lecture 7, 8,: tissues Flashcards
Histology
study of tissue
What type of stain is used to see tissue better? What do they bind to? What do each stain?
Hemetoxylin and Eosin (H&E)
H:
binds to (-) charged olecules
stains DNA & RNA
E:
binds to (+) charged molecules
stains (+) charged amino acids of protein
List the 4 major types of tissue:
epithelial
nervous
muscle
connective
Describe the structural characteristics common to all types of epithelia:
include:
cellularity
polarity
attachment
vascularity
regeneration
What are the different cell to cell junctions?
Tight junction
Anchoring
Gap
What is the function of a tight junction?
- prevents diffusion
- fuses the outer layers of two plasma membranes
What is the function of a gap junction?
- permits diffusion
What are the two different types of anchor junctions? What are their functions
desmosomes:
ties two cells together
hemidesmosomes:
attaches cell to basement membrane
What are the different shapes and sizes of epithelial tissue?
size:
simple
stratified
pseudostratified
shape:
squamous
cuboidal
columnar
What is the size difference between squamous, cuboidal, and columnar?
squamous: width > height
cuboidal: width ≈ height
columnar: height > weight
What is transitional epithelial?
stretches when organs expand and protects organs
Exocrine vs Endocrine secretion
exo:
secretions produced by epithelia
through ducts
onto epithelial surfaces
endo:
secrete hormones
no ducts
into bloodstream/interstitial fluid
What are the 4 types of gland secretions?
serous glands
- water, serous solutions, protein rich
mucous glands
- thick, viscous, carb rich
- gel like mucin glycoproteins
sebaceous glands:
sebum - oily, waxy secretions
mixed glands:
both serous & mucous
What are the different “modes” of glandular secretion?
merocrine
apocrine
holocrine
How does merocrine secretion work?
- enclosed in vesicles
- move up to apex
- contents released via exocytosis
- no damage to cell
