ANAT2012 definitions Flashcards
cleavage
rapid mitotic division of zygote
blastomere
mitotic cleavage product of zygote
morula
precursor of blastocyst
blastocyst
structure containing embryoblast, walled by trophoblast
trophoblast
part of blastocyst which forms placenta
embryoblast
part of blastocyst which forms embryo
conception
implantation (7-10 days after fertilisation)
stress
force/area
strain
extension/original length
Young’s modulus/modulus of elasticity
stress/strain
parathyroid
enhances Ca2+ release from bone
indirectly stimulates osteoclast activity
calcitonin
inhibits Ca2+ absorption in intestines
inhibits osteoclast activity
elasticity
the ability of a solid to recover its shape when deforming forces are removed
viscoelasticity
materials for which the relationship between stress and strain depends on time
creep
if the stress is held constant the strain increases with time
stress relaxation
if the strain is held constant, the stress decreases with time
cyclic loading
application of repeated stress or strains
mechanotransduction
bone remodelling process due to stressors applied
anisotropy
the property of being directionally dependent
windlass mechanism
winding of the plantar fascia shortens the distance between the calcaneus and metatarsals to elevate the medial longitudinal arch
hysteresis
the energy put into the tissue is more than that recovered (lost as heat)
complex joint
contains intracapsular disc, labrum or meniscus
osteokinematics
movement of bones (not joints)
arthrokinematics
movement of joints (no reference to forces)
anatomical axis
related to structure (eg. longitudinally through long bone)
mechanical axis
related to joint (perpendicular to joint surfaces)
spin
mechanical axis is centre of rotation
slide
orientation of mechanical axis does not change, position does
roll
orientation of mechanical axis constantly changing
chondral-apophyseal enthesis
more zones
small attachment sites
periosteal-diaphyseal enthesis
less zones
large attachment sites
mechanobiology
mechanical load influencing the structure of MSK tissue
tribology
the science of interacting surfaces in relative motion
boundary layer lubrication
few molecules thick
relies on chemical properties
fluid film lubrication
finite thickness
relies on physical properties
medial and ventral motorneuron pools
proximal limb
dorsal and lateral motorneuron pools
distal limb
central pattern generator
a flexible network of interneurons than can produce purposeful movement in response to stimulus
inhibatory neurotransmitter
GABA
glycine
excitatory neurotransmitter
glutamatergic
pacemaker cell
triggers rhythmic activity of non-pacemaker cells
V0 interneuron
left-right alternations
V1 interneuron
locomotor rhythm regulation
V2a interneuron
left-right alternations
rhythm robustness