Peripheral and Autonomic Nervous System and Eye Dissection, Lab Report Example

Introduction

During this week of lab activities, the focus was on the peripheral nervous system, the autonomic nervous system, and a dissection of the special senses: eye. This was relatively short set of lab activities when compared to some of the others. These activities required more microscope usage and comparison to the models and charts. Dissection of the eye required a delicate hand to keep from destroying the entire eye. Sometimes the information is difficult to imagine when you first read it. However, when you use the microscope or handle a structure with your hands, it puts the information in a clearer perspective. I think these laboratory exercises serve as a method of reinforcement for remembering all the information.

Procedures:

As a continuation of the study of the nervous system, the lab had several activities for us to do. The Peripheral Nervous System activity one required us to study a typical neuron and all of its structures. Then identify the structures on the neuron model.  The Peripheral Nervous System activity two required an examination of a cross section of a peripheral nerve under a compound microscope. Then, identify the structures of the nerve and sketch it if so desired.  Autonomic Nervous System activity one involved using the spinal cord model to identify the structures as we read the material in the lab manual.  Dissection of the Special Senses: Eye required us to first, examine the eye intact and then to make careful incisions to reveal the inner structures.

Materials:

The Peripheral Nervous System materials included a model of a typical neuron, video tape entitled: The Nature of the Nerve Impulse, a microscope viewing area with slides of 1. Ox spinal cord smear under oil, 2. Teased myelinated nerve fibers, and 3. A nerve cross section. The Autonomic Nervous System materials included a cross section spinal cord model, laboratory charts of the spinal cord and spinal nerves, preserved cow spinal cord sections with meninges and nerve roots attached, petri dishes, dissecting tray and razors, dissecting microscope or magnifying glass, and disposable gloves. Dissection of the eye materials included a preserved cow or sheep eyeball, dissecting instruments, dissecting tray, and disposable gloves.

Methods:

The Peripheral Nervous System activity one, first step was to study the neuron shown in fig. 13.1 of the lab manual. Secondly, use the model of the typical neuron to identify all of its structures. Next, go to station 1 with the ox spinal cord smear.  After that, use the microscope to study one of the representative neurons from the smear. When that is done, distinguish between the axon and the dendrites if possible. Then sketch the neuron in the space the lab manual provided.  Continue to station 2 with the teased myelinated nerve fibers. Next, use fig. 13.1, 13.2, and plate 8 in the histology atlas to identify the nodes of Ranvier, neurilemmal, axon, Schwann cell nuclei, and myelin sheath. Lastly, sketch the myelinated nerve fiber and label its parts into the lab manual. The Peripheral Nervous System activity two, step one go to station three to examine a cross section of a peripheral nerve. Then, identify the nerve fibers, myelin sheath, fascicles, endoneurium, perineurium, and epineurium.  Next, sketch the nerve in the provided space in the lab. Lastly, compare your sketch to fig. 13.5 and histology atlas plate 10.   The Autonomic Nervous System activity one use the model of the cross section of a spinal cord to identify lateral horn, dorsal and ventral root, spinal nerves, and white matter. Dissection of the special senses: eye, first step was to put on your disposable gloves. Secondly, examine the external structure of the eye and identify the optic nerve, the remnants of the extrinsic eye muscle, the conjunctiva, the sclera, and the cornea. Next, hold the eye and make an incision above the cornea. After that, use the scissors to cut around the circumference of the eyeball. Continue on by lifting the anterior part of the eyeball away from the posterior portion. Finally, examine the anterior part of the eye and identify its structures

Results     

The results of The Peripheral Nervous System activity one was identification of a neuron and its parts. Also the neuron in the ox spinal smear was easily identifiable because of its large size. The results of the teased myelinated nerve fibers was the clear identification of the axon and the myelinated sheath.

The results of The Peripheral Nervous System activity two were identification of nerve fibers.

The results of activity one The Autonomic Nervous System was identification of structures visible in a cross section of a spinal cord, such as the lateral horn.

The results from the Dissection of the special senses: eye was gaining a better understanding of the components of the eye and how they work. Structures were identified such as the cornea and optic nerve.

Questions

The nodes are the distributed evenly.

The optic nerve is the point of attachment.

Conclusion               

This week of laboratory activities revealed that nerve cells play big roles in the body. Different types of nerves control different functions in the body.  Each part of a nerve has a function and is well protected under a myelinated sheath. I concluded from these activities on the nervous system, that neurons can come in different sizes and shapes. I also concluded from dissecting the eye that the eyeball is filled with some really disgusting fluids.