quick histo test 2 Flashcards
alpha beta crystallin
heat shock protein that protects desmin from mechanical stress
dystrophin
protein that links alpha-actinin/desmin complex to cytoplasmic side of sarcmolemma
anchors actin to sarcolemma and reinforces sarcolemma during muscle contraction
associated with muscular dystrophy
dystroglycan complex
links dystrophin to laminin2
alpha actinin
attaches thin filaments to the Z line
nebulin
acts like a template for the regulation of thin filament length
extends from the Z line to end of actin filament
titin
generates passive tension through elastic extension when the sarcomere is stretched
extends from Z disk to middle of H band and connects ends of thick filaments to Z line
provides myosin with elasticity
centers thick filaments in the sarcomere
desmin
framework of desmin filaments which surrounds Z line and extends into each sarcomere
links myofibrils laterally and to the sarcolemma
plectin
binds desmin filaments
define satellite cells
attach to myotubes before basal lamina is laid down function as stem cells give rise to myogenic precursor cells
what are intrafusal fibers
part of muscle spindle
nuclear bag region is the sensory region, nuclear bag fibers, nuclear chain fibers
what are alpha motor neurons
part of muscle spindle that go to extrafusal fibers
what are gamma motor neurons
go to intrafusal fibers
what do ANP do
secreted by cardiac muscle cells in atria
regulate fluid electrolyte balance
relax vascular smooth muscle: reduces blood volume and pressure
stored as prohormone in secretory vesicles
release stimulated by atrial stress
what do dense bodies do
anchor actin filaments to each and to cell membrane
what is the direction of anterograde transport
cell body toward distal end of axon
what is the direction of retrograde transport
axon toward cell body
define golgi 1
neurons with long axons which leave the grey matter of which they are a part
define golgi 2
neurons with short axons which ramify through the gray matter
what uses anterograde slow SCA component
preassembled microtubules and neurofilaments
what uses SCb component of anterograde
enzymes, actin and clathrin
what uses intermediate anterograde transport
mitochondria and other membrane bound organelles
what uses fast anterograde transport
synaptic vesicles and neurotransmitters
what uses retrograde transport
endocytosed materials and recycled proteins
where are astrocytes found and what do they do
from neural crest and in CNS
regulate intracellular environ, structural support, BBB, development of cerebral cortex, K+ sink, scar tissue
where are oligodendrocytes found and what do they do
CNS (from neural crest)
closely associated with neuron cell bodes in gray matter and function as satellite cells
what are schwann cells and where are they found
derived from neural crest and in PNS
myelinate axons of PNS
what are microglial cells and where are they found
derived from macrophage precursors, in PNS
recruit leukocytes across BBB
immune response along with astrocytes
what are ependymal cells and where are they found
CNS function in transport
what are satellite cells
function as insulators
define intraperiod line
electron-dense line created by extracellular space between adjacent outer leaflets
define major protein zero
transmembrane protein that forms homodimers (only in PNS)
in neuromuscular spindles, intrafusal fibers within the neuromuscular spindles are supplied by which fiber
gamma fibers
what collagen forms a meshwork in the basement membranes
type 4
which type of cell is associated with the BBB
astrocytes
which cell types have a bilobed nucleus and specific granules containing major basic protein that disrupts parasite membranes
eusoinophil
in the hematopoetic lineage of the various granulocytes, which immature cell type may normally be found in the circulation
band cell
PTH stimulates osteoblasts to secrete express what
M-CSF and RANKL
in a skeletal muscle fibers, what extends from one myofibril to another and to the sarcolemma
desmin
what describes the olfactory mucosa
pseudo stratified columnar epithelium lacking goblet cells with no distinct basement membrane
what are osteoblasts characterized by
alkaine phosphatase (not found in osteocytes0 vitamine D3 (regulates expresso of osteocalcin)
what major protein product of osteoblasts has a high binding affinity for hydroxyapatite
osteocalcin
where are cells located in bone
lacunae
which of the following are not part of a aversion system?
periostem, lacunae, lamellae, volkman canal, canaliculi
periosteum
parathyroid hormone stimulates osteoblasts to secrete/express which of the following
M-CSF and RANKL
what do osteoblasts give rise to
osteoblasts and bone lining cells
what is intramembranous bone arrogation of mesenchymal cells controlled by (signals
Wnt, Hedghog, FGF, TGF-beta
what doe the trapped osteoblasts that become osteocytes form
functional syncytium
what does the osteoid include
collagen I and non-collagen proteins
what does the primary ossification center in intramembranous bone formation become
trabecular
how are collagen fibers arranged in woven bone
randomly
where does the primary ossification center occur in endochondral bone formation
future diaphysis of cartilage model
what secretes the vascular endothelial growth factor
chondrocytes
where does the secondary ossification center occur in endochondral bone formation
epiphyses
what is the function of the muscle spindle
detect length change in muscle
define caveolae
permanent depressions of the cell membrane that are involved in fluid and electrolyte transport
what initiates the formation of caveolae
caveolin binds to the cholesterol in the lipid rafts
what does atria natriuretic peptides do (ANP)
secreted by cardiac muscle cells in atria and regulate fluid electrolyte balance
*relax vascular smooth muscle which reduces blood volume and pressure
stored as prohormone in secretory vesicles
what do dense bodies do
communicate force of contraction to cytoskeleton and cell membrane
what is the micro architecture of a typical peripheral nerve
epineurium
perineurium
endoneurium
what is in the epineurium of the microarchitecture
thick fibrous coat, covers entire cell, supplied by blood and lymphatic vessels, type 1 collagen and fibroblasts
what is the perineurium
dense connective tissue, covers bundles of axons (fascicles) within nerve, epithelial-like fibroblasts on inner surface are joined by tight junctions
Blood nerve barrier
define blood nerve barrier
endothelial cells of vessels are also linked by tight junctions
what is in the endoneurium
thin layer of reticular connective tissue
surrounds individual fibers and schwann cells
type 3 collagen
what is plasma membrane associated proteolipid protein (PLP)
stabilizes adjacent stacks of membrane of oligodendrocytes. PLP has tetraspanin structure with short and long extracellular loops and 2 intracellular tails
define choroid plexus
highly infolded simple cuboidal epithelium that extends into the ventricles from the roof plate
what is the ependyma
layer of simple cuboidal epithelium that lines the ventricular walls
what is the difference between the postganglionic axons in sensory and autonomic ganglia
sensory: myelinated
autonomic: not myelinated
