Epithelial Tissues Flashcards
What are mucous membranes?
They line internal tube which open to the exterior and contain mucous secreting cells
E.g. Respiratory tract, urinary tract, Alimentary tract
Mucous membranes consist of what two layers?
Epithelium (attattched to basement membrane)
Lamina propria - adjacent connective tissue
In the alimentary tract there is a third layer of the mucous membrane, called?
Muscularis mucosae - smooth muscle cell layer
What two things are often present in the connective tissue of the lamina propria?
Peyers patches - aggregations of lymphocytes
Mucosal glands
What are serous membranes?
Thin two part membranes that line certain closed body cavities - envelope the viscera and secrete lubricating fluid that promotes relatively friction free movements of the structures they surround
Give three examples of serous membranes
Peritoneum - envelopes abdominal organs
Pleural sacs - envelope lungs
Pericardial sacs - envelopes heart
What are the outer and inner walls of the serous membrane called?
Outer - parietal serosa
Inner - visceral serosa
What does simple epithelia mean?
One cell thick
What s stratified epithelium?
More than one cell thick
What are the two main functions of the basement membrane?
Serves as a strong flexible layer for epithelial cell adhesion
Acts as a molecular and cellular filter
Name 3 places simple squamous epithelium is seen
Line the glomerulus and bow and capsule
Lines the entire circulatory system (called endothelium here)
Lines the serous membranes (called mesothelium here)
What’s the function of simple squamous epithelium?
Allows rapid exchange of nutrients and gases
Allows certain blood cells to enter tissues (active site by pinocytosis)
Name three locations containing simple cuboidal epithelium
Thyroid follicles
Lining small ducts of many exocrine glands
Kidney tubules
Surface of the ovaries
What are some of the functions of simple cuboidal epithelium?
Synthesis and storage or hormones e.g. Thyroxine
Absorption
Secretion
Barrier/covering
Where are simple columnar epithelium found?
Virtually all of the GI tract - stomach to anus
Gallbladder
Large ducts of exocrine glands
Uterus
What are some of the functions of simple columnar epithelium?
Absorption
Secretion
Lubrication
What is pseudostratisfied epithelium?
Looks like more than one layer of cells, but every cell makes contact with the basement membrane
Contains motile cilia and goblet cells
Where is psudostratisfied epithelium found?
Lining of the nasal cavity, trachea and bronchi
Epididymis and ductus deferens
Auditory tube
Large excretory ducts
What are some of the functions of psudostatisfied epithelium?
Secretion and conduit
Absorption
Particle trapping and removal
Where are non-keratinised stratified squamous epithelium located?
Oral cavity Oesophagus Vagina Part of anal canal Surface of cornea
What’s the function of non-keratinised stratified squamous epithelium?
Protection against abrasion
Reduces water loss, but remains moist
What’s the main difference between keratinised and nonkeratinised stratified squamous epithelium?
Keratinised has a dead cell layer on top (Stratum corneum) made up mainly of keratinocytes
Where is keratinised stratified squamous epithelium located?
Skin
Small amount in oral cavity
What are the four layers of skin epidermis?
Stratum corneum
Stratum granulosum
Stratum spinosum
Stratum basale
In which epidermis layer does keratinocyte cell division mainly occur?
Stratum basale
What is the main cell of the stratum corneum?
Corneocytes