CV System - Vascular System & Venous Return Flashcards
What is the vascular system made of
Blood vessels that carry blood through the body
What are the two types of circulation
pulmonary, deoxygenated blood from hearts to lungs and oxygenated blood back to The heart- systemic, oxygenated blood to The body and return of deoxygenated blood back to The heart
What are the five different blood vessels
Artery - Arterioles - Capillaries -Venules -Veins
What is the structure of veins
Thinner muscle - elastic tissues - valves - wider lumen
What is the structure of arteries
more elastic tissue in wall - smaller lumen
What is the structure of capillaries
wide enough for once RBC to pass through (allows exchange of nutrients with the tissues by diffusion)
What is systolic pressure
The pressure in the arteries when the ventricles are contracting
What is diastolic pressure
The pressure in the arteries when the ventricles are relaxing
What is venous return
Return of blood to the right side of the heart via the vena cava
What mechanisms help venous return
Skeletal muscle pump - respiratory pump -pocket valves -gravity
What is the skeletal muscle pump
When the muscles contract and relax they change shape, means that the muscles press on nearby veins causing a pumping effect and squeeze blood towards the heart
What is the respiratory pump
Respiratory muscles causes pressure changes in the thoracic and abdominal cavities. The changes in pressure compress nearby veins and assist blood return to the heart
What are pocket valves
Valves that make sure that blood only flows in one direction. Once the blood passes through the valve it closes.
What could stimulate an increase in venous return
increase in Venous pressure -decrease in right atrial pressure -decrease in Venous resistance
What could stimulate a decrease in venous return
Increasing right atrial pressure
