CH4(lec3) Histology Flashcards
Histology
The study of tissues
4 Type of Tissue
Epithelial 2)connective 3) muscles 4)nervous
Epithelial Tissue Functions
Protection; selective permeability; secretion; sensations
Cellularity Epithelial
Lots of cell (can look like one layer)
avascularity
Lack of blood supply
Characteristics of epithelial tissue(6)
Has cellularity 2) Polarity 3) Attaches to basement membrane 4) Avascularity 5) Innervation 6) High regenerative/reproduce capacity
Structure of Epithelial Tissue
1) Rest on Connective tissue and on top of basement membrane
Apical surface
Free surface
Basal surface
Attachment deeper
Basement Membrane components in order top to bot
Basal lamina and Reticular Lamina
Type of intercellular Junctions
1) Tight junctions 2) adhering junction 3) desmosomes 4) Gap junctions
Tight Junctions Characteristics
Held together Very closely 2) cells attach via membrane proteins at APICAL surface
Adhering junction
1) Has a adhesion belt 2) Deep to tight junction 3) Not as close as tight junction
Desmosomes
Made from Micro proteins and intermediate filaments anchored into PLAQUE only at a stress point
Hemidesmosomes
Half - desmosome - attached to the basement membrane
Gap junction
Gap is formed between cells by proteins called CONNEXONS(6 connexons form a pore between cells and allow for RAPID communication between adjacent cells (IE heart so it contracts at the same time)
Simple vs Stratified vs Pseudo stratified (epithelial cells)
Simple - 1 layer Stratified more than on layer or Pseudostratrified looks stratified but it is not
4 Shape of epithelial
Squamous 2) cuboidal 3) columnar 4) Transitional
Which cells do we make classification of shape on
Outermost
Squamous shape
Flat; Wide
Cuboidal shape
Similar height & width
Columnar shape
Taller than wide
Transition shape
Changes shape
Simple Squamous Epithelium is Found in
LUNGS; lining of alveoli; blood vessels(endothelium) serous cavities(mesothelium)
Simple Cuboidal Epithelium Found where
Kidney tubules
Simple Columnar Epithelium(non-ciliated) Found where and properties
In the digestive tract has microvilli (brush border) can have goblet cells
Stratified Squamous Epithelium Properties and Types
Outer layer is flat other layers are cuboidal or columnar. The basal layer has stem cells(can rapidly divide) Keratin and Non keratinized(protective protein)
Stratified Squamous Epithelium (keratinized) Location/Properties
Epidermis(outer layer skin) outer cell fill with keratin and die flaking off (dry)(color change and space)
Stratified Squamous Epithelium (non-keratinized) Property and location
No keratin cells are moist found in Oral cavity; pharynx; esophagus(slide); vagina(no color change or space)
Stratified Cuboidal Epithelium Location
Rare in Male urethra
Stratified Columnar Epithelium
Rare in Male urethra
Pseudostratrified Columnar Epithelium Location Properties
respiratory track; all cell touch basement membrane but not all cell reach apical surface can be ciliated or non ciliated
Pseudostratrified Columnar Epithelium (Ciliated) Location Properties
Respiratory track; PHARYNX has goblet cells(mucus)
Transition Epithelium Properties and Location
Outer surface is a dome shaped(stretched) Found in Urinal Bladder; ureters(kidney)