Body tissue-epithelia/connective tissue Flashcards
What is the Epithelial tissue?
Densely arranged layers rich in cells
Arranged as Sheets or glands
Name 6 properties of epithelial tissue
SCALD A
Sheet or gland arrangement of cells
Constantly regenerate
Attach by a basement membrane to connective tissue
Little extracellular matrix
Densely packed cells
Avascular (nutrients thru basement membrane)
4 Functions of epithelial tissue? and an example of each
PASSE
Protection - e.g. tough skin
Absorption - e.g. epithelium of gut and lung
Secretion - e.g. Mucus, sweat
Sensory- e.g. epithelial structures on ear, nose, eye, skin
Excretion - e.g. waste products in kidney
What are the 2 types of epithelial tissue?
Membranous epithelium - lines blood vessels, lymphatic vessels, respiratory tract, digestive tract (oesophagus)
Glandular epithelium - follicles in endocrine and exocrine glands
How do epithelia attatchment to connective tissue?
Via the basement membrane
How do Epithelia obtain nutrients ?
Through basement membrane
What is the extracellular matrix
Outer shell of mammalian cells
Low in epithelial tissue
High in Connective tissue
Made of proteins mostly
Allows flexible strength to tissues
What is the extracellular matrix made up of
Low epithelial tissue
Hight connective tissue
Made mostly of proteins
- collagen ( mostly )
- elastin
- glycoproteins
- Integrin
Name the 4 main proteins in the extracellular matrix
and what they do
Collagen ( the main structural protein)- strong /flexible
Elastin - elastic and flexible, in coils
Glycoproteins - - fibronectin/laminin - attach collagen
Integrin - attaches ECM parts
Explain collagen structure
3 collagen strands twist ->-fibrous molecule
Fibrous molecules twist –> fibril
Fibrils twist in groups –> rope like collagen fibers
Explain a elastin structure
random coils held together by microfilaments (coiled so can stretch )
NAme 3 functions of connective tissue
Support to organs and body ( eg bone )
Transport to tissues/organs ( eg blood)
Defence against foreign invaders ( eg bacteria )
Name 3 main categories ( types of connective tissue )
Blood
Bone
Fibrous connective tissue
Name 5. types of fibrous connective tissue and an example
- Loose fibrous connective tissue ( connects structures in body )-thick gel like ( hyaluronic acid )
- Dense regular eg -tendons (collagen bundles ) or elastin bundles ( in arteries )
- Dense irregular ( outer muscle layers )
- Reticular ( bone marrow)
- Adipose ( fat )