tissues Flashcards
exocrine gland
Secretions through ducts onto epithelial surfaces (Outside)
endocrine
Hormones, no ducts, Into blood & interstitial fluid (inside)
serous glands
Watery, serous solutions
–Often protein-rich
- mucous glands
–Thick, viscous, carbohydrate-rich
–Gel-like mucin glycoproteins
sebaceous gland
sebum – oily, waxy secretions
mixed glands
- both serous & mucous
Merocrine secretion
cell stays intact
ex: salivary gland
secretion from the bottom of epitheliam upward
Apocrine secretion
apex (top) breaks off and becomes part of the secretion
ex: maMMARY glands
Holocrine secretion
whole cell reptures
cells grow and divide at the base and cells at the top die and release secretion
ex: sebaceous gland of hair follicle
Connective tissue function
provides support & structure for
epithelial tissue
diverse and specialized
Extracellular Matrix is made of what
extracellular proteins and fluid like ground substance
Types of Extracellular Matrix (ECM)
Fibers
collagen
* reticular fibers– special type & arrangement of collagen
* elastic fibers
Ground Substance
Fluid & gel-like (except
bone & cartilage)
* Composition varies between tissues
* Often includes:
–glycosaminoglycans
–proteoglycans
–glycoproteins
*
“glyco-”: relating to
sugar
mesenchyme cell
Embryonic tissue
* Type of stem cell
* Loosely connected
& migrate
Stem Cells
- Stem cells can develop into
other types of cells - Stem cells can regenerate &
produce more stem cells
Differentiation
process by which stem cells
become specialized cells
– Stem cells “choose” certain
genes to develop into
specialized cells
Fibroblasts
Most abundant connective tissue cell type
* Secrete all types of ECM protein fibers
* Easily divide & regenerate
* Can develop into mature fibrocytes
blast”
“immature”
embryonic form of a cell
* Can divide to make more cells
cyte”
If a “-cyte” has a “-blast” form,
“-cyte” is the “mature” form
Fibroblasts
Most abundant cell type in Connective tissue proper Secrete proteins(e.g. collagen & elastin
-lots of protein synthesis