Lab 4 Tissues, Skin & Membrane

Tissues, Skin, Membranes Lab

Epithelial Tissue:

 Stratified squamous Plate 2.22

Cuboidal Plate 2.17

Simple Columnar Plate 2.18

Two distinguishing microscopic characteristics of epithelial tissue is that it covers the surfaces of the body, whether external or internal and it acts as a protective covering or boundary for such surfaces, including the outer layer of the skin, as well as the inner surface of "hollow" organs like the stomach, colon, and blood vessels.

Epithelial cells line the major cavities of the body.  Epithelial form the structure of the lung, including the alveoli or air sacs where gas exchange occurs.   Cells line most organs, such as the stomach and small intestine, kidney, and pancreas. They also line the esophagus. 

Connective Tissue:

Loose (areolar) Plate 3.27

Adipose Plate 3.39

  

Hyaline cartliage Plate 3.41

Two distinguishing microscopic characteristics of connective tissue are cells are separated by large amounts of extra-cellular substance or matrix and are scattered in the matrix are thread like microscopic fibers.

The  function of the connective tissue is protection, support & bind tissues together.  The structures matches it's function in the matrix for strength & fibers for support.

Muscle Tissue:

Skeletal (striated) Plate 5.66

Smooth Plate 5.81

Cardiac Plate 5.76

Two distinguishing characteristics of muscle tissue are the cells or fibers are elongated with tapered ends and gap junctions are seen.

The structures of the cells have fibers that allow them to contract or get shorter.  They are used to move materials & body parts.  They help move materials in the body.

Nervous Tissue:

 Motor neuron Plate 6.89

Two distinguishing characteristics of the nervous tissues are many cells are packed close4ly together and strongly branching.

The function of these cells is to help carry messages throughout the body.  They have branching ends that help pick up & send out impulses as well as long strands that carry the impulse over distances through the body.

Tissue Membranes

Synovial  Membrane at a Macroscopic view

The Synovial membrane lines the thin cavities between bones, secrete lubricating watery fluid and are composed of connective tissue only. 

Body Position & Directional Planes

 

A friend tells you she has a blister on the inferior surface of her foot.  She adds that it is posterior, not anterior.  You need to explain to her that her blister is on the back of her foot.

Skin Structure and Function:

Visualizing Changes in Skin Color

Palm of hand was flesh color until pressed firmly against a glass plate.  After a few seconds the skin turned white due to the compression (blood flowing out).  I believe that after an extended amount of time with the compression on the palm, the palm would become numb due to lack of circulation and blood flow.

Testing Tactile Localization and Adaptation:

Table 1. Average Discrepancy Between Subject and Experimenter Touch Point

  Palm                        Fingertip                       Forearm               Back of Hand

      Average Discrepancy       Average Discrepancy     Average Discrepancy    Average Discrepancy

         1.75 mm                            .5 mm                                1.25 mm                     1.5 mm

• First Attempt         8.72seconds for sensation to go away
  

• Second Attempt    6.82 seconds for sensation to go away

• Third Attempt       13.70 seconds for sensation to go away.  by adding 3 more coins the pressure  caused the sensation to last longer than attempt #2 with a difference of 7.5 seconds.

Appendages of the Skin

The Action of UV Light

1. When I am in the sun for a long period of time I use 30-50 SPF.
2. UV exposure increases the production of melanin in your skin. This would mean exposure to sun and tanning beds.