Body Tissues
DR / Noha Elsayed
2015--2016
Course outline
1. Learning outcome
Learning outcome
By the end of this lesson the student will be able to:
1. Describe the general characteristics and functions of
epithelial tissue.
2. Name the major types of epithelial tissue, and relate
each one to a particular organ.
3. Describe the general characteristics and functions of
connective tissue.
4. Name the major types of connective tissue, and
relate each one to a particular organ.
Learning outcome cont’d
5. Describe the general characteristics and functions of
muscular tissue.
6. Name the major types of muscular tissue, and relate
each one to a particular organ.
7. Describe the general characteristics and functions of
nervous tissue.
Body Tissues
Cells are
specialized for particular functions .
Tissues
 Groups of cells with similar structure and function
Four primary types
Epithelium
Connective tissue
Nervous tissue
Muscle
Epithelial Tissues
 Found in different areas : Body coverings
 Body linings
 Glandular tissue
 Functions :Protection
 Absorption
Filtration
Secretion
Cells fit closely together
Tissue layer always has one free surface
The lower surface is bound by a basement membrane
Avascular (have no blood supply)
Number of cell layers
Simple – one layer
Stratified – more than one
layer
Shape of cells :Squamous – flattened
Cuboidal – cube-shaped
Columnar – column-like
Simple squamous
Single layer of flat cells
Usually forms membranes
Lines body cavities
Lines lungs and
capillaries
Simple cuboidal
Single layer of cube-like cells
Common in glands and their
ducts
Forms walls
of kidney tubules
Covers the ovaries
Simple columnar
 Single layer of tall cells
 Often includes goblet cells, which
produce mucus
 Lines digestive tract
Pseudostratified
 Single layer, but some cells are
shorter than others
 Often looks like a double cell layer
 Sometimes ciliated, such as in the
respiratory tract
 May function in absorption or
secretion
Found everywhere in the body
Includes the most abundant and widely distributed
tissues
Functions :Binds body tissues together
Supports the body
Provides protection
Connective Tissue
Characteristics
Variations in blood supply :Some tissue types are well vascularized
Some have poor blood supply or are avascular
Extracellular matrix :Non-living material that surrounds living cells
Two main elements :Ground substance – mostly water along with adhesion proteins and
polysaccharide molecules
Fibers :Produced by the cells
Three types
 Collagen fibers
 Elastic fibers
 Reticular fibers
Bone (osseous tissue)
Composed of:
 Bone cells in lacunae (cavities)
 Hard matrix of calcium salts
 Large numbers of collagen fibers
 Used to protect and support the body
Hyaline cartilage :Most common cartilage
Composed of:
 Abundant collagen fibers
 Rubbery matrix
 Entire fetal skeleton is hyaline cartilage
Fluid connective tissues-: (blood, lymph)
• Specialized for the conduction of electrical
impulses.
• Two basic types of cells:
– Neurons: basic structure of neural tissue
– Neuroglial cells: divide and support nervous tissue
components
Function is to produce movement
Three types :Skeletal muscle
Cardiac muscle
Smooth muscle
Skeletal muscle
Can be controlled
voluntarily
Cells are striated
Cells have more than one
nucleus
Cardiac muscle : Found only in the heart
 Function is to pump blood
(involuntary)
 Cells attached to other cardiac
muscle cells at intercalated disks
 Cells are striated
 One nucleus per cell
Smooth muscle
Involuntary muscle.
Surrounds hollow organs.
No visible striations.
One nucleus per cell.
Neurons and nerve support
cells
Function is to send impulses to
other areas of the body :Irritability
Conductivity
Regeneration
Replacement of destroyed tissue by the same kind of
cells
Fibrosis
Repair by dense fibrous connective tissue (scar tissue)
Tissues that regenerate easily
Epithelial tissue
Fibrous connective tissue and bone
Tissues that regenerate poorly
Skeletal muscle
Tissues that are replaced largely with scar tissue
Cardiac muscle
Nervous tissue within the brain and spinal cord
 Body tissues are categorized into four types: epithelial,
connective, muscular, and nervous.
 Epithelial is classified according to cell shape and number of
layers. The cell shape can be squamous, cuboidal, or
columnar.
 Simple tissues have one layer of cells, and stratified tissues
have several layers.
Connective Tissue
 In connective tissue, cells are separated by a
matrix (organic ground substance plus fibers).
 A. Fibrous connective tissue can be loose
connective tissue, in which fibroblasts are
separated by a jellylike ground substance, or
dense connective tissue, which contains bundles
of collagenous fibers.
 B.Adipose tissue is a type of loose connective
tissue in which the fibroblasts enlarge and store
fat.
Muscular Tissue : Muscular tissue contains actin and myosin protein
filaments. These form a striated pattern in skeletal and
cardiac muscle, but not in smooth muscle. Cardiac and
smooth muscle are under involuntary control.
 Skeletal muscle is generally under voluntary control.
Nervous Tissue : Nervous tissue contains conducting cells called neurons. Neurons
have processes called axons and dendrites.
 In the brain and spinal cord, axons are organized into tracts. Outside
the brain and spinal cord, axons (fibers) are found in nerves.