Cardiovascular Review 1 Cardiovascular Review 1. Which of the 4 tissue types would line and cover the heart? 2. The covering from #1 would be a part of what type of membrane? What is the specific name of this membrane? 3. What do we call the portion of the membrane that adheres to the surface of the heart? 4. Of what would the myocardium be composed? 5. If the heart is controlled by the autonomic nervous system, what are the 2 neurons called that this system uses? 6. What nerve does the parasympathetic use to get to the heart? Ganglion? NT? Receptors? 7. To increase the heart rate what ganglion does the sympathetic use to deliver impulses? NT? Receptors?

Midsternal line 2nd rib Sternum Diaphragm Point of maximal intensity (PMI) (a) 660

Mediastinum Superior Aorta vena cava Parietal pleura (cut) Pulmonary trunk Left lung Pericardium (cut) Apex of heart Diaphragm (c) 660

Figure 18.2 The pericardial layers and layers of the heart wall. Pulmonary trunk Fibrous pericardium Parietal layer of serous pericardium Pericardium Pericardial cavity (serous fluid) Myocardium Epicardium (visceral layer of serous pericardium) Heart wall Myocardium Endocardium Heart chamber Simple Squamous (Endothelium) 661

Cardiac muscle bundles Motor Unit 1 Motor Unit 2 661

Left To Body ventricle To Lungs Right ventricle Interventricular septum 670

Figure 18.2 The pericardial layers and layers of the heart wall. Anchors Pulmonary trunk Fibrous pericardium Parietal layer of serous pericardium Pericardium Pericardial cavity Myocardium Epicardium (visceral layer of serous pericardium) Heart wall Myocardium Endocardium Heart chamber Pericarditis 661

(right atrioventricular) valve Pulmonary valve Aortic valve Area of cutaway Mitral valve Tricuspid valve Myocardium Tricuspid (right atrioventricular) valve -separates the 2 motor units -separates them electrically -supports heart valves Mitral (left atrioventricular) valve Aortic valve Pulmonary valve Fibrous skeleton (a) Annulus Fibrosus Anterior 666

Aorta Left pulmonary artery Superior vena cava Right pulmonary artery Left atrium Left pulmonary veins Pulmonary trunk Right atrium Mitral (bicuspid) valve Right pulmonary veins Fossa ovalis Aortic valve Semilunar Valves Pectinate muscles Pulmonary valve Tricuspid valve Left ventricle Right ventricle Papillary muscle Chordae tendineae Interventricular septum Trabeculae carneae Epicardium Inferior vena cava Myocardium Endocardium (e) Frontal section Interatrial Septum 665

667 Blood returning to the heart fills atria, putting Direction of pressure against atrioventricular valves; atrioventricular valves are forced open. 1 Direction of blood flow Atrium Cusp of atrioventricular valve (open) As ventricles fill, atrioventricular valve flaps hang limply into ventricles. 2 Chordae tendineae Atria contract, forcing additional blood into ventricles. 3 Papillary muscle Ventricle (a) AV valves open; atrial pressure greater than ventricular pressure Atrium Ventricles contract, forcing blood against atrioventricular valve cusps. 1 Cusps of atrioventricular valve (closed) Atrioventricular valves close. 2 Blood in ventricle Papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria. 3 (b) AV valves closed; atrial pressure less than ventricular pressure 667

668 Aorta Pulmonary trunk As ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them open. (a) Semilunar valves open As ventricles relax and intraventricular pressure falls, blood flows back from arteries, filling the cusps of semilunar valves and forcing them to close. (b) Semilunar valves closed 668

Clicker Question: Which of the following is the correct sequence for blood to pass through part of the heart? A. Right atrium-> mitral valve-> right ventricle-> pulmonary semilunar valve B. Right atrium-> tricuspid valve -> right ventricle-> aortic semilunar valve C. Left atrium-> mitral valve-> left ventricle-> aortic semilunar valve D. Left atrium-> tricuspid valve-> left ventricle-> aortic semilunar valve

(a) The major coronary arteries Aorta Pulmonary trunk Superior vena cava Left atrium Anastomosis (junction of vessels) Left coronary artery In Left atrioventricular sulcus Right atrium Circumflex artery Right coronary artery In Right atrioventricular sulcus Left ventricle Right ventricle Anterior interventricular artery Right marginal artery Posterior interventricular artery In Anterior Interventricular Sulcus In Posterior Interventricular Sulcus (a) The major coronary arteries 670

(b) The major cardiac veins Superior vena cava Great cardiac vein Anterior cardiac veins Coronary sinus Small cardiac vein Middle cardiac vein (b) The major cardiac veins 670

Aorta Above armpits Left pulmonary artery Superior vena cava Right pulmonary artery Left atrium Left pulmonary veins Pulmonary trunk Right atrium Mitral (bicuspid) valve Right pulmonary veins Fossa ovalis Aortic valve Pectinate muscles Pulmonary valve Tricuspid valve Left ventricle Right ventricle Papillary muscle Chordae tendineae Interventricular septum Trabeculae carneae Epicardium Inferior vena cava Myocardium Below armpits Endocardium “Lub” “Dub” Systole & Diastole Veins = towards heart Arteries = away from heart (e) Frontal section 665

Blood flow through Coronary Vessels Aortic blood pressure Intramural blood pressure

(a) Anatomy of the intrinsic conduction system showing the Autorhythmic Cells Superior vena cava Contractile Cells 1% Right atrium 100 BPM Atria Contract The sinoatrial (SA) node (pacemaker) generates impulses. 1 Intercalated Discs Internodal pathway The impulses pause (0.1 s) at the atrioventricular (AV) node. 2 Gatekeep-er 40 BPM Left atrium The atrioventricular (AV) bundle (Bundle of His) connects the atria to the ventricles. 3 Purkinje fibers The bundle branches conduct the impulses through the interventricular septum. 4 Inter- ventricular septum The Purkinje fibers depolarize the contractile cells of both ventricles. 5 (a) Anatomy of the intrinsic conduction system showing the sequence of electrical excitation 675

Sarcomeres 672 Nucleus Intercalated discs Cardiac muscle cell Gap junctions Desmosomes (a) Cardiac muscle cell Mitochondrion Nucleus Intercalated disc Mitochondrion T tubule Sarcoplasmic reticulum Z disc Nucleus Sarcolemma (b) I band A band I band Sarcomeres 672

Autorhythmic and Contractile Cell Depolarizations

Dorsal motor nucleus of vagus The vagus nerve (parasympathetic) decreases heart rate. Cardioinhibitory center Para. Medulla oblongata Cardiac Center Cardio- acceleratory Center Symp. Sympathetic trunk ganglion Thoracic spinal cord Sympathetic trunk Sympathetic cardiac nerves increase heart rate and force of contraction. Vagus -ACH to Muscarinic -K+ ion channels open -SA, AV Cardiac -NE to Beta -Ca+2 ion channels open -SA, AV & Myocardium AV node SA node Parasympathetic fibers At rest vagus dominates = Vagal tone Sympathetic fibers Interneurons 677

Brain Sensory nerve fiber in cranial nerve IX (pharyngeal branch of glossopharyngeal) External carotid artery Internal carotid artery Carotid body Common carotid artery Cranial nerve X (vagus nerve) Sensory nerve fiber in cranial nerve X Aortic bodies in aortic arch Aorta Heart 837

Factors that Increase HR Increased Carbon Dioxide Decreased Blood Pressure Bainbridge Reflex Adrenaline Hypercalcemia Factors that Decrease HR Decreased Carbon Dioxide Increased Blood Pressure Hyperkalemia Hypernatremia Hypocalcemia

Approximately 70ml from each ventricle App 70 BPM CO2 Ions Bainbridge Exercise (by skeletal muscle and respiratory pumps; see Chapter 19) Heart rate (allows more time for ventricular filling) Bloodborne epinephrine, thyroxine, excess Ca2+ Exercise, fright, anxiety Venous return Sympathetic activity Parasympathetic activity Contractility EDV (preload) ESV Starling’s Law CO=HR x SV EDV-ESV Stroke volume Heart rate Approximately 70ml from each ventricle App 70 BPM Cardiac output ml/min Increased CO= Increased BP Initial stimulus Physiological response Result Blood loss? 682

Clicker Question Select the correct statement about cardiac output. A Clicker Question Select the correct statement about cardiac output. A. A slow heart rate increases end diastolic volume, stroke volume and force of contraction. B. Decreased venous return will result in increased end diastolic volume. C. If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased. D. Stroke volume increases if end diastolic volume decreases.

Depolarization & Atrial Rep. QRS complex Sinoatrial node Ventricular Depolarization & Atrial Rep. Ventricular repolarization Atrial depolarization Atrioventricular node S-T Segment P-Q Interval Q-T Interval 677

SA node 678 Slide 1 SA node R R T P P T Q S Depolarization Repolarization R SA node R P T Q P T S 1 Atrial depolarization, initiated by the SA node, causes the P wave. Q S 4 Ventricular depolarization is complete. AV node R R P T P T Q S 2 Q With atrial depolarization complete, the impulse is delayed at the AV node. S 5 Ventricular repolarization begins at apex, causing the T wave. R R P T P T Q S Q 3 S Ventricular depolarization begins at apex, causing the QRS complex. Atrial repolarization occurs. Ventricular repolarization is complete. 6 678

Arrhythmias Heart Block Bradycardia Tachycardia Fibrillation Myocardial Infarction

Treatments Remove tissue Beta blockers (High blood pressure) Calcium Channel blockers (High blood pressure) Digitalis (Slows rate and strengthens contractions; heart failure) Pacemaker