Which of the following would occur as a result of this?
A back-up of blood in the left atrium and pulmonary circulation, which will put more strain on the right ventricle and reduce the lungs’ ability to exchange oxygen.
What is the purpose of the cardiovascular system?
To transport gasses, nutrients, wastes
Which valves prevent regurgitation from the ventricle to the atria?
the atrioventricular valves
Which valves prevent regurgitation back into the ventricles?
The semi-lunar valves
What makes the LUB sound?
The atrioventricular valves closing
What makes the DUP sound?
The Semi-lunar valves closing
How many layers of heart and what are they?
3
Endocardium (inside)
Myocardium (muslce)
Pericardium (around)
What is cardiac arrest a problem with?
The electrical signals
What is the diagnosis when there is a blockage to the heart?
Myocardial Infarct
Describe the arteries and their role.
Pressure vessles, elastic and tough
They carry blood away from the heart
Describe the veins and their roles
Hold capacity
They carry blood to the heart via valves and with the help of muscle contraction.
Describe the arterioles and their roles
They are pressure vessles - like a garden hose/straw and vary their resistance
This allows them to direct flow or change pressure
Where is most of the blood in the circulatory system held?
In the system vanes and venules
Describe the capillaries and their roles
Exchange vessles - small, thin, fragile vessles
the vascular bed allows excanges of gasses, nutrients and waste
Where does gas excange occur?
at the capillaries via diffusion
Oxygen and nutrients diffuse from the capillaries into the tissues, while carbon dioxide and waste products diffuse from the tissues into the capillaries
What is the systole reading?
When the atrioventricular valves contract and the semi-lunar valves relax
What is the diastole reading?
When the atrioventricular valves relax
How is blood pressure controlled?
Nervous System and Endocrine System
How is arterial pressure monitored?
With baroreceptors in the aorta and carotid arteries
How is blood pressure changed by the autonomic system?
Heart rate
Beat Strength
Dialating or Constricting arterioles
What hormonal system helps to control blood pressure
RAAS
What x What = Blood pressure
CO x TPR = BP
Cardiac Output x Total Peripherial Resistance
What x What = Cardiac Output
SV x HR = CO
Stroke Volume x Heart Rate
What + What = Mean Arterial Pressure
Diastolic + 1/3 Pulse Pressure (Systolic - Diastolic) = Mean Arterial Pressure
What things effect HR (heart rate)?
Autonomic System (BP)
Hormones (RAAS and ADH)
Age
Fitness Levels
What things effect SV (stroke volume)?
Heart size
Fitness Levels
Gender
Contractility
Preload
Afterload (resistance)
Describe the path blood takes transporting blood in and out of the heart
Deoxygenated blood enters the heart through the superior and inferior vena cava, filling the right atrium, through the tricuspid valve into the right ventricle. The right ventricle then pumps blood through the pulmonary valve into the pulmonary artery, which carries it to the lungs for oxygenation. Oxygenated blood returns to the heart through the pulmonary veins, entering the left atrium, then the mitral valve into the left ventricle, which pumps blood through the aortic valve into the aorta, the main artery that distributes blood to the rest of the body.
What is the cardiovascular system and what is its purpose
The cardiovascular system consists of the heart, blood vessels, and blood. Its purpose is to transport oxygen, nutrients, hormones, and waste products throughout the body.
What two systems help to control the cardiovascular system?
The nervous system and the endocrine system
The left atrioventricular valve is closed:
by the contraction of the left ventricle
The blood supplying oxygen and nutrients to the myocardium would be flowing through the:
coronary arteries
What is required for cardiac muscle to contract?
An electrical signal from inside the heart
Blood returning to the heart from the systemic circuit first enters the
right atrium
Blood flowing into the heart from the venae cavae flows next through the ________ valve
right atrioventricular (tricuspid)
What is the normal pacemaker of the heart
Sinoatrial node or SA node
The P wave of the electrocardiogram represents the:
electrical activation (depolarisation) of the atria
The arterial blood pressure is greatest:
when the ventricles are contracting.
At the arterial end of a capillary, water is forced out of the capillary by:
the hydrostatic pressure of the blood in the capillary.
A person whose ECG shows no P waves, but regular QRS and T complexes is likely to have:
an SA node that is not operating
