Tissues And Irgans Flashcards
Tissue definition
A collection of cells that are adapted to perform a specific function
Organ Definition
2 or more tissues combined to create a structural unit that has a particular function that are a sum of its parts
3 Cells That don’t form part of tissues
Ova
SPermatozoa
Blood corpuscles
Epithelial Tissues
Form continuous layers that cover surfaces and line cavities of the body
Mesothelium
The tissue that lines closed cavities like:
-Peritoneal
-Pleural
-Periocardial
Epithelium also lines heart, blood and lymphatic vessels as endothelium
Endothelium = specialised form of epithelium
Epithelial CLassified by shape of cells and their arrangement in tissues
Classified morphologically (by shape and structure)
Epithelial functions
-Protection
-SSecretion
-Absorption
-Reproduction
-Sensation
-Lubrication
-Excretion
Simple Squamous Epitheelium
Lines heart, blood vessels, pleural and peritoneal cavities
Exchange of substances, secreting lubricants
Simple Cuboidal Epithelium
Ducts of exocrine glands, kidney tubules, parenchyma of glands
Lining , secretory activities or absorption
Simple columnar epithelium
Line GI Tract and large excretory ducts of glands
Secretion of enzymes, mucus and absorption of nutrients and fluids
Pseudostratified columnar epithelium
Lining and protein secretion
Also for sensory reception
Can be ciliiated
Upper respiratory system
Nasal cavity and ear
Stratified squamous epithelium
Protects underlying tissues form external environment
Epidermis covers exterior of body and some interior surfaces of body cavities.
(Non keratinised, mouth, oesophagus,vagina)
(Keratinised, epidermis of skin)
Stratified
Arranged in layers
Pseudostratified
Closely packed cells which look like they are arranged in layers but are actually all attactched to a basement membrane.
Squamous
flat scale shaped cells