Download 6.2 - The Blood System

Nicole Boylan, Ava Gulino & Jack
McBride
• 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
• Arteries convey blood @ 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 blood @ low pressure from the tissues of the body
& return it to the atria of the heart
• 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
• Veins- Blood vessels that collect blood from capillaries and
return to 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
• 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!
• http://www.nobelprize.org/educational/medicine/ecg/ecg.htm
l
• 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:
http://watchlearnlive.heart.org/CVML_Player.php?moduleSelec
t=hrtatk
• https://www.youtube.com/watch?v=ruM4Xxhx32U Cute video
on the heart and its functions.
• https://www.youtube.com/watch?v=EA2DY0tjpFI Slightly less
cute video explaining with more detail the heart and its
functions.
• http://www.hhmi.org/biointeractive/cardiology-virtual-lab Fun
virtual lab!
• Enjoy! 