misc Flashcards
what is the epiglottis, what does it do
the flap covering the trachea protecting it from food/debri
what are alveoli lined with and why
simple squamous epithelium, for easy diffusion of CO2 and O2 as alveoli are site of gas exchange
what is the trachea lined with and why
pseudostratified ciliated columnar epithelium, to clear away dust by secreting and clearing mucus
what are fibroblasts, where are they found, what do they do
fibroblasts are cells found widespread in most types of connective tissue. they secrete components of the ECM; collagen, elastin, GAGS/proteoglycans of the GS. they also secrete the reticular lamina of the BM.
what is the basement membrane made of, where does it come from.
basal lamina: secreted by epithelium, made of collagen, laminin, heparan sulphate, and more.
reticular lamina: secreted by connective tissue/fibroblasts. made of collagen, laminin, reticular fibres (which is collagen III), fibronectin, and more.
what is hyperacusis, what is a possible cause
sensitive hearing, could be caused by damage to the stapedius muscle which protects the stapes
what characteristic of GAGs allows them to attract water; why is this important
they are hydrophilic. allows them to trap water, thus creating the supportive gel-texture of the ground substance.
describe the cells involved in the making of bone
osteogenic cells are precursor cells which differentiate into osteoblasts. osteoblasts secrete collagen to form the bone matrix, which becomes mineralised (with Ca and P) to form solid bone.
what shape are skeletal muscle fibres
cylindrical, unbranched.
what does the M line do
hold together the thick filaments - keep them in correct orientation
order the zones/bands of the sarcomere from darkest - lightest
A band, H zone, I band.
what enzyme is involved in creation of IP3, how does it do this, what is its other product, and how does IP3 trigger further signalling?
phospholipase C. it is activated by a G-protein, and cleaves PIP2 phospholipid into DAG (a lipid) and IP3, which diffuses through the cytosol to open a gated ion channel in the ER, allowing Ca2+ to diffuse out along the conc gradient.
what is aminoacyl-tRNA synthesise?
enzyme that reloads amino acids to tRNA molecules in the cytoplasm
inter/intra molecular bonds are generally stronger? give example of each.
intra. e.g hydrogen bonds, even as the strongest bond between molecules, aren’t as strong as polar bonds within a molecule.
what is a tripeptide chain
a molecule consisting of three connected amino acids
give examples of contractile proteins, what do they do and where
e.g myosin and actin. they enable contraction, primarily but not exclusively in muscle fibres.
