Epithelial Cells Flashcards
(30 cards)
What does a mucous membrane consist of?
An epithelium (type depends on the site) lining the lumen of a tribe
An adjacent layer of connective tissue (often referred to as the lamina propria)
In the alimentary tract a third layer consisting of smooth muscle cells referred to as the muscularis mucosae
What is a serous membrane?
A thin, two part membrane which lines certain closed body cavities. They envelop the viscera.
They line the peritoneum (which envelops many abdominal organs), the pleural sacs (which envelop the lungs) and the pericardial sac (which envelops the heart)
What are epithelia?
Sheets of continuous cells, of varied embryonic origin, that cover the external surface of the body and line internal surfaces
Do all epithelia sit on a basement membrane?
Yes
Describe the basement membrane:
thin, flexible, acellular layer
It lies between epithelial cells and the subtending connective tissue
What does the basement membrane consist of?
Basal lamina- laid down by epithelial cells (and therefore lies close to them) Reticular fibrils (type III collagen), elaborated by the subtending connective tissue.
When simple stratified epithelium lines the pleural sac, pericardial sac and peritoneum what is it called?
Mesothelium
What is endothelium?
Simple squamous epithelium lining all vascular elements (arterial, venous, capillary and lymphatic)
Locations of simple squamous epithelia
Lining of blood and lymph vessels (endothelium)
Lining of body cavities - pericardium, pleural sac, peritoneum (mesothelium)
Gas exchange epithelium (pulmonary alveoli)
Bowman’s capsule (kidney)
Loop of Henle (kidney)
What are the functions of epithelia?
Lubrication (pericardium, pleura, peritoneum/viscera)
Gas exchange (pulmonary alveoli)
Barrier (Bowman’s capsule)
Active transport by pianocytosis (mesothelium and endothelium)
Where can you find simple cuboidal epithelium?
Thyroid follicles
Small ducts of many exocrine glands
Kidney tubules
Surface of ovary (germinal epithelium)
What are the functions simple cuboidal epithelium?
Absorption and conduit (exocrine glands)
Absorption and secretion (kidney tubules)
Barrier/covering (ovary)
Hormone synthesis, storage and mobilisation (thyroid)
Where would you find simple columnar epithelium?
GI tract Stomach lining and gastric glands Small intestine and colon gallbladder Large ducts of some exocrine glands Oviducts Uterus Ductility efferentes of testis
Functions of simple columnar epithelium
Absorption - small intestine and colon
Secretion - stomach lining and gastric glands, small intestine and colon
Lubrication - small intestine and colon
Transport - oviduct
Do all pseudostratified cells have contact with the basement membrane?
Yes
Where would you find pseudostratified epithelium?
Lining of nasal cavity, trachea and bronchi
Epididymis and ductus deferens
Auditory tube and part of tympanic cavity
Lacrimal sac
Large excretory ducts
Functions of pseudostratified epithelia?
Secretion and conduit (respiratory tract, ductus deferens)
ABsorption (epididymis)
Mucus secretion (respiratory tract)
particle trapping and removal (respiratory tract)
When you’re naming stratified squamous cells, which cells do you look at to describe the shape?
A. Cells closest to the basement membrane
B. Cells furthest from the basement membrane
B. Cells furthest from the basement membrane.
Where would you find stratified squamous non-keratinised epithelium?
(Think about places where there may be abrasion)
Oral cavity Oesophagus Larynx Vagina Part of anal canal Surface of cornea Inner surface of eyelid
What are the functions of stratified squamous non-keratinised epithelium?
Protection against abrasion (all sites)
Reduces water loss but remains most (all sites)
What is the difference between keratinised and non-keratinised squamous epithelium?
Keratinised epithelium lose their nucleus e.g. Top layer of skin.
The epidermis has a rich blood supply. True or false?
False. The epidermis don’t have a blood supply. They get their nutrient by diffusion.
The dermis is well vascularised. True or false?
True.
Which cells wander round the dermis?
Langerhans cells.
Professional antigen presenting cell - present an antigen to present to T cells.
Good because we are often cut.
