2. Interesting Facts
The heart beat is strong enough to squirt blood 30 feet
The longer a boy’s ring finger is, the less likely they are to have a heart attack
(according to one study)
The human heart beats ~35 million times per year
The heart pumps ~1,000,000 barrels of blood in a lifetime
Most heart attacks occur between 8-9 a.m.
3. Interesting Facts
The blue whale has the largest heart – it weighs ~ one ton
The hummingbird has a heart that beats 1000 times per minute
Your entire volume of blood goes through your entire body once every minute
Humans have ~60,000 miles of blood vessels in their bodies (more than twice the
circumference of the earth!)
Your heart beats 100,000 times and pumps ~2000 gallons of blood every day
Pig and baboon hearts have been transplanted into humans
6. The Heart
Size of a fist; less than a pound
In thorax; flanked by lungs; rests
on diaphram
Top: base
Bottom: apex
7. Pericardium
Double-layered sac covering the
heart
Outer layer anchors heart in chest
Inner layer (epicardium) attached
to heart wall
Lubricating fluid in pericardial
space (between layers) reduces
friction
8. Heart Chambers
Four Chambers
2 atria: top of heart – receive blood
from veins
2 ventricles: bottom of heart –
pump blood through arteries
Valves
Septum: divides left from right heart
Valves: keep blood flowing in one
direction
Four valves:
2 AV valves,
2 semilunar valves
10. Heart Polarization
3 Stages:
SA node fires, atria contract
(depolarize)
Impulse travels to AV node, then
travels thru bundle of His, bundle
branches, & Purkinje fibers –
ventricles contract (depolarize)
Contraction of ventricles has
‘wringing’ action, pushing blood
upward and out through large
arteries
Heart muscle repolarizes
12. Blood Vessels
Arteries: carry oxygenated blood
away from the heart
Veins: carry deoxygenated blood
towards the heart
Capillaries: connect arteries to
veins & exchange gases with
tissues
16. Blood Composition
55% Plasma (fluid matrix of water, salts, proteins, etc.)
45% Cellular elements:
Red Blood Cells (RBCs): 5-6 million RBCs/ml of blood. Contain
hemoglobin which transport oxygen and CO2.
White Blood Cells (WBCs): 5,000-10,000 WBCs/ml of blood.
Play an essential role in immunity and defense. Include:
Lymphocytes: T cells and B cells
Macrophages: (phagocytes)
Granulocytes: Neutrophils, basophils, and eosinophils.
Platelets: Cellular fragments, 250,000- 400,000/ml of blood.
Important in blood clotting.
17. Components of Blood
Centrifuged blood
45% Red blood cells (erythrocytes)
Hematocrit: RBC volume = ~45%
<1% Buffy Coat: White blood cells
(leukocytes)
55% Plasma: Serum and fibrinogen
18.
19. Blood Circulation :
A. Pulmonary Circulation
Right ventricle pumps deoxygenated blood through pulmonary
artery to the lungs
The blood picks up O2 from the lungs and dumps CO2 into the
lungs
Oxygenated blood is returned to the left atrium thru the
pulmonary vein
20. Blood Circulation :
B. Systemic Circulation
Oxygenated blood is pumped
from left ventricle thru aorta to
the body
Blood dumps oxygen into
tissues and picks up CO2
Deoxygenated blood travels
from body to vena cava to the
right atrium
24. Erythropoiesis
2.5 million RBCs are produced/sec
Lifespan of 120 days
Old RBCs removed from blood by
phagocytic cells in liver, spleen, & bone
marrow
Iron recycled back into hemoglobin
production
27. Atherosclerosis
Narrowing of vessel lumen due
to plaque/fat formation on
inside of walls
Causes: diet high in fat,
cholesterol, salt; inactive
lifestyle; smoking
Risks: high BP, enlarged heart,
embolus blocking circulation;
stroke
28. Coronary Artery Disease
When Atherosclerosis affects
the arteries that supply the
heart muscle
Symptoms: short of breath
after simple exertion, angina
(chest pain)
Risk: MI, cardiac arrest,
death
29. Vessel Disorders
Varicose Veins: twisted, dilated
veins resulting from pooling of blood
due to long periods of standing,
obesity, or inactivity
30. Aneurysm
Weakening in the wall of a
vessel, causing it to balloon
outwards.
Rupture of the site causes
◦ Stroke (if in the brain)
◦ Death (in a large artery –
aorta).
