Download File - Different Diseases

Name: _________________________
Hour: __________
HISTOLOGY LAB: OBSERVING EPITHELIAL TISSUE
DUE: MOnday, September 23rd
Introduction:
The repeated cell division (mitosis) that occurs in a newly fertilized ovum (egg)
creates hundreds of identical daughter cells. However, once the mass of daughter cells is
implanted along the inner wall of the uterus, mitosis stops temporarily. When cell
division resumes, the cells that are produced are not all identical – they have
differentiated and the mass of cells is referred to as an embryo. Initially, the embryo has
three distinct layers: the ectoderm (outermost layer, which becomes nervous tissue and
the outer epithelial tissue); the mesoderm (the middle layer, which becomes connective
and muscle tissue), and the endoderm (the innermost layer, which becomes the internal
epithelial tissues and visceral organs).
Each variety of epithelium is given two classification names (except transitional
epithelium). The first name indicates the number of layers present; the second describes
the shape of the cells.
Layers:
Simple = One layer
Stratified = Several layers
Pseudostratified=All cells touch the basement membrane, but not the apical surface.
Shapes:
Squamous = flattened or “squashed” in appearance.
Cuboidal = “Cubed” shaped (I know, very original name…)
Columnar = Tall columns (think of the white house)
Transitional = Changeable, random shapes
Epithelial cells can be unciliated, ciliated, or have the presence of microvilli.
Ciliated cells function to move substances or cells past the epithelial cells, and microvilli
function to increase the surface area of the cell that is involved in absorption.
Procedure:
1.
Using the compound microscope, observe the prepared slides of the various types
of epithelial tissues. Complete a total of seven slides, making sure that you follow
each of the following guidelines:
•Include the magnification (all images must be at 400X), give specific
information from the slide’s label, and label all relevant structures within the
tissue (basement membrane, cilia, nucleus, etc.)
•Images can be shared amongst students if need be
2.
When you have completed your drawings, test your ability to recognize each type
of epithelial tissue. To do this, have your lab partner select one of the prepared
Name: _________________________
Hour: __________
slides, cover the label with a sticky note or scrap piece of paper, and focus the
microscope on the tissue. Try to see if you can determine the tissue correctly!
3.
After your drawings are complete use your class notes to research each tissue
type. You may view the slides in any order. Include examples of locations that
contain each tissue type as well as the function(s) next to each drawing in
your lab report.
EPITHELIAL TISSUE IMAGE SECTION
A. Simple Squamous Epithelium
•Simple Cuboidal E.T.
Name: _________________________
Hour: __________
•Pseudostratified columnar E.T.
•Stratified Squamous E.T.
•Transitional E.T.
Name: _________________________
Hour: __________
FOLLOW UP QUESTIONS
Please complete these questions in BOLD type in the spaces provided.
1.
Epithelial tissue is avascular. Nutrients are needed by the cells that make up
epithelial tissue to carry out cellular functions, repair damaged portions, and
remove cellular waste. Explain how this avascular tissue receives nutrients,
oxygen, and disposes of waste.
Avascular tissue receives nutrients, oxygen, and disposes of waste by
diffusion from blood vessels in nearby connective tissues or from free
surface.
2.
Why is learning about epithelial tissue important when it comes to understanding
how disease occurs in the human body?
It is important to learn epithelial tissue when understanding how disease
occurs in the human body because epithelial tissue protects most organs.
3.
Match the each epithelial tissue with the characteristics (1 answer is used twice):
(A) simple squamous
(B)= simple cuboidal
(C) = simple columnar
__B___ a.
__A___ b.
__G___ c.
__D___ d.
__A___ e.
__C___ f.
__E___ g.
(D) = pseudostratified
(E)= stratified squamous
(G) = transitional
consists of many layers of cells, which the apical surface cells all appearing
flattened, lines the throat, mouth, and vagina.
forms the air sacs of the lungs where gas exchange occurs.
forms the inner lining of the urinary bladder and uterus.
forms the lining of large ducts of glands;functions in secreting glandular secretion
forms the walls of the circulatory system’s capillaries, site of gas exchange.
lines the stomach and small intestines where absorption of nutrients occurs.
functions to move the ovum (egg) from the ovaries to the uterus, specialized
goblet cells produce mucus.
Name: _________________________
Hour: __________
Matching: A. connective
5. ___C____
6. ___D____
7. ___A____
8. ___D____
9. ___B____
10. ___C____
11. ___A____
B. Epithelium
C. Muscle
D. Nervous
Allows movement of limbs and for organ movements within the body
Uses electrochemical signals to carry out its functions
Cells of this tissue may absorb and/or secrete substances
This tissues cells shorten to exert force
Forms endocrine and exocrine glands
Allows you to smile, grasp, swim, ski, and throw a ball
Forms the brain and spinal cord
MULTIPLE CHOICE
12. ___D_____Which of the following is not characteristic of epithelial tissue?
a. Has no blood vessels
b. Covers free surfaces of the body
c. Typically involved in secretion, excretion, or absorption
d. Contains an extensive nonliving matrix
13. ___A_____Through which epithelial tissue would diffusion most easily take place?
a. Simple squamous
b. Transitional
c. Cuboidal
d. Pseudostratified columnar
14. ___C_____What tissue types are found in the intestinal tract?
a. Cuboidal epithelium, smooth muscle
b. Stratified squamous epithelium, stratified muscle
c. Simple columnar epithelium, smooth muscle
d. Pseudostratified columnar epithelium, reticular tissue
15. ___C____The criterion for categorizing epithelia as simple, stratified, or pseudostratified
is
a. Cell size.
b. Secretions of cells.
c. Cell shape.
d. Arrangement of cells.
When you are finished with your lab, make sure your name is on it and submit to Moodle drop box, if you have
trouble with the Moodle dropbox, print off a copy and bring to class.
Name: _________________________
Hour: __________