A/P 2 chapter 17-19

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Chapter 18

Coverings of the Heart-

Pericardium-

Fibrous Pericardium- tough outer layer

Serous Pericardium- Inside of the pericardium has two layers with pericardial fluid in the center

Structure of the Heart-

Epicardium- outer layer

Myocardium- thick contractile middle layer that compresses the heart cavities.

Endocardium- delicate inner layer (single layer of endothelial cells)

Atria- “receiving chamber”

Auricle- earlike flap protruding from each atrium

Ventricles- “pumping chambers” THICKER Myocardium

Valves of the Heart-

Atrioventricular valve (AV) Connected to papillary muscle by Chordae Tendineae

Tricuspid-right (Between Atria and Ventricles)

Bicuspid/Mitral- left (Between Atria and Ventricles)

Semilunar Valve (SL)-

Pulmonic Valve- Entrance of Pulmonary artery

Aortic Valve- Entrance of Aorta

Blood supply to the Heart-

Coronary arteries- left and right deliver blood to myocardial cells. Branches from the ascending aorta

Cardiac Veins- drains into the right atrium.

Conduction in the heart-

SA Node (pacemaker) initiated

AV NODE-

Bundle of his-

Purkinje fibers-

Nerve supply to the heart-

Sympathetic- increases stroke volume, hr, vasoconstriction

Parasympathetic- inhibits constriction

Blood Vessels-

Arteries- Carry Blood AWAY from the Heart

Veins- Carry blood TOWARD the Heart. Reservoir blood.

Muscular artery- distributing

Arterioles- regulates BP

Metarterioles- between arterioles and capillaries

Capillaries- gas exchange occurs

True- precapillary sphincter....

Continuous caps- cont.....

Fenestrated- has holes to let protein etc. pass

Sinusoids- large. Porous.

Layers of Blood Vessels-

Tunica adventitia- outermost, in Art/Vein

Tunica media- middle in Art/Vein

Tunica intima- single layer capillaries

Building blocks-

Endothelial cells- lining....

Collagen fibers- woven, keeps lumen vessel open....

Elastic fibers- protein... smooth- active tension....

Circulation-

Systemic circulation- leaving right vent. Returning to right atrium

Systemic arteries-arterial anastomosis- artery to artery

AV anastomoses- art to vein

Systemic veins- superior vena cava and inferior vena cava

Hepatic portal circulation- veins from organs filter to liver, then from liver to inferior vena cava.

Pulmonary Circulation- Flow within the heart and Lungs

Two umbilical arteries- carry fetal blood to placenta....

Placenta- oxygen/substance exchange....

Umbilical vein- returns oxygenated blood from placenta to fetus, becomes round ligament of the liver....

Ductus venosus- continuation of umbilical vein, drains to ivc, becomes ligamentum yenosum of the liver....

Foramen ovale- opens in septum between atria, becomes fossa ovalis... Ductus arteriosus- connects pulmonary artery with descending thoracic aorta

Chapter 19

Conduction- know each section and what it does

EKG/ECG-

Ventricles contract-depolarization

P wave- depolarization of the atria

QRS- depolarization of ventricles/rep of aria

T- re-polarization of ventricles...

Atrial systole- begins at p wave. Contraction of atria completes emptying out of atria into ventricles.

Isovolumetric ventricular contraction- coincides with the R wave. First heart sound. Start of ventricular systole and SL valve opening. AV closure makes noise.

Ejection- coincides with T wave. SL valves open.

Isometric ventricular relaxation- second heart sound is heard. All valves closed.

Passive ventricular filling- pressure builds until AV valve opens.

Heart sounds-
systolic- first- closing AV valve

diastolic-second sound- closing of SL....
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