1. Blood Vessels and Circulation

2. Veins and Arteries have 3 wall layers
Intima- Inner layers
Media- Middle Layer
Adventitia- Outer layer

3. Veins and Arteries Arteries: Carry blood away from the heart
Veins: Return blood to the heart

4. Other vessels Arterioles: Are the smallest branches of arteries
Capillaries: Smallest blood vessels, serve to distribute oxygenated blood from arteries to tissue around the body
Venules: Small blood vessels that merge with veins and return blood from tissue to the heart

6. Capillary Beds
Connect one arteriole and one venule

7. Veins Collect blood from capillaries from tissues
Larger in diameter than arteries
Have thinner walls
Have lower blood pressure

8. Venous Valves
Folds within veins which prevent blood from flowing backwards
Compression pushes blood toward heart

9. Factors affecting blood flow
Pressure (P)
Heart generates P to overcome resistance
Blood Pressure (BP)
Arterial pressure
Venous Pressure
Pressure in the venous valvues
Vascular Resistance
Due to friction between blood and vessel walls
Depends on vessel length and vessel diameter

10. Pressures Systolic Pressure
The blood pressure when the heart is contracting
The maximum arterial pressure during contraction of the left ventricle
When measuring blood pressure, it is the first number (120/80) mm Hg (Millimeters of mercury)

11. Pressures Diastolic Pressure
The time when the heart is relaxing and dilating.
The minimum arterial pressure of the ventricles of the heart when they fill with blood
When measuring BP, it is the second number (120/80)

13. Filtration Capillary moves materials across membrane by Filtration
Osmosis

14. Filtration Driven by hydrostatic pressure
Water and small solutes forced through capillary walls
Leaves large solutes in blood stream

15. Osmosis
Caused by suspended blood proteins that are too large to cross capillary walls

16. Both control filtration and reabsorption through capillaries
Hydrostatic Pressure
Forces water out of a solution
Osmotic Pressure
Forces water into solution
Both control filtration and reabsorption through capillaries

17. Tissue Perfusion
Blood flow carries O2 toward tissue, carries CO2 away

18. Adjusting flow of blood
Vasodilators
Accelerate blood flow at the tissue level by widening blood vessels
Vasoconstrictors
Decrease blood flow to tissue by narrowing blood vessels
Often used on heart attack patients