BIOL 431 - LEC 2

Atria and ventricles

Interatrial septum

Fossa ovalis marks the location of the foremen ovalis (only present during fetal circ) atria bypasses the lungs

small ear like projections that increase atria volume

ridged muscles on anterior surface (provides contraction to empty atrium during heart beat

From superior vena cava (SVC - regions superior to axilla), Inferior vena cava (IVC - regions inferior to axilla = organs, leg, pelvis), Coronary sinus - mycordarium), Blood is low in O2, High in CO2

R & L pulmonary veins, High O2, Low CO2

The divider between the two ventricles

Atrioventricular Valves - point in direction of blood flow and maintains one way flow.

Crossbars of flesh, irregular ridges f muscle on the interior surface

bundles of muscle projecting into the ventricles, Function = assist valve control by anchoring caordae tendineae

Thin bands that come from the papilary muscles to prevent prolapse

Atria and ventricles

Artery = away from heart, Veins = towards the heart

1. Superier vena cava 2. inferior vena cava 3. pulmonary trunk 4. pulmonary veins 5. aorta

Brings blood from parts of the body superior to the heart, drains into R atrium

brings blood form parts of the body inferior to the heart, R atrium

Leads to R & L pulmonary artery, Exits R ventricle and carry’s blood to lungs

Brings blood from the lungs, Drains in left atrium

carries blood to the body via left ventricle,

Ascending = part immediately exiting the ventricle traveling upwards 4-5 cm, aortich arch = curved part of the aorta where it turns and travel inferior (descend), Descending = part of aorta that travels downward towards the legs

Pulmonary circuit, Systemic Circuit

Left side, High O2 blood enters L atrium > L ventricle, Blood delivered to body via aorta, O2 given off CO2 picked up, Blood delivedered back to R atrium via Vena cava

Atrioventricular valves = open during atria contraction & semi lunar valves = open during ventricular contraction

Tricuspid - R side, between R atrium and L ventricle, 3 flaps. Bicuspid - L side between L atrium and L ventricle, 2 flaps

pulmonary valve - located @ opening of pulmonary artery and R ventricle. aortic valve - located @ opening of aorta and L ventricle. Both have 3 flaps

sound made during ventricle contraction. First heart sound (S1) makes a lubb sound

low pressure, AV opening , Semi lunar close, Second sound (S2) dub sound

1+ cusps prolapse back into L atrium, causes Marian’s syndrome, rheumatic fever, ruptured caordae tendineae

Blood pushed back into the L atrium secondary to prolapse, or other disease

Leakage when a valve is closed

originate from ascending aorta, circles the heart in atrioventricular groove

Anterior ventricular artery - follows anterior ventricular sulcus, supplies blood to IV septum and anterior wall of both ventricles. Circumflex - supplies to L atrium and posterior wall of left ventricle

To R side of heart, supplies SA node

Marginal artery - supplies lateral side of heart. Posterior interventricular artery - travels to apex, supplies posterior ventricular walls, merges with the anterior interventricular artery @ apex (known as = Anastomoses)

Greater cardiac (anterior IV sulcus), Middle cardiac (posterior IV sulcus), Small Cardiac (along right cardiac margin) All empty into R atrium

A blocked cornoary artery leads to ischemia of the myocardium