BIOL 2030 Human Anatomy & Physiology II Why do we need vessels? At one point blood believed to be replenished as it was consumed by the tissues. Let’s calculate the cardiac output of a resting student… (70ml/beat) * (70 beats/min) = 4900 ml/min How much blood “used up” per day? How many liters of water would you have to drink? What’s the route of blood flow through the body? What are the similarities between vessels? 3 Main layers (or tunics) 1) _____________ connective tissue 2) ____________ smooth muscle and elastic fibers 3) ____________ connective tissue, basement membrane and endothelium What are the differences between vessels? Vessels classified by: 1) __________ ____________ Arteries = A____ Veins = __v____ 2) _________ What are the differences between vessels? Vessels classified by: Medium vein 3) ___________ 4) _________ Elastic artery Muscular artery What’s unique about capillaries? •The 3 tunics not present •_____________ continuous with _____________ •___________ ____________ •___________ What are the differences between capillaries? •___________________ *no gaps in endothelium *found in muscles and nerves etc. •___________________ * “windows” in cell membranes *found in intestines, choroid processes, kidneys (WHY?) •____________________ *big gaps in endothelium *found near endocrine glands (WHY?) Which type most common? How is capillary flow regulated? What function(s) do these sphincters accomplish? What are the physics of flow? __________: Smooth flowing fluids in concenctric layers __________: Rough, irregular flow in multiple directions __________: A fluid’s Resistance to flow Flow, Pressure & resistance Poiseuille’s law Critical closing pressure What is your blood pressure and how can you measure it? Determining blood pressure indirectly relies on: 1) 2) 3) What is your pulse and how can you measure it? Your pulse is a measure of the # of heart beats per minute Can be determined via: __________ = apical pulse ______________ = temporal, facial, carotid, axillary, brachial, radial, femoral, popliteal, dorsalis pedis and posterior tibial __________ = carotid Take 5!!! Predict the effect of each of the following conditions on blood flow: a) vasoconstriction of blood vessels in the skin in response to cold b) vasodilation of dermal vessels due to heat c) polycythemia vera (> hematocrit)! What are the physics of phlow? Velocity and Area Pressure & Resistance 100 95 30 Pulse pressure 10 0 Take 5!!! Explain the consequences of worsening arteriosclerosis on a large aortic aneurysm. How is blood flow to tissues regulated? Flow regulated by: 1) ______________ Needs of organs/tissues met by demands. As metabolism > so does what? These cause relaxation of ________________ and ____________. __________________ Demand & _____________ What is mean arterial blood pressure? M.A.B.P. is proportional to __________ CO = _____________________ Venous return can influence _________________ End-systolic volume can decrease because of increased ________________ Difference between CO at rest and maximal CO is known as _________________ How is blood flow to tissues regulated? Flow regulated by: 2) _______________ Most vessels (except capillaries) innervated sympathetically, & are associated with the ________ _________ of the brain (pons/medulla oblongata). Consists of _________ and _________ regions Constant excitatory signals result in ________________ How is blood pressure regulated? Short term ____________: What do they do? How do they respond? ____________: What do they do? How do they respond? ____________________________: When stimulated? What result? __________________: When medulla is metabolically stressed fires many action potentials…results in > vasomotor tone. Emergencies and short-lived How is blood pressure regulated? Long term Renin-Angiotensin-Aldosterone Mechanism: series of enzymes that influence ____________________________ Vasopressin (ADH): both names imply function... Atrial natriuretic hormone: Name again describes origin and function Fluid shift: As b.p. ___ fluid moves from interstitial spaces back _________________ Stress-Relaxation response: Depending on stress level, __________________ contract and relax accordingly. Where does blood go? 2 main categories of circulation: •Pulmonary to and from lungs •Systemic to and from body Refer to pg. 718 and know the listed arteries! Where does blood go? Where does blood go? Where does blood go? Refer to pg. 729 and know the listed veins! Where does blood go?