- Center of the cardiovascular system

- Artieries carry blood away from the heart, which is generally oxygen rich (except for the pulmonary arteries)

- Veins carry blood towards the heart that is generally oxygen-poor (except for the pulmonary veins)

- Arteries and veins entering and leaving the heart are called the great vessels

- Structure of the heart ensures the unidirectional flow of blood through both the heart and the blood vessels

- Backflow of blood is prevented by valves within the heart

- Divided into two independent, coordinated pumps

- Blood pressure develops through alternate cycles of heart wall contraction and relaxation

- Minimum blood pressure is essential to push blood through blood vessels to the body tissues for nutrient and waste exchange

- Fist-sized, conical organ; weighs ~250-350 grams

- Located left of the body midline

- Posterior to the sternum in the mediastinum

- Rotated such that its right side or border (right atrium and ventricle) is located more anteriorly

- While its left side or border (left atrium and ventricle) is located more posteriorly

- The base is the posterosuperior surface of the heart, formed primarily by the left atrium

- The pulmonary veins that enter the left atrium border this base

- The apex is the inferior, conical end

- It projects slightly anteroinferiorly toward the left side of the body

- The heart sits in the mediastinum, wrapped up in its own protective sac

- PERI (around)+ CARDIUM (heart)

- Parietal layer lines inside of fibrous pericardium

- Visceral layer directly covers outer surface of the heart

- Secretes fluid for lubricaiton

- Heart composed of four hollow chambers

- Atria (R and L) are thin-walled chambers that are located superiorly; anterior part of each atrium is a wrinkled, flaplike extension called an auricle

- Right atrium receives blood from the systemic circuit and from heart tissue itself

- Left atrium receives blood from the bulmonary circuit

- Blood that enters an atrium is passsed to the ventricle of the same side

- Ventricles are the inferior chambers

- Two large arteries, the pulmonary trunk and the aorta exit the heart at the basal surface

- The pulmonary trunk carries blood from the right ventricle into the pulmonary circuit

- Aorta conducts blood from the left ventricle into the systemic circuit

- Pericardium (visceral)/epicardium

- Base

- Apex

- Superior Vena Cava

- Inferior Vena Cava

- Right Atrium

- Right Auricle

- Left Atrium

- Left Auricle

- Right Ventricle

- Left Ventricle

- Pulmonary Trunk

- Pulmonary Arteries

- Pulmonary Veins

- Aorta (and arch)

- Ligamentum Arteriosum

- Inter and Atrioventricular Sulci (Sulcus)

A is for Aortic Arch

B is for Brachiocephalic Trunk

C is for (left) common carotid artery

S is for (left) subclavian artery

- Atria are separated from each other by interatrial septum; ventricles by interventricular septum

- Within the septa is the fibrous skeleton of the heart (dense irregular connective tissue)

- Separates the atria and ventricles

- Anchors heart valves by forming supportive rings

- Electrical insulation between atria and ventricles; ensures that muscle impulses are timed properly

- Provides a rigid framework for the attachment of cardiac muscle tissue

- Superior Vena Cava drains blood from the head, upper limbs, and superior regions of the trunk

- Inferior Vena Cava drains blood from the lower limbs and trunk

- Coronary sinus drains blood from the heart wall

- Separates the right atrium from the right ventricle

- Has three triangular flaps

- Venous blood flows from the right atrium through the valve into the right ventricle

- Valve is forced closed when the right ventricle begins to contract, preventing blood backflow into the right atrium

- Receives deoxygenated venous blood from the right atrium

- Internal surfaces of right and left ventricles have three cone-shaped, muscular projections called papillary muscles

- Papillary muscles anchor chordae tendineae

- Chordae attach to the cusp of the right AV valve and prevent eversion during contraciton

- Narrows at its superior end into a smooth-walled, conical region called the conus ateriosus

- Pulmonary semilunar valve located between conus arteriosus and pulmonary trunk

- Composed of three thin, pocket-like cusps

- Blood is pumped into pulmonary trunk forces the valves open

- When ventricular contraction ceases, blood cannot backflow because it enters the pockets of the semilunar valve

- This causes the cusps to "inflate" and meet at the artery center, effectively blocking blood backflow

- Pulmonary trunk divides shortly into right and left pulmonary arteries; carries deoxygenated blood into the lungs

- Once gas exchange occurs in the lungs, the oxygenated blood travels through the pulmonary veins to the left atrium

- Smooth posterior wall of the left atrium contains openings for four pulmonary veins

- Bicuspid (mitral) valve also anchored via chordae tendinae and papillary muscles to the wall of the left ventricle

- Oxygenated blood flows through the valve, from the left atrium to the left ventricle

- First you ride a TRIcycle, then you ride a BIcycle

- Largest of the four heart chambers with walls typically 3x thicker than in right ventricle

- Thick walls required to generate pressure to force oxygenated blood into the aorta and thorugh the entire systemic circuit

- Two large papillary muscles attach to the chordae tendineae help support the left AV valve

- At the superior end of the ventircular cavity, the aortic semilunar valve marks the end of the left ventricle and the entrance into the aorta

- Aortic (semilunar) valve

Pulmonary (semilunar) valve

Tricuspid (AV) Valve

Bicuspid (Mitral or AV) Valve

Chordae Tendineae

Papillary muscles

Trabeculae carneae

Pectinate Muscles

Fossa Ovalis

Interatrial septum

Opening of coronary sinus

Interventricular septum

Myocardium

Endocardium 

Atrioventricular=AV

- Left and right coronary arteries originate superior to the aortic semilunar valve (openings are visible inside the aorta)

- Travel in the coronary sulcus (atrioventricular groove) of the heart to supply the heart wall

- Coronary circulation gives blood to the myocardium (epi and endo)

- Marginal artery (supplies the right border of the heart)

- Posterior interventricular artery (supplies both the left and right ventricles)

- Anterior interventricular artery- also called the LAD=left anterior descending artery; supples the anterior surface of both ventricles and most of the interventricular septum

- Circumflex artery- supples the left atrium and ventricle; often anastomosis (union) between anterior and posterior interventricular