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