Title: Lab 1 Histology
URL Source: blob://pdf/62ed9daa-d749-47fd-ae8c-e2933100a722
Markdown Content:
Prepared by: Scott Lehbauer & Stacia Nelson
Simple columnar epithelial tissue by Ramona Stewart Tissues - are groups of similar cells that are specialized to perform specific functions.
>
For example, nervous tissue is specialized to conduct impulses that help control and coordinate body activities.
>
The study of tissues is called histology . tissues that cover all the body surfaces inside and out.
>
tissues that are composed of at least one layer of cells.
>
More specifically they make up the:
outer layer of the skin,
form the inner lining of body cavities,
cover organs,
line the chambers inside hollow organs, and
are the major tissue component of glands. Epithelial tissues always have one side exposed to the outside or to an open space internally.
> Apical Side
>
The underside of all epithelial tissues is anchored to connective tissue by a non-living layer called a basement membrane.
> Basal side
>
Epithelial tissues are avascular (lack blood vessels)
> Basement Membrane
Epithelial tissues obtain nutrients from the vessels in the underlying connective tissue.
>
Epithelial tissues reproduce rapidly, therefore injuries to epithelial tissues repair quickly.
>
Epithelial tissues are tightly packed together. (little intercellular space)
>
Epithelial tissues are classified according to their shape, arrangement and function of their cells 1. According to arrangement
2. According to shape Simple one layer thick
Simple Squamous Epithelium Simple Cuboidal Epithelium
Stratified two or more layers
Stratified Squamous Epithelium Transitional Epithelium Epithelial Tissue: Classification
## Shape
Examples of Shapes of Epithelial Tissues. Wikipedia 2022. 1. Glandular in skin, intestines, endocrine glands they make and secrete substances .
> 2.
# Absorption through microvilli on the top surface of the cells .
> 3.
# Protection the densely packed cells provide a protective layer for the underlying tissues.
> 4.
# Secretion of fluid, enzymes mucus and other substances.
# Epithelial Functions: GAPS Location
>
Lining of alveoli
>
Lining of capillaries
>
Lining of lymph vessels
>
Covering around organs Description
>
Elongated column shaped cells
>
One cell layer thick
>
Nuclei are arranged near the bottom of cells Function
>
Absorption, secretion of mucus, movement of materials (mucus and reproductive cells) Goblet Cells secrete mucus which protects and lubricates the tissue.
>
Brush Border contains microvilli which vastly increase the surface area of the cell for absorption.
> Brush Border
> Nucleus
> Basement
> Membrane
> Goblet
> Cell
Location
>
Lines the digestive tract from stomach through to the rectum.
>
Also found in the gall bladder and oviducts.
> Wikipedia 2007
Description
>
Short cube shaped cells with a large centrally located nuclei Location
>
small glands,
>
ovaries,
>
kidney tubules and
>
the retina.
> X Section of Kidney Tubule
Function
>
In glands cuboidal epithelial cells secrete substances.
>
In the kidney tubules they absorb substances (water and solutes).
> Cube Shaped
> Cells
Description
>
Cells vary in height, only the tallest cells reach the free surface. (simple tissue)
>
Cell nuclei are at different heights giving the tissue a false (Pseudo) stratified appearance.
>
Cells are again columnar in shape Location
>
Found in the trachea and the upper respiratory tract.
>
Also found in sperm-carrying ducts Function
>
This type of epithelium secretes and absorbs substances.
>
It also protects the respiratory tract by sweeping dirt and bacteria toward the pharynx.
> Nuclei
> Basement Membrane
Cilia sweep dirt and bacteria back towards the pharynx.
>
Goblet Cells secrete mucus which collects bacteria and moistens the respiratory tract.
> Cilia
> Goblet Cell
Description
>
Thick membrane composed of several cell layers.
>
Cells near the basement membrane are cuboidal or columnar in shape and alive.
>
Cells near the surface are squamosal in shape and are full of keratin and dead. Location
>
This epithelium is found in areas of high wear and tear. Any area in the body exposed to the outside world.
>
Examples - Epidermis of the skin, the lining of the mouth, anus and vagina Keratin is a tough, insoluble, fibrous structural protein.
>
Keratin accumulates in the cells as they approach the outer surface.
>
Cells rely on diffusion for nutrients so cells near the basement membrane are viable and cells near the surface are less viable.
> Living Cells
> (Cuboidal)
> Dead Cells full of Keratin
> Basement Membrane
Function
>
This epithelium protects against scrapes, cuts and bacteria.
>
Also it provides a water proofing layer around the body .Description :
>
Layers of cuboidal and elongated cells are held tightly together
>
NOTE: outer cells are rounded not flattened as in Stratified Squamous Location :
Ureters
>
Urinary bladder
>
Parts of the urethra Function
>
Able to distend which allows for expansion and contraction
>
Prevent any passage of urine into the surrounding areas. Where in the body would you find this type of Epithelial Tissue? Name this type of Epithelial Tissue. What is the function of the structure labeled A?
# AName one main function of this tissue. Name this type of Epithelial Tissue. 1. Small glands, ovaries, kidney tubules, retina.
> 2.
Pseudostratified Ciliated Columnar Epithelium
> 3.
Secrete mucus
> 4.
Protection against cuts and scrapes, waterproofing
> 5.
Simple Columnar Epithelium.