what does the vascular system consist of? - Answer- -vessels for transporting fluid such as blood or lymph -any disease in the vascular system impairs the delivery of oxygen and nutrients to the affected cells and retards elimination of carbon dioxide and waste products from cellular metabolism arteries - Answer- -the heart pumps freshly oxygenated blood through the arteries to all body tissues -the pumping heart makes this a high-pressure system -the artery walls are strong, tough, and tense to withstand pressure demands -arteries contain elastic fibers, which allow their walls to stretch with systole and recoil with diastole -each heart beat creates a pressure wave, which makes the arteries expand and then recoil -all arteries have a pressure wave (pulse) throughout their length, but you can only feel it at the body sites where the artery lies closest to the skin and over a bone temporal artery - Answer- -palpated in front of the ear carotid artery - Answer- -palpated in the groove above the sternomastoid muscle and trachea arteries in the arm - Answer- -major artery in arm is brachial, which runs in the biceps-triceps furrow of the upper arm and surfaces at the antecubital fossa in the elbow medial to the biceps tendon -brachial artery bifurcates into the ulnar and radial arteries -radial pulse lies just medial to the radius at the wrist -ulnar artery is deeper and often difficult to feel arteries in the leg - Answer- -major artery in leg is femoral, which passes under the inguinal ligaments -femoral artery travels down the thigh, at the lower thigh is courses posteriorly; then it is termed the popliteal artery -the anterior tibial artery travels down the front of the leg on the dorsum of the foot, where it becomes the dorsalis pedis -in the back of the leg the posterior tibial artery travels down behind the medial malleolus and forms the plantar arteries in the foot what is the function of the arteries? - Answer- -to supply oxygen and essential nutrients to the cells what is ischemia? - Answer- -a deficient supply of oxygenated arterial blood to a tissue caused by obstruction of a blood vessel -a complete blockage leads to death of the distal tissue -a partial blockage creates an insufficient supply, and the ischemia may be apparent only at exercise when oxygen needs increase what is peripheral artery disease (PAD)? - Answer- -affects non-coronary arteries and usually refers to arteries supplying the limbs -it is usually caused by atherosclerosis (deposit of plaque from high cholesterol) and less commonly by embolism, hypercoagulable states, or arterial dissection veins - Answer- -the course of the veins is parallel to the arteries, but the direction of flow is opposite -the veins absorb carbon dioxide and waste products from the periphery and carry them back to the heart -the body has more veins, and they lie closer to the skin surface -walls of veins are thinner veins in the arm - Answer- -each arm has two sets of veins: superficial and deep -the superficial veins in the subq tissue are responsible for most of the venous return veins in the leg - Answer- -3 types of veins: deep veins, superficial veins, and perforators -deep veins: run alongside the deep arteries and conduct most of the venous return from the legs, these are the femoral and popliteal veins, as long as these veins remain intact, the superficial veins can be excised without harming the circulation -superficial veins: great and small saphenous veins, the great saphenous, inside the leg, starts at the medical side of the dorsum of the foot. the small saphenous, outside the leg, starts on the lateral side of the dorsum of the foot and ascends behind the lateral malleolus -perforators: are connecting veins that join the two sets, they also have one way valves that route blood from the superficial into the deep and prevent reflux to the superficial veins venous flow - Answer- -veins drain deoxygenated blood and its waste products from tissues and return it to heart -veins are a low pressure system what is the mechanism of venous blood flow - Answer- (1) the contracting skeletal muscles milk the blood proximally, back toward the heart (2) the pressure gradient caused by breathing, in which inspiration makes the thoracic pressure decrease and the abdominal pressure increase (3) the intraluminal valves, which ensure unidirectional flow, each valve is a paired semilunar pocket that opens toward the heart and closes tightly when filled to prevent backflow of blood -in the legs this mechanism is called the calf pump or peripheral heart what does efficient venous return depend on? - Answer- -contracting skeletal muscles -competent valves in the veins -patent (clear) lume