The Cardiovascular System Flashcards
Four chambers of the heart?
- Left Atrium
- Right Atrium
- Left Ventricle
- Right Ventricle
Formula for Cardiac output
Heart rate X Stroke Volume
What is the Septum?
Muscular bands that separate the left and right ventricles and contributes to cardiac function
Name the valve on the right side of the heart
Tricuspid Valve
Name the valve on the Left side of the heart
Bicuspid Valve
what is meant by SAN
Sinoatrial node
Function of the SAN node?
The natural pacemaker of the heart which is responsible for regular contraction of the heart muscle
What is the Vena Cava?
A large vein
Function of the Superior vena cava
The superior vena cava carries blood from the head, neck, arms, and chest.
Function of the inferior vena cava
The inferior vena cava carries blood from the legs, feet, and organs in the abdomen and pelvis.
Function of the right pulmonary artery?
Carries deoxygenated blood to the right lung
Function of the left pulmonary artery?
Carries deoxygented blood to the left lung
What is the Aorta?
The largest artery of the body
What is the function of the Aorta?
Carries oxygenated blood to the body
What is the Semilunar Valve and its function?
It is a half-moon-shaped leaflet of endocardium and connective tissues which prevents the backward flow of blood.
What is the bundle of HIS
A group of fibres that carry electrical impulses through the centre of the heart. if the signals are blocked, you will have problems with your heartbeat.
Function of HIS
Transmits impulses from the AV node to the ventricles.
Structure of Arteries
-relatively thick wall
-smooth muscle
-elastic fibres
-lined with a smooth layer of endothelial cells
-narrow lumen
Structure of the Capillaries
-thin wall (one cell thick)
-small lumen
Structure of the Veins
-thin wall
-smooth muscle
-elastic fibres
-wide lumen
-valves
Function of the arteries
-withstand high blood pressure
-walls stretch and recoil to smooth blood flow
-low friction surface to ease blood flow
Function of the veins
-blood under low pressure
-no stretching and recoiling
-acts as a blood reservoir due to large volume
-valves stop backflow, ensuring a one-way flow of blood toward the heart
Function of the capillaries
-allows exchange between blood and tissues
-links arteries and veins
What is the Cardiac Cycle?
blood fills the atrium via gravity
-right and left atria contract together
-blood leaves the atrium
-atrial kick happens to push blood into the ventricle
-blood moves into the ventricles
-AV valves close
-ventricular pressure rises
-volume rises
-pockets fill with blood
-as the ventricles finish contracting the ventricular pressure rises above the pressure in the aorta and pulmonary artery
-apex contracts and semi-lumar valve opens
-blood passes from ventricles into the semi-lumar valve
What is AVN?
Atrioventricular node
Describe what happens in the contraction of the heart
-Contraction is initiated by the SAN, which sends out a wave of contraction around the walls of the atria. this causes the atria to contract together, pushing blood into the ventricles
-Waves of contraction cant pass into the ventricles because there is a barrier of insulating tissue separating the atria and the ventricles; instead, the AV node passes the wave of contraction into the ventricles. The AV node is a slow-conducting bridge through the insulating tissue. it carries the contraction into the ventricles but does it slowly, so there is time for the ventricles to fill before it contracts
-The AV node is connected to the Purkinje fibres (through the bundle of his), the fibres are fast conducting and lead the contraction to the bottom of the ventricles. This means that the ventricles contract bottom-upwards, ensuring that all the blood is forced into circulation.
What are Purkinje fibres?
Specific heart muscle tissue that is responsible for the generation of heart impulses.
What is sinus arrhythmia
Irregular heartbeat
What is Bradycardia?
Slow heartbeat
What is tachycardia?
Fast heartbeat
What is a T wave?
Shows diastole
What happens between the P-R waves
Delay in excitation from the SA node to the AV node
What is the QRS complex?
Activation of ventricle
What is a P wave
Activation of the atria
What is Diastole
Period of ventricular/ atrial relaxation
what is Systole
Period of ventricular/ atrial contraction
Indications of Arrhythmias?
Tachycardia, Bradycardia,ventricular fibrillation, sinus arryhthmia, flat line
What is meant by CVD
Cardiovascular disease
What factors increases the risk of CVD
- Genetics
- Age
- Gender
- Diet
- High blood pressure
- Smoking
- Inactivity
Treatments for CVD
- Transplants (heart ofc)
- Low dose asprin
- Statins
- Antihypersentives
