Cardio - General Function, Organization and Anatomy of Circulation Flashcards
What are the 4 functions of the cardiovascular system?
- Transports O2 and nutrients to body tissues
- Removes CO2 and waste products from tissues
- Functions to regulate body temp and pH
- Transports and distributes hormones and other substances throughout the body
- all an effort to maintain homeostasis
What are the 3 components of the cardiovascular transport system?
- Central pump
- Closed system of blood vessels
- Blood (fluid medium) through which various substances are transported
What are the 2 circular systems?
Pulmonary circulation
Systematic circulation
What is the difference between pulmonary and systematic circulation systems?
Pulmonary has blood vessels that carry to and from the lungs
Systematic has blood vessels that carry blood to and from the rest of the body
Why is the heart excluded from both circulatory systems?
Because the term circulatory system revers only to the blood vessels
What is the main function of the pulmonary circulation?
In combination with the lungs provides an exchange of gases between the atmosphere and the blood
How does blood go into the pulmonary artery?
By contracting the right ventricle (RV)
-this blood is low in O2 but high in CO2
What does the pulmonary artery turn into?
Branches into smaller and smaller vessels until they become pulmonary capillaries
What happens in the tiny pulmonary capillaries?
Blood takes up O2 from the air and removes some CO2
Where to the pulmonary capillaries drain into?
Venules–> Pulmonary vein which carries the O2 rich blood back to the left atrium (LA)
What happens when the LA contracts?
The blood is pumped into the left ventricle (LV)
What happens when the LV contracts?
Blood is pumped into the aorta
-start of the systematic circulation
What does the aorta split into?
Numerous and smaller arteries for distribution of blood into the tissues
What do arteries split into?
Arteries–>smaller arteries–>Arteriols–>Capillaries
What happens at the arterial capillaries?
Capillaries are the exchange vessels where O2 and nutrients pass into the tissues and CO2 and waste are taken up into the blood
What do the arterial capillaries join up with?
Reunite to form the venues and veins which return the venous blood back to the RA, then blood flows to the RV
What are the main functions of the valves in the heart?
To ensure the forward movement of blood
What is TBV?
Total blood volume
What is a normal TBV?
5-6L
What is the breakdown of TBV?
Heart + pulmonary circulation= 15% (750ml)
Systematic + arterial system= 10% (500ml)
Systematic capillaries= 5% (250ml)
Systemic circuit= 70%
Why is 5% significant TBV for the capillaries?
Capillaries have the largest combined cross sectional area in the circulatory system. When a small amount of blood is exposed to a very large surface area it facilitates very efficient exchange of substances between blood and tissue
Why are valves important in the 70% TBV of the systemic circuit?
Low pressure environment of the veins requires the presence of valves to ensure that the blood flows in only one direction
What is the superior and inferior vena cava?
Superior brings blood back to the RA from anywhere above the heart
Inferior brings blood back to the RA from anywhere below the heart
What is the RA?
Contains the CO2 rich blood from all parts of the body to be pumped into the RV
What is the right AV valve?
Also known as the tricuspid valve is the valve that allows blood flow from the RA to the RV
What is the Pulmonary artery?
After contraction occurs, the CO2rich blood is pumped into the pulmonary valve and taken to the lungs
What is the pulmonary veins?
Bring oxygenated blood back from the lungs into the LA
What is the LA?
Left atrium contains the O2 rich blood from the pulmonary veins
What is the left AV valve?
Also known as the bicuspid valve, allows O2 rich blood to flow into the LV
What is the LV?
Left ventricle contains O2 blood and is pumped to the rest of the body through the aortic valve
Why is muscle thickness different on the left vs right ventricle?
Thin on the right side is because the blood only has to be pumped into the lungs which aren’t too far away.
Thick on the left because the heart needs more force to push the blood to the rest of your body
What separates the 2 ventricles?
The septum
