Tissues Flashcards
Epithelium
Thin tissue, forming the outer layer of a body’s surface and lining the alimentary canal and other hollow structures. It connects cells, separates compartments, forms glands and provides a protective barrier.
Simple squamous epithelium
Approximately one cell thick, it enables diffusion and is found in blood vessels.
Simple cuboidal epithelium
Appears the same height and width, used for hormone synthesis, found in the thyroid gland, gut and ovary.
Simple columnar epihelium
It is taller than it is wide making it more active. It aids digestion, absorption and lubrication found in the small intestine.
Stratified squamous epithelium
Appears like layers of cells on top of each other. It is protective and found in skin
Stratified cuboidal epithelium
Contains at least 2 layers and is found in the salivary gland to produce saliva.
Stratified columnar epithelium
At least 2 layers, found in the salivary duct to produce saliva.
Psuedostratisfied columnar epithelium
It contains a mix of cell types, all layered which lines the airways.
Transitional epithelium
It is rounder in appearance and allows distension of the bladder
Epithelial components of the liver
Essentially, the liver, is an enormous gland made up of epithelial cells. The parenchyma are the hepatocytes. They are arranged in rows between blood vessels and aid secretions, protein synthesis, lipid metabolism and bile ducts.
Epithelial components of the kidneys
It filters blood and removes excess fluid to be excreted in urine. Parenchyma; epithelial cells organised into nephrons which are tubules which help to remove excess water, waste and other substances from the blood. They also return substances like sodium, potassium or phosphorus when running low.
List the consequences of abnormal functioning epithlia
Over/under proliferation can lead to rapid (under)production of a cell part or organism. Over/under secretion will lead to a lack in mucous or too much. Loss of cilia/ciliary beat will alter the movement of cells with possible infection.
Glands
An organised collection of secretory epithelial cells which produce hormones that regulate metabolism, growth/development, tissue function, sexual function, reproduction, sleep, mood…
Glandular epithelium
Membranous tissue made up of cells that cover all glands in the body. Allows for the secretion of fluids into ducts or fluids of the body. Normally cuboidal or columnar.
Exocrine glands
These glands have ducts which secrete directly onto a surface. E.g. sebaceous, sweat, salivary, mucous glands.
