Chapter 19 - Heart Part 1

Pericardium

• membrane, protects and surrounds heart

• allows movement of contraction while keeping heart in position

Fibrous pericardium

• superficial

• dense irregular CT

• open end fused with CT of blood vessels entering and exiting heart

• prevents overstretching, anchors heart in position

Serous pericardium

• deep

• think double layer

• includes the parietal and visceral layer, and pericardial cavity

Parietal layer

fused to fibrous pericardium

Visceral layer

aka epicardium, bout to heart surface

Pericardial cavity

potential space between serous layers

What are the two layers of the heart?

• Epicardium, myocardium, and endocardium

Epicardium

• outer layer

• visceral pericardium, fibroelastic tissue, adipose tissue

• Adipose varies, is thickest over the ventricles

• contains blood and lymph vessels, nerves

Myocardium

middle layer

Endocardium

• inner layer

• endocardium and connective tissue

• decreases the friction of blood moving through the chambers

• coninuous wiht endothelum of blood vessels

How many chambers of the heart are there?

4 chambers

What do the two atrias do?

they are the upper receiving areas

What do the ventricles do?

they are the lower pumping chmabers

Whats the difference between the Right and Left artiums and ventricles

Right = pulmonary pump = weaker

left = systemic pump = stronger

Auricle

• pouchlike structure on anterior surface of each atrium

• increases surface of each atrium

Sulci

• grooves on heart surface where blood vessels travel

• Coronary sulcus - between the atria and ventricles

• anterior interventricular sulcus - between R and L ventricles

• posterior interventricular sulcus - between R and L ventricles

Fibrous skeleton of the heart

• dense CT, 4 rings surround valves

• structural foundation for valves, insertion for myocardia, electrically insulates atria and ventricles

What happens when AV vlaes open?

• cusps project into ventricles

• bloo moves form atria to ventricles

• atrial pressure > ventricular pressure

What happens when AV valves close?

• edges of cusps form opening backwards into atria

• atrial pressure< ventricular pressure

Semilunar valves

• 3 crescent moon cusps

• open for blood to pass from ventricles into arteries

• ventricular pressure > arterial pressure