Skeletal System Flashcards
What are the general characteristics of cartilage and what are the two types?
- formed thru shape of protein fiber matrix
- indirect blood flow
- no nerves
- Elastic: flexible
- ear - Hyalin: rigid
- larynx
What function does Hylain Cartilage serve and what can its destruction lead to?
- covers regions of moving bones
- lacking can cause pain
What’s the function of Fibrocartilage and what are three examples?
- backed by collagen to withstand lots of force
1. Intervertebral disks, pubis, and knee joint
What is elastic cartilage used for and what are two examples?
- Used for its springy/flexible nature
Ear and epiglottis
What are the four methods of classifying bone?
- Regional: appendicular vs. axial
- Histology: compact, spongy, cellular, acellular
- Embryonic origin: visceral vs. somatic
- Type of Ossification: membrane vs. endochondral
What does dermal bone consist and what is it? Examples?
- Membrane bone: directly formed in membrane w/o pre-existing cartilage
Bony structures like plates/ scales that develop in skin
- dermatocranium, dentary, clavicle
- adventitious (secondary cartilage) in mammals/birds
- dermally derived
What is sesamoid bone associated with? Examples?
- within tendons
- growth depends on tendon pressure/stress
Ex: patella,pisiform bone of wrist
What is perichondral or periostea’s bone formed from and what is its function?
1.from connective tissue
- over cartilage or bone
- Forms bones in adult (osteoblasts)
What is secondary cartilage’s function?
- Cartilage forms after initial bone
- mostly at points of trauma - Replaced by endochondral bone ossification
What is endochondral bone and what is its function
- forms from ossification of preexisting cartilage
- limb bones
What are the three main regions in endochondral development?
- Epiphysis: ends of bone
- Metaphysis: growing region (area between)
- Diaphysis: middle shaft of bone
What are the layers of a mature bone (dermal and endochondral) and its composition?
- Cortical bone: cortex of bone
- compact bone: dense
- Medullary bone: lines core of bone
- spongy bone: hemopoietic tissue and porous
What is the purpose of bones and give an example?
- Use to support and give structure
Ex: urostyle in frog: supports pelvic region for jumping
What’s the germ layer composition of exoskeleton?
Dermis: bone
Epidermis: keratin
What is the germ composition the endoskeleton?
- Mesoderm: tissue, bone, cartilage
What does the chondrocranium protect and what is it composed of?
- Base and back of brain
- supports brain and protects sensory organs - Endochondral bone
What are the five stages of Chondrocranial development?
- Notochord —> caudal plate
- Cranial vertebrae —> occipital arch
- Parachordal cartilage fuses to the basal plate
- Trabeculae fuses to form the ethmoid plate
- Sense capsules form around organs
What is the splanchnocranium derived from?
- neural crest of visceral arches 1-6
In Teleosts do gill arches 3-6 and 1-2 do?
3-6: support gill filaments
1-2: jaw suspension
What is the evolutionary trend in the pharyngeal skeleton?
It is reduced from early vertebrates to birds and mammals
What is the make up of the primitive splanchnocranium?
- 7 arches
A1: mandibular: palatoquadrate and mer
A2: hyoid: hyomandibulae
Levels of Bone:
-pharyngo, epi, cerato, hypo, basil
What is feature in placoderms is homologous to the jaw?
Placodermal plates
What is paleostylic jaw style?
- no brachial arches connected to skull
- only cartilage
What jaw style does group Agnathans have?
- none: no official jaw
- paleostylic
What jaw type are placoderms and acanthodians?
Euautostylic
What is the euautostylic jaw style entail?
Palatoquadrate connected to neurocranium
- hyomandibulae no part in jaw suspension
Which groups have an amphistylic jaw style?
- Crossopterygii (rhipidistians and coelocanths)
- Extinct osteicthyes
- Extinct chrondricthyes
What describes the amphistylic jaw style?
- Hyomandibular and palatoquadrate connected independently to braincase
- Palatoquadrate: 1 or more articulations with chondrocranium
What are the two independently evolved types of hyostylic jaws?
- Hyostyly
Connected by hyomandibular—otic capsule; palatoquadrate—hyomandibular
-elasmobranchs
2 modified hyostyly: have symplectic bone aids in connection
- SC osteichthyes
- teleosts
What is secondary autostylic?
Palatoquadrate — chondrocranium
- H.M has no involvement in suspending PQ
What groups are secondary autostylic?
Holocephali and dipnoi
What is metautostylic?
- Jaw connected by quadrate to braincase
- type of 2* autostylic
-hyomandibular—> columnella - 2nd arch —> hyoid apparatus
What groups are metautostylic?
- Amphibians
- Reptiles
What describes craniostylic jaw type?
- Jaw articulated by squamosal and dentary
- Splanchnocranium: hyoid apparatus and ear bones
-Quadrate —> incus
-articular—> malleus
- 2* autostylic
What groups were craniostylic?
Mammals and reptiles
What does the palatoquadrate ossify to form?
- Quadrate
What comprises the jaw joint in teleosts and most mammals?
Articular and quadrate bones
What comprises jaw joint in mammals?
- Dentary (meckles surrounds by dermal bone)
- Squamosal
- fused in humans to form temporal
What are the 6 series of dermatocranial bones?
- Facial
- Orbital
- Temporal
- Vault
- Palatal
- Mandibular
What region is the facial series and what does it include?
- snout
Premaxilla, maxilla, and nasals
What region is the orbital series and what does it include?
- encircles the eyes
- lacrimal, prefrontal, postfrontal, postorbital, and jugal
What region is the temporal series and what does it include?
-posterior wall of braincase
- intertemporal, surpratemporal, tabular, squamosal, quadratojugal
What region is the vault series and what does it include?
- roofing bones
-frontal, parietal, postparietal
What region is the palatal series and what does it include?
- covers roof of mouth
- pterygoid, vomer, palatine, ectopterygoid, parasphenoid
What region is the mandibular series and what does it include?
- encases meckles cartilage
- Lateral: dentary,splenials, angular, surangular,
-Medial: pre articular, coronoids
What are the head skeleton of ostracoderms and cyclostomes (Agnatha)?
Ostracoderms- dermal head shield
Cyclostomes: cartilaginous brain case
What did placodermy head skeleton look like?
- Dermal bone plates, ossified upper jaw
- No spiracle
What did the head skeleton of cartilaginous fish look like?
- no dermatocranium
- chondrocranium —> braincase
- splanchnocranium
- jaws suspended by ceratohyal and meckles cart
What characterizes head skeleton of Actinopterygians?
- operculum (dermal bone)
- hyoid arch
What characterized the sarcopterygians head skeleton?
- Dermatocranium like actinopterygii
- I. Early lungfish: PQ fused to braincase
II. Rhipidipstians: strong jaw & Labrynthodont teeth
What is the amphibian head skeleton?
- reduced splanchnocranium
- hyomandibular—collumnella
- reduced hyoid
- dermal bones lost or fused
What is the head skeleton of reptiles and birds?
Depending on temporal fenestrae and muscle connection
-anapsid, synapsid, diapsid, euryapsid
How does the apparence during evolution of the secondary palate affect the pharyngeal region?
Separates the oral/nasal pharynx for better eating and breathing
What is the evolutionary trend behind choanae?
They move caudally
-towards throat in mammals
What is the head skeleton of mammals?
- Braincase: dermal and endochondral bone
- Turbinate Bones:
- for turbinates which allow for better scent
What type of bone are bones in the dermatocranium?
Dermal bone
