Download Macroscopic and Microscopic Study of Tissues

Physiology Laboratory V
Macroscopic and Microscopic Study of Tissues
Cells are highly organized units, but they do not function by themselves. They work
together in groups of similar units called tissues. Knowledge of tissue structure and
function is important in understanding how individual cells are organized to form tissues,
organs, organ systems and the complete organism. The microscopic study of tissues is
called histology. The four basic tissue types are: epithelial, connective, muscular and
nervous tissue. In this two part lab you will be examining representatives of the four
tissue groups both macroscopically, through a dissection of a chicken wing and
microscopically, using the oil immersion lens with prepared tissue slides.
Part I: A Study of Tissues Through the Dissection of a Chicken Wing
Introduction:
A bird’s wing is made up of groups of tissues working together to perform the
job of flight. In this investigation you will dissect a chicken wing and look for the
following tissues: epithelial (skin); muscle (skeletal); connective (adipose, bone,
cartilage, blood vessels, ligaments, tendons, fascia) and finally nerve tissue.
Procedure:
1. You will be working in pairs and each pair needs a dissecting tray, chicken wing,
scissors, probe, and forceps. Everyone needs to ‘3G’ - glove, gown & goggle.
2. Before you begin the actual dissection, study the external appearance of the
wing. Examine the web-like skin between the bones. Look for evidence that the
skin was covered with feathers. What evidence did you find?
3. Remove the skin from the largest bone and joint. The most efficient way to do
this is to start at the proximal end of the chicken wing with your thumb and lift
the skin (epithelial tissue), place your thumb under the skin and pull back on the
skin. When you do this you will be ripping below the dermis and above the
muscle. Remove as much skin as possible.
4. Locate the tissues below. The following descriptions may help you identify each
tissue.
a. Connective tissue proper – this tissue resembles a flat, thin, clear film
or membrane (like saran-wrap). It is found in many places in a chicken’s
and human’s body.
b. Muscle tissue – The pink orange bundles of fiber found in the wing are
skeletal muscle. Skeletal muscles are attached to bones via tendons.
When the fibers expand or contract they produce motion in the wing.
You should be able to identify several muscle bundles and determine
whether they are extensor muscles (straightens wing out) or flexor
muscles (bends wing) by pulling on them. I will demonstrate this in
class.
c. Adipose Tissue – Fat is stored in many places in the chicken’s body.
Fat can be recognized by its yellow color and greasy feel.
d. Tendon – Especially strong connective tissues attach skeletal muscle to
bones and are shiny white in appearance. Pull on a tendon gently, and
see what effects your action has.
e. Bone – these hard tissues are made primarily of calcium. Inside many
bones are hollow spaces where red blood cells are manufactured. The
mass of red tissue that manufacture the red cells is called “red marrow”
f. Cartilage – This white glassy, firm but flexible tissue is found at the end
of bones. Move the joint back and forth and you can surmise what the
function of the cartilage is.
g. Ligament – Not as easily seen as tendons, these strong white bands of
connective tissue are similar to tendons. Ligaments connect two bones
together and can best be located at the joints.
h. Blood Vessels – Arteries, veins and capillaries are the vessels that
transport blood throughout the body. Arteries have a thicker wall than
veins and capillaries are too small to be seen without the microscope.
Blood vessels are the thin red tubes that are frequently seen at the
surface of the skeletal muscle.
i. Nerves – Nerves are usually buried deep within an organism, often lying
close to the bones. Sometimes an artery, vein and a nerve are held
together in one bundle of connective tissue running along a muscle.
Nerves can be recognized by their thin, white threadlike appearance.
5. Clean-Up: Take the chicken pieces parts and wrap them in paper towel and
throw them in the large gray garbage pail by the back sink/door! That is the
ONLY garbage we use for dissected animals!!! All the dissecting equipment must
be washed using warm soapy water. This can be done at the sinks at your desks
OR at the large sink at the side of the room. Dry everything and return it to the
supply tables in front of the hood. Make sure you then wash down your lab
table. I will tell you what solution to use for this in class. Finally, remove your
lab gown, fold it nicely and put it away, put away your goggles and wash your
own hands with SOAP and WATER before you leave class!
Part II: Microscopic Study of Tissues
Introduction: The aim of this part of the lab is to fine-tune your microscopic
techniques by studying several representative samples of the different tissue groups
found in the human body.
The following is a list of tissue samples that will be available for study. You are to
choose ONE from each category to view. Since our VHP objectives are not
working, ALL SLIDES are to be DRAWN under high power (400x - TM). Make
sure you label as many of the following structures as you can, BUT, ONLY IF
YOU SEE THEM!!
Before you view your slide under the microscope, log onto the desktop computer you
have been assigned and open the program Real Anatomy. Under the histology section
you will be able to view examples of all the tissue slides you can choose from today.
You CANNOT draw from Real Anatomy, but this program will be extremely helpful to you
for identifying structures and labeling, as well as making sure you are looking at the
right cells. SO…make sure you look at your cell types on Real Anatomy BEFORE you try
to find them on your microscope.
Cell structures to identify in your drawings:
cell membrane
cilia
nucleus
goblet cells
cytoplasm
vacuoles
1. Epithelial – this tissue group either covers or lines both internal and external
organs. The cells are differentiated based on their shape, number of layers
and special features. In all members of this category, the cells rest on a
basement membrane.
a. Simple squamous
b. Simple cuboidal
c. Pseudostratified ciliated columnar epithelial
2. Muscle - special proteins that cause contractions, which allow for all types of
movement, characterize this tissue group.
a. Skeletal
OR
b. Smooth
3. Nerve – is made up of neurons, which conduct bioelectrical messages and
other cells, which serve to support the neurons in a number of ways.
4. Connective – is a varied group of tissues, though all connective tissues types
are characterized by cells embedded in an intracellular matrix, which may be
solid, semisolid, liquid or fibrous.
a. Cartilage
b. ????? Let’s see what I can find in the cabinet.
5. CLEAN – UP: When you are done with a slide, return it to the tray from
which you took it. At the end of the period, make sure you put your microscope away
properly
 lowest magnification (4x)objective over the stage
 wrap the electric cord around the arm under the stage
 put cover over microscope
 place the microscope in the correct #’d space in the cabinet in my office
What goes in your lab notebook?
1. Team Introduction – on Google Docs: Write two paragraphs about a
disease that affects one of the tissue types. Be detailed and descriptive in
your discussion as to how the disease affects the tissue. Remember to
properly cite your 2 sources of information!
2. Observations: Write a paragraph about the tissues you saw during the
dissection (macroscopic observation) and then write a few sentences about
the microscopic view of the same tissues. Hint: once again think structure to
function.
3. Drawings: 4 drawings…one tissue from each category. Large and labeled.
All four must be under high power (40x). 3 bullet points per tissue slide
from Real Anatomy
4. Analysis Question: Most chickens have short, rounded wings, not suitable
for flying long distances. Think of birds that spend much of their life in flight.
In what ways would you expect the wings of a flying bird to be different from
that of the wings of a chicken, a non-flying bird. (Remember to cite your
source of information.)
5. Conclusion: reflection paragraph - this is your first dissection – what did
you think?
Name: _____________________________________
Chicken Wing Diagram