Name ________________________________________________
Date ____________
Period _______
Lab # ______ Observing the Parts of the Circulatory & Respiratory System
A system is a collection of parts that interact together for a common purpose. But a system is not
just any old collection of parts. The parts are related in such a way that each depends on the
others to do whatever job there is to be done. No single part can do the job alone, and any
malfunction or delay is likely to affect the whole system.
A body system is a set of body parts that do a particular task. The human body itself is an example
of a complex system—many sets of interacting parts that work to keep the human machine running.
On any single day, we can estimate that your heart beats 103,689 times, your blood travels
168,000,000 miles, your digestive system processes 7.8 pounds of waste, and your lungs take in
438 cubic feet of air. These are only a few of the multitude of functions the human body
performs. And while the least little mishap could cause a glitch in the system, amazingly, day in and
day out over most of our lifetime, our bodies operate almost flawlessly.
In this lab we are going to look at how the circulatory and respiratory systems work together to
deliver oxygen and other important nutrients to every cell in our bodies. All of our body cells
require oxygen to conduct cellular respiration. In this process, oxygen burns the nutrients from
the foods we eat, providing energy for the cells. The respiratory system is responsible for bringing
oxygen into the body and removing waste gases, and it is the job of the circulatory system to
deliver it to the body’s trillions of cells.
Directions: Draw and label all parts of the following slides. Take a cross section slide of the
following seven slides, arteries, veins, capillaries, red blood cells, sickle cell, lung tissue and lung
tissue with emphysema. USE COLORED PENCILS IN ALL SKETCHES TO SHOW DETAIL.
ARTERIES – can be distinguished under the slide by finding the elastic layer.
Sketch the artery below.
1. Blood flows ________________________ from the heart in arteries.
2. What is the only artery which has deoxygenated blood? ___________________________
3. Arteries can be distinguished by their thick elastic layer. What is the function of the
elastic layer?
____________________________________________________________________
____________________________________________________________________
4. What is the largest artery in the body? ______________________________________
5. Why does the largest artery in the body branch off so quickly into smaller arteries?
____________________________________________________________________
____________________________________________________________________
VEINS – do not contain elastic membranes.
Sketch the vein below.
6. Blood flows ____________________ the heart in ________________________.
7. What do veins contain which prevent the backflow of blood? _______________________.
8. Explain why veins have low blood pressure compared to arteries.
____________________________________________________________________
____________________________________________________________________
9. What is the difference between the superior and inferior vena cava?
____________________________________________________________________
____________________________________________________________________
CAPILLARIES – are only one cell thick and can allow only one red blood cell to pass. Hint: If they
are only one cell thick you may have to use a higher power to see detail.
Sketch the capillary below.
10. How thick are capillaries? ________________________________________
11. How many red blood cells can pass through a capillary at the same time? ______________
12. What is the function of the capillary? Explain in detail.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
13. What are the two small vascular tissues which hare on either side of the capillary?
Hint: Names we give to small veins and arteries
____________________
CAPILLARIES
____________________
RED BLOOD CELL (RBC) vs. SICKLE RED BLOOD CELL
Normal red blood cells are disc-shaped and look like doughnuts without holes in the center. They
move easily through your blood vessels. Red blood cells contain hemoglobin, an iron-rich protein
that gives blood its red color. Hemoglobin carries oxygen from the lungs to the rest of the body.
Sickle cells contain abnormal hemoglobin that causes the cells to have a sickle, or crescent, shape.
These cells don't move easily through your blood vessels. They're stiff and sticky and tend to form
clumps and get stuck in the blood vessels.
The clumps of sickle cells block blood flow in the blood vessels in the limbs and organs. Blocked
blood vessels can cause pain, serious infections, and organ damage.
Directions: On the next page you will draw a sketch of the red blood cell on the left under highest
power. Draw a sketch of the sickle cells under highest power on the right. NOTE: The sickle
cell slide is not stained and very hard to see. Try lowering the light source so it creates a
shadow on the cells.
RED BLOOD CELL
SICKLE RED BLOOD CELLS