micro anatomy - bone, cartilage and epithelia Flashcards
a. define and identify epithelia on a histological section
Epithelium forms continuous sheets of cells that line internal surfaces and cover the external surface of the body. It is a selective barrier that protects tissues and is often involved in absorption or secretion.
relate histological structure of epithelia to their functions
describe loose connective tissue histological sections
loose arrangement of fibres - finer elastin fibres and thicker collagen fibres.
viscous fluid matrix.
describe dense irregular tissue histological sections
dense woven network of collagenous (and some elastic) fibres in a viscous matrix.
- looks a bit more swirly Tham regular
joint capsules in the connective tissue that envelops muscle, and it forms dermis of skin. It is impact resistant.
describe dense regular connective tissue and function
collagen fibres are densely packed, and arranged in parallel. - more linear looking than irregular
found in ligaments and tendons. These are powerfully resistant to axially loaded tension forces, but allow some stretch.
describe the structure of three different types of cartilage and their distribution
hyaline -
- a layer of dense irregular connective tissue that surrounds the cartilage of developing bone,
- 2 fibrous layer and chondrogenic layer.
- ribs, nose, larynx and trachea. It is a
precursor of bone.
-looks smooth with circles in the middle
fibrous
elastic cartilage.
The chondrocytes found in a thread like network of elastic fibres within the matrix
• Elastic
strength and elasticity and maintains the shape of certain structures such as the external ear. It has a perichondrium.
• Is found in the epiglottis and larynx.
distinguish compact and spongy bone on histological section
spongy - large white vascular cavities - look like blobs with purple dots (granulocytes) inside the white and purple dots outside cavity (osteocytes)
compact - white central canal of osteon with rings of bone canaliculus circling central canal.
bone canaliculus made of osteocytes and outside of rings is interstitial lamellae
describe Haversian systems, bone lacunae and canalicul
Haversian systems
The Haversian canals (surround blood vessels and nerve fibres throughout the bone and communicate with osteocytes) and the surrounding lamellae
Bone lacunae - bone cells that become surrounded by the bone matrix and are located in cavities called lacuna (check)
Canalicul
microscopic canals between the lacunae of ossified bone
histology of Simple squamous epithelium
consists of a single layer of flattened cells. The thinness of these cells facilitates the transfer of materials (e.g., gases, fluids or nutrients) across the epithelium.
histology of Simple cuboidal epithelium
epithelium consists of a single layer of cuboidal cells. This epithelium is often associated with absorption, secretion, or excretion of waste matter.
histology of Simple columnar epithelium
consists of a single layer of cells that are taller than they are wide. This epithelium is often associated with absorption or secretion.
histology of Pseudostratified epithelium
appears to be stratified because the nuclei of the epithelial cells are at different levels. However, every cell is in contact with the basement membrane, but not all cells reach the lumen.
histology of Stratified cuboidal epithelium
multiple layers of cells with an outermost layer of cuboidal cells. Limited distribution - found in the lining of larger ducts.
histology of Stratified squamous epithelium
has multiple layers of cells becoming flattened as they move from the basal layer to the apical layers. It provides protection from abrasion and is keratinized on the external surface of the body.
histology of Transitional epithelium (urothelium)
adapted for extensibility and is restricted to the urinary tract. It has multiple layers of cells with an outermost layer of much larger, dome-shaped cells (umbrella cells) that change shape during contraction and distention.
