HEART QA Questions a muscular organ that is essential for life because it pumps blood through the body heart is a member organ of the cardiovascular system, which consists of the The heart of a healthy adult, at rest, pumps approximately ________ of blood per minute For most people, the heart continues to pump at approximately that rate for more than the heart’s right side pumping to the lungs and back to the left side of the heart through vessels of the left side of the heart pumps blood to all other tissues of the body and back to the right side of the heart through vessels of the double-layered sac that anchors and protects heart membrane around heart’s cavity membrane on heart’s surface space around heart extends around the heart, separating the atria from the ventricles Two grooves indicate the division between the right and left ventricles extends inferiorly from the coronary sulcus on the posterior surface of the heart carry blood from the body to the right atrium carry blood from the lungs to the left atrium carry blood away from the ventricles of the heart arising from the right ventricle The pulmonary trunk splits into the right and left carry blood to the lungs carries blood to the rest of the body separates atria from ventricles Holding chambers Pumping chambers Small, thin walled Contract minimally to push blood into ventricles separates right and left atria Thick, strong walled Contract forcefully to propel blood out of heart separates right and left ventricles Valves between the atria and ventricles AV valve between RA and RV 3 cusps AV valve between LA and LV 2 cusps Each ventricle contains cone-shaped, muscular pillars called These muscles are attached by strong, connective tissue strings called A plate of connective tissue consists mainly of fibrous rings that surround the atrioventricular and semilunar valves and give them solid support This connective tissue plate also serves as __________between the atria and the ventricles and provides a rigid attachment site for cardiac muscle supply blood to heart wall Answers heart heart, blood vessels, and blood 5 liters (L) 75 years Pulmonary circulation Systemic circulation pericardium Parietal pericardium Visceral pericardium Pericardial cavity coronary sulcus Sulci Two grooves or sulci posterior interventricular sulcus superior vena cava and inferior vena cava four pulmonary veins arteries Pulmonary trunk Pulmonary arteries Pulmonary arteries aorta Coronary sulcus Atria Interatrial septum Coronary sulcus Interatrial septum Interatrial septum Interventricular septum Interventricular septum Tricuspid valve Bicuspid valve (mitral) papillary muscles chordae tendineae cardiac skeleton, or fibrous skeleton cardiac skeleton, or fibrous skeleton electrical insulation Coronary arteries supply blood to anterior heart wall and left ventricle supply blood to right ventricle drain blood from the cardiac muscle surface of heart (outside) thick, middle layer composed of cardiac muscle smooth, inner surface Cardiac muscle used for contractions Connect cells of cardiac muscle Cardiac muscle is rich in 1 centrally located nucleus Changes in membrane channels’ permeability are responsible for producing action potentials and is called Na+ channels open Ca2+ channels open Na+ channels close Some K+ channels open Ca2+ channels remain open K+ channels are open • Ca2+ channels close prolongs action potential by keeping Ca2+ channels open. In skeletal muscle action potentials take in cardiac muscle they take Contraction of the atria and ventricles is coordinated by specialized cardiac muscle cells in the heart wall that form the ________ of the heart All the cells of the conduction system can produce The conduction system of the heart includes the functions as pacemaker action potentials spread slowly through it action potentials are rapidly delivered to all the cardiac muscle of the ventricles divides into a left and right bundle branches where action potential originates action potentials from SA node sent to this node record of electrical events in heart slow rate of action potential conduction allows the atria to complete their contraction before action potentials are delivered to the ventricles diagnoses cardiac abnormalities • uses electrodes • contains P wave, QRS complex, T wave depolarization of ventricles depolarization of atria repolarization of ventricles a summative description of all the events that occur during one single heartbeat. primers for pumps the actual pumps produce pressure changes within heart chambers responsible for blood movement systole Left coronary artery Right coronary artery Cardiac veins Epicardium Myocardium Endocardium Ca2+ and ATP Intercalated disks Mitochondria Cardiac muscle Pacemaker potential Depolarization phase Plateau phase Repolarization phase Plateau phase 2 msec 200-500 msec Conduction system spontaneous action potentials sinoatrial node, atrioventricular node, atrioventricular bundle, right and left bundle branches, and Purkinje fibers Sinoatrial node (SA node) Atrioventricular node (AV node) Purkinje Fibers Atrioventricular bundle Sinoatrial node (SA node) Atrioventricular node (AV node) ECG (EKG) Atrioventricular node (AV node) ECG (EKG) QRS complex P wave T wave cardiac cycle atria ventricles Cardiac muscle contractions Pressure changes Contraction Diastole produced due to the closure of heart valves. used to hear heart sounds first heart sound makes a second heart sound makes a first heart sound is due to the closure of the second heart sound is due to the closure of the volume of blood pumped per ventricle per contraction number of heart beats in 1 min. Stroke volume mm/beat Heart rate beats/min volume of blood pumped by a ventricle in 1 min 5 Liters/min amount of blood that returns to heart the degree ventricular walls are stretched at end of diastole the mechanisms contained within the heart itself that control cardiac output mechanism of the nervous system that plays an important role in regulating heart function. involves chemical regulation of the heart relationship between preload and stroke pressure against which ventricles must pump blood volume influences cardiac output monitor blood pressure in the aorta and carotid arteries changes in blood pressure cause changes in frequency of action potentials can affect heart rate and stroke volume Chemical from the adrenal medulla can increase heart rate and stroke volume excitement, anxiety, and anger can increase has chemoreceptors for changes in pH and CO2 affect cardiac function due to decrease blood supply to the heart - due to closure of one or more coronary arteries - area(s) of cardiac muscle lacking adequate blood supply die, and scars (infarct) procedure opens blocked blood vessels structures inserted to keep vessels open procedure reroutes blood away from blocked arteries Relaxation Heart sounds stethoscope lubb dupp atrioventricular valves semilunar valves Stroke Volume Heart rate 70 milliliters/beat 72 beats/min. Cardiac Output Venous return Preload Intrinsic regulation baroreceptor reflex chemoreceptor reflex Starlings Law of the Heart After load Starlings Law of the Heart Baroreceptors Baroreceptors Chemicals epinephrine and norepinephrine Chemical actions medulla oblongata K+, Ca2+, and Na+ Coronary Artery Disease Myocardial Infarction (heart attack) Angioplasty Stent Bypass BLOOD VESSELS AND CIRCULATION QA Questions transport blood from the right ventricle of the heart through the lungs and back to the left atrium transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium carry blood away from heart Answers pulmonary vessels systemic vessels arteries thick with a lot of elastic carry blood toward heart think with less elastic exchange occurs between blood and tissue fluids Tunica intima Tunica media Tunica adventitia largest in diameter thickest walls can control blood flow to body regions collect blood from small veins and deliver to large veins Example of elastic arteries contain valves blood vessels that carry blood from right ventricle to lungs and back from left atrium of heart blood pump from right ventricle towards lung exit lungs and carry O2 rich blood to left atrium __________carries blood from the left ventricle to the tissues of the body and back to the right atrium distribute blood from the aorta to all portions of the body passes superiorly from left ventricle 3 major arteries which carry blood to head and upper limbs extends through thorax and abdomen to pelvis part of descending aorta that extends through thorax to diaphragm descending aorta that extends from diaphragm where it divides at the common iliac arteries Branch of aortic arch that supplies blood to the left side of head and neck Branch of aortic arch that supplies blood to left upper limbs Branch of aortic arch that supplies blood to right side of head and neck Branches of aortic arch: branches off brachiocephalic artery that supplies blood to right side of head and neck branches off brachiocephalic artery that supplies blood to right upper limbs supply blood deep in clavicle where blood pressure measurements are taken - supply blood to forearm and hand - pulse taken here near elbow supply blood to stomach, pancreas, spleen, liver, upper duodenum supply blood to small intestines and upper portion of colon supply blood to colon supply blood to kidneys supply blood to liver supply blood to diaphragm supply blood to lower limbs supply blood to pelvic area branches from abdominal aorta veins Capillaries Simple squamous smooth muscle with elastic and collagen connective tissue Elastic arteries Muscular arteries Medium sized veins Aorta and pulmonary trunk Large veins Pulmonary circulation Pulmonary trunk Pulmonary veins Systemic circulation arteries Ascending Aortic arch Descending Thoracic abdominal Left common carotid artery Left subclavian artery Brachiocephalic artery - brachiocephalic artery - left common carotid artery - left subclavian Right common carotid artery Right subclavian artery Axillary arteries Brachial arteries Radial arteries Ulnar arteries Celiac trunk arteries Superior mesenteric arteries Inferior mesenteric arteries Renal arteries Hepatic arteries Inferior phrenic arteries External iliac arteries Internal iliac arteries Common iliac arteries return blood to the heart In the systemic circulation, the blood returning to the heart is In the pulmonary circulation, the blood returning to the heart in the pulmonary veins is returns blood from head, neck, thorax, and right upper limbs returns blood from abdomen, pelvis, lower limbs drain blood from head and neck drain blood from brain, face, neck forms brachiocephalic veins join to form superior vena cava empty into axillary vein empty into axillary vein and basilic vein connects to cephalic vein empty into brachiocephalic veins Veins deoxygenated oxygenated Superior vena cava Inferior vena cava External jugular vein Internal jugular vein Subclavian veins Brachiocephalic veins Brachial veins Cephalic veins Median cubital veins Internal thoracic veins
