Cardiovascular System Flashcards
The cardiovascular system is comprised of 3 components
The heart, blood vessels, blood.
Where is the heart located?
Left of the Brett bone(sternum)
How big is the heart?
Approx size of the fiat
What keeps the heart in place?
The pericardium - film of fluid which prevents the heart from moving whilst it beats.
Where is the atria located?
At the top of the heart
Atria blood flow
The left receives blood from the lungs
The right received blood from the body.
Where is the ventricle located?
The bottom 2 chambers
Ventricular blood flow
The left pumps blood to the body and is the strongest.
The right pumps blood to the lungs to pick up O2.
Function of valves
Ensure a one way flow of blood = prevents back flow
List the 4 valves
Aortic
Pulmonary
Mitral
Tricuspid
3 layers of the heart wall
Epicardium
Myocardium
Endocardium
Epicardium
Thin, transparent outer layer of wall
Myocardium
Cardiac muscle responsible for the pumping action of the heart which is involuntary.
Endocardium
Thin layer of heart chambers and valves. Lines the inside of the heart + tendons.
What is pulmonary circulation
The process of re-oxygenating the blood and is the part of the CV system which carries deoxygenated blood away from RV to the lungs.
What is systematic circulation
The part of the CV system which carries O2 blood away from the heart to the body and returns deoxygenated blood.
5 heart functions, give 2 examples
Delivery - oxgyen and nutrients to every cell in the body
Removal - CO2, metabolic waste products
Transport - hormones from the endocrine gland to target receptors. White and red blood cells
Maintenance - maintains body temp and pH
Prevention - prevents dehydration
Do arteries have valves?
No, as the heart provides the necessary pressure needed to send blood through the system.
Do veins have valves?
Veins have valves because venous pressure is often not as great to return blood to the heart.
What are pre-capillary sphincters?
Smallest type of blood vessel which forms a network between arteries to venules.
This band of smooth muscle adjusts blood flow by opening and closing the entrance to a capillary.
What is the Superior Vena Cava?
Large vein that carries blood from the upper half of the body to the RA.
What is the Inferior Vena Cava?
Large vein that carries blood from the lower half of the body to the RA.
Function of the Coronary Arteries?
Aka: the power house
To provide the heart with blood, oxygen and nutrients.
Main Coronary Arteries are:
Left anterior descending artery - supply blood to LV
The circumflex artery - supply blood to RV.
These arteries curl around the surface of the heart and divide to form a dense network of capillaries.
Blood serves the body by:
Providing platelets - allow the blood to clot
Transporting white blood cells - fight infection and offer immunity
Transport O2 via rbc’s, removes CO2 + waste products
Reduces temperature
During exercise skeletal muscle receive up to…
80% of circulation blood. This combined with increased cardiac output which delivers up to 25 times more blood to the active muscles.
Know as BLOOD SHUNTING
What is vaso-constriction?
The narrowing of arteries/arterioles to restrict blood flow to an area.
What is vaso-dilation?
The widening of arteries/arterioles to increase the blood amount of blood to an area.
What is SV?
Stroke volume - volume of blood ejected from the left ventricle per contraction (ml).
What is CO?
Cardiac Output - Volume of blood ejected from the heart in one minute. CO = HR x SV
What is ejection fraction?
The proportion of blood pumped out of the LV in each contraction. Normal EF is around 60%
Define diastole
Period when heart muscle relaxes and allows the heart chambers to fill with blood.
Define systole
Period when heart muscle contracts and pumps blood from the chambers into the arteries.
