Flashcards in Tissues Deck (42):
what is the general function of epithelial tissue? (4)
- cover surfaces
- connect cells
- separate compartments
- attach to basal membrane
what does the basal membrane consist of?
basal lamina and reticular lamina
what is the structure of cilia?
- projections from apical surface
- formed form tubulin (9+2 arrangement)
what are the similarities and differences between cilia and microvilli?
- both projections from apical surface
- microvilli shorter and thinner than cilia
- microvilli supported by actin cytoskeleton and spectrin cross links
what are the types of classification for epithelial cells?
what types of exocrine glands are there? (3)
what is the function of exocrine glands?
to secrete directly onto surfaces or spaces (usually via ducts)
what do mucous glands secrete?
seceretions rich in proteoglycans
what do serous glands secrete?
watery protein rich secretions
what are myoepithelial cells?
epithelial cells that have differentiated into muscle cells
- these surrond exocrine glands and contract to force the secretions out
what do endocrine glands secrete?
- e.g peptide or steroid hormones
where do endocrine glands secrete?
dircetly into the bloodstream
how are steroid hormones stored?
stored as a lipid precursor in a lipid droplet
why are steroids stored as lipid precursors?
steroid hormones can travel directly through cell membrabes
which gland secretes steroid hormones?
what type of epithelial cells are found in the liver?
what structure do epithelial cells in the kidneys form?
what is the parenchyma of an organ?
the main bulk of the organ
what can cause abnormal function of glands?
- under/ over proliferation
- under/over secretion
- loss of cilia
- loss of ciliary beat
what types of tissue are included as connective tissue?
what properties does collagen have? (3)
- high tensile strength
which cells produce collagen?
how many types of collagen are there?
how do collagen fibres form?
1. polypeptides fold to form a triple helix
2. these helices twist together to form a microfibril
3. these microfibrils then join together to form a fibril
4. the fibril goes on the form a collagen fibre
where would type 1 collagen be found?
where would type 4 collagen be found?
in the basal lamina (reticulin)
what are elastic fibres formed from?
fibrin and elastin
what properties do elastic fibres have?
- can stretch 1.5 times and return to original shape
- have a yellow colour
-form flat sheets
what does extracellular matrix consist of? (3)
- glycoproteins (laminin and fibronectin)
- tissue fluid
- ground substance
what does ground substnace consist of?
- proteoglycans (protein core and GAGS)
- hyaluronic acid
what are proteoglycans?
carbohydrate rich chains
what cells are permanent loose conncetive tissue? (5)
- mast cells
- undifferentiated meshenchyme cells
what cells are transient loose conncetive tissue?
white blood cells
what structure does dense regular conncetive tissue have?
collagen bundles aligned in one direction with parallel orientations
give an exmaple of dense regular conncetive tissue
what structure does dense irregular connective tissue have?
bundles arranged in a 3-D shape, allowing force from all directions to be applied
give an example of dense irregular tissue
where would you find simple squamous epitheial tissue?
the lining of all vascular elements e.g lining of arteries
where would you find simple cuboidal epithelial tissue?
in the ducts of many glands
where would you find simple columnar epithelial tissue?
the lining of the gut and larger ducts of exocrine glands
where would you find stratified squamous epithelial tissue?
buccal mucose, pharynx, larynx