Epithelial Tissue Flashcards
What are the 6 characteristics of epithelia tissue?
Characteristics: Cellularity, polarity, attachment, avascular, innervation and regeneration
What are the differences between the apical, basal, and lateral domains of epithelia tissue?
Basal: on basal lamina, anchors cell to connective tissue
Apical: Top part/lumen - exposed to air
Lateral: communicates with neighbor cells/attaches to them
What are the four types of specializations the apical domain can have?
Cilia, Flagella, microvilli, and stereocilia
Characteristics of microvilli? (3)
On apical domain, contain actin core
absorptive properties
increase surface area
Stereocilia/Stereovilli (3)
On apical domain, contain actin core, long and immotile
Increase surface area
restricted to epididymis and sensory cells of inner ear
Cilia (4)
On apical domain, microtubule core
Motile so wave stuff away from tissue
Primary immotile function as sensors
Establish left from right
Flagella
Motile cilia
Provide movement for sperm
very long
Occluding Junctions cell to cell (tight junctions/ zonula occludens)
encircle cells near apical surface.
more junctions= less permeability
contain occludins and claudins
Anchoring junctions
use cadherins to laterally adhese adjacent cytoskeletons
2 types: zonula adherens and macula adheres (desmosomes)
Zonula adherens
interact with network of actin filaments inside cell
Macula adherens (desmosomes)
interacts with intermediate filaments
What type of junction is fluid filled that connect apposed cells, mediates commincation and use connexin?
Gap junctions
What are focal adhesions?
they are junctions that anchor actin filaments to basement membrane using integrins
What type of intracellular junction anchors intermediate filaments to basement membranes using integrins?
Hemidesmosomes
What are the three types of epithelia cells?
Simple/ stratified
Squamous cell, cuboidal cell, columnar cell
Location and function of simple squamous epithelium?
lining of blood/ lymphatic (endothelium), serous membranes (mesothelium), aveoli in lungs
exhange, barrier, lubrication
Location and function of simple cuboidal epithelium?
Kidney tubules, glands, ducts, bronchioles, covering ovaries
absorption, barrier, secretion
Location and function of simple columnar epithelium?
Auditory tubes, uterus, stomach, gallbladder
absorption and secretion
Location and function of pseudostratified columnar ciliated epithelium?
lining of nasal cavity, pharyn, trachea, bronchi
can contain globlet cell for mucous production
absorption, secretion, debris, and particulate movement
Location and function of Urothelium (stratified epithelium)?
dome shaped cells: urinary bladder, ureters, urethra
barrier, distensivle property (can extend:))
Location and function of nonkeratinized stratified squamous?
on apical surface flattened: oral cavity, pharynx, esophagus, anus, vagina, urethra, cornea
barrier and protection(for friction)
Location and function of keratinized stratified squamous?
Epidermis of skin
water barrier and protection (apical layer cells dont have nucleus)
Location and function of stratified cuboidal epithelium?
sweat glands & ducts, ovarian follicles, salivary gland ducts (DUCTS)
barrier and passageway
What is the difference between stratified and simple epithelium cells?
stratified has 2+ layers of cells, simple only has one
Location and function of basement membrane?
sheet of extracellular material under basal domain.
diffuses nutrients
Difference between mucous and serous membranes?
Mucous: secretes mucus eg: respiratory system
Serous: internal cavities of the body: mesothelium
What are the three types of exocrine glands?
Merocine, holocrine, apocrine
Merocrine gland
secretion by membrane bound vesicles to apical surface, undergo exocytosis
Holocrine (sebbaceous) gland
secretion accumulates in cell, apoptosis leads to cell debris released
Apocrine Gland (sweat/mamillary)
release of apical portion of cell, surrounded by cytoplasm in plasma membrane
Globlet cell (unicellular glands)
Mucus secreting cell found lining the intestines and respiratory tract
What will seromucous, mucous, and serous acini look like under microscope?
Mucous: will be clear/white
Seromucous: half white, with a pink/purple ‘hat’
Serous: all fully colored purple/pink
