Topic 6.2.1 – 6.2.7 The Transport System Page 210 - 216.
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Transcript of Topic 6.2.1 – 6.2.7 The Transport System Page 210 - 216.
Topic 6.2.1 – 6.2.7
The Transport SystemPage 210 - 216
What will we learn?
-How the heart works
-Evolution of the heart
-Structure/function of blood vessels
-Structure of blood
Blood is made of plasma and “formed
elements”
“Formed elements” include:
Red Blood CellsWhite Blood Cells
Platelets
45% Cells / 55% Plasma
What does blood circulate?
Oxygen and Carbon Dioxide
Nutrients from the Digestive System
Salts and Minerals
Hormones
Water
Proteins: Antibodies & Clotting Factors
Heat
Wastes
The 3 types of formed elements
Red Blood Cells (erythrocytes)
White Blood Cells (leucocytes)
Platelets (thrombocytes)
Red Blood Cells
Carry O2 or CO2
Are anucleate
Live only 120 days
4.5 to 5.5 million / mm3
Made in bone marrow
Are “biconcave” discs
WBC Types:
MONOCYTES -- phagocytic
NEUTROPHILS -- phagocytic, most common
EOSINOPHILS -- respond to hookworm?
B Lymphocytes -- produce antibodies
T Lymphocytes (Killer/Helper/Memory) --destroy invaders
BASOPHILS -- produce histamines
Circulatory System http://www.youtube.com/watch?v=D3ZDJgFDdk0
The development of the heart
Evolution of the Heart
http://www.mhhe.com/biosci/genbio/biolink/j_explorations/jhbch05.htm
Controlling the Heart
Heart muscle tissue is made of myogenic (self-stimulating) muscle. Once cell’s contraction stimulates its neighbour.
The first impulse is sent from the SA node, to the AV node, which sends the signal through the purkinje fibres.
What Controls the Heart Rate?
There is a nerve connecting brain to heart that will speed up the heart rate
There is a 2nd nerve connecting brain to heart that will slow down the heart rate
The hormone ADRENALIN will also speed up the heart rate
Why Does Wall Thickness Vary?
Why does the left ventricle have the thickest walls?
Why does the right ventricle have the next thickest walls?
Why do the atria have the thinnest walls?
Because it pumps blood to the entire body!
Because it pumps blood only to the lungs and back!
Because they pump blood only down to the ventricles
The Types of Blood Vessels
Artery
Arteriole
Capillary
Venule
Vein
Summary of Differences
Blood Flow?
O2 or CO2?
Pulse? Valves? Wall Size?
ArteryAway from heart
Carries O2
Yes No Thickest
VeinTowards
the heart
Carries CO2
No Yes Thinner
Capillary Changing Changing No No Thinnest
Varicose Veins
This happens when veins weaken and expand. The flaps of the valve cannot touch. Valves stop working and blood pools in the vein.
Homework: Page 216 # 1-4