Take out background
Dispatch
1)
What is the difference between the sizes of an artery, capillary,
and vein?
2)
What do you think the relationship between temperature and heart
beat is?
3) Blood pressure is…the force exerted against blood vessel walls.
Responsible for the flow of blood
The result of:
______________,______________, and ______________
– Pumping action of the heart
– Resistance of the blood vessels
– Volume of blood
Announcements
• Tomorrow 3-6pm
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•
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•
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•
11:15 am Benchmark on Ecology and Evolution
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Draw and explain
Explain
• How does the structure of an
artery relate to its function?
The structure of ______
The function is________
The structure relates to function
because_________
RBC from heart  artery  arteriole  capillary
RBC
O2
Gas
Exchange
RBC back to heart  vein  venule  capillary
Follow a blood cell from the heart…
• Start at the Aorta – largest artery in body
– Contains OXYGEN
• Cell leaves aorta = ARTERY
• Continues to travel to a small artery =
ARTERIOLE
RBC from heart  artery  arteriole  capillary
Artery
RBC
O2
Arteriole
CAPILLARIES
“Gas Exchange”
O2
CO2 out
• An arteriole becomes and even smaller
CAPILLARY
• This is where OXYGEN leaves the red
blood cell
• This is where CARBON DIOXIDE enters
the red blood cell
Oxygen leaves RBC and enters tissue;
Carbon dioxide leaves tissue and enters RBC
TISSUE
CO2
RBC
bicarbonate
O2
Follow a blood cell back to the
heart…
• Red blood cell with CARBON DIOXIDE
• Cell travels in blood through a capillary and enters
a VENULE (small vein)
• Continues to travel to a VEIN
• Returns to HEART
RBC
bica
rbo
nate
Venule
VEIN
RBC back to heart  vein  venule  capillary
• Blood moving through the
blood vessels exerts
pressure against the
vessel walls. This blood
pressure is highest in the
aorta. It decreases as the
blood moves through the
arterioles, capillaries,
venules, and veins.
Understanding Blood Pressure
• When we measure blood pressure, we are actually
measuring the systolic pressure and the diastolic
pressure separately.
• This is why you always see blood pressure reported as
two numbers, one "over" the other. For example:
• In a blood pressure reading of 110/80,110 = systolic
pressure80 = diastolic pressure.
• The numbers refer to the number of millimeters the
pressure will raise a column of mercury.
• The blood pressure of teenagers is frequently in the
range of 120/70.
Hypothesis
• Will blood pressure be higher or lower if
lying vs standing?
• Will cold temp increase or decrease
Daphnia heart beat?
Daphnia
• Humans are homeothermic (warm blooded) in that the body
generates heat internally to maintain a certain temperature level.
Lower animals do not generate heat internally and thus relay on
external sources for their warmth.
• This is known as poikilothermic (cold blooded). Daphnia is such an
animal. This small, about 1 mm, aquatic crustacean draws its heat
from the surrounding water in which it lives. As the temperature of
the water increases, so does its body temperature. An increase in
temperatures means an increase in activity, both physically and
metabolically. This increase can be seen as an increase in heart
rate. The object of this lab is to record the temperature vs heart rate
for Daphnia.
Data for Daphnia
Copy and graph. Interpret graph
Temperature
(celsius)
Heart Rate
(beats/min)
5
108
10
152
15
211
20
290
Discussion Questions
1) Why does temperature affect heart rate in
ectothermic organisms?
2) Discuss what results you might obtain if you
repeated this experiment using an endothermic
organism
3) Why does smoking cause a rise in blood
pressure?
4) Explain why blood pressure and heart rate
differ when measured in reclining position and
in a standing position.
• Blood pressure is a measure of how hard
your blood is pushing against the walls of
your veins while it is pumped. Blood
pressure is lower when standing due to
gravity.
• http://www.medicalvideos.us/play.php?vid=
615
• http://www.bing.com/videos/search?q=Blo
od+Pressure+arterial+flow+video&view=d
etail&mid=B7DE91E4E45BF379F077B7D
E91E4E45BF379F077&first=0
Why do some people feel faint when
they go quickly from lying down to
standing?
The force of gravity causes the blood
pressure in vessels going to the brain to
drop. This causes temporary faintness
until homeostatic mechanisms elevate
blood pressure in these vessels.
How and why does heart rate
change with body position?
The heart rate generally increases from lying
to sitting to standing as more energy is
required to maintain each of these
postures.
Virtual Lab
• http://www.mhhe.com/biosci/genbio/virtual
_labs/BL_08/BL_08.html
Lab Quiz 1
• http://www.phschool.com/science/biology_
place/labbench/lab10/quiz1.html