Histo Epithelial Tissue Flashcards
What are the 2 main characteristics of Epithelial tissue?
Avascular and Innervated
What does Epithelial tissue rest on?
Basement membrane
Epithelium that is primarily involved in secretion is arranged as ____
Glands
What are the 3 surfaces to Epithelial tissue?
Apical Surface- faces the exterior surface/lumen of an enclosed tube
Basal Surface- rests on basement membrane and anchors the underlying CT
Lateral Surface- Communicates/attaches to the adjacent cells
What are the 3 types of Intracellular Junctions?
Tight/Occluding Junctions
Gap/Communicating Junctions
Anchoring Junctions
Describe Tight/Occluding Junctions
Impermeable by forming a barrier
Made up opf Occludins and Claudins
Describe Gap/Communicating Junctions
Fluid filled channels thaty connect cells and allows ions to pass through
Connexin aggregates to form the channel
What are the 3 types of Anchoring Junctions? Describe each
Adherins- Lateral adhesions involving cadherins that ineract with actin filaments
Desmosome- lateral adhesions involving cadherins that interact with intermediate filaments
Hemidesmosome- basal adhesions that involv integrins and intermediate filaments that anchor to the basal lamina
What type of Junction Does Bacteria that cause food poisoning affect and what does this cause?
What type of Junction Does H. Pylori affect and what does this cause?
Tight junctions are targeted within the intestines, which imparis them and leads to loss of tissue fluid into the intestinal lumen
Tight junctions are targeted within the stomach and impairs them, leading to gastric ulcers and increased permeability
What type of junctions does the Autoimmune disease Pemphigus Vulgaris affect? What does this cause?
Desmosomes
Leads to a reduction in cell-to-cell adhesion, caudsing blistering of the oral mucosa
What is the function of the basement membrane and where is it found?
Selective barrier between tissues and permists the diffusion of nutrients
Surrounds the cell
What is the function of Microvilli? Where are they found? What disease is associated with the loss of these?
Where are Microvilli found on the cell?
Increase the surface area by 20-30 times, which increases the cells ability to absorb nutrients
Celiacs disease is caused by the loss of microvilli on absorbative cells in the small intestines
Found on the apical surface
Where on the cell are Stereocilia found?
What is the function of stereocilia?
What are the 2 locations within the body that these cells are found?
Found on the apical surface of the cell
Long microvilli with very little to no mobility
Locations:
Epidydymis (non-motile)
Hair Cells of the Inner Ear (Motile)- the bending of these allow hearing
Where on the cell are cilia found?
What is the function of cilia?
What make up cilia?
Embryologically, what do they determine?
Found on the apical side of the cell
Their function is to beat like a wave and propel substances across the tissue
Made up of long, highly motile Microtubules
Cilia determine the location of the bodies organs such as the heart due to the way the wave is moving. Typically, our heart is on the left side of our body, but if the cilia are moving the opposite way this can displace our heart
What are the 2 types of simple squamous epithelium? Where are each found?
What is the function of simple squamous epithelium?
Endothelium- lining og blood and lymphatic vessels
Mesothelium- lining of serous membranes around alveoli in lungs and the loop of Henle in Kidney
Function- exchange, barrier, and lubrication
Where are simple cuboidal cells found?
What is their function?
Kidney tubules, bronchioles, and covering the ovary
Function is absorption, barrier, and secretion
Where are simople columnar cells located?
What is their function?
Auditory tubes, uterus, oviducts, stomach, small and large intestines, gallbladder
Function is absorption and secretion
Where are pseudostratified colunar cilia found?
Nasal cavity
Pharynx
Trachea
Bronchi
Functionis in absorption and secretion, debris and particulate movement