17 Flashcards
where is connective tissue found
between two other tissues
What is CT made of
cells and ECM
what are the 5 types of connective tissue
Loose connective tissue – lines serous membranes
Dense connective tissue-dermis of skin
Bone and cartilage
Adipose tissue (also example of loose CT)
Blood (also example of loose CT)
what cells make up connective tissue and what is their main function
Fibroblast: found in skin dermis
Adipocytes-fat
Chondrocytes- in Cartilage
Osteocytes-in Bone
Haemopoietic (blood) cells
They all synthesise the ECM
What is one important structure that determines tissue physical properties)
the ECM
eg bone - abundant calcified ECM because of bone function
What are the two main classes of macromolecules in the ECM and what is their main function=
Polysaccharide chains (glycosaminoglycans, GAG) usually linked to a protein hence making proteoglycans --> gel in which cells and fibrous proteins are embedded
Fibrous proteins (collagen, elastin and fibronectin) important for structure, strength, flexibility, adhesion, cell positioning
where do proteoglycans assemble
in the ER and Golgi
GAG and proteoglycans can bind water to make gels. what is the main function of gels?
resist compressive force
permit rapid diffusion of nutrients, hormones, metabolites
What is the structure of GAG
linear chain of 20-100s disaccharides (usually sulfated) such as heparin sulfate
what’s a proteoglycan
one or more GAG attached to a core protein
e.g of proteoglycan is Biglycan: protein core+2 dermatan sulfate chains
ECM is also made up of fibrous proteins: collage, fibronectin, and elastin. what’s the most common type of collagen and what is its main function
collagen type I
provides tensile strength
mutation in collagen disease?
Ehlers-Danlos syndrome–> very elasticky skinm with very little structure integrity.
ECM is also made up of fibrous proteins: collage, fibronectin, and elastin. what’s the main characteristics and functions of elastin?
polymer of tropoelastin associated with fibrillin (glycoprotein)
To form elastic fibres (elastic fibres most common in arteries)
elastin is made of polymers of tropoelastin associated with fibrillin. what disease results from fibirilin gene mutaiton?
Marfin syndrom –> Ruptured arteries because of their rigidity.
ECM is also made up of fibrous proteins: collage, fibronectin, and elastin. what’s the main characteristics and functions of fibronectin?
Fibronectin fibre in ECM; circulating soluble fibronectin in plasma, body fluids
Fibronectin fibres binds other cells through PM proteins (integrins) and ECM proteins (collagen)
Cell attachment to ECM and matrix organisation
Guiding cell migration
– development, wound healing
Fibronectin fibres secreted and assembled by cultured cells
What are the three layers of the BM
Lamina densa (electron rich) Lamina lucida (electron light) and reticular lamina under thatattaches to the underlying dermis.
what’s the name of a cancer that has not broken through the BM
in situ carcinoma.
What diseases do mutations in junctional proteins of the BL result in
Junctional EB
What are the 5 types of epithelial junctions and their functions
Tight junctions (prevent passage of mucous across epithelium)
adherens. (tether adjacent cells together)
Desmosomal (Resist mechanical stress)
Gap (allow passage of small molecules between adjacent cells)
hemidesmosome (anchor epithelium to BM)
What kind of junction links the epithelial cells to the BM
hemidesmosome
What infectious. autoimmune and genetic disease is linked with deficiency is desmosomes
infectious: epidermal blisters
AI: pemphigus vulgaris
Genetic: desmoplakin Naxos disease
what are the different types of cilia that exist
primary cilia: non motile- nearly on all cells for signalling pathway and chemosensoring
motile cilia: on trachea to move bacteria
what is flagella made of
microtubule based skeleton
Cells can put up protrusions to help them migrate. examples of those include
Pseudopodia
Large protrusion of the whole front of the plasma membrane
Amoeboid movement - cell crawling. How? By altering surface cytoplasm and plasma membrane
Cell put out protrusions of the plasma membrane through actin polymerisation. Neutrophils move that way.
Lamellipodia and Filopodia
much more finger like movment than pseudopodia
cell movement, contact, environmental sensing
• lamelliopdia – much finer, ruffles; epithelial cells, fibroblasts cell migration
• filopodia – spikes (finger like); migrating neural growth cones, fibroblasts allow cells to sense environment
mirovili disease
infectious by enteropathogenic E coli –Z malabsorption and osmotic diarrhoea.
