SKELETAL SYTEM Flashcards
Considered the most important organ system in the study of vertebrate morphology
significance to morphology of the skeletal system
The __ is a group of organs that originates
from the endodermic cells of the developing embryo. The organs of the skeletal system (osteo-) is primarily
composed of two (2) types of cells
skeletal system
(2) types of cells in the skeletal system
cartilaginous cells (chondrocytes and chondroblasts)
calcified cells (osseous cells –osteocytes, osteoclasts and osteoblasts)
forms an important part of the endoskeleton in ALL VERTEBRATES
cartilage
Comprise the most of the endoskeleton in HIGHER VERTEBRATES
bones
Inorganic components of bone comprises __% of the dry weight (calcium hydroxyapatite
crystal) – gives compressive strength
60%
organic component of bone – gives bone tensile strength
collagen
Provides support and movement
* Protects vital organs
* Major site of red marrow for production of blood cells.
* Plays a role in the metabolism of minerals (calcium and phosphate)
bones
(2) basic structural types of bones
compact bone
spongy bone
type of bone
solid, strong bone that is resisstant to bending located alonf he diaphysis of long bones
provides solid structure to the skeletal frame
forms a hollow tube called the medullary cavity
compact bone
type of bone
made of many branching, bony plates
located in the epiphysis of long bones
spongy bone
type of bone
reduces the weight of the bone
provides strength to bones especially against forces of compression (standing, running)
bone marrow is house between the bony plates
spongy bone
(2) bone formation
endochondral
intramembranous
type of bone formation
highly organizeed transformation of cartilage to bone
occurs at the primary and secondary ossification centers
all tubular and flat bones; vertebrae; base of the skull; the ethmoid; medial and lateral ends of the clavicles
stops after skeletal maturity
contributes to increase in bone length
endochondral bone formation
type of bone formation
appositional periosteal bone formation
cortex of tubula and flat bones; bones of the skll (calvarium); facial bones
increase in bone thicknes
partitcipates in the remodeling process throughout life
intramembranous bone formation
the vertebrate skull conists of (3)
neurocranium/chondrocranium
splanchnocranium
dermatocranium
composition of the vertebrate skull
includes the box that encloses the brain and the capsules surrounding the sense organs
protects the brain
neurocranium/chondrocranium
composition of the vertebrate skull
the visceral portion of the skull that supports the gills and contributes to the jaws
splanchnocranium
composition of the vertebrate skull
the dermal bone that is believed to be derived from the external armor of primitive fish
this bone contributes to the brain case and the jaws
dermatocranium
retin a carilaginous enruocranium (or chondrocranium) throughout life
cartilaginous fishes
retain highly cartilaginous neurocranium that is covered by membrane bone
bony fishes, lungfishes, & most ganoids
embryonic cartilaginous neurcranium is largely replaced by replacement bone (the process of endochondral ossificaition occurs almost simultaneously at several ossification centers)
other bony vertebrates
(4) neurocranial ossification centers
occipital center
sphenoid center
ethmoid center
otic centers
neurocranial ossification center
tend to remain cartilaginous and form:
anterior to sphenoid
cribiform plate of ethmoid & several conchae (or ethmoturbinal bones)
ethmoid centers
neurocranial ossification center
cartilage surrounding the foramen mgnum may b replaced by a many as four bones
occipital centers
neurocranial ossification center
forms the:
basisphenoid bone (anterior to basioccipital)
presphenoid bone
side walls above the basisphenod & presphenoid form:
-orbitosphenoid
-pleurosphenoid
-alisphenoid
sphenoid centers
neurocranial ossification center
the cartilaginous otic capsule is replaced in lower vertebrates by several bones:
prootic
opisthotic
epiotic
otic centers
in most mammals, the nasal chamber is large and filled with ridges from the ethmoid bones called the __ or __. these bones are covered with __ epithelium in life and serve to increase the surface area for olfaction (i.e. a more acute sese of smell)
another ethmoid bone, the __, separates the nasal chamber from the brain cavity within the skull
turbinals
ethmoturbinals
cribiform plate
Several cartilaginous of the embryonic neurocranium remains in adults as more or less independent cartilages
evolution of chondrocranium
retain a chondrocranium throughout life
cartilaginous fishes
retain highly cartilaginous neurocranium
bony fishes, lungfishes, and most ganoids
embryonic cartilaginous neurocranium is larely replaced by bone
tetrapods
(4) types of skull based on fenestrae (temporal openings)
anapsid skull
euryapsid skull
synapsid skull
the primitive skull, has no temporal fenestra, possessed by turtles and other primitive reptiles
anapsid skull
has 2 temporal fenestrae, possessed by most members of the diapsida including crocodile, birds, and lizards
diapsid skull
a derived diapsid
skull where the lwoer temporal fenestra is losr
euryapsid skull
has one fenestra located in a different place than the euryapsid skull
synapsid skull
composed of deermal bones that ovelrie the chondrocranium and splanchnocranium
forms the sides and roof of the skull, protecting the brain, it also forms most of the bony lining of the roof of the mouth and encases much of the splanchnocranium
completes the protective cover of the brain and jaws
dermatocranium
__ and _ have simple skull and the number of dermal bones present is reduced, some have tended to be lost or fused
modern fishes
amphibians
in __, the dermal bones predominte, forming most of the braincase and lwoer jaw; they are divided into 6 series of bones
amniotes
(6) parts of dermatocranium
facial series
orbital series
temporal series
vault series or roofing bones
palatal series
mandibular series
part of dermatocranium
enciircles the external naris forming the snout
facial series
part of dermatocranium
encircles the eye defining the orbit
orbital series
part of dermatocranium
lis behind the orbit completing the posterior wall of the braincase
temporal series
part of dermatocraniumlocatedacross the top of skull covering the brain beneath
vault series or roofing bones
part of dermatocranium
dermal bones of the primary palate covering the roof of the mouth
palatal series
part of dermatocranium
encases the Meckel’s cartilage
mandibular series
an ancient chordate structure associated with the filter feeding surfaces
arises from the neural crest cells departed from the sides of the neural tube and migrate into the walls of the pharynx between successive pharyngeal slits
splanchnocranium
make up the skeleton of the jaws and gills in fishes and amphibians
may remain cartilaginous or become covered by dermal bone
splanchnocranium
(6) types of jaw attachments
paleostylic
euautostylic
amphistylic
hyostylic
metautostylic
craniostylic
type of jaw attachment
Agnathans
none of the arches attach directly to the skull
paleostylic
type of jaw attachment
the earliest jawed conditin
placoderms and acanthodians
the mandibular arch is suspended from the skull by itself without aid from the hyoid arch
euautostylic
type of jaw attachment
early sharks, some osteichthyians and crossopterygians
attached to the braincase through two primary articulations
anteriorly by a ligament connecting the palatoquadrate to the skull
posteriorly by the hyomandubula
amphistylic
type of jaw attachment
most modern bony fishes
the mandibular arch is attached to the braincase primarily through the hyomandibula with the aid of the sympletic bone
hyostylic
type of jaw attachment
most amphibians, reptiles and birds
attached to the braincase directly through the quadrate bone
formed in the posterior pat of the palatoquadrate
metautostylic
type of jaw attachment
mammals
the entire upper jaw is a part of the braincase but the lower jaw called dentary bone is suspended from the dermal lsquamosal bone of the braincase
the palatoquadrate and Meckel’s cartilages remain cartilaginous except at their posterior ends which becomes the incus and malleus of the middle ear respectively
craniostylic
(3) parts of the postcranial skeleton
axial
appendicular
(5) functions of the body skeleton
protects the viscera
contributes to ventilation of the lungs
provides rigidity of the body
provides series of firm and hinged segments needed for locomotion in conjunction withthe muscles
function of the axial skeleton
forms the main axis of the body
(6) composition of the axial skeleton
notochord
vertebral column
ribs
sternum
skull
the primitive axial skeleton, replaced by the vertebral column
notochord
unsegmente and composed of dense fibrous connective tissue
notochord
the first skeletal element to appear in the embryo of chordates
notochord
main axial support of vertebrates
vertebral column
a __ is composed of a centrum, one or two arches, and various processes
vertebra
it protects the spinal cord and provides rigidity to the body
vertebral column
(10) types of vertebra based on centra
aspondyly
monospondyly
- stereospondyly
diplospondyly
- embolomerous
polyspondyly
aspidospondyly
- rhachitomous
holospondyly
- lepospondyly
type of vertebra based on centra
no centra
aspondyly
type of vertebra based on centra
with only on centrum per segment
monospondyly
type of vertebra based on centra
a monospondylous vertebra in which the single centrum (intercentrum) is separate
seterospondyly
type of vertebra based on centra
with two centra per segment
diplospondyly
type of vertebra based on centra
a diplospondylous vertebra in which the approximate equal-sized centra are separate
embolomerous
type of vertebra based on centra
with five to six centra per segment
polyspondyly
type of vertebra based on centra
the centra and spines are separate
aspidospondyly
type of vertebra based on centra
an aspidospondylous vertebra with numerous separate parts that constitute each vertebral segment
rhachitomous
type of vertebra based on centra
the centra and spines are fused into a single bone
holospondyly
type of vertebra based on centra
a holospondylous vertebra with a husk-shaped centrum usually pierced by a notochordal canal
lepospondyly
(5) types of centra based on shapes
amphicoelous
procoelous
opisthocoelous
heterocoelous
acoelous
the notochord is persistent in (8)
adult jawless vertebrates
Placoderms
Chimaeras
Pleurachants
Dipnoans
Acanthodians
Crossopterygians
Primitive ray-finned fishes
anurans have no freen caudal vertebrae, instead have a ___
rod-like urostyle
most __ have a mroe distinct cervical regions and two sacral vertebrae
reptiles
__ have a more specialized and more uniform spines that other tetrapods with munerous cervical vertebrae, 10-20 heterocoelous vertebrae, 10-20 trunk, 5-6 caudal vertebrae fused to the two sacral vertebrae
free caudal vertebrae have been reduced to 6-7 vertebrae
pygostyle derived from the fusion of 4-7 vertebrae which supports the tail feathers
birds
the two sacaral vertebrae in birds
synsacrum
vertebral column in birds
__ derived from the fusion of 4-7 vertebrae which supports the tail feathers
pygostyle
mammals are unique in forming bony plalte-like caps or __ at the ends of their centra posterior to the first itnervertebral joint
epiphyses
mammals have __ cervical vertebrae
7
evolution of vertebral column in mammals except __ and __
edentates
sirenian
mammals have __ trunk vertebrae - anterior thoracic with ribs and posterior lumbar without ribs
20
evolution of vertebral column in mammals
___ vertebrae have larger centra, shorter and stouter neural spine and monger transverse process than thoracic vertebrae
lumbar
evolution of vertebral column in mammals
three or more sacral vertebrae fused to form _-
sacrum
evolution of vertebral column in mammals
in primates, the last 3-5 cudal vertebrae fused to form the __ or __
coccygeal (coccyx)
tail bone
series of cartilaginous or elongated bony structures served as attachment for the vertebrae extending into the body wall
ribs
(3) functions of ribs
provides sites for secure muscle attachment and help suspend the body
form a protective case (rib cage) around viscera
in Amniotes, contributes to the breathing mechanism
(3) types of ribs
true ribs
false ribs
floating ribs
type of ribs
meet ventrally with the sternum, consist of two jointed segments
true ribs
type of ribs
articulate with each other but not with the sternum
false ribs
type of ribs
do not articulate ventrally
floating ribs
(3) parts/segment of the true ribs
vertenral/costal rib (proximal segment)
sternal rib (distal segment)
joint between costal and sternal ribs allows changes in chest shape during respiration
a midventral skeletal element that usually articulates with the more anterior thoracic ribs and with the pectoral girdle
strictly a tetrapod structure and primarily, and amniote characteristic
sternum
(4) functions of the sternum
strengthen the anterior part of the trunk and body wall
helps protect the thoracic viscera
accomodates muscles of the pectoral limbs
in aminotes, helps in ventilating the lungs
the sternum forms eother __ or __ __ that are regarded as new structures not derived from the pectoral grdle or ribs
paired
midventral primordia
the appendicular skeleton is composed of how may bones
126
(4) composition of the appendicular skeleton
forelimb
pectoral girdle
hindlimb
pelvic girdle
the median fins occur in __ and __
all jawless vertebrates
fishes
(3) types of median fins
doral fin
anal fin
caudal fin
type of median fin
located along the middorsal line
dorsal fins
type of median fin
located between the anus and tail
anal fins
(2) types of median fins
prevent the body from turning aorund the vertical axis (yawing) and round the longitudinal axis (rolling)
dorsal fins
anal fins
dorsal and anal fins
in primitive vertebrates, each fin is supported within the contour of the body by a series of rod-like radials or __
pterygiophores
dorsal and anal fins
the esposed membrane of fins is ___ and some __ are supported only by dosal scales
cephalaspids
placoderms
(4) types of caudal fin depending on size and shape of the spine
diphycercal
hypocercal
heterocercal
homocercal
type of caudal fin
if the spine is straight to the tip of the tail with equal dersal and ventral lobe of the tail
diphycercal
type of caudal fin found in:
Cyclostomes
pleuracanths
some sarcopterygiaans
lungfish
type of caudal fin
if the spine tilts downward with longer ventral lobe than dorsal lobe
hypocercal
type of caudal fin found in:
anaspids
type of caudal fin
if the spine tilts upward with longer dorsal lobe than ventral lobe
heterocercal
type of caudal fin found in:
cephalaspids
placoderms
most chondrichthyes
primitive osteichthyes
shark
heterocercal
type of caudal fin
if all the fin membrane is posterior to the spine with equal dorsal and ventral lobe
homocercal
type of caudal fin found in:
all teleosts
perch
homocercal
the __ of __ is older, larger, and more complicated than pelvic girdle.
it includes one or more cartlage or replacement bones and several dermal bones derived from ancestral and armour plates
pectoral girdle
fishes
girdle of fises
___ was related to overlyin plates of dermal skeleton
placoderms cartilaginous fins
girdle of fishes
cartilaginous fishes has ____
no dermal elements
girdle of fishes
the rigt and left halves fused in the mdline forming a U-shaped girdle
scapulocoracoid
___ have a blade-like scapula that is oriented parallel tothe spine
- with large nterior coracoid that is articulated with the sternum
- the posterior coracoid has been lost
- two clavicles fuse ventrally forming the furcula or absent in some
birds
the only membrane bone retained ___ is the clavicle
- the anterior coracoid is completely lost
- the posterior coracoid fuses to the scapula forming the coracoid process of the scapula
- the scapula is unique in having spine which represents its anterior border
- the ventral end of the spine is continued as the acromion process to articulate with the clavicle
Therian Mammals
the pelvic girdle of __ is much enlarged over that of fishes and is relatively uniform in basic structure
tetrapods
each half othe pelvic girle (of tetrapods) is a single cartilaginous unit in the embryo. (3) bones are constant in the adult
dorsal ilium - articulates with one or more sacral vertebrae
anterior pubis
posterior ischium
girdle and tetrapod
the bones of one side usually fuse in the adult forming the ___
innominate bone
girdle and tetrapod
one or both of the ventral bones of the two sides usualyl articulates of fuse across the midventral line, the contact is called __
pelvic symphysis
___ has a solid, triangular shaped pelvic girdle with the ilium forming the apex
primitive amphibians
girdle in primitive amphibians
the pubis can be distinguished from the ischium by having a ___ that accomodates a nerve
obturator foramen
in __, the girdle has a long, anteriorly inclined ilium and cartilaginous pubis
frog
girdle and tetrapod
REPTILES has vairous shaped patterned after the basic plan of
labyrinthodonts
girdle in __
the contact with the spine is firmer
the large pubo-ischiadic fenestrum is present between the two ventral bones
reptiles
birds have a large pelvic gidle that is firmly attached to the __
synsacrum
girdle in __
the long ilium extends both anterior and posterior to the socket for the femur or acetabulum: the pubis is turned backward below the ischium and there is no symphysis
birds
__ have a long and expanded ilium extending only forward from the acetabulum
mammals
girdle in mammals
the ___ represents both the obturator foramen and the pbo-ischiadic fenestrum of the ancestor
large obturator fenestrum
girdle in mammals
a __ is always present
symphysis
girdle in mammals
__ and __ have epipubic bones that articulate with the pubic bones extending forward in the ventral body wall
monotremes
marsupials
__ skeleton forms from cartilaginous elements within the developing limb bud
limbs
development of limbs
first to appear is a single piece - __ (forelimb) or __ (hindlimb)
humerus
femur
development of limbs
it next bifurcates to form __ and __ OR __
radius
ulna
tibia-fibula
development of limbs
The remainder of the limb skeleton develops asymmetrically in special and temporal sequence from the body outward by __ or by __.
segmentation
branching
development of limbs
Ancestral tetrapod learned to walk or crawl using their strong __
lobe-shaped fins
development of limbs
__ and __ are stronger and more firmly related to the axial skeleton
Pectoral fins
pelvic fins
bones of the wrist
carpus
bones of the ankle
tarsus
collective term for carpal and tarsal bones
podials
bones of the forefoot
manus
bones of hindfoot
pes
collective term for metacarpals and metatarsals
metapodials
development of limbs
Skeletal pattern of the various tetrapod feet are derived from the primitive patterns of deletions and fusions that can be usually be verified by embryonic development (t/f)
true
(9) types of locomotion used by tetrapods:
aquatic
fossorial
scansorial
arboreal
graviportal
cursorial
volant
saltatorial
locomotion in mammals
__ provide rapid acceleration and often support the greater part of the weight
posterior limbs
miscellaneous bone
bones embedded in or interrupting tendon
sesamoid bone
the largest sesamoid bone
patella OR knee cap
miscellaneous bone
bone in the penis or carnibores, bats, insectvores, rodents, and some primates
baculum (or penis)
miscellaneous bones
additional small bones are found in the different structure among the TETRAPODS (4)
in the eyelids of CROCODILIANS
in the crest of a BIRD
in the snout og PIGS
at the base of the external ear of some RODENTS
evolution of limbs in mammals
tarsus, fibulae forms the __ or __
heelbone
calcaneum
evolution of limbs in mammals
Tibiale joins the intermedium forming a large bone called __ that lies over the calcaneum
astragalus
evolution of limbs in mammals
__ is between the astragalus and tibia
ankle joint
evolution of limbs in mammals
t/f - fusion among tarsal are common
true
evolution of limbs in mammals
basic phalangeal formula
2-3-3-3-3
evolution of limbs in mammals
have __ on each end of the long bones
distal ends of the metapodials, and on the proximal ends of all but the terminal phalanges, the __ is retained
bony epiphyses
pisiform
evolution of limbs in birds
uniform and specialized limb structure
__ are cartilaginous in immature and absent in adults
epiphyses
evolution of limbs in birds
avian wing has __ digits
three
phalageal formula of foot (birds)
2-3-4-5-0
phalageal formula in reptiles (manus)
3-4-5-3
phalageal formula in reptiles (pes)
2-3-4-5-4
limbs or reptiles are usually stronger than amphibians (t/f)
true
reptiles
__ is disproportionally larger than the forelimbs
hindlimbs
evolution of limbs in reptiles
__ are usualy cartilaginous but may ossify in lizards
epiphyses
evolution of limbs in reptiles
a new bone, __, may be added to the outside of the carpus, and the __ is no longer a free bone in the tarsus
pisiform
tibiale
evolution of limbs in reptiles
the join of the foot is often between
podials
__ have limbs positioned far to the sides of the body except some dinosaurs and mammal-like reptiles which are under body
reptiles
evolution of limbs in amphibians and higher vertebrates
__ of long bones produce blood cells, a function not performed by the skeleton of fishes
marrow
__ have short limbs splayed on the sides of the body
amphibians
evolution of limbs in amphibians
there are only __ digits on the manu and ___ on the pes with ___ in each toe
4
4-5
1-3
the podials in amphibians are always __c
catilaginous
amphibians
the principal joint of the foor is between the __ and __
podials
metapodials
