CHAPTER 20

BLOOD VESSELS

 

STUDY OBJECTIVES

         State the function of arteries, capillaries and veins. Contrast the anatomy of arteries, capillaries and veins.

         Describe the three layers that typically form the wall of a blood vessel and state the function of each. Define vasoconstriction and vasodilation.

         Contrast elastic arteries, muscular arteries and arterioles.

         Explain how blood is directed through capillaries by precapillary sphincters.

         State which vessel type acts as a blood reservoir. Describe how the structure of veins helps to return low pressure blood to the heart. Define varicose veins and hemorrhoids.

         Describe blood pressure, peripheral resistance, blood viscosity, and blood vessel diameter. Explain how each is related to blood flow. Ignore the section titled "Relationship Between Blood Flow, Blood Pressure, and Resistance".

         Explain how blood pressure makes blood move through the various regions of the cardiovascular system. Describe systolic and diastolic pressure.

         Explain how valves in veins, breathing, and skeletal muscle contractions help venous blood return to the heart.

         From lecture, describe the factors that influence blood pressure. Explain how blood pressure is regulated. Explain why baroreceptors are unable to regulate chronic hypertension. You will not be tested on chemical controls or renal regulation of blood pressure.

         Define pulse. State which blood vessel is easily used to take a pulse measurement. State which blood vessel is commonly used for blood pressure measurements. Describe the mechanism for measuring the systolic and diastolic blood pressures with a sphygmomanometer.

         Define hypotension and hypertension. Explain why chronic hypertension is dangerous.

         Describe the autoregulation of blood flow to the depth covered in lecture.

         Describe circulatory shock. You will not be tested on the various types.

         State the effects of aging on veins and blood pressure.

         Using Table 20.10, state which vein is commonly used to obtain venous blood samples or for administration of medication or transfusions. Explain how the azygos system provides collateral circulation.

         State the function of the hepatic portal circulation.

         Identify and be able to state the location of the following arteries and veins. Also state the area supplied or drained by each (refer to text). Trace the path of blood through the body using these assigned blood vessels. Learn the arteries and veins in order of blood flow. Therefore, the arteries would be studied from major vessels to smaller tributaries, while the veins would be followed from the smaller tributaries to major vessels.

 

         Start by following the arterial blood away from the heart:

ascending aorta

aortic arch

brachiocephalic artery (note that there is no left brachiocephalic artery)

common carotid artery

external carotid artery

internal carotid artery

subclavian artery

vertebral artery

axillary artery

brachial artery

radial artery

ulnar artery

palmar arches

digital arteries of the hand

thoracic aorta

posterior intercostal arteries

abdominal aorta

celiac trunk

common hepatic artery

gastric artery

splenic artery

superior mesenteric artery

suprarenal artery

renal artery

gonadal (ovarian or testicular) artery

inferior mesenteric artery

common iliac artery

internal iliac artery

external iliac artery

femoral artery

popliteal artery

anterior tibial artery

posterior tibial artery

plantar arch

digital arteries of the foot

 

Now follow the venous blood back to the heart. (Veins and arteries usually run parallel to each other.)