CILIA
Trachea of the rodent
Pseudostratified columnar cells with CILIA- you can see striations and individual cilia, which are
attached to basal bodies, and made up of microtubules
Cilia are 7-10 micrometers in length, present in the trachea and Fallopian tubes
Cilia vs microvilli- cilia are clumped and striated, whereas the brush border is homogenous—you
can’t see individual microvilli
Trachea H&E- note cartilage blue ring
Trachea- note clumped cilia
More cilia
Two different stains
FLAGELLA
Sperm smear- made up of axoneme= microtubules ; red box=darkly staining sperm heads in
epididymus
More sperm in an epididymus
Electon micrograph of bat sperm-the mitochondria are the ovals alongside the axoneme
EM IMAGES
TYPES OF EPITHELIAL CELLS
Epithelial cells = secretory parenchyma of many cells. This is because glands develop from a surface
layer of epithelial cells which invaginate into a connective tissue stroma
Epithelial tissue is avascular and therefore is dependent upon the underlying connective tissue for
its vascular needs.
The epithelial cells "rest" on the basement membrane in the extracellular matrix. It is derived both
from the epithelium as well as from the connective tissue. This tri-layered structure (basement
membrane) consists of the lamina lucida (an amorphous component) and the lamina densa (an
electron dense area), both of which are of epithelial origin. These two regions together are known
as the basal lamina Finally, there is the lamina reticularis (a fibrillar component), which is
connective tissue in origin Can only see the three layers with EM, but can see overall basement
membrane with LM. Also, basement membrane not really a membrane.
The basement membrane is important clinically as it is a factor used in the prognostic staging of
carcinomas (uncontrolled, malignant growths of epithelial cells).
1.) Simple squamous epithelium
Neurovascular Bundle
Red box - Simple squamous epithelium = endothelium of the vein in neurovascular bundle
Paraffin causes constricted vessel- but perfused fixation causes flattened, smooth vessel
Simple squamous epithelium = endothelium in the artery of the neurovascular bundle
NOTE; Black stain is the internal elastic lamina
This simple squamous epithelium lines the heart and the blood/lymph vessels and in these
locations is called endothelium. They also line the body cavities and the periphery of many visceral
organs where they are called mesothelium.
Lines the pulmonary alveolar or renal capsule- Bowman’s capsule