Exercise 1: The Microscopic Structure of Cutaneous Membranes
2. Observations: Sketch your observations from the microscope slide in the lab report assistant. Indicate the keratinized layer on the sketch and describe the observed structures and cells.
A. What is keratin?
The fibrous protein that helps give the epidermis its protective properties
B. Why is the skin keratinized?
To help protect itself
Exercise 2: Microscopic Structure of Mucous Membranes
Draw and describe the structures observed for the following slides:
Pseudostratified ciliated columnar epithelium of the trachea
Single layer of cells of differing heights, some not reaching the apical surface, nuclei located at different levels give the appearance of a mulitlayerd (stratified) tissue.
Mucous secreting goblet cells are common in this tissue. There are both ciliated and non-cilated types.
Stratified squamous epithelium (non-keratinized) of the esophagus
Distinguished by multiple layers of cells with nuclei distributed throughout, basal cells are cuboidal or columnar in shape, are metabolically active and have a high rate of mitosis
Simple columnar epithelium (duodenum) of the small intestine
Single layer of column shaped cells with either a round or oval shaped nucleus, unicellular glands that secrete mucous are common in this tissue, microvillia extensions of the plasma membrane of the apical surface, are present in the small intenstine
A. Compare and contrast the roles of the three mucous membranes.
Mucous membranes are composed of epithelial cells lying on top of loose connective tissues. Serous membranes are epithelial cells that are attached to a small amount of areolar connective tissues. These membranes are unique because they occur in two layers. Synovial membranes are composed entirely of connective tissue and are found lining the cavities around the joints. These membranes help provide a smooth surface for the