Transcript Crimson Landscape Template

The Circulatory System
Some Interesting Facts
• No cell is further than two cells away from a blood
vessel that carries nutrients!
• Your circulatory system has 96 000 km of blood
vessels…strung together they could circle the globe
2.5 times!
• Your heart is the size of your clenched fist!
• Your heart beats ~ 30 million times per year!
• An adult heart pumps nearly 18 173 litres of blood
each day!
• During an average lifetime, the heart pumps enough
blood to fill two ocean tankers!
• The average three year old has 1.1 litres of blood in
their body; the average adult has 5 times that!
Purpose of the Circulatory System
•Brings oxygen and
nutrients to cells
•Takes away wastes
from cells
•Relays chemical
messages (hormones)
•Maintains fluid levels
•Important in
immunity
Blood Flow Through the Heart
Types of Blood Vessels
1. Arteries:
• Carry blood away
from the heart
• Usually at high
pressure
• Thick, muscular
walls
• Branch into smaller
“arterioles”
Types of Blood Vessels
2. Veins:
•Carry blood to the
heart
•Less pressure
•Thin, less muscular
walls, and valves to
prevent backflow
•Branch into “venules”
Types of Blood Vessels
Types of Blood Vessels
3. Capillaries:
•Carry blood from arterioles to venules
•Form a fine network through cells (capillary bed)
•No tissue is more than 0.1 mm away from a capillary!
•1 cell thick – easy diffusion!
Types of Blood Vessels
4. Coronary Arteries:
•Supply heart muscles
with blood!
Components of the Blood
•Blood is composed
of water, plasma and
blood cells (P. 319)
Plasma:
•The fluid portion of
the blood
•55% of a blood
sample
Components of the Blood
Red blood cells:
•Contain hemoglobin
(O2 taxis)
•No nucleus = more
hemoglobin (280
million per RBC)
•Biconcave form –
allows them to fit
through small
capillaries
•44.9% of a blood
sample
Components of the Blood
White Blood Cells:
•Are less numerous
than RBC’s (1:700)
•Have a nucleus
•Destroy invading
microbes using
phagocytosis
•Form antibodies
•0.1% of a blood
sample
Components of the Blood
Platelets:
•Are responsible for
blood clotting
•Are cell fragments
•Stick to sharp edges
in otherwise smooth
vessels
Bone Marrow
•RBCs, WBCs and
platelets are all
produced in the bone
marrow
Blood Doping
• See Page 323
Regulating Heart Beat
• The S.A. (sinoatrial) node, also known as
•
•
•
•
the pacemaker sends an electrical
impulse to start the heart contraction.
Both atria contract
The A.V. (atrioventricular) node then
tells the ventricles to contract.
Double pump
“Lub Dub” is the sound of the valves
flapping shut
Regulating Heartbeat
ECG - Electrocardiogram
Blood Pressure
1. Systolic (top number)
•Normal = 120 mmHg
•The pressure of blood
surging through the
artery, causing
expansion
2. Diastolic
(bottom number)
•Normal = 80 mmHg
•Heart rests, blood is
still, pressure drops
The Circulatory System and Exercise
• Exercise increases CO2 content in blood, which
leads to higher breathing and heart rates
(think HR lab).
• The benefits of exercise are many:
1. Improved body system functions.
2. Improved blood supply to muscles, organs,
tissues, etc.
3. Reduced ‘bad’ cholesterol levels.
4. Improved strength, bone density and
self-esteem.
5. Improved oxygen capacity and usage!
Circulatory System Problems - Jigsaw
• Form expert groups!
• Share info!
Circulatory System Technology
• Nitroglycerine: A drug used to treat
angina by dilating the coronary arteries.
• Bypass surgery: A blood vessel is
removed from leg and is used to redirect
blood flow around a blocked coronary
artery.
• Angioplasty: A small balloon is inserted
through a catheter and inflated in order
to reduce the narrowing of an artery.
• Pacemaker: An artificial device that
electrically stimulates the heart to beat
Bypass Operation