BACKGROUND:
Comparative anatomy examines how structures are similar
or different in vertebrates. It wasn't until the 16th century that
it was realized that all animals are constructed with a similar body plan.
It was through studies of comparative anatomy that people realized that
there may have been an evolution or changing of animals through time.
When you compare and contrast structures like limbs, organs, and body systems
you see how animals have adapted to their specific environments.
The heart is a muscle whose function is to pump blood
through the circulatory system. It is located in the upper part of the body
in all large animals. In humans, the heart is as large as a closed
fist. The heart grows in size until the adult stage.
The eye is a sensory organ and is located on the head, but different
animals have different directions of sight. Humans can see straight,
but do not have a large area of sight around their heads but then that
is why our necks can't rotate. Other animals have their eyes more
to the back, so they can see a larger area without turning their heads.
The intestine is part of the digestive system. Most animals have their
intestines at the bottom of the body.
The brain is part of the central nervous system and is located
under the skull. Different animals have different sizes of brain,
which the size of the skull usually reflects.
PROCEDURE:
- Use the Human Body Placemats to make sure that students
can find the brain, eye, heart, stomach, and lungs. You may
want them to locate other organs like the kidney, liver, small and large
intestines. Instruct students to point on their body to make
sure that they can locate the organs.
- Show the students how to use the stethoscope. You may
want to have alcohol to wipe the eyes of the stethoscope before the students
use them. Alcohol will disinfect the stethoscope from any bacteria
or viruses. Make sure the stethoscope is flat on a person’s surface.
It is better to put the stethoscope directly on the skin. Listening
through clothes may cause the sound to be muffled. Instruct
the students to record the sound that they hear from the organ they are
asked to listen. You may want to add other organs.
- The second part of the lab has the students "thinking" about
other animals and how they can be compared to humans. Discuss
the functions of each of these organs. If you have a local dog or
cat to bring in, you may want to use a live example. You can have
the students use the stethoscope to listen to the organs of the animal.
Dogs especially have a very active stomach sound!
