Epithelial Cells And Surface Specialisations Flashcards
Define epithelia.
Sheets of contiguous cells, of varied embryonic origin, that cover the external surface of the body and line internal surfaces, including the body’s vessels.
What’s the embryologic origin of epithelial tissues?
Derived from the ectoderm, endoderm and mesoderm.
Function of simple squamous epithelia.
Fast material exchange and barrier to fluids, also a barrier in the brain and CNS.
Function of simple cuboidal.
Absorption and conduit (exocrine glands), absorption and secretion (kidney tubules), barrier/covering (ovary). Hormone synthesis, storage and mobilisation (thyroid).
Location and function of simple columnar.
Location: stomach lining and gastric glands, small intestine and colon, gallbladder. Function: absorption, secretion and lubrication.
What causes cystic fibrosis?
A mutation in the CFTR gene, causing a deficiency of chloride ion release, which results in a very sticky and immovable mucus.
Location and function of pseudostratified epithelium.
Location: lining of nasal cavity, trachea and bronchi. Functions: secretion and conduit, mucous secretion, particle trapping and removal.
Location and function of stratified squamous keratinised epithelium.
Location: surface of skin, limited distribution in oral cavity, oesophagus. Functions: protection against abrasion, reduces water loss but remains moist.
Location and function of stratified squamous keratinised epithelium.
Location: surface of skin, limited distribution in oral cavity. Functions: protection against abrasion, prevention of water loss and microbial ingress, shielding against UV light damage.
Location and function of transitional epithelium.
Location: urinary tract. Functions: distensibility, protection of underlying tissue from toxic chemicals.
Function of club cells.
To protect the bronchioles epithelium, detoxification of harmful substances inhaled into the lungs.
