Phys exam 1 review questions

what are the 3 layers of the basement membrane and what tissues are they made of?

basal lamina- lamina lucida, lamina densa - epithelial cells
reticular lamina - connective tissue cells

lamina propria

connective tissue found under basement membrane

what are the layers that make up the mucosal layer?

epithelium, lamina propria, muscularis mucosae

does epithelial tissue or connective tissue have direct blood supply?

epithelial do not, while most connective do

can epithelial cells undergo cell division?

yes they do undergo cell division

is extracellular matrix associated only with connective tissue?

no it's present in multiple cells

what is extracellular matrix made of?

fibers and ground substance

what are the 3 types of fibers in extracellular matrix?

elastic fibers, collagen fibers, reticular fibers

what are the 3 structural categories of collagen fibers and where do the collagen types fall?

FIbrillar collagens - types I,II,III
network/sheet-forming collagens - type IV
linking/anchoring collagens- type VII

what type of collagen is located in the basal lamina?

anchoring/linking collagens

which nutrient is required for synthesis of collagen?

vitamin C

what type of collagen is found in reticular fibers?

type III

how does elastin differ from collagen?

its more diverse - it's made of amino acids

how far can an elastic/collagen fiber stretch beyond its resting length?

elastic can stretch 50%, fibrillar can stretch 5-10%

genetic mutations in collagen or elastin lead to which diseases?

blue sclera, osteogenesis imperfecta
bleeding gums, loss of teeth, rupture of blood vessels, skin wounds fail to heal, weakened bones

alpha1-antitripsin deficiency affects which type of protein fiber?

elastin- body degrades elastin prematurely due to excess elastase activity
lung disease common

which large protein molecules are found in the ground substance of ECM?

glycosaminoglycans (GAGs), proteoglycans, glycoproteins, water

what are proteoglycans made of?

hyaluronic acid and sulfated glycosaminoglycans
GAGs bristles on a protein brush core

what are the most common GAGs?

what impacts does the negative structure of GAGs have on its function?

negative charges repel each other and are slippery to slide past each other

what is the difference between a proteoglycan monomer and aggregate?

proteoglycan monomer is singular bottle brush structure, aggregate is many monomers on a hyaluronic acid backbone attached to cell surface

what are the functions of proteoglycans within the ECM?

they resist compression and are hydrophilic to attract positively charged ions and water for rehydration

what are the 3 binding domains for adhesive glycoproteins?

fibronectin, laminin,

what is the main adhesive protein in connective tissue?

fibronectin

what is the main adhesive protein in epithelial tissue?

laminin

how does the ECM prevent or slow down infections?

what is extracellular fluid? how does its composition compare to that of blood plasma?

body fluid that is not contained in cells
blood plasma

what are the 5 types of cell junctions discussed in lecture?

gap junctions, desmosomes, tight junctions, hemidesmosomes, adherens junction

which type of cell junction is generally found holding epithelial cells together?

tight junction

which cell junction anchors bundles of actin myofilaments between cells? which cell junction anchors intermediate filaments between cells?

adherens junction

which is the difference between a desmosome and a hemi-desmosome?

hemi-desmosome is desmosome sewed in half, hemi-desmosome anchors intermediate filaments to basal lamina while desmosome joins intermediate filaments to each other

which cell junction is involved in passage of ions or small molecules between adjacent cells?

gap junction

what are the 4 types of cell adhesion molecules discussed in lecture?

cadherin, selectin, integrin, immunoglobulin superfamily

which type of cell junctions contain cadherin proteins?

adherens junction

what do integrins bind to for cell-cell or cell-ECM interactions?

cell-cell bind integrin, cell-ECM bind collagen fibers or fibronectin

improper function of which cell adhesion molecule is involved in cancer and pemphigus?

cadherin- activity loss lead to epithelial tumors, pemphigus is autoimmune disrupting cadherin adhesion

improper function of which cell adhesion molecule is involved leukocyte adhesion deficiency?

integrins - they can't migrate, so they can't bind to anything

which type of cell adhesion molecule is overexpressed during asthma and rheumatoid arthritis?

ICAM-1 in asthma, integrin LFA-1/ICAM-2 in rheumatoid arthritis

what does selectin do?

allow cells to transiently interact with other cells
bind specific sugars (sugar code)

how are cell adhesion molecules involved in the 4 steps of extravasion?

1- selectin on leukocyte binds to its ligand causing rolling of leukocyte
2- activation of integrin on leukocyte
3- integrin can bind to its ligand
4- diapedesis occurs- movement of leukocyte through endothelial layer