diagram of upper digestive system

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					NAME ________________________________CLASS ________________________________

                          BIO 156 LAB 15: HISTOLOGY - A SURVEY OF HUMAN TISSUES
                          Campbell, Mitchell & Reece, Customized Biology: Ch. 20
 Loose Connective         Perry/Morton Photo Atlas pg. 9-29 (each is referenced below with PM
   Tissue Proper            and the page number)
                         MULTIMEDIA SUPPORT AND MATERIALS IN THE LAB: (Check out videos
                         from Lab Staff or tutors)
                          CMR Interactive Study Partner CD – ISP – Ch. 20
                          Bio 156 Epithelium, CT, Muscle and Nerve tissue 35 mm slide
                            carousels of examples of these tissues: use the list that tells you the
Simple Cuboidal             name of the slide in each slot of the carousel.
  Epithelium              Tissue posters on the back wall; these also contain excellent examples
                          Anatomy & Physiology Videodisk Ch. 4 with alphabetical index or
                            frame index
                         SUGGESTED WEB SITES:
                          http://www.kumc.edu/instruction/medicine/anatomy/histoweb                (an
                            excellent site: has descriptions and photomicrographs of all tissue
       Bone                 types)
                          http://www.cord.edu/faculty/todt/336/lab (contains slides at different
                            magnifications - some have labels)
                          http://www.cbu.edu/~aross/histol.htm (also contains links to lots of
                            other histology sites)
                          www.meddean.luc.edu/lumen/MedEd/Histo/frames/histo_frames.html
                            (Loyola University Cell and Molecular Biology - includes "lab
 Cardiac Muscle             practicals" for self quizzing)
                          http://www.cedarville.edu/dept/sm/sullivan/histology (includes great
                            labeled diagrams and a fun "histo-Hangman" game to review vocab!)

                         *NOTE: You might consider purchasing the text that you will be using in
                         Bio 201/202 at this point. Chapter 4 in the Anatomy and Physiology book
    A Neuron             provides a more thorough discussion of tissues than your text does. This
                         text is also on reserve in the library, should you wish to make a copy of
                         chapter 4 to use as an additional reference.

 Explain the relationship between tissues and the other levels of organization: atoms,
    molecules, cells, organs and organ systems.
 Define the terms and cell types listed in bold in this lab.
 Identify each of the selected tissues in the microscope.
 Describe the structure and function of each of these selected tissues.
 List at least one place in the human body where each of these tissues can be found.

J. Fiello; DVC Biology                       2003/2004                                              1
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        A challenge for many biology students is developing a clear understanding of the levels
of organization – the description of what biological parts are composed of which other parts
(sec. 20.2). As you have learned in previous sections of this course, atoms are the smallest
building blocks of all matter. Both life and non-life are also composed of bonded atoms –
molecules. Cells, the smallest units of life, contain organelles, which are, in turn, built of
molecules.     In the Biology 156/201/202 sequence, you will study the human organism by
examining its parts, and the parts of its parts. From simplest (smallest) to most complex in a
single organism they are:
        atoms  molecules  cellular organelles  cells  tissues  organs  organ systems
Higher levels of organization exist as well. These levels describe groups of organisms of the
same or different species (populations and communities, respectively), and the interactions
between living and non-living components at the ecosystem level.
        The organ systems and most of the organs that comprise them are visible with the naked
eye, and thus easier to visualize and understand than the cell and molecular levels of
organization. You know, for example, the trachea and lungs are organs found in your respiratory
system, while the esophagus, stomach and intestines are parts of your digestive system. A list
that includes some of the major organs found in and the general functions of each of the organ
systems in the human body appears below:

J. Fiello; DVC Biology                 2003/2004                                            2
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        You have completed an introduction to cells, and so this level, though microscopic,
should be somewhat familiar as well. In this lab, we explore the link between the two: the tissue
level of organization. Tissues are groups of cells and intercellular materials that have a similar
developmental origin, structure and function (sec. 20.3). All organs are composed of at least two
different tissues (sec. 20.8), so as we continue to explore body systems, you will review the
tissues described in this lab.
        The study of tissues is called histology. There are four primary types of tissues
(epithelium, connective tissue, muscle and nerve) that are found in the human body; each has
sub-categories. Each of these four types is described in detail in this histology lab. By the date
of the lab exam, you must know the structure (S) and function (F) of each type, and understand
where in the body it is likely to be found (E). The descriptions in the lab also include, where
appropriate, special information or issues (I) that relate only to that tissue type.
        Your instructor will demonstrate each of these tissues using the 35 mm slides in the
carousels and/or videodisk images to help you become familiar with their unique, identifying
characteristics. You will then view glass slides of the tissues using your own microscope. Your
lab task is simply to review the glass slides again and again until you can name the tissue as you
see it in a microscope. However, it’s critical to know what you are looking for before you
attempt to view these slides in your microscope.       Begin by opening your Photo Atlas to the
correct photomicrograph listed with each tissue demonstration. Read the description of the
tissue in this lab and your text, and find the important regions or identifiers by attending to the
labels in the photomicrographs in the Atlas and on the posters on the wall. It is best to do this
activity with your partner; one of you might recognize an important feature or method of
identifying the tissue that the other does not! Remember that your textbook’s information is not
as thorough as that in an anatomy and physiology text, and so some of the required tissues
described in this lab are not found in your text. Therefore, it will be important to refer to other
sources to develop a complete understanding of histology. Consistent recognition of the slides
will require repeated viewing, so you are encouraged to spend extra time with the glass slides
and other support materials outside of class sessions. See the tutor or our science technicians to
check out a microscope, the 35 mm projector and slides.

J. Fiello; DVC Biology                     2003/2004                                            3
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 Each slide box contains specific types of tissue slides. Please check the handout and
    determine which slides you wish to look at.
 Take one slide at a time and return it to the box from which it came. (Please check the lid of
    the box to make sure you are putting it away correctly!)
 Remember to follow the appropriate storage and care restrictions whenever you use a

(S) Epithelial tissue is any tissue that lines or covers body cavities, surfaces, tubes or glands
    (sec. 20.4). Epithelium may be single- or multi-layered, and the cell shapes in the different
    subtypes vary (see summary figure on page 6). All epithelium:
       is avascular – it does not contain blood vessels, which means that epithelium does not
        contain a direct supply of nutrients and oxygen; it may, however, contain nerve endings
        (it may be innervated) and so may be directly capable of sensation. (Note: in some
        cases, the nerve endings are in other tissues below the epithelium.)
       consists of closely packed cells with specialized junctions.
       is formed of cells that have two distinct surfaces: the side of an epithelial cell next to the
        open space or surface is called the apical side, and the surface that is next to cells of a
        different tissue type is termed the basement side (see figures on the next page); the layer
        underneath the basement side of the epithelium is typically connective tissue, and since
        connective tissue (CT) usually contains blood vessels, the CT is typically the source of
        food and oxygen for the epithelial cells.
       the basement membrane, a matrix of polysaccharides and proteins underneath the
        basement cells of the epithelial layer, is secreted by both the epithelium and connective
        tissue under it; this layer (which is not a phospholipid bilayer) attaches the epithelium to
        the tissue underneath it (usually connective tissue).
       is made of cells that have a high regenerative capacity (i.e., they divide frequently by
        mitosis to replace dead cells); this feature ensures that epithelial tissue readily heals itself.
(F) The functions of epithelial tissue depend on the number of layers and types of cells in the
    particular tissue. They include covering, protecting, allowing for exchange, secretion, and
    sensation. Some epithelial cells have surface modifications on the apical side of epithelial

J. Fiello; DVC Biology                     2003/2004                                                  4
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    cells that face a lumen (the inside of a tube) which allow for special functions. For example,
    the apical surface of intestinal epithelial cells contain microvilli – microscopic foldings of
    the epithelial membrane – that increase surface area and thus increase the ability of these
    cells to absorb materials. Cilia – tiny hair-like structures on the apical side of respiratory
    cells – create a current that helps propel mucus.
(I) Epithelial tissue names include a description of the number of cell layers and the shape of the
    cells at the side of the tissue facing a lumen or outer surface. Section 20.4 in your text has
    diagrams of some of these types.
       The figure below demonstrates that epithelium composed of a single layer of cells is
        called simple epithelium, while multiple-layered epithelium is stratified. One type of
        epithelium has only a single layer of cells, but the varied shape of the cells makes it
        appear on first glance to be multi-layered. Since this epithelium appears multi-layered but
        is not, it is said to be pseudostratified (“falsely stratified”) epithelium.
                         Epithelial Layers                            Epithelial Cell Types

       Epithelial cells at the surface of the tissue take on the three characteristic shapes shown
        on the right side of the above figure. Squamous cells are flattened like pancakes or
        scales. They have a central nucleus and look like a mosaic from the surface. The cheek
        cells that you observed in the cell lab are squamous cells. Cuboidal cells are roughly
        cube-shaped in cross section and also have a central nucleus. Columnar cells are so
        named because they are long and tall (column-shaped) in cross section; their nuclei are

J. Fiello; DVC Biology                       2003/2004                                          5
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        usually found near the basement side of the cells. In stratified epithelium, the cells
        bordering the basement membrane may be differently-shaped than those on the lumen or
        surface side; it is always the shape of the cells bordering the space that is used to name
        the tissue.
Summary diagram of some of the epithelial tissue types:

J. Fiello; DVC Biology                   2003/2004                                             6
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         Listed below and on the following pages are the names, structures and functions of most
of the types of epithelium found in the human body. (Some rare types such as stratified cuboidal
epithelium have been eliminated). Remember that you will be asked to recognize each of these
types for the exam, and will need to identify at least one place in the body where each can be
found, as well as any special information that is relevant to the tissue type.

Simple Epithelium: (single layered for areas of minimal wear and tear)
Simple Squamous Epithlium (Sec. 20.4a, PM 9e, Cheek smear stained with methylene blue,
    A&P Box 4 Frog Skin, Carousel 3 spaces 1 - 5, poster):
    S: is composed of a single layer of flattened cells.
    F: ideal for transport (diffusion, filtration, osmosis) into underlying tissue layers since the
         layer is so thin.
    E: is found lining lung cavities, glomerulus and Bowman's capsule in the kidney, and
         capillary walls – all sites of transport.
    I:    Epithelium lining the heart and blood and lymph vessels is called endothelium;
         epithelium lining serous membranes (membranes of body cavities that do not open to the
         outside) is called mesothelium.

Simple Cuboidal Epithelium (Sec. 20.4b, PM 9f, A&P Box 3 Simple Cuboidal, Carousel 3
    spaces 7 & 8, poster,):
    S: is composed of a single layer of cube-shaped cells.
    F: provides a thin lining layer that often functions in secretion (exocytosis of materials built
         by the cell) and absorption (diffusion of soluble substances) into underlying tissues.
    E: is found on the ovarian surface, as part of eye lens and retina, lining kidney tubules (with
         microvilli for increased absorption), and in portions of small glands.

Simple Columnar Epithelium (Sec 20.4c, PM 10a, A&P Box 3 Simple Columnar, Carousel 3
    spaces 10 - 12, poster):
    S: is composed of a single layer of tall, long cells with basal, oval nuclei; some cells have
         cilia or microvilli at their apical surface; some simple columnar epithelium contains
         interspersed goblet (mucus-secreting) cells.

J. Fiello; DVC Biology                       2003/2004                                            7
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    Simple Columnar Epithelium cont.
    F: is thicker than squamous and cuboidal epithelium, so it provides some protection; surface
        modifications (cilia and microvilli), if present, allow for movement of material and
        improved absorption; if goblet cells are present, the mucus may trap materials (e.g., in the
        respiratory tract) or facilitate movement through the system (e.g., in digestion).
    E: is found lining the gastrointestinal (GI) tract (upper intestine has microvilli), gall bladder,
        excretory ducts of glands, upper respiratory tract (this region is ciliated), uterine tubes
        and some regions of the uterus, and the central canal of spinal cord.

Pseudostratified Columnar Epithelium (not in text, PM 10b, A&P Box 3 Pseudostratified
    ciliated columnar, Carousel 3 spaces 14 & 15, poster):
    S: is composed of one layer of cells, but not all of the cells reach from basement membrane
        to lumen; the nuclei are found at different levels and thus give the appearance that the
        tissue is multilayered, but it is not; goblet cells may be interspersed, and cilia may be
        found on the apical surface.
    F: like columnar epithelium, this tissue is somewhat thick, and so provides a small amount
        of protection; it may also function in secretion; if cilia are present, movement through the
        system is facilitated.
    E: can be found lining the excretory ducts of many glands, parts of male urethra, and the
        auditory tubes; the trachea and most of the upper respiratory tract are lined with ciliated
        pseudostratified columnar epithelium.

Stratified Epithelium: multiple layers are useful for areas of high wear and tear; fast
replacement of damaged tissue; remember that the name depends on the type of cell at the
surface or lumen side
Stratified Squamous Epithelium (Sec. 20.4d, PM 10d and 11a, A&P Box 3 Stratified
    Squamous, Carousel 3 spaces 17 - 22, A&P Box 4 Skin, Skin with hair Explanomounts,
    S: is multilayered, with flattened cells at surface (apical) side; cells next to the basement
        membrane are often cuboidal/columnar in shape; since the upper cells are far from the
        blood supply in the underlying CT, they do not receive nutrients and oxygen and

J. Fiello; DVC Biology                    2003/2004                                                8
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        dehydrate (shrink and harden) and die; the rapid mitotic rate of the basal cells pushes new
        cells out to replace the dead cells that fall off; in skin, surface cells are filled with the
        protein keratin that is waterproof and friction-resistant (PM 11.d and skin slides).
    F: the multiple layers make this tissue ideal for protection (keratinized cells provide extra
    E: is often found covering or lining where high wear-and-tear is expected; the upper GI
        tract, female urethra and vagina are lined with non-keratinezed stratified squamous
        epithelium; skin is keratinized.

Stratified Cuboidal Epithelium (not in text, PM 10c, no glass slide):
    S: is composed of two (or more) layers of cubes; is rare.
    F: provides a small degree of protection due to the multiple layers.
    E: is found in large sweat gland ducts, eye fornix, male urethra, mammary glands, salivary

Stratified Columnar Epithelium (not in text, not in PM, no glass slide)
    S: is multilayered with columnar cells at lumen/surface; polyhedral cells underlie the apical
        cells; is also rare.
    F: functions in protection and secretion.
    E: is found in male urethra, large excretory ducts of some glands, small areas of anal
        mucous membrane.

Transitional Epithelium (not in text, PM 11 b & c, A&P Box 3 Transitional, Carousel 3 spaces
    24 & 25, poster):
    S: looks similar to nonkeratinized, stratified squamous with outer layer of large and rounded
        cells (structure of surface cells varies with degree of organ stretch).
    F: is distendable and stretchy, for lining areas that expand (when the cells are stretched, the
        surface cells lose their cuboidal appearance and look more like squamous cells).
    E: is found in the urinary bladder, ureters and urethra and parts of uterus.

J. Fiello; DVC Biology                     2003/2004                                              9
NAME ________________________________CLASS ________________________________

Glandular Epithelium
A gland is group of cells or a single cell (e.g. a goblet cell) that secrete (produce and release)
a specific product. Often, multi-cellular glands are composed of clusters of cells that are
deep to the covering epithelium (i.e., part of the gland is often in the connective tissue). If
the gland releases its product to the surface the epithelium covers (e.g., a sweat gland) or to
the lumen the epithelium lines (e.g., a gland producing digestive enzymes), ducts carry the
products from the base of the gland to the opening. Glands that secrete their products into
ducts/tubes that empty at surface/lumen are called exocrine glands. Endocrine glands
secrete their products (typically hormones) into the blood stream; these hormones then
regulate body functions. The pituitary, thyroid, parathyroid, adrenals, ovaries and testes,
and thymus glands are examples of endocrine glands.CONNECTIVE TISSUE = CT
        There are many types of connective tissue (sec. 20.5) ranging from the material that
literally connects your muscles to your bones (your tendons), to blood and bone that do not
connect one part to the other in the formal sense. The figure below shows some of the more
prevalent subtypes found in the connective tissue category.

J. Fiello; DVC Biology                  2003/2004                                              1
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        These tissues are grouped together because of their similar developmental origin. The
subtypes also share many structural features. The figure on the next page identifies the primary
types of connective tissue, and shows their shared developmental origin. Note that they are all
derived from an embryonic tissue called mesenchyme. After mesenchyme cells divide in the
fetus, they differentiate by turning on selected genes and producing the proteins that allow these
cells to take on their unique functions.

J. Fiello; DVC Biology                     2003/2004                                           1
NAME ________________________________CLASS ________________________________

(S) Unlike epithelium, most connective tissue is highly vascular (i.e., there are many blood
    vessels found in the tissue). Recall that the blood in the connective tissue is the source of the
    food and oxygen for the epithelium above it. There is, however, a range of vascularity in the
    different connective tissues. Cartilage, for example, contains no blood vessels, but loose
    connective tissue proper is highly vascular. The prevalence of blood is correlated to the
    ability of the connective tissue to heal itself when injured. Unlike epithelium, connective
    tissue is typically composed of scattered cells plus a lot of cellularly-produced matrix or
    ground substance. The molecular matrix surrounding the cells determines the specific
    structure and function of the tissue, so you must know the names and qualities of the cells
    and of the matrix in each type of connective tissue. Blood matrix (plasma), for example, is
    fluid and designed to carry dissolved molecules, while calcium and proteins found in your
    bone matrix results in their hardness. Different fibers give connective tissue types unique
    properties as well.

J. Fiello; DVC Biology                    2003/2004                                               1
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(F) Connective tissues (CT) have many different functions including protecting, supporting,
    binding, separating, storing energy reserves, and transporting materials. As with epithelium,
    it is most important to understand the function of each of the sub-categories.
(I) All connective tissues are derived from the same embryonic tissue; all have some type of
    matrix, cells and fibers. The matrix or ground substance is non-cellular. It fills the spaces
    between the cells and contains fibers, fluid and dissolved molecules. The cells secrete matrix
    and are living component of connective tissues. They are active especially in repair of
    damaged CT. Learning the following consistent prefixes and suffixes will help you identify
    the cell types of each CT:
            -blast = precursor cell                           adipo = fat
            -cyte = fully formed and functional cell          chondro - cartilage
            -clast = destructive cell                         osteo = bone
                                                              fibro = fiber
           So, for example, an osteoblast is a cell that is destined to become a bone cell, and a
            chondrocyte is a mature cartilage cell. A fibroblast is a cell that produces fibers.
There are three important types of fibers typically found in CT matrix. Collagenous (white
fibers) occur in bundles of parallel minute fibrils made of protein collagen. These fibers are
resistant to stretching and thus provide high tensile strength. They are somewhat flexible. Your
tendons and ligaments are composed primarily of collagenous fibers. Elastic (yellow fibers) are
thinner than collagenous fibers and are often branch. They are composed of the protein elastin,
which provides some strength and great elasticity. Reticular fibers are thin/fine and form
branching networks like webs that give some support and structure to many soft organs such as
your liver or kidneys.The figure below of areolar connective tissue (which is also called loose
connective tissue proper) serves as a model for the basic structure of connective tissues.
Multiple types of fibers and cells are surrounded by a ground substance or matrix.

J. Fiello; DVC Biology                    2003/2004                                                1
NAME ________________________________CLASS ________________________________

Embryonic CT/mesenchyme is found primarily in the fetus; differentiation of these cells gives
rise to all the types found in the adult (not in text, PM 12a, Carousel 1 spaces 1 - 4, Box 10 CT
Dev - mesenchyme sec):
        S: the cells are highly branched and star-shaped; the matrix is fluid (this tissue lacks the
            unique, defining characteristics of other CT types such as cartilage, bone or blood).
        F: is the precursor of all other CT types; it also produces fibroblasts for healing.
        E: is present under the skin and along the developing bones in the fetus; in the adult, it is
            present in other CT.
    Mucous CT (Wharton's jelly):
        S: the cells are flattened or spindle shaped; the matrix is mucus-like with fine collagenous

J. Fiello; DVC Biology                    2003/2004                                                 1
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        F: supports wall of umbilical cord.
        S: is found only in the fetal umbilical cord.

Adult Connective Tissues:
The following types of CT (areolar, adipose, fibrous and reticular CT) are all grouped into a
general category called Connective Tissue Proper. In these cases, the fibroblast cells that
produce the matrix and fibers found in the matrix are large & flat with branching processes. The
matrix is mostly fluid. These CT all differentiated from mesenchyme CT; the cells do not de-
differentiate after birth.

Loose CT Proper = Areolar CT Proper (Sec. 20.5a, PM 12b, Box 7 Areolar tissue spread film/
    sec, Carousel 1 spaces 6 - 8, poster):
    S: the cells are scattered fibroblasts; some blood cells (macrophages; mast cells) will be
        found in vessels in the matrix or moving directly though the matrix; the matrix is a
        viscous fluid with loose network of collagenous and elastic fibers.
    F: attaches the skin to underlying muscles, supports internal organs, blood vessels and
        nerves, and wraps and cushions organs; white blood cells (WBC) like macrophages in the
        matrix phagocytize bacteria; the collagenous fibers are hydrophilic, so this tissue also
        functions as a water/salt reservoir.
    L: is found under the epithelium in “skin”, and around organs and capillaries.

Reticular CT (CT Proper) (not in text, PM 14b - d, Carousel 1 space 18, poster)
    S: the reticular cells are found in a web-like network of reticular fibers; the loose matrix is
        similar to that of areolar CT.
    F: provides a soft, internal “skeleton”-like structure to support other cells such as blood
    L: is found in lymphoid organs (lymph nodes, bone marrow, spleen).
Adipose (CT Proper) (Sec. 20.5b, PM 13c - e, Box 7 Adipose tissue, Brown Adipose, Carousel
    1 spaces 20 - 22, poster):
    S: fat cells (adipocytes) contain triglyceride molecules in a large, central vacuole; the cells
        are closely packed so there is little matrix, but what’s there is similar to that of areolar
        CT; this tissue is highly vascular (since blood brings fat molecules to and from the cells).

J. Fiello; DVC Biology                       2003/2004                                            1
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    F: stores excess nutrients as fat, cushions internal organs, and insulates the body for warmth.
    L: is found under the skin, around some organs, in bones (esp. of an adult), and in breasts.
Dense, Regular/Fibrous CT Proper (Sec. 20.5d, PM 12d, Box 7 tendon teased, white fibrous
    CT ls, muscle tendon connection, Carousel 1 spaces 10 - 11, poster):
    S: the fibroblast cells are tightly packed in rows between parallel bundles of collagenous
        fibers (look for difference in nuclei vs. smooth muscle – collagenous fibers are not cells
        and do not have nuclei, so you’ll only see nuclei between the fibers here); there is little
        matrix; the tissue is poorly vascularized (so it doesn’t heal quickly).
    F: provides a strong attachment of bones to muscles, bones to bones, and muscles to
        muscles; this tissue withstands great tensile stress in one direction.
    L: is found in tendons, ligaments, and aponeuroses (flattened sheets of CT on the skull).
Dense, Irregular CT Proper (not in text, PM 12, Box 5, 6 Skin slides (under the stratified
    squamous epithelium, Carousel 1 spaces 17 - 22):
    S: like dense, regular CT, there are tightly-packed fibroblast cells and fibers with little
        matrix; the collagenous fibers, however, are irregularly arranged.
    F: withstands stress in many directions (vs. dense regular CT proper, that withstands stress
        in one direction)
    L: is found in the dermis (deep layer) of the skin and in fibrous capsules around many
        organs and joints
Elastic CT Proper (not in text, PM 13a,b Box 12 Artery and Vein cs, Carousel 1 spaces 13 -
    S: contains fibroblasts that produce elastic fibers as well as collagenous fibers; the matrix is
        similar to that of dense, regular and dense irregular CT.
    F: the elastic fibers provide additional durability and stretch to the tissue.
L: is found in the aorta wall, walls of other large arteries, parts of trachea and bronchi, vocal
    cords, and ligaments which connect vertebrae.Adult Connective Tissues cont.: due to their
    unique matrix and/or cell qualities, these are not grouped into the CT Proper sub-category.
Cartilage (Connective Tissue) (Sec. 20.5e, PM 15a, b, A&P Box 5, Hyaline cart. H&E and
    trachea, Carousel 1 spaces 24 - 27, poster):
    S: all cartilage types contain chondrocytes (mature cartilage cells) found lacunae (holes); as
        the chrondrocytes mature, they secrete a firm, homogeneous, gel-like (bluish-white)

J. Fiello; DVC Biology                    2003/2004                                                1
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        matrix with “invisible” collagen fibers around themselves, which results in the final
        placement in the lacuna. Hyaline cartilage matrix appears blue and glassy. Elastic
        cartilage contains black, branching elastic fibers in the matrix. Extra collagenous and
        elastic fibers in fibrocartilage can be seen with special stains; a piece of fibrocartilage
        has the consistency of a car tire.
    F: Hyaline cartilage protects bones at joints, attaches the ribs to the sternum, forms part of
        the nose and supports the walls of air passages (it holds the airway open) and provides a
        pattern for bone development in the fetus; the support and protection in these areas is due
        to the resilient cushioning provided by the collagen. Elastic cartilage provides some
        support and structure but is very flexible. Fibrocartilage is very strong and somewhat
        flexible and so acts as a protective shock absorber.
    I: Hyaline cartilage is found at the tip of your nose, between the bones of many of your
        joints, in the walls of your trachea; it also comprises the embryonic skeleton and
        epiphyseal plates (bone replaces cartilage in development and in long bone growth).
        Elastic cartilage is found in the external ear (consider how it provides a flexible shape to
        this area) and epiglottis. Fibrocartilage composes the intervertebral disks (the disks
        between the vertebrae in your spine), and forms the cartilagenous pads in the knee joint
        and the cushion between the symphysis pubis.

Bone (Connective Tissue) (Sec. 20.5f, PM 16 a - d, A&P Box 6 Bone, dry ground human cs,
    Carousel 1 spaces 41 - 50, 2 posters). Identify Compact Bone only (You will examine bone
    in more depth with the skeletal system in Bio 201):
    S: Osteocyte cells are found in lacunae, as chondrocytes are in cartilage; canaliculi (tiny
        canals that extend from the lacunae) contain the osteocyte processes and allow the cells to
        "feed" from the blood; the matrix is composed of hard calcium phosphate which is
        deposited on proteins in lamellae (rings); a central Haversian canal contains blood
        vessels and nerves; a set of lamellae etc. is called a Haversian system.
    F: Compact bone forms the sides and surfaces of the skeleton that provides support for the
        body and protection for vital organs, and allows for movement when connected to
        muscle; blood develops in hollow cavities within bones and in smaller spaces between

J. Fiello; DVC Biology                       2003/2004                                           1
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        the spongy bone process that are found in your flat bones and at the ends of your long

Blood (Connective Tissue) (Sec. 20.5c, PM 93 a - g, A&P Box 8 Blood smear Wright (also
    Giesma stain and with arteries and veins on the artery/vein slide), Carousel 1 spaces 52 - 60,
    2 posters. (You will study blood in depth with the cardiovascular system in Bio 201.):
    S: There are three categories of blood cells: the numerous red blood cells are flattened with
        a thinner center than edge and have no nuclei; these cells carry oxygen. White blood
        cells are rarer and have differently-shaped nuclei; these cells comprise part of your
        infection/disease fighting system. Platelets are small cell “chips” (they do not have a
        nucleus) which function in clotting. Blood plasma is the fluid matrix of this connective
        tissues. Dissolved nutrients, wastes, gasses, clotting proteins, and hormones are found in
        the plasma.
    F: Blood carries materials/information throughout the body and helps prevent many
        diseases. Small injuries to blood vessels are often healed due to the action of blood

    This section provides a brief introduction to the three types of muscle: skeletal, cardiac and
smooth muscle (sec. 20.6). A diagram below shows the identifying structural variations in the
cells of the three important muscle types, and demonstrates where they can be found.

J. Fiello; DVC Biology                   2003/2004                                             1
NAME ________________________________CLASS ________________________________

You will study muscle tissues in greater detail in Bio 201, so this section is relatively brief.
    There are chapters devoted to studying skeletal muscle structure and function, and the
    cardiovascular system chapter contains a detailed discussion of heart (cardiac) muscle
    structure and function. Smooth muscle is reviewed in many systems such as the digestive
    system in Bio 202.:(S) Muscle tissue is the only tissue in your body that is contractile (it can
    shorten on demand). Contraction occurs when proteins (actin and myosin) within muscle
    cells grab on to each other and pull together in a process that requires a significant energy
    expenditure. Thus muscle cells must produce a lot of ATP to power this work. (What ATP-
    producing organelle is likely to be found in high numbers in muscle cells?) Muscle cells

J. Fiello; DVC Biology                   2003/2004                                               1
NAME ________________________________CLASS ________________________________

    have lost the ability to divide, but will add contractile proteins and thus become thicker cells
    when demand increases.
(F) Muscle tissues do many different types of work. Skeletal muscles allow for movement and
    support.    Shivering (rapid contraction of these muscles) produces heat for temperature
    regulation. Cardiac muscle in your beating heart ensures that blood will be transported
    throughout the body.     Smooth muscle contracting in the walls of your esophagus and
    intestine moves food through your gastro-intestinal tract.

Skeletal Muscle (Sec. 20.6a, PM 20 a-c, 21 a-c, A&P Box 9 Muscle composite, teased skeletal,
    muscle tendon connection, Carousel 2 spaces 1 - 10, poster).
    S: Skeletal muscle is any muscle attached to a bone. Skeletal muscle cells are crossed with
        striations (alternating dark and light bands - see sarcomere structure in model); unlike
        other cells, they have peripheral, multiple nuclei.
    F: Skeletal muscle contraction is voluntary and fast to moves bones/body

Cardiac (Sec. 20.6b., PM 22 a-b, A&P Box 9 Muscle composite, intercalated disks heart; 35mm
    space 42, 43, 44, 45; Carousel 2 spaces 12 - 17, poster
    S: in the heart; looks similar to skeletal (it's striated), but has intercalated disks between
        the cells; each cell has a single, central nucleus
    F: heart muscle contraction; involuntary, rhythmic contractions (circulation)

Smooth Sec. 20.6c, PM 22 c-e, A&P Box 9 Muscle composite, smooth muscle cs and ls; 35mm
    space 40, 41; Carousel 2 spaces 19 - 21, poster).
    S: cells are elongated, tapered, non-striated with a single, central nucleus; lines GI tract
        and other hollow, internal organs and blood vessels
    F: involuntary, slow contraction
You'll study nervous tissue in depth when you focus on the nervous system in Bio 201, so this
section is also brief.
(S) Nerves are bundles of nerve cells (neurons) along with surrounding cells (neuroglia) that
    perform a variety of tasks that facilitate the functioning of the entire body. We’ll focus today

J. Fiello; DVC Biology                    2003/2004                                              2
NAME ________________________________CLASS ________________________________

    on the structure and function of a single neuron (see fig 3.20). Nerve cells typically contain
    three important regions. The cell body contains the nucleus and many of the organelles (e.g.,
    SER and RER, mitochondria). Two types of long, thin processes extend from the cell body.
                                                         Two types of processes extend from the cell
                                                         body. Dendrites receive information from the
                                                         outside world (e.g., in sensory neurons) or
                                                         from other neurons.       Most neurons have
                                                         multiple dendrites. A typical neuron contains a
                                                         single axon that transmits a signal (an action
                                                         potential) down its length. When the action
                                                         potential reaches the end of the axon,
                                                         neurotransmitters are released from the ends
                                                         of the axon; these molecules transmit the signal
                                                         to the next neuron, muscle or gland.       This
                                                         connection with the next cell is called a

The processes identified in the figure below synapse. In sum, the signal travels from the
are either axons or dendrites. Though these end of the dendrite to the cell body and down
processes    carry       information   in   different the axon to a synapse with the next cell in line.
directions, they are indistinguishable in slides.

(F) Nerve tissue is excitable: electrical signals travel along neurons, and these signals are
    transmitted to other neurons or effector organs (muscles, glands) via chemical signals to
    allow for sensation, rapid transmission of information, stimulation of muscle cells that
    initiates their contraction, and storage of information.

Neurons: (Sec. 20.7)., PM 24 a-c, 25 a-c, 26c, 28d, Neuron models, A&P Box 10 Giant
multipolar neurons, motor nerve ending, cerebral cortex and cerebellum; 35mm space 47, 48, 49,
50; Carousel 4, poster)

       For the lab exam, be able to identify the parts of a “generic neuron”; focus on slides or
        perkinje cells, giant, multipolar neurons and motor neurons.

J. Fiello; DVC Biology                       2003/2004                                                2

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