Laboratory 3: Tissues and Membranes

Exercise 6 & 8

 

Objective

The objectives of Lab 3 are to learn the histology, location, and function of:

1. Connective tissue

2. Muscle tissue

3. Nervous tissue

4. Membranes.

 

Exercise 6: Classification of Connective Tissue

Connective tissue (CT) is the most common tissue type. The general function of CT is to fasten, connect, support, and protect.  All CTs are composed of a non-living matrix and several types of cells.  The matrix may be hard (e.g., bone), flexible (e.g., cartilage), or fluid (e.g., blood).  The consistency of any matrix is dictated by its specific composition.  The matrix is composed of a ground substance and fibers.  Both the ground substance and fiber types and number vary among tissues. 

 

A. Types of fibers

1. Elastic

2. Collagenic

3. Reticular 

 

When the matrix is solid, as in cartilage and bone, the living cells reside in cavities called lacunae. 

 

B. Categories of Connnective Tissue

1. Embryonic

2. Loose

3. Dense

4. Cartilage

5. Bone

6. Blood. 

 

Learn the histology, location, and function of all 11 CTs.  

 

Exercise 6: Classification of Muscle 

All muscle types consist of elongated cells bundled together. When a muscle contracts (shortens) it moves (or stablizes) some body part. Skeletal muscle is voluntary and is responsible for the movement of the skeleton. Smooth muscle is involuntary, producing movement in visceral organs and glands. Cardiac muscle is found only in the heart, which pumps blood through the circulatory system.  Key tissue features: (1) Skeletal muscle is striated, multinucleated, and the nuclei tend to lie on the periphery of the cells. There are no intercalated discs. (2) Smooth muscle is not striated, it is uninucleated, and the nucleus tends to lie in the center of the cell. (3) Cardiac muscle is striated, and the cells branch and fit together at junctions called intercalated discs. Be sure to identify these under the microscope. Know the histology, location, and function of the three kinds of muscle. 

 

Exercise 6: Classification of Nervous Tissue

The function of Nervous Tissue is to propagate signals in the form of action potentials.  Nervous tissue is composed of two functional cell types: (1) neurons- cells that conduct action potentials, and (2) neuroglia- the joint name given to several cell types that support neurons. 

 

Exercise 8: Membranes

Body membranes line surfaces and function to protect and lubricate organs.

 

All membranes are divided into two categories:

1. Epithelial membranes

2. Synovial membranes

 

Epithelial membranes consist of an epithelial sheet bound to an underlying layer of connective tissue. 

 

A. Types of epithelial membranes

1. Cutaneous membranes- the skin (considered in Exercise 7)

2. Mucous membranes- line all body cavities that open to the exterior (digestive, urinary, respiratory)

3. Serous membranes- line cavities that are not open to the exterior (abdominopelvic, thoracic). 

 

Serous membranes occur in two layers.  The parietal layer of serous membranes lines the body cavity while the visceral layer lines the exterior surface of organs.  Unlike epithelial membranes, synovial membranes are composed entirely of connective tissue (no epithelial tissue), and line the cavities surrounding joints.  There are no lab activities for

 

You will not be asked to identify any membrane under the microscope. However, you should know the figures in Exercise 8.