Where on the chest wall can you hear the heartbeat the best? 2. Name this structure 3. Name this valve 4. When the ventricles are in systole, is this valve open or closed? 5. What is a heart murmur?

Blood Vessels structure of vessel walls arteries maintaining constant blood pressure aneurisms capillaries veins variations in circulatory pathways examples of portal systems blood supply to the brain

Tunica intima Tunica media Tunica externa endothelium BM smooth muscle collagen some elastin L. vein L. artery Tunica externa loose CT vasa vasorum Medium sized vein Medium sized artery venule arteriole capillary

To heart Valve open Vein Valve closed Contracted skeletal muscles Relaxed skeletal muscles

Precapillary sphincters Sphincters open Sphincters closed When are sphincters closed? Fingers? Muscles? Around gut? Sphincters open Sphincters closed

1 capillary bed Pulmonary trunk (artery) Pulmonary vein

hypothalamus Portal system (2 capillary beds) Anterior pituitary

Hepatic portal system IVC Hepatic sinusoids Gastric veins spleen pan Superior Mesenteric V

Portal system Arteriovenous anastomosis Arterial anastomoses Venous anastomoses Dark blue = portal light blue = systemic

Internal carotid Vertebral artery

Internal carotid Basilar Circle of Willis Vertebral Cerebrovascular Accident = CVA = stroke

How to maintain constant blood pressure 1. Conducting arteries expand & recoil With increasing and decreasing pressure 2. measure pressure, adjust HR and dilate or constrict BV’s High BP Lower HR

Fig. 21.4(TE Art) Carotid body Baroreceptors Aortic body Baroreceptors Carotid sinus Baroreceptors Common carotid artery Aortic body Aortic arch Baroreceptors

Fig. 16.1(TE Art) Glossopharyngeal Nerve (CN IX) Baroreceptors sense increased blood pressure Vagus nerve (CN X) Heart rate decreases

Aneurysm: weak point in an artery or heart wall common in abdominal aorta renal arteries & brain

Cerebral vascular accident (CVA) = stroke