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.:Introduction:.
.:The study of Histology focuses on cells and different tissues of the body. The following information
will give you a basic understanding of different somatic tissues and the cells that make them up. We will begin with different
types of tissues and extrapolate upon what they look like and what purposes they serve.
.:Epithelial Tissue:.
Epithelial Tissue is tissue that covers and makes up different parts of the human body. It comes
in many different variations and types.
.:The first type of epithelium is simple squamous. It consists of one layer of flat, scale like cells.
.:Slightly similar to Simple Squamous is Stratified Squamous epithelium. It comes in two denominations, keratinized and
non-keratinized. Keritanized stratified squamous tissue has no nucleus at upper layers, and the cells are technicaslly dead.
That type of stratified squamous would be found on your exterior skin.
Non-keratinized squamous cells have nuclei up into the upper layer,s meaning all the cells are alive in all layers. This
type of tissue would be found on mucous membranes in the mouth and other inner parts of the bdy that come in contact with
the outside environment.
.:The next type of cells are Cubiotal cells. These are found in glandular tissue and make up the tubes within the glands
of the body. Note the square shape and ringed consistency in its structure.
.:Now we turn to Simple Columnar tissue. These cells are rectangular in shape and have linear nuclei. Generally they
can be found in the intestines on the villi and microvilli.
.:Pseudostratified Ciliated Columnar cells are very deceiving. They seem like stratified columnar cells, but are actually
all in one row. These cells are always ciliated and thier nuclei are unaligned. This type of tissue is generaly found in the
trachea.
.:Connective Tissue:.
Connective tissue is one of the most abundant elements in the human body. This tissue is very
vascular, elastic, strong and trustworthy. It is broken into 5 major types: Adipose Tissue, Areolar Tissue, Dense Connective
Tissue, Elastic Tissue and Reticular Tissue.
.:Adipose tissue is fat. Its that hard to get rid of, do-20billion-crunches-to-tighten tissue that everybody hates. However,
these cells are very important. They store energy and help out bodies work correctly. They also act as impact resistors and
protect the organs. Note the small nuclei and large, honeycomb-like appearence.
.:Areolar Tissue is integral to holding us together. Its 'the glue of the body' and assists in the correct placement
of organs and other structures. Its very fibrous and chaotic in appearence.
.:Dense Connective Tissue is what makes up your tendons, ligaments, and aponderoses. These are extremely strong, smooth
fibers that can withstand great forces. It is integral to motion and movement.
.:Elastic Tissue is a very supportive and elastic part of the Connective Tissue family. It acts at a connector and resistor
to stretching and returns to its original shappe easily.
.:Reticular tissue is rare, yet very important. It holds other types of tissues together and is make up of reticular
fibers, primarily.
.:Cartilage is somethign that everybody has heard of. Its what whols together the joints in our bodies, and the
abscence of it causes us great pain.
The firt stype of cartilage is Hyaline and its the most prominent type of cartilage. It is between every articulation
of bone in the body and makes up fetal skeletons. It transfroms from cartilage to bone and has great abilities to withstand
abuse.
.:Fibrocartilage is extremely resistant to any type of movement. It resides in places that require the most stability
and resistance to sharp movements, such as between each vertebrae in your back.
.:The final and third type of cartilage is Elastic. It is found in places where movenent is necessary such at the nose
and pinna of the ear.
.:Muscle Tissue:.
Muscles are what make our body move. By electrical contractions, your muscles coordinate movement
by pulling and relaxing the bones thye are attachted to. There are three types of muscular tissue, Smooth, Striated, and Cardiac
muscle.
.:The first type of muscle is Smooth Muscle. It is smooth in appearence and is found withing organs of the body. The
movement of this tissue is involuntary and cannot be influenced like skeletal muscles are. These muscles attribute peristalsis
in the digestive system.
.:Striated, or Skeletal muscle is found all across the body. It is broken up and striped in appearence and is completely
voluntary in the average person. This type of muscle is easy to identify due to the appearence of the tissue itself.
.:The final type of muscle tissue is Cardiac muscle. It is almost exactly the same as skeletal muscle, only cardiac muscle
has small, black structures called intercalated disks that help coordinate the movemnt of the muscle.
.:Nervous Tissue:.
Nervous tissue is the last type of tissue identified in the body. It makes up the brain and
nervous system. The cells are easy discernable from others due to thier unique appearence. EVery cell has an Axon head which
has branch-like extentions called dendrites. These receive impulses from other neurons. A tail like structure called the soma
extends from the Axon, and it is covered by a myelin sheath that protects and sevres other purposes. The final structure on
a neuron is terminal buttons whoch send out the impulses to the next neuron.
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