Why do we study histology?
metastatic cancer
CONNECTIVE TISSUE
…connects!
The most abundant tissue in
the body!
Characteristics of Connective Tissue
1) Vary in blood supply
 Most are highly vascular (have a
blood supply)
 Some exceptions:
 Tendons, ligaments, and cartilage are
avascular
 heal very slowly when injured!
Characteristics of Connective Tissue
2) Have an extracellular MATRIX
 a nonliving substance found
between cells
 Matrix can be liquid, semisolid, or solid
depending on tissue type
 enables C.T. to withstand weight and
stretching
Functions of Connective Tissue
1) Protection of organs
2) Support of organs
3) Binds together body tissues
Areolar (Loose connective)
Associated with the
epithelial tissue of the
body
Adipose
Fat storage
Dense Connective Tissue
Tendons and
ligaments
Hyaline Cartilage
Ends of bones, ribs,
nose…
Osseous
Bone: living cells
(osteocytes) in a hard
matrix
Blood
Red blood cells, white
blood cells, and
platelets within blood
plasma
1) Loose Connective (areolar)
 DESCRIPTION: Areola means small
open space – most of the matrix of this
tissue appears to be empty space
 FUNCTION: Wraps and cushions organs;
holds internal organs together – acts as
“glue”
 LOCATION: Around organs
Areolar
2) Adipose
 DESCRIPTION: FAT cells
 FUNCTION: is reserve “fuel” or energy,
protects organ by cushioning them,
and functions in insulation
 LOCATION: Found around organs,
under skin, within abdomen, in breasts
Adipose
3) Dense Connective Tissue
 DESCRIPTION: Collagen fibers in matrix
give tissue flexibility, fibroblasts are cells
that make the fibers
 FUNCTION:
tendons connect muscle to bone and
ligaments connect bone to bone;
they withstand stress when pulled
 LOCATION: tendons, ligaments
Dense Connective Tissue
Tendons and
ligaments
4) Hyaline Cartilage
 DESCRIPTION: Hyaline cartilage is the
most abundant type of cartilage!
- One cell is called a chondrocyte
 FUNCTION: supports and reinforces
organs
 LOCATION: covers ends of bone at
joints, in ribs, etc.
Hyaline Cartilage
5) Bone
 DESCRIPTION: Bone cells called osteocytes
are in cavities called LACUNAE
- One large circle (unit of bone) is an OSTEON
 FUNCTION: Osseous tissue has a very strong
and hard matrix that protects internal organs
and supports the body; provides levers for the
muscles to act on
 LOCATION: bones
Osseous
6) Blood
 DESCRIPTION: Contains blood cells!
Red blood cells appear pink on the slide
and white blood cells are purple
The fluid matrix is called blood plasma
 FUNCTION: transport for the circulatory
system carrying nutrients and wastes
 LOCATION: Throughout the entire body
Blood
Blast Cells
 Each major type of CT contains an
immature class of cells with a name
ending in –blast
 Loose and dense CT: fibroblasts
 Cartilage: chondroblasts
 Bone: osteoblasts
Blast Cells
 Retain the capacity for cell division
 Secrete the matrix
 In cartilage and bone, once that matrix is
produced, the blast cells differentiate into
mature cells – end in –cyte
 Cartilage – chondrocyte
 Bone - osteocyte
 Basic unit of osseous tissue: OSTEON
 Basic unit of osseous tissue: OSTEON
 Each osteon is composed of:
 Lamellae – concentric rings of matrix made up of
minerals (calcium), which gives the bone its
hardness, and collagen fibers, which gives bone its
strength
 Basic unit of osseous tissue: OSTEON
 Each osteon is composed of:
 Lamellae – concentric rings of matrix made up of
minerals (calcium), which gives the bone its
hardness, and collagen fibers, which gives bone its
strength
 Lacunae – Small spaces between lamellae that
contain osteocytes
 Basic unit of osseous tissue: OSTEON
 Each osteon is composed of:
 Lamellae – concentric rings of matrix made up of
minerals (calcium), which gives the bone its
hardness, and collagen fibers, which gives bone its
strength
 Lacunae – Small spaces between lamellae that
contain osteocytes
 Canaliculi – small canals that provide routes for
nutrients and wastes to be transported to and from
osteocytes
 Basic unit of osseous tissue: OSTEON
 Each osteon is composed of:
 Lamellae – concentric rings of matrix made up of
minerals (calcium), which gives the bone its hardness,
and collagen fibers, which gives bone its strength
 Lacunae – Small spaces between lamellae that contain
osteocytes
 Canaliculi – small canals that provide routes for
nutrients and wastes to be transported to and from
osteocytes
 Central canal – contains blood vessels and nerves
Define terms on Worksheet
 Pg 80-81
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Collagen fibers
Fibroblasts
Mast cells
Macrophages
Elastic fibers
Blood vessels/blood cells
Adiopocytes
 Collagen fibers:
 Strong and resist pulling forces, but are not
stiff. Often occur in bundles lying parallel to
one another.
 Fibroblasts:
 Large, flat, spindle-shaped cells with
branching processes. Present in all
connective tissues. Secrete fibers and matrix.
 Mast cells:
 Abundant along blood vessels that supply
connective tissue. Produce histamine, a
chemical that dilates small blood vessels as
part of the body’s reaction to injury or infection
 Macrophages
 Develop from white blood cells. Can engulf
bacteria and other debris.
 Elastic fibers
 Smaller than collagen fibers. Form a network
within a tissue. Made up of elastin and fibrillin.
Strong, but can be stretched up to 1 ½ times their
relaxed length without breaking. Can return to
their original shape (elasticity).
 Blood vessels
 A vein, artery, or capillary. Tubular structure
carrying blood through tissues
 Blood cells
 Cells circulating the body in blood vessels,
transporting oxygen & nutrients, and also
assisting the immune system
 Adipocytes
 Cells of adipose tissue which are specialized
for fat storage
Muscle and Nervous Tissue
MUSCLE TISSUE TERMS
*Voluntary or Involuntary
(conscious control) or (happens unconsciously)
*Striated or Non-striated
(stripes)
(no stripes)
*Uni-nucleated or Multi-nucleated
(one nucleus)
(many nuclei per each cell)
MUSCLE TISSUE
Overall Function:
To CONTRACT to produce MOVEMENT
Skeletal Muscle Tissue
Cerebrum – Nervous Tissue
.
Skeletal Muscle Characteristics
* Voluntary
* Striated
* Multi-nucleated
Nervous Tissue
 Description
 Neurons and neuroglia (support cells)
 Function
 Neurons initiate and transmit nerve impulses
to coordinate body activities
 Location
 Brain, spinal cord, peripheral nervous system
Nervous Tissue
Skeletal Muscle
 Description
 Striated, voluntary, multinucleated
 Function
 Body motion, maintain posture, heat
production
 Location
 Attached to bone
 By what?
Skeletal Muscle Tissue
Cardiac Muscle
 Description
 Striated, involuntary, uninucleated
 Function
 Pumps blood
 Location
 Heart wall
Cardiac Muscle
Smooth Muscle
 Description
 Nonstriated, involuntary,
uninucleated
 Function
 Propel food and body fluids
 Location
 Walls of organs of the
respiratory, circulatory,
digestive, and urinary
systems
Smooth Muscle