Chapter 18 the heart

3 layers of the heart wall

Epicardium, Myocardium, and Endocardium

Epicardium

covering, visceral pericardium

Myocardium

middle layer, cardiac tissue

Endocardium

lining, endothelial tissue (simple squamous tissue)

4 chambers of the heart

2 atrias and 2 ventricles

2 atrias

receive blood from the body

2 ventricles

pump blood out of the heart

Veins

carries blood towards the heart

The right atrium receives blood from 3 veins

Superior Vena Cava, Inferior Vena Cava, Coronary Sinus

Arteries

Carry blood away from the heart

The left atrium receives blood from

pulmonary veins

Pathway of blood through systematic

RA—> pumps oxygen poor blood——> RV——- pumps oxygen poor blood———> pulmonary arteries ———> pumps oxygen poor blood——> lungs—→ pumps oxygen rich blood—→ Pulmonary Veins

Pulmonary circuit pathway

La——> pumps oxygen rich blood—→ LV——→ pumps oxygen rich blood—→ aorta—→ pumps oxygen rich blood —→ body tissues —→ oxygen poor blood— > vena cava—→ pumps oxygen poor blood ——> RA

Coronary Circut

Aorta——> pumps oxygen rich blood——> Coronary Arteries —> pump oxygen rich blood——> myocardium—> pumps oxygen poor blood—→ coronary veins—→ oxygen poor blood—→ coronary sinus—→ pumps oxygen poor blood—→ RA

The Right Ventricle

Pumps blood into pulmonary arteries to lung

The Left Ventricle

pumps blood in the aorta to all body tissues expect the lungs

Pulmonary circut length and pump

Medium length circut and pump is the right ventricle

Systemic Circuit length + pump

longest circuit and pump is the LV

Coronary circuit length + pump

Shortest circuit + pump ia the LV

Pulmonary Circuit

Blood vessels that carry blood to and away from lungs

Systematic circut

blood vessels that carry blood to and from all body tissues expect the lung

Cornary Circuit

Blood vessels that carry blood to and from the myocardium

4 heart Valves

2 atrioventricular and 2 semi lunar valves

2 atrioventricular valves

between atria and ventricles

2 semilunar valves

Between ventricles and arties carrying blood out of the heart

What are two Av valves

Triscuspid valve and Biscuspid valve

Triscuspid Valve

Between RA and RV

Biscuspid Valve

LA and LV

2 seminlumar valves

Aortic valve and Pulmonary Valve

Aortic Valve

Between LA and Aorta

Pulmonary Valve

Between RV and Pulmonary Artery

Heart Valves

Allow one way flow of blood to the heart and prevents backflow

Heart valves open or close due to ____

Pressure differences

Heart sounds are heard when the ___

valve closes

1st heart sound heard when both ____

Atrioventricular valves close

2nd heart sound heard when _____

Semilunar valves close

Heart sounds are not heard when ____

valves are open

Pressure difference causes

Valves to open or close

The Av Valves Open (no sound)

Venous return causes atrial pressure increase ventricular pressure—> AV valves open (no sound)

1st heart sound

Ventricles contract ventricular pressure decreases atrial pressure—> The av valves close first heart sound

Papillary are attached to?

Chordae Tendineae (heart strings)

Function of papillary muscles and chordae tendneae

Holds av valves in their closed position so blood can't flow upwards in the heart.