Midterms_Lecture_Skeletal System Flashcards
General function of bones where the formation of blood cells from hematopoietic stem cells found in the bone marrow.
hematopoiesis
General funtion of bones where bone is a reservoir holding
adipose tissue within the bone marrow and calcium within
the hydroxyapatite crystals.
lipid and mineral storage
General function where bones form the framework and shape of the body.
Support
Bone General Function where the axial skeleton which surrounds the major organs of the body.
Protection
Bone general function where it is used for movement
Leverage for locomotion
Give the two organizations of the skeletal tissues
Skeleton
-Exoskeleton: Keratinized / Bony
-Endoskeleton: Bony endoskeleton, Cartilogenous, notochord
Skeleton
-Cranial Skeleton: splanchnocranium, chondrocranium, dermatocranium
- Postcranial: Axial skeleton (Vertebral column, notochord), Appendicula skeleton (limbs and Girdle)
Enumerate the origin of the mineralized tissues
Mesenchyme: Collagen, Scleroblast, Myoblast
Scleroblast: Osteocytes-bone, Chondroblast- cartilage, Odontoblast-teeth, Ameloblast, enamel
Explain the synthesis of cartilage and bone
A preliminary step in the formation of skeletal tissues is the synthesis of collagen by the fibroblast. Collagen is a proteinaceous fibril. Fibrils aggregate to form collagen fibers. The fibers form dense collagen bundles that are woven into a compact network of dense connective tissue like that found in dermis, tendons and ligaments. It is on this network that minerals are deposited to form cartilage and bone.
State organic and inorganic bone compositions
Organic: Collagen fibers, CHON, Polyssacharides
Inorganic: Calcium phosphate, calcium carbonate, Hydroxyapatite ions
Each end of the long bone is called the?
epiphysis
What comprises longbones?
spongy and compact bone
is a flat plate of hyaline cartilage seen in young, growing bone
epiphyseal plate
The site of bone growth
Epiphyseal plate
This is a remainder that can still be seen in adults once growth has stopped.
epiphyseal line
The epiphysis is covered with what type of cartilage?
articular
Articular cartilage is made of what cartilage?
Hyaline
Purpose of articular cartilage in epiphysis?
decrease friction
The long shaft of the bone is called the?. It makes up most of the bone’s length.
diaphysis
diaphysis is made of what type of long bone?
compact
The outside of the diaphysis is covered by?
periosteum
It is a fibrous connective tissue membrane
periosteum
What are these fibers that secure the periosteum to the underlying bone?
sharpey’s fibers
Is a thin layer of connective tissue lines the inside of the bony tissue, creating the medullary cavity.
endosteum
The hollow inside of the bone is referred to as the?
medullary cavity
what bone marrow are present in medullary cavity?
red and yellow
cells responsible for forming new bones.
osteoblasts
When the area surrounding an osteoblast calcifies, the osteoblast becomes trapped and transforms into an
osteocyte
osteoblasts synthesize and secrete what?
collagen matrix and calcium salts
The most common and mature type of bone cell.
osteocyte
the cells that break down and reabsorb bone
osteoclasts
osteoclasts come from?
monocytes and macrophages
T or F
There is a continual balance between osteoblasts generating new bone and osteoclasts breaking down bone.
True
The microscopic structural unit of compact bone is called an?
osteon
Osteon is also known as?
Haversian system
Each osteon is composed of concentric rings of calcified matrix (mineralized collagenous bundles) called?
lamellae
Running down the center of each osteon is the?
Haversian canal
This structure contains blood vessels, nerves, and lymphatic vessels
Haversian canal
blood vessels, nerves, and lymphatic vessels branch off at right angles through a perforating canal, also known as?
volkmann’s canals
Haversian systems are characteristics of?
amniotes
The osteocytes are located inside spaces called?
lacunae
a tubular, mineralized, dental and skeletal tissue, comprises the bulk of true teeth
Dentine
Dentin is produced by dentine-forming cells known as?
odontoblasts
Is a plesiomorphic character in vertebrates found in both primitive craniates and vertebrate lineages
acellular bone
What is aspidin?
A type of acellular bones
However, ___________ are the only vertebrates with a skeleton composed solely of acellular bone
teleost fishes
is the process of bone development from fibrous membranes. It is involved in the formation of the flat bones of the skull, the mandible, and the clavicles
Intramembranous ossification
is the process of bone development from hyaline cartilage. All of the bones of the body, except for the flat bones of the skull, mandible, and clavicles, are formed through endochondral ossification.
Endochondral ossification
Bone deposited directly within a membranous blastema without having been preceded by a cartilaginous model is a
membrane bone
is deposited where hyaline cartilage already exist. The existing cartilage undergoes degenerative changes and disappears.
replacement bone
arises from mesenchyme without passing through cartilaginous intermediate
membrane bone
arises from existing cartilage
replacement bone
is a non-vascular type of supporting connective tissue that is found throughout the body .
cartilage
precursor of replacement bone, articular surfaces of bones within joints of tetrapods
hyaline cartilage
Cartilage: thick, dense collagenous bundles in the interstitial matrix, intervertebral discs of mammals
firbocartilage
collagenous and elastic fibers, pinna of ear in mammals, walls of the outer ear canal, epiglottis and elsewhere
Elastic cartilage
is formed when calcium are deposited within the interstitial substance of hyaline cartilage or fibrocartilage. It is often mistaken for bone. The jaws of sharks, no matter how large are calcified cartilage.
calcified cartilage
fibrous sheath is called?
perichondrium
Bone remodeling (or bone metabolism) is a lifelong process where mature bone tissue is removed from the skeleton, a process called?
bone resorption
Process of forming new bone tissue
ossification
Process of bone remoddeling
The remodeling cycle consists of three consecutive phases: resorption (breakdown), during which osteoclasts digest old bone; reversal, when mononuclear cells appear on the bone surface; and formation, when osteoblasts lay down new bone until the resorbed bone is completely replaced.
These cells regulate local mineral deposition and chemistry at the bone matrix leve
osteocytes
Hormones that influence or regulates the withdrawal of calcium to maintain calcification
Parathormone and Calcitonin
In some animals certain bones may be present which do not belong either to the axial skeleton or to the appendicular skeleton, they are called as?
heterotopic bones
are formed by ossification of a tendon where the tendon moves over a bony surface, such as patella or knee cap which appears first in some lizards, and two sesamoid bones are commonly present in the wrist (pisciform bones) of tetrapoda. They are a radial sesamoid anterior to the radiale, and a pisciform posterior to the ulnare.
sesamoid
is a bone in the interventricular septum of deer and bovines.
Os cordis
is a bone giving rigidity to the penis in marsupials, insectivores, rodents, Carnivora, Chiroptera, Cetacea, walrus and lower primates.
Os penis
is a bone in the snout of some ungulates, such as pigs.
os rostralis
is an additional bone in the palm of moles which helps in digging.
Os falciforme
Bones that form a ring in the eyeball of lizards and birds.
Sclerotic bones
present in the clitoris of otters, rabbits and several rodents.
os clitoridis
Bone that is found in syrinx of birds.
pessulus
bone that is found in ventral abdominal wall of monotremes and marsupials.
epipubic
What causes heterotopic bone formation?
Result from trauma and injury (usually)
The cranial skeleton includes?
the skull and visceral skeleton
The postcranial skeleton includes all the bones and cartilages caudal to the head skeleton; it is subdivided into?
axial components and appendicular components.
includes the box that encloses the brain and the capsules surrounding the sense organs.
neurocranium
Neurocranium function?
protects the brain
is 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
is the visceral portion of the skull that supports the gills and contributes to the jaws.
Splanchnocranium
Nuerocranium in made of what cartilage?
It is replaces by?
chondrocranium
replacement bone
Neurocranium cartilaginous stage,
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
partially surrounding the olfactory epithelium
olfactory capsule
surrounds inner ear & also develops into sclera of the eyeball
otic capsule
what animals retain a cartilaginous neurocranium (or
chondrocranium) throughout life?
Cartilaginous fishes
What animals retain highly cartilaginous neurocranium that is covered by membrane bone?
Bony fishes, lungfishes, & most ganoids
what animals have embryonic cartilaginous neurocranium that is largely replaced by replacement bone (the process of endochondral ossification occurs almost simultaneously at several ossification centers)
bony vertebrates
cartilage surrounding the foramen magnum may be replaced by as many as four bones
Occipital region
Sphenoid region
Ethmoid region
Otic region
Skulls based on fenestrae (Temporal openings)
- Anapsid skull
the primitive skull, has no temporal fenestra
turtles and other primitive reptiles - Diapsid skull
has two temporal fenestrae,
crocodiles, birds and lizards - Euryapsid skull - this is a derived diapsid skull where the lower temporal fenestra is lost
- Synapsid skull
- has one fenestra located in a different place than the euryapsid skull
Composed of dermal bones that overlie the chondrocranium and splanchnocranium
dermatocranium
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
Dermatocranium
Completes the protective cover of the brain and jaws
Dermatocranium
Dermatocranium that encircles the external naris forming the snout
Facial series
Dermatocranium that encircles the eye defining the orbit
Orbital series
Dermatocranium that lies behind the orbit completing the posterior wall of the braincase
Temporal Series
Dermatocranium that is located across the top of skull covering the brain beneath
Vault Series
Dermatocranium where dermal bones of the primary palate covering the roof of the mouth
palatal series
Dermatocranium that encases the Meckel’s cartilage
Mandibular series
5 roofing bones
Nasal
Frontal
Parietal
Orbital
Squamosal
Dermatocranium Lower Jaw
- largest
– small, dorsomedial
- lateral
– medial, becomes typanic bulla
– medial
– medial & caudal – becomes anterior malleus in mammals
Lower Jaw
Dentary - largest
Splenial – small, dorsomedial
Surangular - lateral
Angular – medial, becomes typanic bulla
Coronoid – medial
Prearticular – medial & caudal – becomes anterior malleus in mammals
Part of the skull that Supports & allows movement of jaws, gill, tongue
splanchnocranium
The splanchnocranium consists of the?
gill arches and their derivatives (branchial region).
It support the gills and offer a site for respiratory muscle attachment
gill arches
Splanchnocranium
The first arch is called the ________ Arch and it’s divided into dorsal and ventral elements:
A- dorsal element-called the ______________. It contributes to the upper jaw
B- ventral element-called _________. It contributes to the lower jaw
The second arch is called the ____ arch, most prominent component is the hyomandibula. In mammals, the ventral portion is involved in support the tongue, muscles used for swallowing and jaw movements.
_______ are associated with the gill apparatus. In mammals they eventually contribute to the larynx
mandibular
palaloquadrate (incus)
Meckel’s cartilage (malleus)
hyoid arch
Branchial arches I-V
Splanchnocranium
1st visceral arch- _________
Meckel’s cartilage 🡪 ______
Palatoquadrate (quadrate) 🡪 _____
2nd visceral arch- ______
hyomandibula 🡪 ______
______ 🡪 styloid process and anterior horn of hyoid
_______ 🡪 body of hyoid
Mandibular Arch
Malleus
Incus
Hyoid Arch
Stapes
Ceratohyal
basihyal
This is a rather primitive arrangement found in Crossopterygii and some primitive sharks (e.g. Heptanchus, Hexanchus).
The quadrate or the basal and otic processes of upper jaw (mandibular arch) are attached by ligaments to chondrocranium.
Similarly, the upper end of hyomandibula (hyoid arch) is also attached to chondrocranium, while the two jaws are suspended from its other end.
This arrangement makes a double suspension (amphi = both+style = bracing) since both the first and second arches participate in bracing the jaws against the chondrocranium.
Amphistylic
It is found in most elasmobranchs and all bony fishes.
Upper jaw (palatoquadrate) is loosely attached by anterior ethmopalatine to cranium.
Both the jaws are braced against hyomandibular, the upper end of which fits into auditory region of skull.
Since only hyoid arch braces or binds the two jaws against cranium, this jaw-suspension is termed hyostylic. It provides the jaws a wider movement and helps in swallowing larger preys.
Hyostylic
This condition is found in extinct placoderms, chimaeras, lung fishes and most tetrapods (amphibians, reptiles and birds).
Hyomandibular does not participate but becomes modified into columella or stapes of middle ear for transmitting sound waves.
Upper jaw (palatoquadrate) is directly and intimately bound to cranium by investing dermal bones (auto = self)
Autostylic
The articular of lower jaw articulates with the quadrate of the upper jaw. Autostylic suspensorium is widespread and has at least 3 variation or subtypes
_____________ :- In Holocephah (chimaeras), upper jaw is firmly fused with skull and lower jaw suspended form it. Hyoid arch is complete, independent and not attached to skull.
__________:- In many tetrapods, hyomandibular forms columella and articular articulates with quadrate. However, the quadrate remains immovably attached with skull.
_____________ :-In some reptiles (lizards, snakes) and birds, quadrate is loosely attached and is movable at both ends, a condition known as streptostylism.
Holostylic
Monimostylic
Streptostylic
This type of jaw-suspension is characteristic of mammals and some consider it as a modification of autostylic suspension.
Upper jaw fuses throughout its length with cranium, and hyomandibular forms the ear ossicle stapes.
But articular and quadrate also become modified into ear ossicles malleus and incus, respectively.
Consequently, two dermal bones, dentary of lower jaw and squamosal of skull, provide the articulation between jaw
Craniostylic
Types of Vertebra Based on Centra
– no centra
- one centra
- two centra per segment
Aspondyly
Monospondyly
Diplospondyly
Importance of centra
centra supplement replace the notochord as mechanical elements of the axial column Each centrum constitues the body of the vertebra.
Centra and their neural arches
_______- all elements are separated
_________- all vertebral elements in a segment are fused into a single piece
Aspidospondyl
Holospondyl
Types of Centra based on shape
concave at both ends
most fish, a few salamanders (Necturus), & caecilians
convex in front & concave in back
most salamanders
concave in front & convex in back
anurans & present-day reptiles
flat-ended
mammals
saddle-shaped centrum at both ends
Types of Centra based on shape
Amphicelous
Opisthocoelous
Procoelous
Acoelous
Heterocoelous
provide for secure muscle attachment
help suspend the body
form a protective case around viscera (rib cage)
serve as accessory breathing devise
Embryologically, ribs preform in cartilage within myosepta, that is within the dorsoventral sheets of connective tissue that partition successive blocks of segmental body musculature.
Ribs
Many fishes have 2 sets of ribs: _______and ______ ribs
Dorsal and Ventral
In tetrapods, ventral ribs are lost, ________ become
the trunk ribs of terrestrial vertebrates
dorsal ribs
Ribs of primitive tetrapods are ______ (two head articulate with the verterbrae)
______ (ventral rib head) articulates with the paraphophysis (ventral process)
______ (dorsal head) articulates with the diapophysis(process on the neural arch).
If these verterbral process fail to develop, the articular surface persist, forming a small concavity or _______, to receive the rib
bicipital
capitulum
Tuberculum
facet
In the thoracic region, the first several ribs are _______followed by _____ that articulate with the sternum. Some floating and most true ribs bear _______ processes, projections that extend posteriorly from proximal rib segments. These processes act as lever arms for inhalatory muscles that flare the rib cage.
Similar rib projections are found in some living and fossil _______, as well as in some early labyrinthodonts.
floating ribs
true ribs
uncinate
reptiles
Although ribs function in locomotion, in tetrapods they also become important in respiration.
Classification of tetrapod ribs is based on the type of association with the sternum.
Ribs that meet ventrally with the sternum are true ribs.
Consist of two jointed segments, the vertebral (costal) rib and the proximal (sternal) rib.
The joint between these two rib segments allows for changes in chest shape during respiration
Those that articulate with each other but not the sternum are false ribs.
And those that do not associate with anything are floating ribs.
In most mammals, the sternum consists of a chain of ossified elements in series, the _________. The first and last of these sternebrae are modified and are called the ________ and _________. Thus, a sternum occurs in some modern amphibians and most amniotes.
Sternebrae
Manubrium and xiphisternum
A __________ in bird anatomy is an extension of the sternum which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs.
keel or carina
The _________ provides an anchor to which a bird’s wing muscles attach, thereby providing adequate leverage for flight.
Keel
In some vertebrates, posterior to the sternum is another set of skeletal elements, the _______, or abdominal ribs.
Gastralia
-_________occur between successive vertebrae. They resist tension and shear forces
-______ protect viscera and contribute to respiratory movements
in tetrapods.
-In the buoyancy of water, ________ serves primarily as a
compression girdle, resisting telescoping of the body during
locomotion and translating axial muscle into lateral swimming
undulations.
-In terrestrial environments, the axial column has the function
of suspending the weight of the body. The tetrapod VC
incorporates anti-twisting features such as the __________.
Invertebral disks
Ribs
Axial column
zygopophyses
First vertebra allows greater freedom of head rotation
Cervical vertebra
site of attachment of pelvic girdle to VC
Sacral region
In birds, locomotion is accompanied by fusion and flexion
of vc: fusion of synsacrum with the innominate produces a
stable and firm platform while flight; multiple, ______ give head flexibility
heterocoelus cervical vertebrae
2 sets of elements for appendicular pectoral Girdle
Replacement bones
____,___,____
Membrane bones
____,____,____
Coraroid, Scapula, suprascapula
Clavicle, Cleithrum, supracleithru
T or F
Pelvic girdle has no dermal elements
true
Limbs: composed of three regions
Autopodium (wrist/ankle + digits)
Zeugopodium (ulna-radius, tibia-fibula)
Stylopodium (humerus, femur)
Overview of the appendicular skeleton:
It includes any projection from the body that plays a role in locomotion or steering. Limbs consist of three major divisions: the proximal, medial, and distal divisions.
- _________: the bone that articulates with the girdle and projects laterally from the body:
Humerus (anterior limb)/ Femur (posterior limb). - ______: the two bones that articulate with the proximal bone at the knee or elbow. Distally, they articulate with the bones of the hand or foot.
Radius and ulna (anterior limb)
Tibia and fibula (posterior limb) - ______ is made by three subdivisions:
a- Carpus or wrist (anterior limb)/ tarsus or ankle (posterior limb)
b-Palm and sole bones: metacarpal (anterior limb) /metatarsals (posterior limb)
c-the free portion of each digit: phalanges
Proximal
Medial
Distal
a depression within the pectoral girdle, articulates with the humerus
glenoid fossae
a deep socket in the pelvis, articulates with the femur
acetabulum
Hypotheses in transition from fin to limb
Drought
Predatory stress
Breathing
