Start date: 4/5/12

End date: 4/6/12

Project members: Naheen, Kyle, Mesha, Amna, Sandhya

Teacher’s name: Mr. Green

Background Information:

Also known as the control center of the body, the nervous system is made up of your brain, spinal cord, and a vast network of nerves throughout your body. Nerves are thin threads of nerve cells, called neurons, that bundle together and carry messages back and forth. Sensory nerves send messages to the brain and use the spinal cord to connect to the brain. Motor nerves carry messages back from the brain to all the muscles and glands in your body. When neurons are stimulated, whether by vibrations, heat, or coldness, they generate tiny electrical pulses. The electrical pulse in the cell causes chemicals to be released that carry the pulse to the next cell. These processes take place at mind blowing speeds. The two different aspects of the nervous system are the peripheral nervous system and the autonomic nervous system.

In this investigation, we will discover how the nervous system can be observed in fetal pigs.

Purpose: How can we observe the nervous system of the human body in fetal pigs?

Hypothesis: If we believe that fetal pigs are mammals with a similar body form as humans, then we should be able to observe the major nervous system organ, the brain, in the fetal pig and how it functions in the nervous system.

Materials:

•Fetal pig

•Dissecting tools (scalpel, scissors, probe)

•Disposable gloves

•Camera

Procedure:

1.) Using your scalpel, make incisions through the skin of the head. Peel off the skin. Look for lines in the skull, which indicate where the bones meet. Carefully insert the pointed end of your scissors between the bones. Then use the tips of your forceps to pull or break off pieces of the skull until you have opened up most of the skinned area. 2.) Cut through the dura mater, exposing the brain. Identify the right and left cerebral hemispheres. Notice the deep longitudinal fissure. Identify the cerebellum and medulla. Try to locate the olfactory lobes in your pig. 3.) Name the parts of the brain that you identified in your pig and describe the external appearance of each.

Observations:

Brain

Parts of the Brain Functions

Cerebrum Responsible for motor commands, thought, senses, auditory and visual processing, memory, emotions

Cerebellum Balance, posture, cardiac and respiratory centers

Brain Stem Receives nerve signals

Analysis:

In this lab, I was able to observe the human nervous system in a fetal pig. Two very important parts of the nervous system are the brain and spine, which serve as interpreters and highways in order to operate nerve cells properly. The three membranes surrounding the brain are known as meninges, which envelope the central nervous system. These meninges consist of the dura mater, arachnoid mater, and the pia mater. The dura mater is a thick, durable membrane close to the skull. The arachnoid mater received its name because of its spider-web appearance. It serves as a cushion for the central nervous system. The pia mater is a very thin, delicate membrane whose blood vessels travel to the brain and spinal cord, and its capillaries nourish the brain. These parts make up the central nervous system, which coordinates behavior, thought process, attention, problem solving, personality, intellect, coordination, eye movements, sense of smell, muscle movements, vision, reading, and other senses.

Some involuntary actions that the medulla oblongata controls include digestion, respiration, and heartbeat. If someone damaged their cerebellum, they may be unable to coordinate themselves while driving, or possibly lack certain senses that they once have.

Conclusion:

In conclusion, my hypothesis was correct. I was able to observe the human nervous system in a fetal pig.

Fetal pigs are often used in classroom dissections. These mammals have similar hair, organ systems, metabolic levels, and body forms as humans. Their soft tissue and underdeveloped bones (cartilage) make them easier to dissect than other organisms. Since these pigs were never born, their nervous system was never able to fully function. In a pig’s life, the most important nervous system is the central nervous system because they need to function properly as animals in order to survive.

During this lab, I was able to learn that dissecting the brain of a fetal pig is challenging. When watching my instructor, I noticed how protective our skulls are of our brains. Since the skull was not fully ossified, this pig was much easier to dissect than an adult one.