CIRCULATORY SYSTEM A&P 4 By Angie Lawson RN, BSN

HEARTS LAYERS & COVERINGS Endocardium- innermost layer Endocardium- innermost layer Myocardium – middle layer, muscle tissue Myocardium – middle layer, muscle tissue Epicardium – outermost layer, cont. with pericardium Epicardium – outermost layer, cont. with pericardium Pericardium – sac the heart lies in Pericardium – sac the heart lies in

HEARTS CHAMBERS Right Atrium – thin walled receives unoxygenated blood Right Atrium – thin walled receives unoxygenated blood Right Ventricle- sends unoxygenated blood to the lungs Right Ventricle- sends unoxygenated blood to the lungs Left Atrium- receives oxygenated blood from lungs Left Atrium- receives oxygenated blood from lungs Left Ventricle- thickest chamber sends oxygenated blood to the body Left Ventricle- thickest chamber sends oxygenated blood to the body

HEART VALVES (Purpose: Keep blood flowing forward) Atrioventricular Valves – between the atrium & ventricles Atrioventricular Valves – between the atrium & ventricles Tricuspid valve – right AV valve Tricuspid valve – right AV valve Bicuspid valve – mitral valve Bicuspid valve – mitral valve Semilunar Valves – between the ventricles and main arteries Semilunar Valves – between the ventricles and main arteries Pulmonic valve (pulmonary) Pulmonic valve (pulmonary) Aortic valve Aortic valve

BLOOD FLOW THROUGH THE HEART Right atrium Tricuspid valve Right ventricle Pulmonic semilunar valve Pulmonary artery Pulmonary arteries R & L Pulmonary capillaries Four pulmonary veins Left atrium Bicuspid valve Left ventricle Aortic semilunar valve Aorta

CORONARY BLOOD SUPPLY Right Coronary Artery Right Coronary Artery Left Coronary Artery Left Coronary Artery Left Anterior Left Anterior Descending Descending Circumflex Artery Circumflex Artery Coronary Veins Coronary Veins Coronary Sinus Coronary Sinus

CARDIAC CONDUCTION Sinoatrial Node (SA) Sinoatrial Node (SA) Atrial Conducting Fibers Atrial Conducting Fibers Atrioventricular Node (AV) Atrioventricular Node (AV) His-Purkinje System His-Purkinje System

ELECTROCARDIOGRAM P Wave P Wave QRS Complex QRS Complex T Wave T Wave P-R Interval P-R Interval

CARDIAC CYCLE Atrial Systole – atrium contract Atrial Systole – atrium contract Ventricular Systole – ventricles contact, atrium relax Ventricular Systole – ventricles contact, atrium relax Diastole – both the ventricles and atrium relax Diastole – both the ventricles and atrium relax

CARDIAC OUTPUT CO = HR X SV HR = Heart Rate HR = Heart Rate SV = Stroke Volume SV = Stroke Volume

TYPES OF CIRCULATION Pulmonary Pulmonary Systemic Systemic

BLOOD VESSELS Arteries Arteries Capillaries Capillaries Veins Veins

BLOOD VESSEL WALLS Tunica Intima Tunica Intima Tunica Media Tunica Media Tunica TunicaAdventitia

VESSELS IN ORDER Arteries – conductance vessels Arteries – conductance vessels Arterioles – resistance vessels Arterioles – resistance vessels Capillaries- exchange vessels Capillaries- exchange vessels Venules- capacitance vessels Venules- capacitance vessels Veins – larger venules Veins – larger venules

SYSTEMIC CIRCULATION ARTERIES Aorta Aorta Branches of the: Branches of the: Aorta Aorta Ascending aorta Ascending aorta Aortic arch Aortic arch Descending aorta Descending aorta Thoracic aorta Thoracic aorta Abdominal aorta Abdominal aorta

SYSTEMIC CIRCULATION VEINS Venae Cavae Venae Cavae Superior Superior Inferior Inferior

SUPERIOR VENAE CAVAE Cephalic vein Cephalic vein Basilic vein Basilic vein Median cubital vein Median cubital vein Subclavian vein Subclavian vein Internal juglar vein Internal juglar vein Brachiocephalic vein Brachiocephalic vein Azygos vein Azygos vein

INFERIOR VENAE CAVAE Tibial vein Tibial vein Peroneal vein Peroneal vein Posterior tibial vein Posterior tibial vein Femoral vein Femoral vein External iliac vein External iliac vein Common iliac vein Common iliac vein Great saphenous vein Great saphenous vein Renal & Hepatic vein Renal & Hepatic vein

SPECIAL CIRCULATIONS Head & Neck Head & Neck Head & Brain Head & Brain Liver & Hepatic Portal Liver & Hepatic Portal Fetal Fetal

HEAD & NECK ARTERIES Common carotid arteries Common carotid arteries External carotid arteries External carotid arteries Internal carotid arteries Internal carotid arteries Vertebral arteries Vertebral arteries Basilar artery Basilar artery Circle of Willis Circle of Willis

HEAD & BRAIN VEINS Internal jugular vein Internal jugular vein External jugular vein External jugular vein

LIVER & HEPATIC PORTAL CIRCULATION Portal vein Portal vein Superior mesenteric vein Superior mesenteric vein Splenic vein Splenic vein Inferior mesenteric vein Inferior mesenteric vein

FETAL CIRCULATION Umbilical vein (1) Umbilical vein (1) Umbilical arteries (2) Umbilical arteries (2) Placenta - serves as Placenta - serves as the lungs the lungs

BLOOD PRESSURE Systolic pressure Systolic pressure Diastolic pressure Diastolic pressure Pulse pressure Pulse pressure

DETERMINING B/P B/P = CO X VR CO = Cardiac Output CO = Cardiac Output VR = Vascular Resistance VR = Vascular Resistance

BARORECEPTOR REFLEX Receptors Receptors Sensory nerves Sensory nerves Medulla oblongata Medulla oblongata Motor nerves Motor nerves

WHY CAPILLARIES WORK Thin walls Thin walls Holes in walls Holes in walls Slow flow Slow flow Diffusion Diffusion Filtration-osmosis Filtration-osmosis