Human Anatomy & Physiology
3/8/2016
03A.2 Connective Tissue
Connective Tissue Characteristics:
1. More matrix than cells
2. Fibers running through the matrix
3. Vascularity varies with different connective tissues
4. Cells are named by the tissue they make
Types of Fibers:
Collagen fibers
 These are one of the strongest proteins the body makes.
 It is formed (through protein synthesis) by the cell.
 Vitamin C and the mineral copper are needed to form strong
collagen fibers.
 They are known as White fibers.
Reticular fibers
 These are the tiny versions of collagen fibers.
 They look like spider webs and are found throughout the body
anchoring tissues to one another.
Elastic fibers
 These fibers can do what collagen cannot do...which is return to
their original position once they have been pulled or stretched.
 These fibers are known as Yellow fibers.
Vascularity
 The more concentrated the matrix is with fibers the less room for
Blood vessels.
 The bone tissue matrix creates canals for blood vessels to enter
and feed the tissue because the matrix is compact and hard.
 Loose ct is very vascular and heals quickly.
 Dense ct is less vascular and is a slow healer.
 Cartilage is non-vascular because the matrix is so full and thick.
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 Any tissue that is non-vascular has to be fed by diffusion.
 Osseous (bone) is very vascular because of the canals that are
formed in the matrix for blood vessels to travel and deliver
nutrients.
 Hemo (blood)...well. it goes without saying...it is blood so it is as
vascular as you can get!
Cell types:
If the prefix of the cell’s name is:
 Fibro- ‘I am connective tissue proper!’
 Chondro- ‘I am cartilage!’
 Osseous- ‘I am bone!’
 Hemo- ‘I am blood!’
o The cell’s prefix gives away the type of tissue it belongs to.
If the suffix of the cell’s name is:
 -blast: ‘I make or form the tissue.’
 -cyte: ‘I maintain the tissue.’
 -clast: ‘I break down the tissue.’
 Bone will be the only tissue that has this cell.
 The cell’s suffix gives away the cells function in the tissue.
Types of Connective Tissue
1. Connective Tissue Proper
1.1 Loose Areolar CT
Leave 5-7 lines for a DIAGRAM
A. Fibroblast
 These cells are creating the tissue
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B. Collagen fibers
 thick white fibers that are very strong and are made
by the fibroblast through protein synthesis
C. Capillary
 the more room in the matrix the more blood vessels
will be found
D. Mast Cell
 This is a type of white blood cell (basophile when in
the blood) commonly found in CT. This cell can
release histamine, which stimulates goblet cells OR
(not both) releases heparin, which is an
anticoagulant (prevents blood clotting). These
substances help the immune system to respond to
damage in the area.
E. White Blood Cell
 These WBC can be neutrophils (the most common
fighter or foot soldier of the immune system) or
monocytes (very large macrophages that help fight
long term infection and clean up messes!)
F. Reticular fibers
 small collagen fibers secreted by fibroblasts
 (These fibers make up the basement membranes and
look like spider webs.)
G. Matrix or interstitial fluid
 fluid filled spaced found between the cells
 (CT has fibers running through this space.)
1.1 Loose Areolar CT
 Refer to the last diagram you made
 Look! Lots of space for blood vessels! Very Vascular
Spaces in the matrix can be used to take in extra fluids
(edema)
 & act as a cushion for the tissue sitting on top of the CT.
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 This is a common CT found under skin because of its
vascularity and high nutrient content.
 When the skin suffers a 3rd degree burn, the wound oozes
with this fluid and nutrients from this connective tissue.
1.2 Adipose Tissue
 A.k.a. (our friend, FAT!)
Leave 3-5lines for a DIAGRAM
 Notice how these cells have a large vacuole in the center that
store triglycerides.
 If these cells are cut in a cross section (x-section), they look
like honeycombs or chicken wire.
 Rule Breaker! This tissue has cellularity.
 This tissue is very vascular.
 An example of how vascular this tissue can be: ‘for every
pound of fat there can be up to a mile of blood vessels.’
 Liposuction (a procedure to remove fat) can be life
threatening if too much fat tissue is removed.
 When removing adipose tissue, the doctor must measure
the amount of tissue and fluid being removed.
 If too much is removed, the blood pressure and fluid
levels can send a patient into shock and possible death.
 This tissue can be increased as calories are taken in and not
used (which is a common problem in the U.S.)
 OR decreased as the tissue’s storage is used to supply extra
energy when more calories are needed without the food
intake.
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1.3 Loose Reticular CT
Leave 3-5 lines for a DIAGRAM
 This tissue makes up the framework of non-hollow organs
such as the spleen, liver, & lymph nodes.
 This is a picture of a lymph node. (Look at all the WBC’s.
Lymph nodes are the home to many types of WBC’s!)
 This tissue is also very vascular because the lymph system
drains through the lymph nodes in order to filter the lymph,
which will become plasma once it is dumped into the vena
cavas!
1.4 Dense Irregular CT
Leave 3-5 lines for a DIAGRAM
 Notice how this matrix is PACKED with fibers!
 This doesn’t leave much room for blood vessels.
 Vascularity and healing are much slower with dense CT!
 The fibers run in ALL directions, which give this tissue
strength in ALL directions.
 This tissue is found wrapping around bone (periosteum),
 cartilage (perichondrium),
 muscles (perimysium and epimysium),
 blood vessels and the gastrointestinal tract.
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1.5 Dense Regular CT
Leave 3-5 lines for a DIAGRAM
 Again, notice how many fibers run in the matrix and reduce
the space available to blood vessels.
 Because of this, this tissue will heal slowly.
 Notice in this tissue that ALL the fibers run in the SAME
DIRECTION!
 This tissue is only strong in one direction.
 This tissue only makes up tendons, ligaments, and fibrous
membranes that increase surface areas of the body.
1.6 Dense Elastic CT
Leave 3-5 lines for a DIAGRAM
 This tissue is mainly found under the transitional epithelium
(urinary bladder), wall of respiratory pathways, and wall of
blood vessels.
 This tissue can also form elastic ligaments that give support
and allows movement of the vertebrae.
 Notice that the elastic fibers are yellow.
 Even though there are collagen fibers within the tissue, the
elastic fibers out number them.
 This allows the tissue the ability to return to its original
shape after being stretched.
o (Dense Reg. and Irreg. do not have this ability and
develop small to large tears in the tissue.
o You would know these as sprains or tears.
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2. Cartilage Connective Tissue
2. Cartilage Connective Tissue Characteristics
 The matrix is firm (like old Jell-O) because of
proteoglycans
 Avascular! In fact, this tissue discourages blood vessel
formation.
o (Any time we have an avascular tissue; nutrients must
be diffused to the matrix.
o Because the matrix is so firm, this diffusion is very
slow and healing is slow to none in cartilage!)
 Cells (chondrocytes) must live in little pools (lacus) because
of the firm matrix. These little pools are called Lacunae
 No room for nerves (Pain from cartilage damage usually
result from pressure or tears from surrounding tissues.)
 Perichondrium (peri=around; condro=cartilage) surrounds
the cartilage.
o (It has two layers; outside layer is made of dense
irreg. CT for support & to anchor to surrounding
tissues
o inside layer contains cells that maintain and help in
cartilage growth.)
3 Types of Cartilage:
 Key on the fibers in the matrix and position of the lacunae
2.1 Hyaline Cartilage
Leave 3-5 lines for a DIAGRAM
 Notice the ‘back to back’ lacunae!
 This is the toughest cartilage there is....so the body places it
where there is wear-n-tear, such as joint surfaces of bones
(known as articulating surfaces).
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 This cartilage is white! It is loaded with collagen fibers!
 This tissue can be found at the ends of bones at joints where
there is movement, nose, trachea and bronchiole tubes, and
connects the ribs to the sternum.
2.2 Fibrocartilage
Leave 3-5 lines for a DIAGRAM
 Notice how the lacunae and collagen fibers form alternating
rows!
 This alternating rows of cells, matrix, and fibers creates a
tissue that can take compression forces.
 A lot like a spring! It forms discs of the knee (meniscus),
intervertebral discs, and the pubic symphysis.
2.3 Elastic cartilage
Leave 3-5 lines for a DIAGRAM
 Notice the high amount of yellow (elastic) fibers!
 This cartilage is strong like hyaline, but because of the
elastic fibers it is able to return to its original shape after
extreme bending.
 This cartilage forms your external ears and epiglottis (the
flap that covers your airway when you swallow).
3. Bone (Osseous) Connective Tissue
Bone (Osseous) CT Characteristics:
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 The gel-like matrix of the cartilage has calcium salts added.
o This causes the matrix to harden.
 Two types of bone tissue:
o compact bone
o spongy bone
 Very vascular!
o Unlike cartilage, bone tissue has tiny canals
containing blood vessels running through the matrix
(compact bone) to give excellent nutrient delivery or
houses red bone marrow (spongy bone), which
directly feeds the osteocytes.
 Large nerve supply.
o Along with blood vessels, bones have tremendous
nerve supply.
 The matrix has a high amount of collagen fibers for
strength
o The collagen fibers give the bones their white
appearance.
 Three types of cells belong to this tissue:
o Osteoblasts
o Osteoclasts
o Osteocytes.
4. Blood Connective Tissue
Leave 3-5 lines for a DIAGRAM
 Matrix is a fluid known as plasma.
Blood Characteristics:
 Fibers are used for blood clotting. They stay in an inactive
form and do not become visible until the clotting process is
activated.
 platlets
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 Cells all originate from the red bone marrow.
 The cell that forms all of these different types of cells is
known as the Hemocytoblast (Hemo=blood; cyto=cell;
blast=maker).
 The three types of cell groups are
o erythrocytes (Red Blood Cells: RBC)
o leukocytes (White Blood Cells: WBC)
o Thrombocytes (platelets).
 Blood is a connective tissue because it has MORE matrix
than cells.
 Also, think of blood this way...it connects all systems
together by feeding them and carrying messages to them.
Connetive Tissue Summary:
Connective Tissue Proper
 (very vascular)
A. Loose Areolar
B. Adipose Tissue
C. Loose Reticular
Connective Tissue Proper
 (decreasing vascular)
D. Dense Irregular
E. Dense Regular
F. Dense Elastic
Cartilage
G. Hyaline
H. Fibrocartilage
I. Elastic
(overview)
J. Bone
K. Blood
STUDY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 Remember to use your flashcards for quick 3-5 minute study
moments in your day (waiting for a ride or someone, mute the
TV commercials and review, or just talking on the phone with
your friend who has told the same story 3 times now!).
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 Repetition! Repetition! Repetition! (It works for
commercials...so it will work for you!)
Remember to:
Reduce, Recite, Reflect, & Review!
Make your Flashcards & Study 3 x 5!
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