Flashcards in The Cardiovascular System Deck (56):
What is the cardiovascular system made up of?
Heart, blood and blood vessels.
True or False - Sympathetic nerves release chemicals that increase the heart rate and force of contractions?
Is the vagus nerve part of the sympathetic or para sympathetic system?
What is the function of the vagus nerve in relation to the heart.
When activated by the parasympathetic system it releases checmicals to slow the heart rate and reduces cardiac output.
What is blood composed of?
Plasma with different types of cells and corpuscles floating in it.
What is the ideal PH balance of blood?
What do arteries do?
Transport oxygenated blood from the heart to the capillary beds.
What do veins do?
Transport deoxygenated blood from the capillary beds to the heart.
True or False - some veins have valves to stop blood from backflowing?
What part of the body is responsible for changing the size of blood vessels?
The medulla oblingata through nerves of the autonomic nervous system.
What is oxyhaemoglobin?
Oxygen bound to haemoglobin in the blood.
What is osmotic pressure?
The pressure developed across a semipermeable membrane which forces water to pass from a more dilute solution to a more concentrated solution in an attempt to establish equilibrium.
What is the location of the heart in the body?
Midiastinum between the lungs and above the diaphragm in the thoracic cavity.
What are the three layers of the heart called?
Describe the epicardium.
Outermost wall of the heart and the pericardium covers this layer.
Describe the myocardium.
The middle layer of the heart and is the muscle layer which contracts and expels blood into the heart chambers.
This layer conducts electricity and blood is supplied by the coronary arteries.
Describe the endocardium.
Is the inner most layer of the heart and is cells that adhere to the myocardium.
What do the superior and inferior vena cava bring to the heart.
Which part of the heart does deoxygenated blood go into.
The right atrium.
What is located between the right atrium and the right ventricle of the heart.
Explain the location of the pulmonary artery.
Between the right ventricle/pulmonary valve of the heart and the lungs.
Where does oxygenated blood go when it comes from the lungs.
Through the pulmonary veins into the left atrium of the heart.
What valve is located between the left atrium and the left ventricle?
What takes oxygenated blood away from the heart?
Which is bigger the left or right ventricle?
Why is the left ventricle bigger than the right ventricle?
Requires more force to send blood to the body.
Its force is 4-6 times more than the right ventricle.
Has thicker muscle walls
What are coronary arteries?
Arteries that supply oxygenated blood to the heart.
What do arteries do?
Take blood away from the heart.
Do arteries carry blood at high or low pressure?
Do veins carry blood at high or low pressure?
Fill the space:
The................is between the left ventricle and aorta?
What valve is between the left atrium and left ventricle?
By which way is oxygenated blood returned to the heart and which chamber does it go in?
By way of pulmonary veins and goes in to left atrium.
What is the pericardium?
Sack around the heart
What type of muscle is the myocardium made up of?
What is the function of the heart?
To maintain a constant circulation of blood throughout the body.
What is the SA node?
Is the hearts pacemaker because capable of initiating impulses to stimulate myocardium without influence from nervous system.
What is the AV node?
Where is the SA node located?
Top of the right atria.
Where is the AV node located?
Near the tricuspid valve.
What is the cardiac cycle?
A heart beat
Describe the cardiac cycle and what happens?
Atrial systole - contraction of the atria
Ventricular systole - contraction of the ventricles
Complete cardiac diastole - relaxation of the atri and ventricles.
How long is a cardiac cycle in general?
Atrial systole = 0.1 sec
Ventricular systole = 0.3 sec
Complete cardiac diastole = 0.4 sec
ECG - What does the P wave represent with relation to the cardiac cycle?
Atrial systole/Atrial contraction
ECG - what does QRS wave represent with relation to the cardiac cycle?
Spread of impulse of contraction from AV node, through bundle of HIS to purjinke fibres and the contraction of the ventricle.
ECG - what does T wave represent with relation to the cardiac cycle?
Respresents relaxation of the ventricular muscle.
What is blood pressure?
The force/pressure which the blood exerts on the walls of the blood vessels.
Explain what systolic blood pressure is?
When the left ventricle contracts and pushes blood into the aorta this is the systolic blood pressure.
Explain what diastolic blood pressure is?
Diastolic blood pressure is complete cardiac diastole occurs and the heart is resting.
What is the formula for cardiac output and explain what it means?
Cardiac Output = Heart Rate x Stroke Volume
Amount of blood ejected by the left ventricle in one minute.
What is preload?
The amount of blood sitting in the heart right before the ventricle contracts.
The end diastolic volume, when the heart relaxes how much blood flows into the ventricle.
What is afterload?
Afterload is the resistance the heart must overcome to eject the blood into the rest of the body.
The mean arterial pressure.
What regulates blood pressure?
Baroreceptors and chemoreceptors.
What is the average blood volume of adults per kilogram of weight?
What is Frank-Starling law of the heart?
As blood fills the left ventricle, the muscle fibres stretch to house the blood. The stretch of the muscle fiber at the end of diastole determines the force available to eject the blood from the ventricle.
In short, the volume of blood in the ventricle automatically generates a contraction forceful enough to eject it.