Blood Vessels

1. Blood Vessels December 2009

3. Do Now What two conduction systems impact heart rate?

4. Objectives 1. Compare and contrast the structure and function of arteries, veins, and capillaries. Identify the body's major arteries and veins, and name the body region supplied by each. Discuss the unique features of special circulations of the body: arterial circulation of the brain, hepatic portal circulation, and fetal circulation.

5. Types of Blood Vessels?

6. Blood Vessels: The Vascular System

7. Blood Vessels: Microscopic Anatomy Three layers (tunics) Tunic intima Endothelium Tunic media Smooth muscle Controlled by sympathetic nervous system Tunic externa Mostly fibrous connective tissue

8. Blood Vessels: The Vascular System

9. Your turn! Compare and contrast the structure and function of arteries, veins, and capillaries. (Include diagrams.)

10. Characteristics of Blood Vessels Arteries Walls of arteries are the thickest Must be able to expand as blood is forced into them, and then recoil passively as the blood flows off into the circulation during diastole

11. Characteristics of Blood Vessels Veins Lumens of veins are larger Pressure tends to be low Larger veins have valves to prevent backflow Skeletal muscle �milks� blood in veins toward the heart When we inhale, the drop in pressure in the thorax causes large veins near the heart to expand and fill

12. Venous Blood Flow Aided by skeletal muscle contraction Adds to exercise�s influence on blood pressure and heart rate

13. Characteristics of Blood Vessels Arterioles Supply blood to the capillary beds in the tissues Venules Capillary beds drain into venules, which in turn empty into veins

14. Characteristics of Blood Vessels Capillaries What must they be able to do?

15. Characteristics of Blood Vessels What are varicose veins? How are they treated? Elastic stockings Elevating legs Exercise Sclerotherapy Vein stripping Radiofrequency ablation Endovenous laser therapy

16. THINK! Assume you are viewing a blood vessel under the microscope. It has a lopsided lumen, relatively thick externa, and a relatively thin media. Which kind of a blood vessel is this?

17. Major Blood Vessels

18. Major Blood Vessels

19. 1) Label major blood vessels and 2) Name the area of the body where it supplies blood. Arteries: Aorta Common carotid arteries Brachiocephalic trunk Common iliac Digital arteries Femoral artery Dorsalis pedis artery Renal artery Subclavian artery Coronary artery Celiac trunk Radial artery Posterior tibial artery Brachial artery Veins: Superior/inferior vena cava Internal jugular vein Great cardiac vein Hepatic portal vein Great saphenous vein Dorsal venous arch Basilic vein Subclavian vein Common iliac vein Mesenteric vein

20. Blood Vessels Walls of arteries are the thickest Lumens of veins are larger Larger veins have valves to prevent backflow Skeletal muscle �milks� blood in veins toward the heart Walls of capillaries are only one cell layer thick to allow for exchanges between blood and tissue

21. Arterial Supply of the Brain Internal carotid arteries divide into Anterior and middle cerebral arteries These arteries supply most of the cerebrum Vertebral arteries join once within the skull to form the basilar artery Basilar artery serves the brain stem and cerebellum

22. Arterial Supply of the Brain Posterior cerebral arteries form from the division of the basilar artery These arteries supply the posterior cerebrum

23. Circle of Willis Anterior and posterior blood supplies are united by small communicating arterial branches Result�complete circle of connecting blood vessels called cerebral arterial circle or circle of Willis

24. Arterial Supply of the Brain

25. Fetal Circulation How does fetus receive nutrients?

26. Fetal Circulation Fetus receives exchanges of gases, nutrients, and wastes through the placenta Umbilical cord contains three vessels Umbilical vein�carries blood rich in nutrients and oxygen to the fetus Umbilical arteries (2)�carry carbon dioxide and debris-laden blood from fetus to placenta

27. Fetal Circulation Blood flow bypasses the liver through the ductus venosus and enters the inferior vena cava ? right atrium of heart Blood flow bypasses the lungs Blood entering right atrium is shunted directly into the left atrium through the foramen ovale Ductus arteriosus connects the aorta and pulmonary trunk (becomes ligamentum arteriosum at birth)

28. Fetal Circulation

30. Hepatic Portal Circulation Veins of hepatic portal circulation drain Digestive organs Spleen Pancreas Hepatic portal vein carries this blood to the liver Liver helps maintain proper glucose, fat, and protein concentrations in blood

31. Hepatic Portal Circulation Major vessels of hepatic portal circulation Inferior and superior mesenteric veins Splenic vein Left gastric vein

32. Hepatic Portal Circulation

33. Hepatic Portal Circulation

34. Did you get it? In what part of the body are the femoral, popliteal, and arcuate arteries found? What is the ductus venosus, and what is its function? Which vessel- the hepatic portal vein, hepatic vein, or hepatic artery- has the highest content of nutrients after a meal?

35. Homework Read pg. 372-374 Written assignment: Describe the effect of each of the following on heart rate: stimulation by the vagus nerve, exercise, epinephrine, and various ions. Be ready to discuss in class.

37. What is a Pulse? Pulse Pressure wave of blood Monitored at �pressure points� in arteries where pulse is easily palpated Pulse averages 70�76 beats per minute at rest

38. PressurePoints

39. Blood Pressure Measurements by health professionals are made on the pressure in large arteries Systolic�pressure at the peak of ventricular contraction Diastolic�pressure when ventricles relax Write systolic pressure first and diastolic last (120/80 mm Hg)

40. Why is blood pressure taken in a standard body area? Pressure in blood vessels decreases as distance from the heart increases

41. Echocardiogram A sonography of the heart Also known as a cardiac ultrasound Gives information about size and shape of the heart and blood vessels