Tissues
• Definition?
• Histology- study of tissues within the body
systems
• Classified based on:
– Embryonic development
– Intercellular space
• Four Tissue Types
EPITHELIAL TISSUE
 Very Little intercellular space material
Derived from all three embryonic layers
Regeneration??
 Arranged in sheets with a basement membrane
Exposed surface (internal or external)
Function
Protection
Cover internal and external surfaces
Secretion and absorbtion (Glands)
Classified by shape of cells and number of layers
EPITHELIAL TISSUE
SIMPLE SQUAMOUS
Single layer
Squamous shape
Lining of body cavity, lungs,
blood vessels
EPITHELIAL TISSUE
SIMPLE CUBOIDAL
Single layer
Cuboidal shaped
Kidney tubules, glands
EPITHELIAL TISSUE
SIMPLE COLUMNAR
Single layer
Columnar shape
Lining of digestive tract
Modified by presence of cilia
EPITHELIAL TISSUE
STRATIFIED SQUAMOUS
Multi layer
Outer most layer- squamous cells
Inner- cuboidal or columnar
Lining of mouth, esophagus, skin
EPITHELIAL TISSUE
PSEUDOSTRATIFIED
COLUMNAR
One layer
Appears stratified
Respiratory tract
Glands
• One cell or a group of specialized epithelial
cells to secrete substances into ducts, the
surfaces or blood
– Exocrine
• Example- sweat or salivary glands
– Endocrine
• Example- hormones
CONNECTIVE TISSUE
 Abundant extracellular material
Derived from the mesoderm
Matrix (dominant part)
Fiber, cells in liquid, gel, or solid matrix
Highly vascular
 Function
Bind and/or support other tissue
Store nutrients
CONNECTIVE TISSUE
Tendons
Dense fiberous
Abundant, well organized
fiber
CONNECTIVE TISSUE
ADIPOSE TISSUE
Loose connective
Semisolid matrix
Store large droplets of fat
BLOOD
Lymph
Liquid, fluid matrix
Sometimes in different category
RBC- Red Blood Cells
WBC- White Blood Cells
CONNECTIVE TISSUE
CARTILAGE
Chondrocytes
Small cavities- lacunae
Dense, solid elastic matrix
Ear, nose
CONNECTIVE TISSUE
BONE
Osteocytes
Solid, rigid matrix
Hardest CT
Impregnated w/ calcium salts
MUSCLE TISSUE
Derived from mesoderm
Little intercellular matrix, fibers close together
Cells have ability to contract
Function
Locomotion
Other body movement
Pg 156-157,162; slides 161
SKELETAL
MUSCLE TISSUE
Voluntary movement
Typically attach to bone
Long and cylindrical
Transverse striation
Each fiber is multi-nuclear
MUSCLE TISSUE
SMOOTH
Involuntary movement
Nonstriated
Predominant
Long, spindle shape
Single nucleus
Internal organs
MUSCLE TISSUE
CARDIAC
Striations
Involuntary
One nucleus
Deep center
Heart muscle
NERVE TISSUE
Derived from ectoderm
Little intercellular matrix
Cells very high ability to
Respond to stimuli
Transmit impulses
Two types:
Neurons and Neuroglia
NERVE TISSUE
NEURON
Cell Body(3)
Dendrites (5)
Axon(1)
List of intercellular matrix
• Least to most
– Epithelial
– Muscular
– Nervous
– connective