Date post: | 31-May-2015 |
Category: |
Technology |
Upload: | mbbs-ims-msu |
View: | 7,362 times |
Download: | 1 times |
Simple Squamous Epithelium
Composed of a single layer of flattened cells lying on a
basement membrane. In section only their flattened nuclei are
often visible. Function: Provides a selective barrier which
allows for filtration, passive diffusion and pinocytosis.
A single layer of cuboidal cells with rounded nuclei, lying on a
basement membrane. They are often found lining ducts and may possess
basal infoldings. Function: They transport fluids and may modify the
contents of the lumen by selective absorption.
Function:
Absorption, lubrication or movement of luminal contents.
Uterian tube
Pseudostratified Epith. Treachea
Pseudostratified Epididymis
Stratified columnar/cuboidal epith
Multiple layers of cells in which the surface layer is cuboidal or
columnar.
Function: Protection or secretion.
Location examples: Male Urethra, Large Glanduclar Ducts, Sweat
Glands
Transitional
Simple Cuboidal Epith
Simple Cuboidal Salivary gland
Fig. 20.7
to protect
where diffusion is important
where tissues are
involved in secretion
and absorption: larger
cells because of the
machinery of
production, packaging,
and energy
requirements
“ciliated” literally = eyelashes
(see next page)
Stratified: regenerate from below
Rare…
Rare…
Endothelium
A simple squamous
epithelium that lines the
interior of the
circulatory vessels and
heart
Mesothelium
Simple squamous epithelium that lines the
peritoneal, pleural and pericardial cavities and covers
the viscera
Glands
• Epithelial cells form them
• Production & secretion of needed substances
• Are aqueous (water-based) products
• The protein product is made in rough ER, packed into secretory granules by Golgi apparatus, released from the cell by exocytosis
Classification of glands
• By where they release their product
– Exocrine: external secretion onto body surfaces
(skin) or into body cavities
– Endocrine: secrete messenger molecules
(hormones) which are carried by blood to target
organs; “ductless” glands
• By whether they are unicellular or
multicellular
Exocrine glandsunicellular or multicellular
Unicellular: goblet cell scattered within epithelial lining
of intestines and
respiratory tubes
Product: mucin
mucus is mucin & water
Multicellular exocrine glands
Epithelium-walled
duct and a
secretory unit
• Cilia
– Whiplike motile extentions of the apical surface membranes
• Flagellum
– Long isolated cilium
– Only found as sperm in human
Classes of Connective Tissue: note the cell types
and great variety of subclasses
*
Classes of Connective Tissue
*
Classes of Connective Tissue
Classes of Connective Tissue
*
Classes of Connective Tissue
*
Membranes that combine epithelial sheets
plus underlying connective tissue proper (see
next slide)
• Cutaneous membranes– Skin: epidermis and dermis
• Mucous membranes, or mucosa– Lines every hollow internal organ that opens to the outside
of the body
• Serous membranes, or serosa– Slippery membranes lining the pleural, pericardial and
peritoneal cavities
– The fluid formed on the surfaces is called a transudate
• Synovial membranes– Line joints
(a)Cutaneous membrane
(b)Mucous membrane
(c)Serous membrane
• Four basic types of tissue
– Epithelium
– Connective tissue
– Muscle tissue
• Skeletal
• Cardiac
• Smooth
– Nervous tissue
• Four basic types of tissue
– Epithelium
– Connective tissue
– Muscle tissue
– Nervous tissue
• Neurons
• Supporting cells
Tissue response to injury
• Immune: takes longer and is highly specific
• Inflammation
– Nonspecific, local, rapid
– Inflammatory chemicals
– Signs: heat, swelling, redness, pain
• Repair – two ways
– Regeneration
– Fibrosis and scarring
• Severe injuries
• Cardiac and nervous tissue
Tumors (neoplasms): abnormal growth of
cells
• Adenoma – neoplasm of glandular epithelium,
benign or malignant
• Carcinoma – cancer arising in an epithelium
(90% of all human cancers)
• Sarcoma – cancer arising in mesenchyme-
derived tissue (connective tissues and muscle)
STEM CELLS….
STEM CELLS
______Inner cell mass becomes the baby