Docstoc

faculty ucc edu biology potter Connective tissue

Document Sample
faculty ucc edu biology potter Connective tissue Powered By Docstoc
					          The Connective Tissues

         PREPARED BY HUGH POTTER, Ph.D
                BIOLOGY DEPARTMENT
              UNION COUNTY COLLEGE




All images derived from the video disk Slice of Life with the
permission of the publisher.
Connective Tissue - Introduction
 The connective tissues bind, protect and support the body.
All connective tissues have three characteristics in common:

1. Cells such as fibrocytes, chondrocytes and osteocytes.

2. Three principal types of fiber found in connective tissues.
  A. Collagen - abundant in tendons and bones.
  B. Elastic fiber - found in the walls of arteries and in
     flexible cartilage like the epiglottis.
  C. Reticular fiber is the support material of soft organs
     like the spleen and liver.

3. Ground substance, a complex mixture of organic and
   inorganic materials, fills the spaces between the cells and
   fibers.
          Mesenchyme
Mesenchyme is the first connective
tissue to appear in the embryo. All
other connective tissues arise from
mesenchyme by a process known as
differentiation. The image to the right
shows a very early fetal stage. The
asterisk labels a region filled with
mesenchyme.
                                          *
       Mesenchyme cells appear to have fine
projections and are separated from one another by a
ground substance that contains delicate protein
fibers. Many adult connective tissues such as bone
and cartilage contain remnants of mesenchyme
which permit repair and growth of the adult tissues.
       Connective Tissues -Types

Liquid Connective Tissue – The Blood
LOOSE CONNECTIVE TISSUES
  1. ADIPOSE
  2. AREOLAR
DENSE CONNECTIVE TISSUES
  1. DENSE FIBROUS TISSUE - TENDON
  2. SUPPORT CONNECTIVE TISSUES
    A. CARTILAGE
    B. BONE
            Blood
Blood is considered to be a
fluid connective tissue. It
consists of formed elements or
cells and a liquid ground
substance called plasma. The
cells are primarily erythrocytes
(RBC’s) and leukocytes
(WBC’s). Fibers are only found
in the blood during the process
of clotting.
              ADIPOSE TISSUE
• Adipose tissue is a loose
  connective tissue. It is
  located throughout the
  body. It is especially
  common in the
  subcutaneous region
  beneath the dermis where
  it provides insulation
  against heat loss. Fatty
  tissue also stores
  nutrients and vitamins
The adipocytes, the cells of
adipose tissue account for most
of the volume of fatty tissue.
Adipose cells are very active
metabolically. When we fast, the
cells deflate like spent balloons
as the oil stored in the center of
the cell is broken down for
energy. The adipocytes remain
intact and can refill with lipid
with an increase in nutrient
uptake.                              Sub dermal Adipose Tissue
  AREOLAR CONNECTIVE TISSUE

• Areolar connective
  tissue is the most
  abundant connective
  tissue is the body. It is
  commonly found in the
  papillary region of the
  dermis of skin and in
  the lamina propria of
  mucous membranes.
        Areolar conntective tissue
contains a very fluid ground
substance. It also has a high
concentration of elastic fibers
which allow this tissue to return
to its original shape following
pressue or pinching.
        Areolar tissue contains
almost all of the cell types
found in any connective tissue.
Mesenchymal cells, fibroblasts,
macrophage, adipocytes,
melanocytes and leukocytes are
found in areolar tissue.
• Tendon is a dense fibrous    TENDON
  tissue in which the fibers
  are oriented in parallel.
  The fibers are
  predominantly collagen
  and organized as primary
  tendon bundles grouped
  together as fascicles.
  Blood vessels and nerves
  do not enter the fascicle.
  Tendons are designed to
  withstand great tension
                                          Perichondrium
            Cartilage
        Cartilage is set apart from its
surrounding tissues by a dense
covering layer called the
perichondrium. The perichondrium
is divided into two layers, the fibrous
portion and the inner cellular layer.
        New cartilage cells called
chondrocytes arise from the cellular
layer. These young cells produce the
gel-like ground substance of cartilage
which is rich in a polysaccharide
derivative called chondroitin sulfate.
       Chondrocytes occupy
small chambers in the matrix of
cartilage called lacunae.
       Cartilage is avascular.
This lack of blood vessels is due
                                    lacunae
to the production of a
compound by the chondrocytes
called anti-angiogenic factor
(AAF). This substance inhibits
the growth of blood vessels into
cartilage. AAF is being tested as
an anti-cancer drug.
• Hyaline Cartilage
  contains fiber in its outer    HYALINE
  layer, the perichondrium.
  Chondroblasts arise from      CARTILAGE
  the perichondrium. As
  the cartilage ages, the
  cells appear in clusters of
  2, 4 or 8. The matrix
  consists primarily of
  chondroitin sulfate.
  Hyaline cartilage can be
  found at the articular
  ends of long bones, as
  well as the trachea,
  bronchi and larynx.
              FIBROCARTILAGE
• The matrix of fibrocartilage
  shows a preponderance of
  coarse collagenous fibers
  arranged in bundles.
  Cartilage cells are arranged
  between collagenous
  bundles often in rows. This
  cartilage lacks a
  perichondrium.
  It is found in the intervertebral disks, pubic symphysis
  and the lining of tendon grooves. Fibrocartilage is
  always found merging with neighboring hyaline cartilage
  or fibrous tissue.
•
    Elastic cartilage is very
    similar to hyaline cartilage
                                    ELASTIC
    except that it contains        CARTILAGE
    abundant elastic fiber in
    the matrix. Unstained, it
    has a yellow color due to
    the elastic fiber. It is
    located in the auricle or
    external ear and the
    eustacian tube. In the
    larynx, elastic cartilage
    forms the epiglottis, the
    corniculate, cuneiform and
    the arytenoid cartilages.
             COMPACT BONE
• Compact bone is a dense
  connective tissue. The
  Haversian systems can be
  seen in this view.
  Osteocytes are arranged
  in concentric rings around
  the central Haversian
  canal. Fine, thread-like
  canaliculi can be seen.
  Compact bone is found
  around the shafts or
  diaphyses of long bones
COMPACT BONE-Haversian canals
• Compact bone consists of
  bone matrix laid down in    Haversian Canals
  concentric layers called
                                         oc
  lamellae. The lamellae         oc
  surround a central
  Haversian canal(Hc)
  which contains blood
  vessels, nerves and
  lymphatics. Very delicate             oc
  thread-like lines can be
  seen connecting the black
  osteocytes (oc)with the
  Haversian canal.
                                     oc

       In this view of a
Haversian system, the
fine thread-like
canaliculi can be seen
connecting the                  Hc
osteocytes (oc) with the   oc
Haversian canal (Hc)

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:81
posted:8/20/2011
language:English
pages:19