Connective Tissues
Directions:
Insert and install your Interactions: Foundations CD.
a. Click the "Contents" button.
b. Open the Tissue Level of Organization file.
c. Click on Anatomy Overviews.
d. Work through Connective Tissues.
Complete the following worksheet and add it to your notes.
Interactions Foundations CD/Contents/Tissue Level/Anatomy Overviews/Connective Tissues
1. What are the functions of connective tissue?
to connect and bind other tissues and organs together. They
provide structural and nutritional support, maintain form and
shape, provide insulation & protection for the body. It also
defends the body against harmful agents.
Cell Matrix
2. Describe the function of fibroblasts.
Fibroblasts are cells that synthesize the components of the
connective tissue matrix including the protein fibers and
ground substance.
3. What is ground substance? What is its function?
Ground substance is the component of connective tissue between the cells and the fibers
It provides a support medium for the exchange of substances between the connective
tissue cells and blood and it resists compression.
Identify the function for each type of connective fiber:
Reticular –
a fiber that provides a supportive framework or stroma for organs like the liver, spleen
lymph nodes and bone marrow as well as help form basement membranes.
Elastic can stretch to 1 ½ times their length and recoil back like a rubber band. They also add
strength and stability,
Collagen Collagen fibers are strong yet flexible, providing resistance to tension stretch and
pressure.
4. Using the text as a guide, identify the cells found in connective tissue:
fibroblasts most numerous cells that are large flat cells with branching process. They are
present in several connecting tissues, They migrate through connectice tissue and secrete
fibers and ground substances of the extracellular matrix.
macrophages are a type of white blood cell known as monocytes. Have an irregular
shape. Engulf bacteria and cellular debris by phagocytosis. Wandering macrophages can
move through out the tissue. Fixed Macrophages reside in a particular tissues
plasma cells -are small cells that develop from a type of white blood cell called B
lynphocytes.
Plasma cells secrete antibodies, they are an important part of the immune response.
Although found in many places in the body most reside in connective tissue. They are
also abundant in bone marrow, spleen, salivary glands and lymph nodes.
mast cells - are abundant along side blood vessels that supply connective tissue. They
produce histamine a chemical that helps the body react to injury or infection. They can
also bind and ingest bacteria.
adipocytes - also known as fat cells. They are connective tissue that store fats. They are
found deep in the skind and around organs such as heart and kidney used for insulation
and protection
white blood cells – are not found in great numbers in connective tissue. Some gather at
the site of infections while others will migrate to site of parasitic invasion.
Loose Connective Tissue
5. Identify each tissue type, by sight. You are expected to identify these tissues and will be asked to do so on
your tests. Note how the fibers are "loosely" arranged between the cell types.
Areolar - Areolar tissue is found in the subcutaneous
(under the skin) layer.
Adipose - These are our "fat cells." They are found
anywhere areolar tissue is found. Adipose tissue is our
stored energy reserves, insulates us from temperature
extremes, and, it is an excellent protective cushion.
Reticular - Reticular tissue forms the supporting structure,
or stroma, of many organs. This function is much like the
internal beams supporting a house or building.
Dense Connective Tissue
6. Identify each dense connective tissue type, again, by sight.
Note how these tissues contain more numerous, and thicker,
fibers arrayed densely among considerably fewer cells.
Dense Regular - Found in tendons and ligaments, this
tissue can withstand tension along the axis of the
fibers. Lateral tension can result in tears or strains.
Dense Irregular - Generally found in sheets underlying
the epidermis (skin). This tissue withstands pulling
forces from various directions.
Elastic - Found in the lungs and elastic arteries, this
tissue can recoil to its original dimensions after
stretching.
Cartilage
7. First, consult your text to identify the following and determine what they do:
Chondrocytes -are the cells of mature cartilage. They occur alone or in groups within the spaces called
lacunae .
Lacunae – small spaces in the extra cellular matrix.
Perichondrium - a membrane of dense irregular connective tissue
8. Examine each type of cartilage from the CD. Once again, learn to identify these by sight.
9. Cartilage matrix consists of a dense network of collagen and elastic fibers embedded in chondroitin
sulfate, a rubbery component of the ground substance.
Cartilage withstands more stress than either loose or dense
connective tissues.
Hyaline - This is the most common cartilage in the
body. It provides flexibility, support, cushioning, and
reduces friction at the joints. The fine collagen fibers are not visible with ordinary staining
techniques. Due to its level of flexibility, hyaline cartilage is the weakest of the cartilage types.
Fibrocartilage - Found in the inter-vertebral discs,
fibrocartilage combines strength and rigidity to be the
strongest of the cartilage types. Collagen fibers are
clearly visible between the chondrocytes.
Elastic - Found in structures needing strength and
elasticity, like the outer ear, elastic cartilage is the most
flexible of the three types. Elastic fibers are visible
between the chondrocytes.
Bone (Osseous) Tissue
10. Examine the following on your CD. Remember, click on the red words to progress for more information
on that structure.
Compact Bone - Define or describe each of the following for
compact bone:
Compact bone function - Supports soft tissue, protect
internal organs, acts as a lever during muscle contraction,
storage of calcium and phosphate, resists stresses
produced by weight & movement
Osteon - a structural unit of compact bone, aligned in the same direction along the stress lines
Lamellae - ring shaped layer of collagen and calcified matrix within the osteon.
Lacunae is the space between the lamellae housing an osteocyte.
Haversian Canal – also known as the “central canal” It is the central region of an osteon, it
contains blood vesels and nerves.
Canaliculi are small tunnels connecting lacunae : provides a pathway for the exchange between
osteocytes.
Osteocyte – is a cell that maintains bony tissue
Spongy (Cancellous) Bone - Again, define or describe each of the
following:
Function To support and protect red bone marrow.
Trabeculae - is the structural unit of spongy bone. They
are in an irregular lattice shape.
Space provided in between the Trabecule structure to holed red bone marrow.
Blood Tissue
11. It may be difficult to think of blood as a tissue because it is fluid. It is a connective tissue, however, with
two basic types of cells suspended in a fluid matrix. It clearly "connects" to every part of our body, too!
Using your CD, identify each of the following and determine their
function(s):
Plasma The matrix of the blood, mostly water but also
contains sugars, protein, gas and ions.
RBCs (erythrocytes)
Transporst oxygen to the tissues.
WBCs (leukocytes) responds when the body in invaded by microrganisms
Platelets - plays a major role in blood clotting
Embryonic Connective Tissue
12. Using the CD, determine what embryonic connective tissue is.
Although you do not need to identify these two tissues by sight,
you do need to describe the functions of each:
Mesenchyme - has a loose irregular appearance with
reticular fibers, irregularlt shaped cells and a semifluid
groud substance. Gives rise to all adult epithelial and
connective tissue
Mucous c.t. (Wharton's jelly) has fibroblasts that are embedded within a matrix containing
collegen fibers and a gel lik ground substance. It provides support