Lecture 2 Flashcards
What are the functions of the simple squamous?
Diffusion, Secretion (lube), Filtration
What is the main function of epithelial tissues?
Covering, Secretion, Receptors
What are the three sections of epithelium?
Apical, Lateral, Basal
Where are simple squamous epithelium located?
Bowman’s capsule (kidney), Insides of Cardiovascular and Lymphatic systems, alveoli, linings of blood vessels and heart. Eardrum tympanic membrane.
What are the subtypes of simple squamous?
Mesothelium (pericardial, pluera, peritonium), Endothelium (insides of heart and blood vessels)
What is the appearance of simple squamous?
Thin, Flat, like lots of fried eggs
What is the function of simple cuboidal tissues?
Absorption and Secretion
What is the appearance of Simple Cuboidal Epithelium?
Cuboidal or Hexagonal, Nuclei are positioned at the centre of
Where are simple cuboidal epithelium located?
Pancreas ducts, kidney tubules, secretory chambers of thyroid, anterior surface of eye lens, smaller ducts of many glands, ovaries surface
What is the function of Non Ciliated Simple Columnar Epithelium?
Absorption, Secretion/lubrication
What is the function of ciliated simple columnar epithelium?
Moving foreign particles, mucus and oocytes
What is the appearance of simple columnar epithelium
Rectangular or tall hexagonal, elongated nuclei are positioned near the base
What types of Epithelia have ciliated and non ciliated (microvilli) subtypes?
Simple arrangements only (Pseudostratified Columnar and Simple columnar)
Why is simple columnar epithelium more metabolically active than simple squamous?
It has more organelles/cytoplasm
Where are non ciliated simple columnar epithelium located?
Lines gut mucosa from stomach to anus, ducts of many glands, gallbladder
where are ciliated simple columnar epithelium located?
some bronchioles, uterine fallopian tube, central canal of spinal cord, brain ventricles
Where are stratified cuboidal epithelium cells located?
Ducts of certain endocrine glands (mammary, sweat, salivary), parts of male urethra
What is the function of stratified cuboidal epithelium?
Limited Protection and Secretion
What is the appearance of stratified cuboidal epithelium?
Multiple layers of cuboidal epithelium
What is the function of stratified columnar epithelium?
Protection, Secretion, Absorption
Where are stratified columnar epithelium located?
Parts of male urethra, Anus, Pharynx, Conjunctiva of eye
What type of epithelium is transitional?
Stratified
What is the shape of transitional epithelium?
They’re larger and more rounded than normal cuboidal/columnar when tissue is not stretched and squamous when tissue is stretched
What are the functions of transitional epithelium?
Volume control (stretching), Impermeability
Where are Transitional Epithelium located?
Urinary bladder, Ureters, Proximal urethra
What are the proteins involved in tight junctions?
Actin filaments, Claudins, Occludins, zona-occuldins type 1,2,3
Which type of Epithelia can be keratinised?
Stratified Squamous
What is the function of tight junctions
Forms a watertight seal which prevents ions and water from passing through
What are the protein/fibres involved in gap junctions?
Connexons (6 connexins), Keratin filaments
What is the function of gap junctions?
To allow a channel where substances can pass through
What are simple glands?
Singular main duct (can have branches)
What are the proteins involved in Adherens junction
Cadherins, Calcium ions, Catenins, Vinculin, Actin Filaments
What is the function of Adherens Junctions?
Resist abrasive and shearing forces
What are compound glands?
Multiple main ducts which are branched
What are the proteins involved in Desmosomes
Cadherins, (Calcium ions), Desmoplakin, Keratin Filaments
Tubular vs Acinar vs Tubuloacinar
Tube shaped (larger lumen)– Round shaped (smaller lumen) – both tube shaped and round shaped
What is the function of desmosomes?
resisting abrasive and shearing forces (stronger than adherens)
What are the proteins involved in Hemidesmosomes
Integrin, Laminin, Keratin filaments
What is the function of Hemidesmosomes
Anchors the epithelium tissue to basement membrane