How to examine cells and tissues (BL 2)i Flashcards
What does the Latin word ‘tissue’ mean?
Woven
What are the broad tissue classifications?
Epithelial
Connective
Muscle
Nerve
Where are epithelial cells often found?
On the edges of other tissues and surrounding other tissues
What does it mean when epithelial cells are described as polarised? (Usually when they’re at the surfaces)
Their top and bottom parts are very different
What do epithelial cells always have?
A basement membrane on the basal (lower surface)
Basement membrane is composed of the basal lamina and, below it, the reticular lamina
The reticular lamina may not be present but the basal lamina will always be there
What are clusters of epithelial cells found deep within other tissues called?
Glands
Epithelial cells often secrete something. If they do, where do they release it from?
The apical surface or the epithelium
How are epithelial cells held together?
By strong anchoring proteins
How do epithelial cells communicate?
Through junctions at their lateral and basal surfaces, rarely through the apical surfaces
What types of connective tissue are there?
Fibrous (tendons)
Loose (under skin)
Specialised (blood, bone, cartilage, adipose etc.)
What are the main cells in connective tissue?
Fibroblasts, chondrocytes, osteocytes/blasts/clasts, stem cells, progenitor cells, bone marrow, blood, adipocytes
What is the main cell type in connective tissue?
Fibroblasts
This is immature; when it’s mature, it becomes fixed in its phenotype
Can change into chondrocytes, osteocytes etc.
What do the main cells in connective tissues do?
Lay down extracellular proteins and glycoproteins, produce gels for contact between tissues
What are the main products of connective tissues?
Fibres (mainly collagen, some elastin in foetal development and many others)
Ground substance
Wax and gel-like materials (glucosaminooglycans)
What do glucosaminoglycans do?
Attract water, act as a lubricant or as a shock absorber
