Circulatory System Day 2 Innervation Pulmonary Loop Main

Circulatory System Day 2 – Innervation, Pulmonary Loop

Main Ideas

Innervation • Heartbeat = intrinsic – Via medulla oblongata – Influenced by stress, oxygen, blood pressure • Nodal tissue: has both nerve & muscle characteristics

Sinoatrial Node • Initiates heartbeat SA Node

Atrioventricular node • Pulse goes from SA node to AV node – Signal along “purkinje fibres” ventricles SA contraction Node AV Node - Contraction starts at base…moves up like wave

Pulmonary System • Heart must circulate oxygenated blood! – Must connect with lungs for gas exchange

Pulmonary System

Coronary Arteries • Heart needs oxygenated blood too!!! – Can’t diffuse into all cells from ventricle • Coronary arteries (and veins) supply blood

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Circulatory Review Heart Anatomy Video Circulatory rap

Atherosclerosis • Excess fat and cholesterol stick to the arteries, forming a PLAQUE • Plugs up the arteries, restricting blood flow • If the blood flow that is restricted is to the heart, a heart attack may occur

Angioplasty – possible procedure if the blockage isn’t too severe

Heart Attack • When the cells of the heart do not get enough oxygen • The severity of the attack depends on how bad the coronary artery blockage is, and how many heart cells die At first, the victim may suffer angina pectoris (radiating pain in the left arm).

To Do’s • Questions [next slide] • Provincial Q’s – 11, 13, 22, 29, 32, 33, 40 • Dictionary – SA node, AV node, pulmonary artery, pulmonary vein

Questions 1. Draw a heart & lungs. Using no more than 3 arrows, show the path of blood through the heart to the lungs and body! 2. 3. How is the heart controlled/initiated? [include at least 3 steps] 4. Why is it important that our heartbeat is under intrinsic (ie. Not conscious) control?