Part 1 - Get a Lab Appointment and Install Software:
Set up an Account on the Scheduler (FIRST TIME USING NANSLO):
Find the email from your instructor with the URL (link) to sign up at the scheduler.
Set up your scheduling system account and schedule your lab appointment.
NOTE: You cannot make an appointment until two weeks prior to the start date of this lab assignment.
You can get your username and password from your email to schedule within this time frame.
Install the Citrix software: – go to http://receiver.citrix.com and click
download > accept > run > install (FIRST TIME USING NANSLO).
You only have to do this ONCE. Do NOT open it after installing. It will work automatically when you go
to your lab. (more info at
http://www.wiche.edu/info/nanslo/creative_science/Installing_Citrix_Receiver_Program.pdf)
Scheduling Additional Lab Appointments:
Get your scheduler account username and password from your email.
Go to the URL (link) given to you by your instructor and set up your appointment.
(more info at http://www.wiche.edu/nanslo/creative-science-solutions/students-scheduling-labs)
Changing Your Scheduled Lab Appointment:
Get your scheduler account username and password from your email. Go to http://scheduler.nanslo.org
and select the “I am a student” button. Log in to go to the student dashboard and modify your
appointment time. (more info at http://www.wiche.edu/nanslo/creative-science-solutions/studentsscheduling-labs)
Part 2 – Before Lab Day:
Read your lab experiment background and procedure below, pages 1-19.
Submit your completed Pre-Lab 1-3 Questions (pages 9-11) per your faculty’s instructions.
Watch the Microscope Control Panel Video Tutorial
http://www.wiche.edu/nanslo/lab-tutorials#microscope
Part 3 – Lab Day
Log in to your lab session – 2 options:
1)Retrieve your email from the scheduler with your appointment info or
2) Log in to the student dashboard and join your session by going to http://scheduler.nanslo.org
NOTE: You cannot log in to your session before the date and start time of your appointment. Use
Internet Explorer or Firefox.
Click on the yellow button on the bottom of the screen and follow the instructions to talk to your lab
partners and the lab tech.
Remote Lab Activity
SUBJECT SEMESTER: ____________
TITLE OF LAB: Histology – Muscle Tissue
Lab format: This lab is a remote lab activity.
Relationship to theory (if appropriate): In this lab you will learn the underlying principles
behind the histological study of tissues.
Instructions for Instructors: This protocol is written under an open source CC BY license. You
may use the procedure as is or modify as necessary for your class. Be sure to let your students
know if they should complete optional exercises in this lab procedure as lab technicians will not
know if you want your students to complete optional exercises.
Instructions for Students: Read the complete laboratory procedure before coming to lab.
Under the experimental sections, complete all pre-lab materials before logging on to the
remote lab. Complete data collection sections during your online period, and answer questions
in analysis sections after your online period. Your instructor will let you know if you are
required to complete any optional exercises in this lab.
Remote Resources: Primary – Microscope, Secondary – Histology slide set.
CONTENTS FOR THIS NANSLO LAB ACTIVITY:
Learning Objectives.................................................................................................... 2
Background Information ........................................................................................... 2-7
Equipment ................................................................................................................. 8
Preparing for this NANSLO Lab Activity .................................................................... 8
Pre-lab Exercise 1: Skeletal Muscle .......................................................................... 9
Pre-lab Exercise 2: Cardiac Muscle .......................................................................... 9-10
Pre-lab Exercise 3: Smooth Muscle .......................................................................... 10-11
Experimental Procedure ........................................................................................... 11
Exercise 1: Skeletal Muscle ...................................................................................... 11
Exercise 2: Cardiac Muscle ....................................................................................... 12
Exercise 3: Smooth Muscle ...................................................................................... 12
Summary Questions .................................................................................................. 13
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Creative Commons Licensing .................................................................................... 13
U.S. Department of Labor Information ..................................................................... 13
LEARNING OBJECTIVES:
1. Overview of histology tissues and types.
a. Define the term histology.
b. List four major tissue types.
c. Contrast the general features of the four major tissue types.
2. Microscopic anatomy, location, and functional roles of muscle tissues.
a. Classify the different types of muscle tissue based on distinguishing structural
characteristics.
b. Describe locations in the body where each type of muscle tissue can be found.
c. Describe the functions of each type of muscle tissue in the human body and correlate
function with structure for each tissue type.
d. Identify the different types of muscle tissue using proper microscope technique.
BACKGROUND INFORMATION:
A living organism is composed of a variety of cells of different sizes, shapes, structures and
specialized functions. Cells of similar type are usually organized into groups. A group of cells
with similar size, shape, structure and function form a tissue. There are four general classes of
tissues. These classes are epithelial, connective, muscle, and neuronal. In this lab, we will use
histology to examine several muscle tissues.
Histology1 is the branch of biology concerned with the composition and structure of plant and
animal tissues in relation to their specialized functions. The terms histology and microscopic
anatomy are sometimes used interchangeably, but a fine distinction can be drawn between the
two studies. The fundamental aim of histology is to determine how tissues are organized at all
structural levels from cells and intercellular substances to organs.
Muscle tissue2 is the contractile tissue found in animals the function of which is to produce
motion. While there are several different subtypes of muscle tissue, all types of muscle fibers
share the following properties. Movement, the intricate cooperation of muscle and nerve
fibers, is the means by which an organism interacts with its environment. The innervation of
muscle cells, or fibers, permits an animal to carry out the normal activities of life.
An organism must move to find food or, if it is sedentary, must have the means to bring food to
itself. An animal must be able to move nutrients and fluids through its body, and it must be able
to react to external or internal stimuli. Muscle cells fuel their actions by converting chemical
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energy in the form of adenosine triphosphate (ATP), which is derived from the metabolism of
food, into mechanical energy. We distinguish three types of muscles inside our body: skeletal,
cardiac, and smooth.
A muscle is composed of many long cylindrical-shaped fibers from 0.02 to 0.08 mm in diameter.
In some muscles, the fibers run the entire length of the muscle (parallel fibers) up to several
tens of centimeters long. In others, a tendon extends along each edge, and the fibers run
diagonally across the muscle between the tendons. Considerable variation can be found among
the different skeletal muscles. The actual arrangement of the fibers is dependent on the
function of the muscle.
There is a high degree of organization within the fiber – a series of alternately dark and light
bands. Each band extends perpendicular to the length of the fiber. Each fiber is surrounded by a
complex multilayered structure called the sarcolemma. The outermost layer is a fine network of
fibrils, which, at the ends of the muscle, extend into the tendons and form the structural link
with them.
The next layer of the sarcolemma is a foundation, or basement, membrane. The innermost
layer is a plasma membrane similar to the ones that surround most cells. The plasma
membrane consists of a lipid bilayer with proteins embedded in it. Some of the proteins are
embedded entirely within the lipid layer, others extend to one or the other surface, and still
others span the whole width of the two layers. These proteins represent enzymes, receptors,
and various channels (such as those involved in the movement of ions between the exterior and
interior of the cell).
The plasma membrane maintains the electrical potential which plays a major role in stimulating
muscle contraction.
Sarcoplasm is the cytoplasm of a muscle fiber. The most abundant metal in the sarcoplasm is
potassium. Sodium and magnesium are present in lower concentrations. Most of the calcium of
muscle is bound to proteins or stored in the sarcoplasmic reticulum. Contraction is initiated by
the release of calcium ions (Ca2+) upon the depolarization of the membrane which is induced by
nerve impulses.
The myofibril is a column-like array of filaments. In a longitudinal section through a group of
myofibrils (Figure below), there is a light band of low density called the “I band”. In the center
of the I band, there is a prominent dense line called the Z line. Although in reality, considering
the three-dimensional structure of the myofibril, it is more appropriate to speak of Z disks. The
area between two Z lines, a sarcomere, can be considered to be the primary structural and
functional unit directly responsible for muscle contraction. The myofibril can thus be thought of
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as a stack of sarcomeres. The A band, which contains thick filaments partly overlapped with
thin filaments, appears dark.
Figure 1: 3"transverse tubule: ultrastructure of myofibrils . . . Utrastructure of a
group of myofibrils, showing the sarcoplasmic reticulum and transverse tubules,
which constitute the two membrane systems within a muscle fibre.” Art.
Encyclopædia Britannica Online.
Proteins of the myofilaments are composed of several different proteins, constituting about 50
percent of the total protein in muscle. The other 50 percent consists of the proteins in the Z line
and M band, the enzymes in the sarcoplasm and mitochondria, collagen, and the proteins in
membrane structures. The main contractile stricter is the myofilaments which is composed of
the thick and thin filaments. The movement of these filaments over each other causes the
contraction of the myofilaments. The composition of these structures will be discussed next.
The myofilament proteins, myosin and actin are known to play a direct part in the contractile
event. Troponin and tropomyosin, which are located in the thin filaments together with calcium
ions, regulate contraction by controlling the interaction of myosin and actin.
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The main constituent of the thick filaments is myosin. Each thick filament is composed of about
250 molecules of myosin. Myosin has two important roles: a structural one, as the building
block for the thick filaments, and a functional one, as the catalyst of the breakdown of ATP
during contraction and in its interaction with actin as part of the force generator of muscle.
The individual myosin molecule contains two major protein chains and four small ones. The
entire molecule is about 160 nm in length and asymmetrically shaped. The rod like tail region,
about 120 nm long, consists of two chains of protein, each wound into what is known as an
α-helix, together forming a coiled-coil structure.
At the other end of the molecule, the two protein chains form two globular head-like regions
that have the ability to combine with the protein actin and carry the enzymatic sites for ATP
hydrolysis.
Figure 2: 4“Myosin is a molecule-sized muscle that uses chemical energy to perform
a deliberate motion.” Art. June 2001, Molecule of the Month, David Goodsell.
Thick filament assembly.
In the middle portion of the thick filament, the molecules are assembled in a tail-to-tail fashion.
Along the rest of the filament, they are arranged head to tail. The tail parts of the molecules
form the core of the filament. The head portions project out from the filament. The cross
bridges are actually the globular head regions of myosin molecules extending outward from the
filament, and the smooth pseudo-H zone is the region of tail-to-tail aggregation in which there
are only tails and no heads.
Thin filament proteins.
The thin filaments contain three different proteins—actin, tropomyosin, and troponin. The
latter is actually a complex of three proteins.
Actin constitutes about 25 percent of the protein of myofilaments and is the major component
of the thin filaments in muscle. An individual molecule of actin is a single protein chain coiled to
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form a roughly egg-shaped unit. Actin in this form, called globular actin or G-actin, has one
calcium or magnesium ion and one molecule of ATP bound to it. Under the proper conditions,
G-actin is transformed into the fibrous form, or F-actin, that exists in the thin filament in
muscle. Actin is believed to be directly involved in the process of contraction, because the cross
bridges can become attached to it.
Tropomyosin is a rod-shaped molecule about 40 nm long. Two strands of tropomyosin
molecules run diametrically opposed along the actin filaments. Tropomyosin has a structure
similar to that of the myosin tail, being a coiled unit of two protein chains. Each tropomyosin
molecule is in contact with seven actin units.
Troponin is a complex of three different protein subunits. One troponin complex is bound to
every tropomyosin molecule. A troponin molecule is located approximately every 40 nm along
the filament. Troponin and tropomyosin are both involved in the regulation of the contraction
and relaxation of muscles.
The neuromuscular junction.
The signal for a muscle to contract originates in the nervous system and is transmitted to the
muscle at the neuromuscular junction, a point of contact between the motor nerve and the
muscle. As the nerve approaches the muscle, it loses its myelin coat but remains partially
covered by processes of the Schwann cells, which elsewhere surround the nerve and produce
myelin. The nerve then branches several times, indenting the surface of the muscle to form the
end plate that occupies only a small region of the total surface area of the muscle.
The neural signal is an electrical impulse that is conducted from the motor nerve cell body in
the spinal cord along the nerve axon to its destination, the neuromuscular junction. No
electrical continuity exists between the nerve and the muscle. The signal is transmitted by
chemical means that require specialized presynaptic and postsynaptic structures.
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Figure 3: 5"neurotransmitter release". Art. Encyclopædia Britannica Online. Web. 04 Apr. 2014.
Reference:
Encyclopædia Britannica Online
1 http://www.britannica.com/EBchecked/topic/267172/histology
2
http://www.britannica.com/EBchecked/topic/398553/muscle
3
Encyclopædia Britannica Online
http://www.britannica.com/EBchecked/media/2568/Ultrastructure-of-a-group-of-myofibrilsshowing-the-sarcoplasmic-reticulum. Web. Viewed 04 Apr. 2014.
4David
Goodsell & RCSB Protein Data Bank
http://www.rcsb.org/pdb/101/motm.do?momID=18. Web. Viewed 04 Apr. 2014.
5
"neurotransmitter release". Art. Encyclopædia Britannica Online. Web. 04 Apr. 2014.
http://www.britannica.com/science/chemoreception/images-videos/Chemical-transmission-ofa-nerve-impulse-at-the-synapse-The/66782
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EQUIPMENT:

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Paper
Pencil/pen
Slides
o Striated muscle (longitudinal section)
o Cardiac muscle, section
o Smooth muscle (longitudinal section)
Computer with Internet access for the remote laboratory and for data analysis
PREPARING FOR THIS NANSLO LAB ACTIVITY:
Read and understand the information below before you proceed with the lab!
Scheduling an Appointment Using the NANSLO Scheduling System
Your instructor has reserved a block of time through the NANSLO Scheduling System for you to
complete this activity. For more information on how to set up a time to access this NANSLO lab
activity, see www.wiche.edu/nanslo/scheduling-software.
Students Accessing a NANSLO Lab Activity for the First Time
For those accessing a NANSLO laboratory for the first time, you may need to install software on
your computer to access the NANSLO lab activity. Use this link for detailed instructions on
steps to complete prior to accessing your assigned NANSLO lab activity –
www.wiche.edu/nanslo/lab-tutorials.
Video Tutorial for RWSL: A short video demonstrating how to use the Remote Web-based
Science Lab (RWSL) control panel for the air track can be viewed at
http://www.wiche.edu/nanslo/lab-tutorials#microscope.
NOTE: Disregard the conference number in this video tutorial.
AS SOON AS YOU CONNECT TO THE RWSL CONTROL PANEL: Click on the yellow button at the
bottom of the screen (you may need to scroll down to see it). Follow the directions on the pop
up window to join the voice conference and talk to your group and the Lab Technician.
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PRE-LAB EXERCISE 1: Skeletal Muscle
Skeletal (Striated) muscle, also called voluntary muscle or striped muscle, is the most common
of the three types of muscle in the body. Striated muscle is attached to bone and produces all
the movements of body parts in relation to each other. Unlike smooth muscle and cardiac
muscle, striated muscle is under voluntary control. Its multinucleated fibers are long and thin
and are crossed with a regular pattern of fine red and white lines giving the muscle its
distinctive appearance and its name.
Striated or striped muscle constitutes a large fraction of the total body weight in humans.
Striated muscle contracts to move limbs and maintain posture. Both ends of most striated
muscles articulate the skeleton and thus are often called skeletal muscles. They are attached to
the bones by tendons which have some elasticity provided by the proteins collagen and elastin,
the major chemical components of tendons.
Each striated muscle has blood vessels and nerves associated with it. The vessels transport
blood to and from the muscle, supplying oxygen and nutrients and removing carbon dioxide
and other wastes. The signals that initiate contraction are sent from the central nervous system
to the muscle via the motor nerves. Muscles also respond to hormones produced by various
endocrine glands. Hormones interact with complementary receptors on the surfaces of cells to
initiate specific reactions. Each muscle also has important sensory structures called stretch
receptors which monitor the state of the muscle and return the information to the central
nervous system. Stretch receptors are sensitive to the velocity of the movement of the muscle
and the change in length of the muscle. They complete a feedback system that allows the
central nervous system to assess muscular movement and to adjust motor signals in light of the
movement.
PRE-LAB QUESTION 1
How do you predict the appearance of skeletal muscle tissue will be? And, how many nuclei do
you think each muscle fiber (muscle cell) will have?
PRE-LAB EXERCISE 2: Cardiac Muscle
1
Cardiac muscle, also known as heart muscle, is the pump that keeps blood circulating
throughout the body and thereby transports nutrients, breakdown products, antibodies,
hormones, and gases to and from the tissues. The heart consists mostly of muscle. The
myocardial cells (collectively termed the myocardium) are arranged in ways that set it apart
from other types of muscle. The outstanding characteristics of the action of the heart are its
contractility which is the basis for its pumping action and the rhythmicity of the contraction.
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Heart muscle differs from its counterpart, skeletal muscle, in that it exhibits rhythmic
contractions. The amount of blood pumped by the heart per minute (the cardiac output) varies
to meet the metabolic needs of the peripheral tissues (muscle, kidney, brain, skin, liver, heart,
and gastrointestinal tract). The cardiac output is determined by the contractile force developed
by the muscle cells of the heart (myocytes) as well as by the frequency at which they are
activated (rhythmicity). The factors affecting the frequency and force of heart muscle
contraction are critical in determining the normal pumping performance of the heart and its
response to changes in demand.
The heart is a network of highly branched cardiac cells 110 μm in length and 15 μm in width
which are connected end to end by intercalated disks. The cells are organized into layers of
myocardial tissue that are wrapped around the chambers of the heart. The contraction of the
individual heart cells produces force and shortening in these bands of muscle with a resultant
decrease in the heart chamber size and the consequent ejection of the blood into the
pulmonary and systemic vessels.
Important components of each heart cell involved in excitation and metabolic recovery
processes are the plasma membrane and transverse tubules in registration with the Z lines, the
longitudinal sarcoplasmic reticulum and terminal cisternae, and the mitochondria. The thick
(myosin) and thin (actin, troponin, and tropomyosin) protein filaments are arranged into
contractile units (that is, the sarcomere extending from Z line to Z line) that have a
characteristic cross-striated pattern similar to that seen in skeletal muscle.
PRE-LAB QUESTION 2
How do you predict the appearance of the cardiac muscle tissue and the cell’s shape will be?
And, how many nuclei do you think each muscle fiber (muscle cell) will have?
Reference:
Encyclopædia Britannica Online
http://www.britannica.com/science/human-cardiovascular-system. Web. Viewed 04 Apr. 2014.
PRE-LAB EXERCISE 3: Smooth Muscle
1Smooth
muscle, also called involuntary muscle, is found primarily in the internal body organs and
undergoes involuntary, often rhythmic contractions that are not dependent on outside nerve impulses.
This muscle shows no cross stripes under microscopic magnification. It consists of narrow spindleshaped cells with a single, centrally located nucleus. Smooth muscle tissue, unlike striated muscle,
contracts slowly and automatically. It constitutes much of the musculature of internal organs and the
digestive system.
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PRE-LAB QUESTION 3
How do you predict the appearance of the smooth muscle tissue and the cell’s shape will be?
And, how many nuclei do you think each muscle fiber (muscle cell) will have?
Reference:
Encyclopædia Britannica Online http://www.britannica.com/science/smooth-muscle. Web.
Viewed 04 Apr. 2014.
EXPERIMENTAL PROCEDURE
Once you have logged on to the remote lab system, you will perform the following laboratory
procedures.
During the study of each type of human tissue, you are required to photograph and label a
representative sample of each tissue type. You should begin your microscopic examination of
the tissue slide using the 4X objective to give you a perspective of the entire structure. This is
very important since sometimes more than one tissue type is present on each slide. All
observations should be made using the 40X objective lens.
EXERCISE 1: Skeletal Muscle
Data Collection:
1. Select the striated muscle (longitudinal section) slide (Slide Cassette 2: #13) from the
microscope interface. Using the 10X objective, locate the tissue sample and bring it into focus.
2. Carefully work your way through all the objectives focusing with each one until you reach the
40X objective and capture an image of the striated skeletal muscle .
3. Insert your image below. Label the muscle fibers, nuclei, sarcolemma, and the A and I bands.
Analysis:
3. Based on your observation, describe the organization of the skeletal muscle tissue.
4. Do your observations support your initial ideas from Pre-lab Question 1? Use evidence
gathered to explain why you would accept or reject your initial hypothesis.
5. Describe the function of the skeletal muscle in the human body and correlate its
functions with its structure.
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EXERCISE 2: Cardiac Muscle
Data Collection:
1. Select the cardiac muscle slide (Slide Cassette 2: #10) from the microscope interface.
Using the 10X objective, locate the tissue sample and bring it into focus.
2. Carefully work your way through all the objectives focusing with each one until you
reach the 40X objective and capture an image of the cardiac muscle.
3. Insert your image below. Label the intercalated discs, striations, cell branches, and
nuclei.
Analysis:
4. Based on your observation, describe the organization of the cardiac muscle tissue.
5. Do your observations support your initial ideas from Pre-lab Question 2? Use evidence
gathered to explain why you would accept or reject your initial hypothesis.
6. Describe the function of the cardiac muscle in the human body and correlate the
function with its structure.
EXERCISE 3: Smooth Muscle
Data Collection:
1. Select the smooth muscle (longitudinal section) slide (Slide Cassette 2: #7) from the
microscope interface. Using the 10X objective, locate the tissue sample and bring it into
focus.
2. Carefully work your way through all the objectives focusing with each one until you
reach the 40X objective and capture an image of the smooth muscle.
3. Insert your image below. Label the smooth muscle cells.
Analysis:
4. Based on your observation, describe the organization of the smooth muscle tissue.
5. Do your observations support your initial ideas from Pre-lab Question 3? Use evidence
gathered to explain why you would accept or reject your initial hypothesis.
6. Describe the function of the smooth muscle in the human body and correlate the
function with its structure.
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SUMMARY QUESTIONS:
The three types of muscle tissues exhibit similarities as well as differences. Check the
appropriate space in the table below to indicate which muscle type exhibits each characteristic.
Characteristic
Voluntarily controlled
Involuntarily controlled
Striated
Has a single nucleus in each cell
Has more than one nucleus per cell
Found attached to bones
Found in the walls of the stomach, uterus, and arteries
Contains spindle-shaped cells
Contains branching cylindrical cells
Contains long, non-branching cylindrical cells
Has intercalated discs
Concerned with locomotion of the body as a whole
Changes the internal volume of an organ as it contracts
Tissue of the heart
Skeletal
Cardiac
Smooth
For more information about NANSLO, visit www.wiche.edu/nanslo.
All material produced subject to:
Creative Commons Attribution 3.0 United States License 3
This product was funded by a grant awarded by the U.S.
Department of Labor’s Employment and Training Administration.
The product was created by the grantee and does not necessarily
reflect the official position of the U.S. Department of Labor. The
Department of Labor makes no guarantees, warranties, or
assurances of any kind, express or implied, with respect to such
information, including any information on linked sites and
including, but not limited to, accuracy of the information or its
completeness, timeliness, usefulness, adequacy, continued
availability, or ownership.
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