Chapter 4
Tissues
• Histology (histos, tissue) is the
study of tissues.
• Four basic tissues types exist:
–Epithelial tissue
–Connective tissue
–Muscle tissue
–Neural tissue
Epithelial Tissue
General Characteristics:
- Found throughout the body, covers all
body surfaces both inside and out.
- Main glandular tissue.
- Attached to underlying connective tissue
by noncellular nonliving basement
membrane.
- Usually has no vascular tissue - blood
supply
- Cells reproduce rapidly (rapid healing).
- Cells tightly packed together
It takes about 27
days for the
outer layer of
skin to shed and
be replaced; that
works out to 1.5
pounds of skin
cells per year.
Where
does all
the dead
skin you
shed go?
Epithelial tissue is named based on
its description
simple = single layer
stratified = multiple layers
squamous = flat
cuboidal = square
columnar = column (rectangle)
Simple Squamous
Function: diffusion and filtration. Air sacs in lungs, walls of capillaries
Simple Cuboidal
Function: Secretion
and Absorption
Found in kidneys
tubules, ducts and
covering the ovaries
Stratified cuboidal epithelium
Simple Columnar
Function:
Secretion and
Absorption
Found in
Digestive tract
and uterus
*Contains goblet
cells to secrete
mucus
*Can have
microvilli
Stratified Squamous
Multi layer squamous, functions
in protection
Found in skin and mouth
The ink of tattoos must be injected
below the basement membrane.
Basement membrane lies between
epithelium and underlying connective
tissues.
Pseudostratified Columnar
Single layer, nuclei are uneven which gives it a
layered appearance
Can have goblet cells and cilia
Location: lining
air passages
and tubes of the
reproductive
system
Transitional Epithelium
Stretchable
Blocks diffusion (no leaking)
Found in the urinary bladder
Identify the tissues
Connective Tissue Proper
General Characteristics:
-Most abundant tissue in your body, found
throughout
-Binds structures together
-Provides support, protection, framework, fills space,
stores fat, produces blood cells, fights infection, and
helps repair tissue.
-Composed of more scattered cells with abundant
intercellular material ' matrix
-Made up of a ground substance (fluid, semi-solid)
and fibers
-Most has a good blood supply
-Cells can reproduce
Types of Cells in Connective
Tissue
• Mast cells (prevents clots)
• Macrophages (consumers)
• Fibroblasts (produce fibers)
Collagenous (bones,
ligaments, tendons)
Elastic (respiratory)
Reticular (a network)
Connective Tissue Fibers
Collagenous fibers - strong and
flexible,
-bones, tendons and ligaments
Elastic fibers - very flexible,
-ears and vocal cords
Categories of Connective Tissue
Loose Connective Tissue or Areolar Tissue
Adipose Tissue (fat)
Fibrous Connective Tissue
Tendons = muscles
to bones
Ligaments = bones to
bones
Fluid Connective Tissues
• Blood and lymph are connective
tissues that contain distinctive
collections of cells in a fluid matrix
Supporting Connective Tissue
• Cartilage
• The three major types of
cartilage are:
–Hyaline
–Elastic
–Fibrocartilage
Hyaline Cartilage
Covers ends of joints, nose and
respiratory passages
Hyaline cartilage
Hyaline cartilage
Elastic cartilage
External Ear and
Larynx
Fibrocartilage
Bone Tissue (Osseus)
Blood Tissue
Muscle Tissue
Cardiac muscle
Skeletal muscle
Smooth muscle
Nerve Tissue
Nervous tissue (spinal cord)