CV System Flashcards
A&P Revision
What are the 6 main functions of the Cardiovascular system
- Transporting nutrients - O2, glucose, water, fatty acids
- Removing waste products from metabolic processes - CO2, urea, creatine.
- Transporting hormones from endocrine system to target organs
- Regulation of Temperature control by controlling heat distribution between core and skin
- Reproduction, and providing nutrients to unborn foetus
- Host defense by transporting immune cells and other mediators
The CV system composes of which three elements
Heart
Blood Vessels
Blood
The 4 Divisions of the CV system are
Hepatic Portal - Liver supply
Pulmonary - Blood to and from lungs
Coronary - Blood supply to heart itself
Systemic - Oxygenated blood to body, deoxygenated blood back to heart.
Describe the exact location of the heart
In the Thoracic cavity, in the mediastinum.
Behind the sternum, in front of the spine, between the lungs, above the diaphragm.
The heat lays at what degree from the vertical?
60 degrees
The heart is described as having an apex and a base, where are they located
The Base lies behind the sternum in the midline and extends to the 2nd rib.
The apex is approximately 9cm the the left of the midline at the 5th intercostle space on the mid clavicular line.
What is the average size of the heart in cm
9cm x 10cm x 6cm
225-310g
Name and describe the outer layer of the heart
Pericardium - a double layered sac.
The parietal pericardium - the outer fibrous and serous layer
The visceral pericardium - Inner layer adherent to the heart muscle
Name and describe the middle layer of the heart
Myocardium - Forms the greater part of the heart walls and is thickest in the ventricles.
Myo - Muscle
Cardium - of the heart
The specialised cardiac muscle tissue of the heart is
composed of branching elongated cells with the ability to
generate an electrical impulse, termed autorhythmicity
Name and describe the outer layer of the heart
Endocardium - The membrane of endothelial cells lining the inside of the heart, it is continuous with the lining of blood vessels
What is in between the Pericardium and Myocardium
The pericardial space (potential space) with a thin layer of serous fluid to allows smooth movement between layers when the heart beats
The ability for tissue to generate its own electrical impulse is called
Autoarythmicity
Describe the atria
Two thinner walled upper chambers of the heart separated by the inter atrial septum
Describe the Ventricles
Two thicker walled lower chambers of the heart, receive blood from their respective atria and pump it either to the body (left) or to the lungs (right)
Name the four valves within the heart
Bicuspid (Mitral)
Tricuspid
Aortic
Pulmonary
What seperates the two ventricles
Ventricular Septum
The tendons that prevent cusp inversion are
Chordae tendineae
The Chordae Tendinae are attached to what muscles
Papillary muscles
Starting at the Vena cava describe the flow of blood through the heart
Vena Cava - right atrium (deoxygenated) - tricuspid valve - right ventricle - pulmonary valve - pulmonary arteries - lungs - pulmonary veins (oxygenated) - left atrium - bicuspid valve - left ventricle - aortic valve - aorta
List the main coronary arteries
Right coronary artery - supplies right atrium, right ventricle & inferior third of Ventricular septum
Left Coronary artery - suppleness left atrium, left ventricle & supirior two thirds of ventricular septum.
Describe the flow of electrical current from the SA node
Impulse generated at SA node - flows into both atria and to atrioventricular node where there is a small delay to allow the atria to finish contracting before it goes through the AV bundle (bundle of his) where it splits into left and right bundle branches and travels down to the apex where the impulse goes into the purkinje fibers causing the ventricles to contract.
Describe the cardiac cycle
Atrial Systole - contraction of artia
Ventricular systole - contraction of ventricles
cardiac systole - relaxation phase
Blood Pressure is defined as
The pressure exerted of the arterial walls by the blood it is measured as Systolic over Diastolic.
Systolic pressure is defined as
The force at which the left ventricle pumps blood into the aorta
