Bones 1
true or false: flat bones have periosteum and endosteum
true
what percentage of organic and inorganic components make up a bone
35% organic & 65% inorganic
what is the specialized contractile organelle
myofibril
define a triad
a T-tubule flanked by two terminal cisternae
what are the special characteristics of neurons
longevity, no mitosis, and high metabolic rate
what is the least abundant support cell of the CNS and its function
microglial cells, macrophages and phagocytes to engulf dead cells and microorganisms
how does the cornea get its nutrients
from the oxygen of the outside environment and the aqueous humor
how do the macula and otoliths contribute to sensing static equilibrium
the otolithic membrane and otoliths push the cilia which send movement signals to the nerves
what is the name of the spongy bone in flat bones
dipolë
what is osteogenesis
the process of bone tissue formation
what is a sarcomere
a basic unit of contraction
define eccentric v concentric contraction
concentric: the muscle shorten and does work
eccentric: the muscle generates force as it lengthens (resisting gravity)
what are the 5 different types of synapses
axodendritic, axosomatic, axoaxonic, dendrodendritic, dendrodomatic
what is the epithelial support cell of the CNS and its function
enendymal cells, help circulate CSF
true or false: the cornea is avascular but innervated
true
what is the structure in the semicircular canals that sense rotational acceleration
crista ampullaris
what is an osteon
a long cylindrical structure oriented parallel to the long axis of the bone and to the main compression stresses
what embryonic tissue does bone originate from
mesenchyme
what are the boundaries of each sarcomere called
Z discs/ Z lines
what is optimal resting length of a muscle
the length that will generate the greatest pulling force which is slightly stretched and moderate overlap of thick and thin filaments
what are the different structural classifications of neurons
multipolar, bipolar, and unipolar/pseudounipolar
which CNS support cell produces myelin sheath
oligodendrocytes
what is the function of the choroid coat
absorbs light and prevents it from scattering
what are the muscles of the middle ear called
tensor tympani and stapedius
describe the composition of an osteon
composed of concentric tubes like tree rings called lamella which have fibers and crystals that alternate directions between adjacent lamellae
-define endochondral ossification
bone forms by replacing hyaline cartilage
which band of a sarcomere does not change in length
A band
what are the two functions of titin
holds thick filaments in place and contributed to muscle elasticity
what are the support cells of the nervous system
astrocytes, microglial cells, oligodendrocytes, ependymal cells, satellite cells, and schwann cells
which PNS support cell surrounds cell bodies with ganglia
satellite cells
-what do the different types of photoreceptors do
rods: darkness and grey tone photoreceptor
cones: color receptors, work with high light levels
what hearing structure of the spiral organ of corti does not move with vibrations
tectorial membrane
true or false: spongy bone contains osteons
false
define intramembranous ossification
bone develops from mesenchyme without first being cartilage
what ion is used in muscle contraction
Calcium ion
which of the there muscle types are not called fibers
cardiac muscle
what is the most abundant support cell of the CNS and its function
astrocytes, recycle neurotransmitters, ion release and intake, involved in synapse formation
which PNS support cell produces myelin sheath
schwann cells
what are the neural cell layers from superficial to deep
photoreceptors, bipolar cells, ganglion
what is the membrane of the roof of the cochlear duct
vestibular membrane