1. Nicole Boylan, Ava Gulino & Jack McBride
6.2 - The Blood System
Nicole Boylan, Ava Gulino & Jack McBride

2. Basics
Arteries are blood vessels that take blood away from heart that hasn’t reached capillary
Arteries used by autonomic nervous system; used to maintain blood pressure
Arteriole- smallest of arteries
Capillary bed- network of capillaries that drain into single venule

3. Understandings
Arteries convey high pressure from the ventricles to the tissues of the body
Arteries have muscle cells and elastic fibers in their walls
The muscle & elastic fibers assist in maintaining blood pressure between pump cycles
Blood flows through tissues in capillaries. Capillaries have permeable walls that allow exchange of materials between cells in the tissue of the capillary
Veins collect low pressure from the tissues of the body & return it to the atria of the heart

4. Understandings continued
Valves in veins & the heart ensure circulation of blood by preventing backflow
There is a separate circulation for the lungs
The heart beat is initiated by a group of specialized muscle cells in the right atrium called the sinoatrial node
This node acts as a pacemaker
This node sends out an electrical signal that stimulates contraction as it is propagated through the walls of the atria & then the walls of the ventricles
The heart rate can be increased or decreased by impulses brought to the heart through 2 nerves from the medulla of the brain
Epinephrine increases the heart rate to prepare for vigorous physical activity

5. Veins
Veins- Blood vessels that collect blood from capillaries and return to heart

6. Heart
Human heart is a pair of side-by-side pumps; form 2 major routes for blood to flow
Right side of heart- pulmonary circulation (lungs)
Left side of heart- systematic circulation (organs)
Majority of tissue that makes up heart is muscle
Sinoatrical node (SA Node)- acts as pacemaker for heart by sending “electrical signal” to contract

7. Fun Facts Heart activity/blood pressure increases during activity
Fatty/unhealthy foods can cause plaque buildup in arteries and cause heart attacks
The First artificial heart pacemaker was plugged into a wall socket!
The Blue whale has the largest heart weighing over 1,500 pounds!
Your heart beats around 100,000 time a day!
Each minute your heart punmps through about one and a half gallons of blood!

8. Online EKG Lab!

9. Skit
Jack: Oh my goodness! I am having discomfort in my chest and in my upper body! I am also short of breath and nauseous…
Ava: What do you think is wrong with him?
Nicole: These might be signs of a heart attack!
Ava: Wow really? What can we do to help him?
Nicole: Let’s call 9-1-1
A link showing what your heart does during a heart attack:

10. Fun Activities!
Cute video on the heart and its functions.
Slightly less cute video explaining with more detail the heart and its functions.
Fun virtual lab!
Enjoy! 
Ward 2nd Ed. IB biology HL