1. Chapter 11: Circulations and Blood Vessels

2. Blood Vessels ----Structures in the body that convey blood----
Arteries—Carry blood away from the heart
Arterioles—Smaller divisions leading away from arteries
Capillaries—Embedded in tissues where exchange occurs
Venules—Collect blood from the capillaries
Veins—Carry the blood back to the heart
Vena Cavae—Large Veins that dump blood back to the right atrium

3. Flow of blood:
Right Atrium Right Ventricle Pulmonary Arteries Lung  Pulmonary VeinsLeft Atrium Left VentricleAorta Arteries  Arterioles  Capillaries  Venules  Veins  (Inferior or Superior) Vena Cava Right Atrium

4. Flow of blood through the heart

5. Pulmonary & Systemic Circuits

6. Anatomy of a Vessel
Contains 3 layers: 1.) Tunica Intima 2.) Tunica Media 3.) Tunica Externa
Tunica Intimathin endothelial layer
innermost lining of the vessel

7. Anatomy of a Vessel
Tunica Media—bulky, middle coat --smooth muscle layering --controlled by the Sympathetic Nervous System --Dilation of this layer produces decreased Blood Pressure --Constriction of this layer produces increased Blood Pressure Tunica Externa—outermost layer --fibrous connective tissue --function is to support and protect the vessel

9. Vessels
Arteries—must be able to expand with the amount of stroke volume
Veins—lumen is larger than that of an artery
*Have valves to prevent backflow
*Venous return is aided by skeletal muscle “squeezing”
*Inspiration causes a drop in pressure which also aids in venous return
Capillaries—Composed of Tunica Intima

10. 3 Special Circulations
1.) Brain—continuous supply of arterial blood for Oxygen to the tissues “Cirlce of Willis”—complete circle of connecting arteries surrounding the base of the brain **provides for more than one route of circulation

11. Brain Circulation

12. 3 Special Circulations
2.) Hepatic Portal Circulation—drain the digestive organs, spleen, pancreas and delivers it through the liver
**liver processes blood before it travels out into the systemic Circulation
**nutrients are removed and stored here (Glycogen)

13. Liver and Hepatic Portal

14. 3 Special Circulations
3.) Fetal Circulation—mother’s blood nourishes the developing child **Umbilical Cord—composed of a.) one umbilical Vein b.) two umbilical Arteries Umbilical Vein— carries blood rich in nutrients and Oxygen to the fetus Umbilical Arteries—Carbon Dioxide and wastes are carried away to the placenta

16. Pulse and Blood Pressure
Pulse pressure wave created by the flow of blood that is equal to heart rate
Pressure Points sites where arterial flow can be compressed to limit distal blood flow
Blood Pressure Pressure the blood exerts against the inner walls of the vessel keeps the blood circulating Created by a pressure gradient & Blood flows from High to low pressure

17. Common Pulse Locations

18. Blood Pressure
Measuring Blood Pressure Contract / Relax of the heart creates a flow Systolic—pressure in the artery at the peak of ventricular contraction (as blood flows through a valve) Diastolic—pressure in the artery when relaxed (as the blood “Backflows” into the closed valves) **measured in millimeters of Mercury (mmHg) **Normal is 120 / 80

20. Peripheral Resistance
**Narrowing of vessels increases resistance and blood pressure **Atherosclerosis Build up of plaque (fat deposits) along the walls of the artery **Increased blood thickness increases resistance **Autonomic Nervous System can alter controls of the blood pressure **Kidneys can change blood volume **Temperature  cold can change (vasoconstriction) and increase BP **Chemicals are positive and negative controllers (Drugs)

21. Controlling Blood Pressure
**Diet Controls:
1.) low salt diets **all are thought to prevent 2.) low fat diets hypertension 3.) low cholesterol diets
Hypertension High blood pressure (considered high is over 140 / 90)
Hypotension Low blood pressure (considered low if Systolic is below 100)

22. Measuring Blood Pressure