Cells & Tissues Lecture 2 Flashcards
Arrangement of epithelium cells?
Continuous sheets, single or multiple layers
Epithelium cells are held together by?
Cell junctions = tight junctions, adherens junctions, desmosome, gap functions (lateral), hemidesmosome (basal)
Function of epithelial tissues?
Secretory (free surface), protection (abrasion), selective barrier (limit or aid transfer)
Draw tight junction and label
Pic
Draw adherens junction and label
Pic
Draw gap junction and label
Pic
Draw desmosome and label
Pic
Draw hemidesmosome and label
Pic
Cytoskeleton makeup?
Microfilaments - ACTIN -bundles beneath cell membrane and cytoplasm; strength, alter cell shape; link cytoplasm to membrane; tie cells together; muscle contraction
Intermediate filaments - KERATIN -Cytoskeleton strength; may move some materials through cytoplasm
Junctional complex?
Tight junction + adherens junction + desmosome
Basement membrane is made up of two things?
Basal lamina (just underneath the cells) secreted by the epithelial cells containing collagen, laminin, other proteoglycans, glycoproteins Reticular lamina (underneath the basal lamina) produced by cells of the underlying connective tissue known as fibroblasts containing fibrous proteins such as fibronectin, collagen
Epithelium contain _ but not _?
Nerves, blood vessels (avascular)
Where does diffusion of nutrients and waste take place?
From the blood vessels in the connective tissue
What are the functions of the basal membrane?
Supports overlying epithelium, provides a surface where epithelial cells migrate during growth and wound healing, acts as a physical barrier
Melanoma stages…?
A = asymmetry B = blood irregularity (rough edges) C = colour D = diameter > 6mm
Two types of epithelial tissues?
Covering and lining epithelia, glandular epithelia
Three types of arrangement for epithelial cells?
Simple, stratified, pseudostratified
Four shapes of epithelial cells?
Squamous, cuboidal, columnar, transitional
Simple squamous epithelium?
Secretion, filtration, diffusion
Endothelium lining blood vessels; Mesothelium visceral
cavity lining.
In Bowman’s capsule, inside eye, alveoli, visceral cavity linings, inside blood vessels and inside heart
Simple cuboidal epithelium?
Secretion, absorption
Pancreas ducts; parts of kidney ducts; secretory chambers of
thyroid; lens surface; pigmented epithelium at posterior of retina
Non-ciliated simple columnar epithelium?
Secretion, lubrication (mucus goblet cells), absorption
Microvilli (increased surface area), goblet cells
Gastrointestinal tract from stomach to anus ;
ducts of many glands; gall bladder
Ciliated simple columnar epithelium?
Goblet cells, cilia help move mucus and foreign objects or oocytes
Some bronchioles, fallopian tubes, sinuses; central canal of spinal cord, ventricles of brain
Non-Keratinised stratified squamous epithelium?
Protection from abrasion, defence from microbes, require secretions
Mouth, throat, tongue, esophagus, anus, and vagina
Keratinised stratified squamous epithelium?
Dead (keratinised) skin cells sitting atop the living skin cells
Stratified columnar epithelium?
Part of urethra, some large gland
ducts such as oesophageal glands, anal
mucosal membrane, part of conjunctiva
of the eye
Stratified cuboidal epithelium?
Ducts of adult sweat glands, oesophageal
glands, male urethra
Stratified transitional epithelium?
Bladder (some parts of ureter and
urethra)
Non-ciliated psuedostratified columnar epithelium?
No cilia, no goblet cells, absorption and protection
Larger ducts of glands, epididymis, part of male urethra.
Ciliated psuedostratified columnar epithelium?
Cilia, goblet cells, secretes mucus
Upper airway tracts
Two types of glandular epithelia?
Endocrine, exocrine
Endocrine gland?
Secrete directly into blood usually via traversing
interstitial fluid
Pituitary, pineal, thyroid, parathyroid
Exocrine gland?
Secrete into ducts that empty onto the surface of a covering or lining epithelium
Sweat and salivary glands; oil glands; wax glands, pancreas
