1. SISTEM RANGKA
Jumailatus Solihah, S.Si.
Biology Program
State Islamic University Sunan Kalijaga
Yogyakarta
2. Bone
inorganic components of bone comprise
60% of the dry weight (largely calcium
hydroxy-appetite crystals) & provide the
compressive strength
The organic component is primarily
collagen, which gives bone great tensile
strength.
3. Function of Bone
provides support and movement
via attachments for soft tissue
and muscle
protects vital organs
is a major site for red marrow for
production of blood cells
plays a role in the metabolism of
minerals such as calcium and
phosphorus.
4. Bone Cells
Osteogenic cells respond to traumas, such as
fractures, by giving rise to bone-forming cells
and bone-destroying cells
Osteoblasts (bone-forming cells) synthesize and
secrete unmineralized ground substance and
are found in areas of high metabolism within the
bone.
Osteocytes are mature bone cells made from
osteoblasts that have made bone tissue around
themselves.
Osteoclasts are large cells that break down
bone tissue.
bone-lining cells are made from osteoblasts
along the surface of most bones in an adult
5.
6. Types of bone
Compact bone forms the outer shell of all bones
and also the shafts in long bones.
Spongy bone is found at the expanded heads of
long bones and fills most irregular bones.
Short bones are variable in size and shape.
These bones are generally compact in nature
and are distributed throughout the skeleton.
These include the entire vertebral column, carpal
bones, and tarsal bones
7.
8.
9. Intramembranous
ossification
is the process of
membrane bone formation. This process
give rise to:
bones of the lower jaw, skull, & pectoral girdle
dentin & other bone that develops in the skin
vertebrae in some vertebrates (teleosts,
urodeles)
10. Endochondral ossification
is the process in which
bone is deposited in pre-existing cartilage ,
& such bone is called REPLACEMENT
BONE
11. Dermal skeleton
skin of most living vertebrates has no hard
skeletal parts but dermal bone elements are
usually present in the head region
early vertebrates (ostracoderms) had so much
dermal bone they were called 'armored fishes'
after ostracoderms, fish continued to develop
much bone in skin but that bone has become
'thinner' over time
12. Endoskeleton
Somatic - axial & appendicular skeletons
Visceral - cartilage or bone associated
with gills & skeletal elements (such as jaw
cartilages) derived from them
13. Dermal bone of fishes:
Basic structure includes lamellar (compact)
bone, spongy bone, dentin, &, often, a surface
with a layer of enamel-like material
Evolutionary 'trend' = large bony plates giving
way to smaller, thinner bony scales
Ancient armor - not found on living fish
Ganoid scales - found only on Latimeria (coelocanth)
& sturgeons
Placoid scales - elasmobranchs (diagram to the right;
pulp cavity > dentin layer > enamel)
Ctenoid & Cycloid scales - modern bony fish
15. Vertebral column:
Vertebrae - consist of a centrum (or body), 1 or
2 arches, plus various processes
Amphicelous
concave at both ends
most fish, a few salamanders (Necturus), & caecilians
Procelous
concave in front & convex in back
anurans & present-day reptiles
Acelous
flat-ended
mammals
16. Vertebral arches
Neural arch - on top of centrum
Hemal arch (also called chevrons) -
beneath centrum in caudal vertebrae of
fish, salamanders, most reptiles, some
birds, & many long-tailed mammals
17. Vertebral processes:
projections from arches & centra
some give rigidity to the column, articulate
with ribs, or serve as sites of muscle
attachment
18. Vertebral processes:
Transverse processes - most common type
of process; extend laterally from the base of a
neural arch or centrum & separate the epaxial &
hypaxial muscles
Diapophyses & parapophyses - articulate
with ribs
Prezygapophyses (cranial zygapophyses)
& postzygapophyses (caudal
zygapophyses) - articulate with one another &
limit flexion & torsion of the vertebral column
19. Vertebral columns of
tetrapods
Cervical region
Amphibians - single cervical vertebra; allows little head
movement
Reptiles - increased numbers of cervical vertebrae (usually 7) &
increased flexibility of head
Birds - variable number of cervical vertebrae (as many as 25 in
swans)
Mammals - usually 7 cervical vertebrae
Reptiles, birds, & mammals - 1st two cervical vertebrae are
modified & called the atlas & axis
atlas - 1st cervical vertebra; ring-like (most of centrum gone);
provides 'cradle' in which skull can 'rock' (as when nodding 'yes')
axis - 2nd cervical vertebra
Transverse foramen (#6 in above caudal view of a cervical
vertebra)
found in cervical vertebrae of birds & mammals
20. Vertebral columns of
tetrapods
Dorsal region
Dorsals - name given to vertebrae between
cervicals & sacrals when all articulate with
similar ribs (e.g., fish, amphibians, & snakes)
Crocodilians, lizards, birds, & mammals - ribs
are confined to anterior region of trunk
thoracic - vertebrae with ribs
lumbar - vertebrae without ribs
21. Vertebral columns of
tetrapods
Sacrum & Synsacrum
sacral vertebrae - have short transverse processes that brace
the pelvic girdle & hindlimbs against the vertebral column
Amphibians - 1 sacral vertebra
Living reptiles & most birds - 2 sacral vertebrae
Most mammals - 3 to 5 sacral vertebrae
Sacrum - single bony complex consisting of fused sacral
vertebrae; found when there is more than 1 sacral vertebra
Synsacrum
found in birds
produced by fusion of last thoracics, all lumbars, all sacrals, & first
few caudals
fused with pelvic girdle
provides rigid support for bipedal locomotion
22. Vertebral columns of
tetrapods
Caudal region
Primitive tetrapods - 50 or more caudal vertebrae
Present-day tetrapods
number of caudal vertebrae is reduced
arches & processes get progressively shorter (the last few
caudals typically consist of just cylindrical centra)
Anurans - unique terminal segment called the urostyle
(section of unsegmented vertebral column probably
derived from separate caudals of early anurans)
Birds - last 4 or 5 caudal vertebrae fused to form
pygostyle
Apes & humans - last 3 to 5 caudal vertebrae fused to
form coccygeal (or tail bone)
23.
24.
25.
26. Ribs
may be long or short, cartilaginous or bony; articulate medially
with vertebrae & extend into the body wall
A few teleosts - have 2 pair of ribs for each centrum of trunk
(dorsal rib separates epaxial & hypaxial muscles)
Most teleosts - ventral ribs only
Sharks - dorsal ribs only
Agnathans - no ribs
Tetrapods - ribs usually articulate with vertebrae in moveable
joints (see above drawing)
Early tetrapods - ribs articulated with every vertebra from the atlas
to the end of the trunk
Later tetrapods - long ribs limited to thoracic region
Thoracic ribs - most composed of a dorsal element (vertebral rib) & a
ventral element (sternal rib)
Sternal rib - may be ossified (birds) or remain cartilaginous (mammals);
usually articulate with sternum (except 'floating ribs')
Uncinate processes - found in birds; provides rib-cage with
additional support
27.
28. Sternum
strictly a tetrapod structure &, primarily, an
amniote structure
Amphibians - no sternum in early amphibians &,
among present-day amphibians, only anurans
have one
Amniotes
sternum is a plate of cartilage & replacement bone
sternum articulates with the pectoral girdle anteriorly
& with a variable number of ribs
29. The Vertebrate Skull
consists of:
1 - neurocranium (also
called endocranium
or primary braincase)
2 - dermatocranium
(membrane bones)
3 - splanchnocranium
(or visceral skeleton)
30. Neurocranium :
1 - protects the brain
2 - begins as cartilage that is partly or
entirely replaced by bone (except in
cartilaginous fishes)
31. Cartilaginous stage:
neurocranium begins as pair of parachordal &
prechordal cartilages below the brain
parachordal cartilages expand & join; along with the
notochord from the basal plate
prechordal cartilages expand & join to form an
ethmoid plate
Cartilage also appears in the
olfactory capsule (partially surrounding the olfactory
epithelium)
otic capsule (surrounds inner ear & also develops into sclera
of the eyeball)
Completion of floor, walls, & roof:
Ethmoid plate - fuses with olfactory capsules
Basal plate - fuses with otic capsules
Further development of cartilaginous neurocranium =
development of cartilaginous walls (sides of
braincase) &, in cartilaginous fishes, a cartilaginous
32.
33. Neurocranial ossification
centers
1 - occipital centers
cartilage surrounding the foramen magnum
may be replaced by as many as four bones:
basioccipital
exoccipital (2)
supraoccipital
Mammals - all 4 occipital elements typically
fuse to form a single occipital bone
Tetrapods - neurocranium articulates with the
1st vertebra via 1 (reptiles and birds) or 2
(amphibians and mammals) occipital condyles
34.
35. Neurocranial ossification
centers
2 - Sphenoid centers form:
basisphenoid bone
(anterior to basioccipital)
presphenoid bone
side walls above
basisphenoid &
presphenoid form:
orbitosphenoid
pleurosphenoid
alisphenoid
36. Neurocranial ossification
centers
3 - Ethmoid centers tend to remain
cartilaginous & form
anterior to sphenoid
cribiform plate of ethmoid & several
conchae (or ethmoturbinal bones)
37. The ethmoid region is clearly visible within the bisected skull above.
In most mammals, the nasal chamber is large & filled with ridges
from the ethmoid bones called the turbinals or ethmoturbinals.
These bones are covered with olfactory epithelium in life and serve
to increase the surface area for olfaction (i.e., a more acute sense of
smell). Another ethmoid bone, the cribiform plate, separates the
nasal chamber from the brain cavity within the skull.
38. Neurocranial ossification
centers
4 - Otic centers - the cartilaginous otic capsule
is replaced in lower vertebrates by several
bones:
prootic
opisthotic
epiotic
One or more of these may unite with adjacent
replacement or membrane bones:
Frogs & most reptiles - opisthotics fuse with
exoccipitals
Birds & mammals - prootic, opisthotic, & epiotic
unite to form a single petrosal bone; the petrosal,
in turn, sometimes fuses with the squamosal to
39.
40. DERMATOCRANIUM –
lies superficial to neurocranium &
forms:
1 - bones that form the roof of the brain &
contribute to the lateral walls of the skull
2 - bones of the upper jaw
3 - bones of the palate(s)
4 - opercular bones
41. Appendicular skeleton
consists of pectoral & pelvic girdles plus
skeleton of fins & limbs
Some vertebrates have no appendicular
skeleton (e.g., agnathans, apodans,
snakes, & some lizards) & in others it is
much reduced.
42.
43. Limbs
Starting with amphibians, vertebrates typically have 4
limbs. However, some have lost one or both pairs &,
in others, one pair is modified as arms, wings, or
paddles
typically have 5 segments:
Anterior limb
brachium (upper arm) - consists of humerus
antebrachium (forearm) - consists of radius & ulna
carpus (wrist) - consists of carpals
metacarpus (palm) - consists of metacarpals
digits - consist of phalanges
Posterior limb
femur (thigh) - consists of femur
crus (shank) - consists of tibia & fibula
tarsus (ankle) - consists of tarsals
metatarsus (instep) - consists of metatarsals
digits - consist of phalanges
44.
45. joint /articulation
Movable joints (like ball-and-
socket, hinge, gliding and pivot
joints)
Immovable joints (like the bones
of the skull and pelvis) which allow
little or no movement