The Heart
… and blood flow
Heart Facts
►
Your heart is about the same size
as your fist
►
An average adult body contains
about five quarts of blood (1.25
gallons)
►
All the blood vessels in the body
joined end to end would stretch
62,000 miles or two and a half
times around the earth.
Heart Facts continued….
► The
heart circulates the body’s blood supply
~1000 times each day
► The
heart pumps the equivalent of 1,250 to
1,500 gallons of blood each day
► The
heart beats about 42,075,904 times per
YEAR – imagine a lifetime?
3 Layers of the Heart
► Pericardium
= protection, exterior, serous
membrane
► Myocardium = cardiac muscle tissue, involuntary
contractions
► Endocardium = interior layer, lines heart
chambers
Blood Flow
► Pulmonary
Circulation
► No oxygen in blood
► carries
deoxygenated blood away from the
heart, to the lung, and returns oxygenated blood
back to the heart
Overview of blood circulation
Blood Flow continued….
► Systemic
Circulation
► Oxygen in blood
► carries oxygenated
blood away from the
heart, to the body, and
returns deoxygenated
blood back to the heart
Heart Valves
► Allow
blood to flow in only one direction
► Four valves:
--Atrioventricular valves: between atria ventricles
• Bicuspid valve or Mitral valve (left)
• Tricuspid valve (right)
--Semilunar valves: between ventricle and artery/vein
• Pulmonary semilunar valve
• Aortic semilunar valve
Chordae Tendineae
► The
chordae tendineae, or heart strings, are
cord-like tendons that connect the muscles
to the tricuspid valve and the mitral valve in
the heart.
► When the right ventricle of the heart
contracts, the blood pressure pushes the
tricuspid valve closed and prevents a
backflow of blood into the right atrium.
Chordae Tendineae
(a.k.a. “heart strings”)
heart strings
Blood Flow STEP by STEP