CV I Flashcards
What is main role of CV system
Creates a concentration gradient for the entire body
- from blood to cells for nutrients and in opposite direction for waste
Why do we have a CV system
Consequence of increasing size and complexity of multicellular organisms
Primary role of circulatory system
Distribution of dissolved gases and other molecules for nutrition, growth and repair, while simultaneously removing cellular wastes
Secondary roles of circulatory system
- chemical signalling to cells by circulating hormones or neurohormones
- dissipation of heat (increased to skin)
- mediation of inflammatory and host defence responses against invading microorganisms
Until 17th century what were two separate systems involved in circulation
Venous blood was created in liver and distributed to throughout body
Arteries contained air from lungs and spirits which flowed to heart, distributing life and heat
What were tissues believed to do before 17th century
Consume all blood delivered to them and liver constantly made new blood
What did Dr. William Harvey show
- one hour heart pumped more than entire body wight in blood and no way liver constantly produce
- valves in heart and veins created one way flow and veins carries blood back to heart
- blood entering right side of heart was pumped through lungs then left side
What are 3 types of transport in circulatory system
- Materials entering the body (oxygen, nutrients and water)
- Materials moved from cell to cell (wastes, immune cells, hormones, stored nutrients)
- Materials leaving body (metabolic wastes, heat, carbon dioxide)
What is the heart
A dual pump driving blood in two serial circuits
What are the two circuits
Pulmonary circuit (deoxygenated blood through lungs)
Systemic circuit (delivers O2 blood to rest of body)
Arteries
Carrying blood away from the heart
Veins
Carrying blood back to the heart
Capillaries
Smallest vessels where transport (transfer) takes place
- link arteries to veins
What is main output artery of systemic circuit
Aorta
What is main output artery of pulmonary circuit
Pulmonary trunk (deoxygenated blood)
What ensures blood flows in one direction
System of valves in the heart and veins
What are the 3 circulations within the systemic circuit
- Coronary circuit
- Digestive tract/liver portal system
- Kidney portal system
What are the 2 sections of the aorta
Aortic arch : delivers blood to upper part of body
Descending aorta : deliver O2 blood to lower part of body
Right atria receives blood from where and sends blood to
Superior and inferior Vena Cavae and right ventricle
Where does right ventricle receive and send blood to
Right atrium and lungs
Where does the left atrium receive and send blood to
Left and right pulmonary veins and left ventricle
Where does left ventricle receive and send blood to
Left atrium and body except for lungs
End of pulmonary circuit
Left atria
End of systemic circuit
Right atria
What are the septums which separate the left and right ventricles and atrias
Interventricular and interatrial
Where do vena cavae recieve and send blood
Systemic veins and right atrium
Where does pulmonary trunk (pulmonary arteries) receive and send blood to
Right ventricle and lungs
Where does the pulmonary vein receive and send blood
Veins of the lungs and left atrium
Where does the aorta receive and send blood to
Left ventricle and systemic arteries
What is the circulatory system starting at left ventricle
- LV
- Aorta
- Systemic circuit
- Venae cavae
- Right atrium
- Right ventricle
- R + L pulmonary arteries
- Pulmonary circuit
- L + R pulmonary veins
- Left atrium
How does blood flow through the CV system
Liquids and gases flow down pressure gradients from regions of high pressure to regions of low pressure
What is the initial region of high pressure in the CV system created by
Contraction of the heart
What has the highest blood pressure and what has the lowest
Aorta and venae cavae
How is pressure lost as blood flows through the vessels
Due to friction created between the blood and vessel walls
What is the driving pressure
High pressure created in the ventricles
What happens when the walls of the fluid filled ventricles contract
Increased amount of pressure of the blood
- same amount of molecules but exert more pressure because they collide with each other and walls
What happens when heart muscles relax and expand
The pressure exerted by blood within ventricles decreases
Aside from pressure changes within ventricles what can many vessels do which affects blood pressure
Constrict or dilate
What determines the amount of blood flowing through the circuit
Pressure gradient difference between main output and end of circuit
What is the flow of blood in the tube directly proportional to
Pressure gradient at each end of the tube
What does pressure gradient difference of 0 mean
No flow
