Histology Flashcards
histological features of skeletal muscle fibres (5)
striated unbranched multinucleated (syncytium formed) long cylinders peripheral nuclei just under sarcolemma
CT around muscle fibre =
around fascicle =
around muscle =
fibre = endomysium fascicle = perimysium muscle = epimysium
if cut transversely skeletal muscle fibres =
cardiac =
skeletal = cylindrical so all the same diameter cardiac = taper therefore different diameters
fibres in a motor unit are in the same site/scattered in a muscle?
scattered
aerobic fibres resistant to fatigue and produce less force =
type I - slow twitch
relatively uncommon skeletal muscle fibres
Type IIa - intermediate twitch
succinate dehydrogenase stain result on type I , IIa, IIx fibres
I = dark purple IIa = light purple IIx = white
cartilage is nourished by ___ because it is __
ECM diffusion
avascular
___ mature to chondrocytes - live in __ in ECM. __+__ ECM
chrondroblasts
lacuna
secrete and maintain
ECM in hyaline cartilage composition =
75% water
25% organic - 60% Type 2 collagen, 40% proteoglycan aggregates of GAGs bound to core protein and often linked to hyaluronan
thicker and linear bundles = ___ collagen
Type 1
finer and forms 3D meshwork = ___ collagen
Type 2
grossly hyaline looks = \_\_+\_\_ found in (5)
translucent and blue white
articular surfaces, tracheal rings, costal cartilage, epiphyseal growth plates, foetal precursor to bone
2 gross features of elastic cartilage =
light yellow and flexible
bands of packed collagen I interlaced with rows of chondrocytes surrounded by a small amount of ECM
grossly = white =
fibrocartilage
95% of Ca2+ in body is stored __
in bone
locations of haemopoeisis in adults =
axial skeleton
girdles
components of bone (4)
65% mineral (calciumhydroxypatitite crystals)
23% collagen
10% water
2% non collagen proteins
outer shell of diaphysis = ___ bone
cortical
epiphysis = __ bone
cancellous/trabecular
cortical and trabecular bone are both ___
lamellar
in cortical bone:
___ run through and branch to ___ = blood supply
Haversion canals
Volkmann’s canal
lines often found around osteons in cortical bone = ___ due to remodelling
cement lines
osteocytes in cortical bone have ___ that expand into ___ and pass nutrients cell-cell
dendrites
canaliculi
in trabeular bone:
lacks ____ because struts are thin
osteocytes get nutrients from ___
lack haversian canals
marrow spaces
osteoprogenitor cells are found ___ and are a pool of ___
on bone surfaces
reserve osteoblasts
cells that form bone =
osteoblasts
osteoblasts are found ___
they have plentiful __+__
on surface of developing bone
RER and mitochondria
ostecytes are found __
trapped in the matrix of bone
osteoclasts are ___ and ___
found on __
function =
large (>=40microns) multinucleated
bone surface
resorption
osteoclasts are derived from ___
macrophage lineage of cells
cutting cone in remodelling of bone =
osteoclasts drill in to bone > blood vessels form in tunnel and bring osteoblasts which lay down bone to line tunnel > continues until only Haversian canal remains
collection of osteoclasts and blasts involved in remodelling of bone =
BMU
basic multicellular unit
osteoblasts secrete __+++_ collectively known as ___ which becomes mineralised over time
collagen GAGs proteoglycans other organic components of the matrix = osteoid
