Skeletal System Flashcards
ontogeny
embryonic development
gastrulation
process that creates the gut of the animal
neurulation
process of forming the neural tube
Organogenesis
formation of organs from tissue
maturation
process from birth/ hatching to adulthood
ectoderm
embryonic tissue layer
mesoderm
embryonic tissue layer
endoderm
embryonic tissue layer
Old hypothesis of ontogeny: ontogeny recapitulates phylogeny,
ontogeny is a condensed version of evolution, all went through fish phase
Alternative hypothesis of ontogeny: Law of the general to the specific
young embryos are undifferentiated, not until later in development that taxon-specific features arise
pharyngeal pouches
bays inside the embryonic pharynx
isometry
growing at same rate
allometry
growing at a different rate
How do vertebrates move?
by changing the angle between joints at the bone
exoskeleton
derived from the dermis or epidermis
endoskeleton
derived from the mesoderm within the body
dermal bone
ossifies directly from fibrous membranes, common in skull, jaws and shoulder girdle
endocranial bone
ossifies from hyaline cartilage, key to long bone formation
chondrocranium
lies in line with the vertebral column, initially formed from cartilage that supports the brain and sensory capsules, three parts: braincase, nasal capsule, and otic capsule
chondrocranium in bony fish is replaced by
endochondral/ cartilage bone
splanchnocraniumm
supports gills and respiratory structures; derives jaws, hyoid, and gill arches;as well as the jaws in gnathostomes composed of a series of arches that originally supported the pharyngeal slits
compenetns of mandibular (arch) jaws
palaroquadrate and Meckel’s cartilage
Palatoquandrate
dorsal component of the mandibular arch
Meckel’s cartilage
ventral component of the mandibular arch
dermatocranium
dermal bones that originally arose as bony armor in early fishes, in gnathostomes sunk and are associated with chondrocranium and splanchnocranium, in modern fish and amphibians the dermal bone is reduced; most bones are encased by bone-derived from the dermatocranium (surrounds everything)
serial theory
jaws arose from a single arch
composite theory
jaws arose from parts of several arches
palatoquadrate reduced to articular element that are called:
quadrate and epipterygoid
palatoquadrate is places by two bones derived from the facial series of the dermatocranium
maxilla and premaxilla
what forms dentry?
dermal bone that surrounds the Meckel’s cartilage
skull fenestration
increase in the ‘openness’ of the skull
cranial kinesis
increase (or decrease) in skull mobility
Sharpey’s fibres
specific collagen fibres that attach the tendon to the bone
ligaments
connects bone to bone
pterygoid walk
mobile bones slide beyond the brain case, detach upper jaw, crawling/ walking jaw along prey, bite down, move other
mammal akinetic skull
mammals lack cranial kinesis, more restricted jaw movement because of distinctive interlocking teeth
vertebral segments
cervical, thoracic, lumbar, sacral, coccygeal
dorsal arches
protect the neural tube, have neural and interneural arches
ventral arches
protect blood vessels, have hemal and interhemal arches
centra
form the ventral arches, support the notochord, have pleurocentrum and intercentrum arches
aspondyly
lack centra
monospondyly, dispondyly and polyspondyly
1,2, and 5-6 central per segment
true ribs
connect to the sternum
false ribs
connect to each other
floating ribs
have no distal connection
ribs connect othe vertebrate at two processes:
diapophyses and parapohysis
Role of intervertebral ligaments
keeps vertebrae in line
heterocercal
fish tail with unequal upper and lower lobes, creates lift when the are swung back and forth
water vs land
on water, the body of a fish is supported by the water surrounding it
on land, gravity acts to push downwards with the limb to resist
zygapophyses
interlock with adjacent vertebrae to resist torsion during their unique movementsacral regions
sacral region
strengthens the connection between the hind limbs and the axial skeleton
cervical vertebrae
allows the head to be lifted and moved independently from the front limbs
lumbar vertebrate
thoracic vertebrae that have lost their ribs
synsacrum
fusion of the caudal, sacral and lumbar vertebrae in birds
syndovial joints
allow for considerable motion
synarthrosis
joint that greatly restricts or permits relative movement
synovial hoint capsule
defines the synovial cavity
synovial memebrane
secrets synovial fluids
articular cartilage
caps ends of the bone within the cavity
hinge joints
allow motion is only one direction
pivot joints
allows rotary movement around one axis
condyloid joints
allow movement in two planes
saddle joints
shaped like a saddle and allow movement in two direction
ball and socket joints
allows circular motion, shoulder and hip joint
gliding plane joints
relatively flat surfaces between the bone, allowing for a great deal of gliding, writs and ankles
symphysis joints
associates with the midline of the body
syndemosis
bones are connected by dense fibrous tissue
synostosis
bones are directly connected, often called sutures
yield
permanent deformation occurs
strength
how much stress or deformation can be resisted before yield or fracture
fracture
actual separation of material, or break occurs
yield point
material failure, the material has weakened
plastic deformation
cant recover, is permanent
elastic deformation
weaker but can recover
fracture point
material has broken
strain energy absorption capability
the measure of toughness, the area under the curve
cantilever beams
bending with bother tension (top) and compression (bottom) has a neutral axis under no strain
second moment of area
the measure of how the material is distributed in cross-section, the more material distributed from the center,l the stiffer the beam
local buckling
failure in the walls of a tube
endotendon
within tendon
epitendon
surrounds tendon
paratendon
outside epitendon, allows the tendon to move against other tissue (buffer allows movement)
tendons
connect bone to muscle
two types of bone
compact and trabecular
osteon
cylindrical structure composed of osteocytes within the lamellar matrix
haversion canal
canal at center of the osteons, contain the blood supply
lamellae
matrix within the osteons are arranged a lamellae
calcium in bones
when blood Ca drops bone releases Ca into blood
bone marrow in bones
has resources to build red and white blood cells
modeling
changes shape, length and thickness of bone
remodeling
changes density, entirely internal and occurs through a lifetime
ostrocytes
hard matrix in bone
osteoblasts
creates bone material
osteoclasts
remove bone material
bisphosphonates
inhibit reabsorption of osteoclasts
osteoporosis
disease in the bones is associates with increased fracture risk as osteoblasts cant keep up with osteoclasts
fibril sliding
allows for the deformation of bone with out separation
