The Cardiovascular System Flashcards
(12 cards)
Name the three components of the cardiovascular system
The heart
The systemic circulation
The pulmonic circulation
These components work together to deliver oxygen and nutrient rich blood to the organs and tissues of the body.
Expand on the heart
The heart is about the size of an individual’s clenched fist. It lies in the front and middle of the chest, behind and slightly to the left of the breastbone. It is a muscle that pumps blood to all parts of the body to provide it with oxygen and nutrients it needs to function. The heart beats on average 115,000 times per day. The muscle pump is controlled by a sophisticated electrical impulse system which circulates on average 2000 gallons of blood around the body per day.
Identify the main anatomical landmarks of the heart
Left atrium and left ventricle
Right atrium and right ventricle (the four chambers)
The aorta and Vena cava( superior and inferior vena cava)
Coronary arteries
The valves : bicuspid valve/ mitral valve, aortic valve/ aortic semi-lunar valve, pulmonary valve /pulmonary semilunar valve, tricuspid valve
Pulmonary veins
Pulmonary artery
The systemic circulation
The systemic circulation is compromised of arteries, veins and capillaries. These vessels form a transportation network that delivers blood to and from the top of the head down to the tips of the toes and everywhere in between. The left ventricle is the one that pumps blood all through the body (systemic circulation)
Circulation of blood in the heart
Oxygenated blood coming from the lungs into the pulmonary veins to the left atrium. Blood goes through mitral valve into the left ventricle. When the left ventricle contracts that blood will be ejected through the aortic valve into the aorta from there into smaller arteries perfuming systemic circulation.
When it arrives back from top half of the body as deoxygenated blood it goes through the superior vena cava. From the bottom half of the body it goes through the inferior vena cava. These go through the right atrium through tricuspid valve into the right ventricle. When the right ventricle contracts that blood will be ejected through the pulmonary valve into the pulmonary artery to the lungs.
The pulmonic circulation
The pulmonic circulation is compromised of a specific set of arteries and veins whose sole purpose is to deliver blood to and from the lungs and heart.
The heart valves
Connecting to the valves there are tendons called tendonous chords. They are tissues that holds the valves from flapping backwards and ensures one way flow. These tendonous chords are rooted into the wall of the heart by specialised muscles. They are called papillary muscles.
Layers of the heart
The outer fibrous sac that provides physical protection and stops the heart from over expanding , it’s called the pericardium.
Lining the inside of the heart is squamous vascular endothelial cells to make sure there’s smooth blood flow; it’s called the endocardium.
The thick muscular layer in the middle of the heart around left ventricle and thin layers in the rest of the heart consists of striated muscles that allows the heart to contract called the myocardium.
Structure that divides the heart is the cardiac septum.
Left side of the heart is commonly called body pump as it pumps blood to the body
The right side is called the lung pump.
The coronary arteries
The coronary arteries are responsible for supplying oxygenated blood to fuel the myocardium. Like all muscles the myocardium requires a steady stream of oxygenated blood to fuel it’s contractions
The Electrical system
The contraction of the heart muscles is controlled by a complex system of electrical impulses known as the heart’s pacemaker. These electrical impulses control how fast the muscles contract and how the atria and ventricles contract on the best rhythm to maximise the efficiency of blood flow.
The electrical system of the heart
The cell is negative and becomes positive it’s called depolarisation. The area of depolarisation is called the sinoatrial node (SA node) Once they depolarise they connect to the neighbouring muscles and carry on depolarising. It moves then relatively slowly through a band of tissues like a highway from right atrium to the left atrium in a coordination way. This band is called Bachmann’s bundle
There’s also the atrio ventricular node( AV node) this signal comes from intermodal tracts from the SA node.
Both the atria and ventricle contract at the same number of times but there’s a slight delay between the two. This is for to the AV nodes. This moves blood in the right direction from atria to the ventricles in a coordinated way. The AV node then moves to the bundle of his through the right side and a left side that splits. They are called left posterior fascicles and left anterior fascicles. The right side is the right bundle. Then the both split into the purkinge bundles towards the bottom ventricles of the heart.
Waves and their meaning
P wave ; the activation of the atria
QRS complex ; activation of the ventricles
T wave ; the recovery wave
