Introduction to Human Anatomy and Physiology
Chapter 5 - Tissues
1. What is a tissue?
A tissue is defined as a group
of similar cells working together to perform a specific function.
2. What are the tissues of the human body?
Table 5.1 on page 97 of your textbook compares these four main groups, giving their functions, locations, and distinguishing characteristics.epithelial tissueconnective tissue
muscle tissue
nervous tissue
3. What is epithelial tissue?
Tissues that are categorized as epithelial tissues may be found covering the entire outside of our bodies, lining passageways, or covering the surfaces of organs of the body.
Functions of the various epithelia include the ability to absorb, secrete, and/or protect. Some examples of epithelial tissues are:
Since there are so many places that epithelial tissues are found in the body, how are the different kinds categorized or named?the skinthe lining of the mouth & of other openings of the body
the tissue lining the abdominal, chest & heart cavities
the tissue lining blood vessels
The names of epithelial tissues are based on 2 characteristics -- their shape & number of layers they are arranged in. The name of a particular epithelium will include both characteristics Shape:
Two epithelia that do not fit into these categories are:squamous (flattened)cuboidal (equally tall, wide & deep -- somewhat rounded)
columnar (more of less rectangular)
Layers:
simple (1 layer thick)
stratified (many layers thick)
Some examples of epithelia using these category names are:
simple squamous epithelium
stratified squamous epithelium
simple cuboidal epithelium
transitional epithelium -- has the ability to stretch & change in appearance from cuboidal to squamous & back to cuboidal shape
pseudostratified columnar epithelium
-- gives the false appearance of being stratified because the nuclei are
not all basally located, but staggered within their respective cells.
4. What are the connective tissues & why are they placed together in this category?
Connective tissues will all have this in common: they have fibers of some sort, an inorganic "ground" substance, and they contain living cells. Some literally do connect body parts to each other and some support structures of the body. They are quite varied in their appearance and range from very dense (such as bone) to a fluid consistency (blood). The connective tissues include:
Photographs of these tissues taken through the microsope can be seen on pages 105 to 109 in your textbooks.areolar (or loose connective tissue)adipose
dense connective tissue (both regular & irregular)
cartilage
bone
blood
5. Why does damaged cartilage tissue take longer to heal than bone tissue?
Bone tissue is well-supplied with blood vessels to brings nutrients to damaged bone tissue. Cartilage has to depend on diffusion of nutrients from blood vessels adjacent to, but not in, the cartilage tissue.
For additional Information, quizzes, case studies, hot
links to related web sites, and study outlines related to this chapter,
go to the "Hole's
Essentials of Human Anatomy & Physiology" textbook web site.