Transcript Human Circulatory System

Human Circulatory
System
Importance of Circulatory
System
Transports nutrients to cells, wastes
away from cells and chemical
messengers (e.g. hormones) from
cells in one part of the body to distant
cells
 Distributes heat throughout the body
 Defends against invading organisms
that could cause disease.

Structure of Circulatory System

Composed of a four chambered heart
that pumps ~5 L of blood through
96,000 km of blood vessels that come
in contact with every one of the 60
trillion cells in your body
Three Types of Blood Vessels
Arteries
- Carry blood away from the heart to the rest
of the body
- Are thick-walled to withstand higher
pressure, made of muscle and connective
tissue
- Able to stretch
- Subdivide into small arteries called
arterioles

Three Types of Blood Vessels

Veins
- Return blood from the body tissues to the heart
Are thin-walled (because pressure decreases
as distance from the heart increases)
- Blood pressure is very low(15-20mmHg)
- Contain valves that allow a one-way flow of
blood
- Muscular contractions assist forward movement
of blood
- Subdivided into small veins called venules
-
Three Types of Blood Vessels
Capillaries
- Connect arterioles to venules
- Walls are single cell thick
- Exchange of O2/CO2, nutrients and
wastes occur between blood and body
cells through the capillary walls
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ARTERY
arteriole
capillary
venule
VEIN
arteries  arterioles  capillaries  venules  veins
capillaries
arteriole
venule
http://w3.ouhsc.edu/phar5442/Lectures/Cardiovascularexerciseeffects.html
Questions from Text
Read p. 242-243
 Answer questions, p. 243 #2,3,4,5

Read p. 250-253
 Answer questions, p. 253 #1,2,3,4

The Heart
Is a double pump separated by a
muscular wall called the septum
 the right side contains oxygen-poor
blood and pumps it to the lungs
 the left side contains oxygen-rich
blood and pumps it to the cells of the
body

The Heart (con’t)
* is divided into 4 chambers:
- 2 upper, thin-walled atria (atrium sing.)
- 2 lower, thick-walled ventricles
which pump the blood
* is covered and protected by a tough
membrane called the pericardium
PERICARDIUM
The Double Pump



The right side of your heart pumps oxygenpoor blood to the lungs, dumps off CO2,
picks up O2 and returns it to the heart – this
is called pulmonary circulation.
The left side of your heart pumps oxygenrich blood to all your body cells, dumps off
O2, picks up CO2 and returns it to the heart
– this is called systemic circulation.
Coronary circulation takes oxygenated
blood to and deoxygenated blood from the
heart
The Path of Blood: Pulmonary
Circulation
1.
2.
3.
4.
The right atrium collects oxygen-poor
blood from the superior and inferior vena
cavas
From the right atrium, blood flows into the
right ventricle where it is pumped into the
pulmonary arteries.
The pulmonary arteries take the blood to
the lungs to dump CO2 and pick up O2.
This oxygen-rich blood returns to the heart
via the pulmonary veins.
The Path of Blood: Systemic
Circulation
1.
2.
3.
The left atrium passes oxygen-rich blood
to the left ventricle.
The left ventricle pumps blood into the
aorta which branches into arteries and
arterioles that go to all body parts
Arterioles connect with capillaries where
O2 and nutrients are delivered and CO2
and wastes are picked up
The Path of Blood: Systemic
Circulation (con’t)
4.
5.
6.
Capillaries run into venules which
run into veins, which return blood to
the heart.
The superior vena cava collects
blood from the lower body.
This oxygen-poor blood is emptied
into the right atrium of the heart.
Veiw heart animation disc
http://www.nhlbi.nih.gov/health/dci/Dis
eases/hhw/hhw_pumping.html
 http://www.sciencelearn.org.nz/Contex
ts/See-through-Body/SciMedia/Animations-andInteractives/Label-the-heart
 http://www.smm.org/heart/heart/circ.ht
m
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Composition of Blood
• 55% of blood is plasma
• Red blood cells (erythrocytes) make up
most of the rest
• White blood cells (leucocytes)
• platelets
Plasma
• Plasma is mostly water but also contains
important proteins:
- albumin – prevents water from leaving the
blood and entering the cells
- fibrinogen – functions in blood clotting
- globulins – produces antibodies to fight
against invading microbes
RED BLOOD CELLS (RBC)
• Also called erythrocytes; lac a nucleus
• Contain hemoglobin, an iron-containing pigment
that gives blood its red color and metallic taste
• Cary O2 and CO2
• 5,000,000 per drop of blood
• Live for ~120 days produced in bone marrow
• Disc shaped
Red Blood Cells
RED BLOOD CELLS (RBC)
• Lac of RBC causes less efficient O2
exchange in lungs which results in less
energy and fatigue
• Anemia – illness caused by low blood
oxygen carrying capacity due to low
hemoglobin (iron) causing extreme fatigue
• People who live at high altitudes can have
as many as 8 million RBC per drop of
blood.
• Why is this advantagous?
White Blood Cell
White Blood Cells (WBC)
• Aka leucocytes; have a nucleus
• Protect the body from disease caused by
pathogens
• Some are phagocytic, engulfing and
destroying bacteria and viruses
• 8,000 per drop
• Able to move out of the blood stream
closer to the cells to be destroyed
WBC chases Bacteria
• http://www.youtube.com/watch?v=JnlULOj
UhSQ
Platelets
• Cell fragments so no nucleus
• Initiate blood clotting reactions when injury
has taken place
• 250,000 per drop of blood
• Hemophilia – genetic disease in which the
clotting protein cannot be produced and
bleeding cannot be stopped
Platelets, WBC,RBC