Identify the type of junction with its purpose:
 forms an impermeable junction; prevents molecules
from passing between cells
 Let small molecules move directly between
neighboring cells
 reduces tearing, twisting, stretching
 helps form the tight junction around apical lateral
borders
 Location:
 Covers body Surfaces
 Lines body cavities
 Forms glands
 Functions:
 Secretion
 Selective absorption
 Protection
 Transcellular support
 Detection of sensation
 Secretion
 When a cell produces substances and releases those
substances into the environment.
 Ie. Digestive tract has high secretion
 Selective Absorption
 Epithelial tissue is in direct contact with the outer
environment so it selects what materials come into and
out of the cell
 Protection
 Tissue in contact with the external environment has to
have a protective function to protect internal tissue
 Ie. Skin
 Transcellular Transport
 Able to help substances travel through a certain distance
 Detection of Sensation
 Associated with nerve cells because epithelium can be
found on the external part of the body; nerve cells
receive stimuli
 Cells are usually joined by specialized cell-to-cell
junctions
 Little or no intercellular material
 Don’t have a lot of extracellular material around them
 First the name of tissue indicates # of layers (3 types)
1. Simple – one layer of cells (extends from basement
membrane to the apical surface)
2. Stratified – more than one layer of cells
3. Pseudostratified- tissue appears to be stratified,
but all cells contact basement membrane so it is in
fact simple
 Last name of tissue describes shape of cells (3 types)
1. Squamous – cells wider than
tall (plate or “scale” like)
2. Cuboidal – cells are as wide as
tall, as in cubes
3. Columnar – cells are taller than
they are wide, like columns
 Naming the epithelia includes the layers (first) and
the shape of the cells (second)
 i.e. stratified cuboidal epithelium
 The name may also include any accessory
structures
 Goblet cells, cilia, keratin, etc.
 Special epithelial tissues (don’t follow naming
convention)
 Psuedostratified
 Transitional
How do you go about naming
epithelial tissue?
 Description
 single layer of flat cells with disc-shaped nuclei
 Special types
 Endothelium (inner covering)
 slick lining of hollow organs
 Mesothelium (middle covering)
 Lines peritoneal (abdomen), pleural (lungs),
and pericardial (heart) cavities
 Covers visceral (internal) organs of those
cavities (ie. pancreas, stomach, lung, etc.)
 Function:
 Passage of materials by passive diffusion and filtration
 Secretes lubricating substances reducing friction from muscle in
serous membranes
 Location:
 Renal corpuscles (blood filtering component in kidneys)
 Alveoli of lungs
 Lining of heart, blood and lymphatic vessels
 Lining of ventral body cavity
 Pericardium- membrane covering the heart
 Pleura- membrane covering the lung
 Peritoneum- membrane covering the abdominopelvic cavity
Simple
squamous
lining the walls
of the capillary
 Description
 single layer of cube-like cells with large,
spherical central nuclei
 Function
 secretion and absorption
 Location
 kidney tubules, secretory portions of small
glands, ovary surface
 Description
 single layer of column-shaped (rectangular)
cells with oval nuclei
 Some have cilia at their apical surface
 May contain goblet cells (secrete mucus)
 Function
 Absorption; secretion of mucus, enzymes, and
other substances
 Ciliated type propels mucus or reproductive
cells by ciliary action
 Location
 Non-ciliated form
 Lines digestive tract,
gallbladder, ducts of
some glands
 Ciliated form
 Lines small bronchi,
uterine tubes, and
uterus
Identify a location where simple
squamous, cuboidal or
columnar tissue is found?
 Layers: contain two or more layers of cells
 Regeneration: from Basal membrane
 Function: protection
 Naming: according to the shape of cells at apical layer
 Description
 Many layers of cells – squamous in shape
 Deeper layers of cells appear cuboidal or
columnar
 Thickest epithelial tissue – adapted for
protection
 Specific types
 Keratinized – contain the protective protein keratin
 Surface cells are dead and full of keratin
 Non-keratinized – forms moist lining of body
openings
 Function
 Protects underlying tissues in areas subject to abrasion
 Location
 Keratinized – forms epidermis
 Non-keratinized – forms lining of esophagus, mouth,
and vagina
Non-keratinized vs. Keratinized
 Description
 generally two layers
of cube-shaped cells
 Function
 protection
 Location
 Forms largest ducts
of sweat glands
 Forms ducts of
mammary glands
and salivary glands
 Description
 several layers; basal
cells usually cuboidal;
superficial cells
elongated
 Function
 protection and
secretion
 Location
 Rare tissue type
 Found in male urethra
and vas deferens,
largest ducts of salivary
glands, nasopharynx
 Description
 All cells originate at basement membrane
 Only tall cells reach the apical surface
 May contain goblet cells and bear cilia
 Nuclei lie at varying heights within cells
 Gives false impression of stratification
 Function
 secretion of mucus; propulsion of mucus by cilia
 Locations
 Non-ciliated type
 Ducts of male
reproductive tubes
 Ducts of large glands
 Ciliated variety
 Lines trachea and
most of upper
respiratory tract
 Description
 Basal cells usually cuboidal or columnar
 Superficial cells dome-shaped or squamous
 Function
 stretches and permits distension of urinary
bladder
 Location
 Lines ureters, urinary bladder and part of
urethra
Relaxed state
Stretched state
Name three types of tissue, what
they look at and a place where
they can be found.
 Ducts carry products of exocrine glands to
epithelial surface
 Include the following diverse glands
 Mucus-secreting glands
 Sweat and oil glands
 Salivary glands
 Liver and pancreas
 May be: unicellular or multicellular
 Goblet cells produce
mucin
 Mucin + water  mucus
 Protects and lubricates
many internal body
surfaces
What are the two types of
stratified squamous epithelial?
Where can they be found?
Where can simple cuboidal and
stratified cuboidal be found?
What is the difference in the
function of each?