Download Histology - epithelial tissue - Mrs.Simmons Anatomy & Physiology I

Anatomy and Physiology Lab I
Jenny Simmons
Email:
[email protected]
Tissues
• Histology: The study of tissues
• Tissue: A collection of cells that perform
related functions, and are similar in
structure
• 4 Major types of tissues:
– Epithelial
– Connective
– Muscular
– Nervous
Epithelial Tissue
• Found:
– covers body surfaces
– lines hollow organs, body cavities and ducts
– also found in glands.
• Has an apical or free surface which is exposed to the body exterior
or the cavity of an internal organ
• Has a basal or attached surface that adheres to connective tissue
– attachment between the basal surface and the connective tissue is a thin
extracellular layer called the basement membrane.
• Avascular---without blood vessels
– nutrients diffuse in from blood vessels in underlying connective
tissue
• Good nerve supply
• Rapid cell division; responsive to environmental stresses
• Named according to the shape and arrangement of cells
Classification of Epithelia
Simple:
one layer
Stratified:
multiple
layers of
cells
Figure 4.1a
Classification of Epithelia
Squamous, cuboidal,
or columnar
Figure 4.1b
Simple Squamous Epithelia
•
•
Function: filtration (kidneys) and diffusion (air sacs of lungs)
Location: Kidney glomeruli, alveoli of lungs, lining of heart, kidney corpuscles, and
blood and lymphatic vessels.
Simple Squamous
• Microscope
slide #1
Simple Squamous (surface view)
Microscope
slide #22
Stratified Squamous Epithelia
•
•
•
Function: Protects underlying tissue in areas subject to abrasion
Location: lines skin(keratinized), mouth, esophagus, vagina (all non-keratinized)
Microscope slide # 2
**Note: For all stratified epithelia: Name is based off cells on apical surface. All cells
connected to basal membrane will either be cuboidal or columnar!
Epithelia: Simple Cuboidal
• Single layer of cubelike cells with large,
spherical central nuclei
• Function in secretion and absorption
• Present in kidney tubules, ducts and secretory
portions of small glands, and ovary surface
Simple Cuboidal Epithelia
Microscope slide # 3
(you can also see
simple cuboidal in
slide #1)
Simple Columnar
•
•
•
Function: Protection, secretion of mucus, absorption
Location: lining of stomach, intestine, gallbladder, uterine tube, collecting ducts of kidneys
Microscope Slide # 4
Simple Columnar Epithelium
Gall Bladder
Simple columnar epithelium lines the gall bladder. Note the
underlying connective tissue with blood vessels.
Pseudostratified Columnar Ciliated
Epithelia
•
•
•
Function: Secretion and propulsion of mucus
Location: Lining of ducts, ciliated: lines trachea and most of upper respiratory tract
Features: Has goblet cells that secret mucus & is ciliated. Looks layered, but only
has a single layer of cells (all cells are attached to basement membrane
Epithelia: Transitional (Microscope Slide #6)
• Several cell layers, basal cells are cuboidal,
surface cells are dome shaped
• Stretches to permit the distension of the
urinary bladder
• Lines the urinary bladder, ureters, and part of
the urethra
Transitional Epithelium (Ureter)
3 apical
(free)
surface
Transitional Epithelium
Urinary Bladder
The expandable stratified epithelium of the bladder is referred to as transitional
epithelium. Note that its surface cells are large rather than flattened as in stratified
squamous epithelium.
Ureter 100X
transitional epithelium
of mucosa
lamina
propria
adventitia
smooth muscle
* Ureter 400X
lamina propria
smooth
muscle
transitional epithelium
Bladder (Empty)
White line- defines height of epithelium
Bladder (Full)
Orange arrow
- Flattened "plump" cells
White line- defines height of epithelium