Exam 3 Class Flashcards
What is an exoskeleton?
within integument with keratinized exoskeleton (from epidermis) and bony skeleton (from derm0s armadillo)
What is an endoskeleton?
with bony skleteon, cartiliginous endoskeleton, and notochord deep within body
skeleton cranial skeleton, and postcranial made up of the axial skeleton (skull and vertebral column) and appendicular skeleton
What are the different variations of endoskeleton?
amphioxus- notochord
lamprey- notochord, and combination pharyngeal slits of respiration, dorsal nerve cord specializatoin anterior in animal
gnatostomes- jaws and structural supprt in skull with ribs and vertebrae
What loose connective tissue is bone made from?
mesenchyme is part of the system that is going to give rise to skeletal strutuctures the same way demal/endochondral specialized ocnncective tissues
What is the cranium divided into?
3 parts (found in all vertebrates except chondricthyes or elasmobranches where dermatocranium was lost, and some agnathans where dermatocranium did not evolve with splachnocraniums, chondocranium or neurocranium, and dermatocranium.
What order did things evolve/
evolved jaws before brain. then evolving brain areas and then put covering/chondrocranium on top
What is the splagnocranium?
any part of the skull that arises from visceral arches (gill arches), first arose to support pharyngeal slits in filter feeding protochordates, then inbreathing in lamprey, arises form neural crest cells. cartilage (elasmobranches), or ossifies into endocondrial bone. elements contribute to jaw, hyoid, and/or ear formation in various gnathostomes.
Where did our gill arches go?
We had 7 gill arches in agnathes, with 1st branchial arch of agnathes gives rise to palatoquadrate and meckel’s carilage. While the second arch gives rise to hyomandibula becoming the stapes in several vertebrates.
What is the evolution of the splanchocranium?
embryonic gnathostomes begin with seven brachial arches that modify during development with mandibular arch (jaws) making up the palatoquadrate (upper) and meckel’s cartilage (lower). with the hyoid or hyomandibula (coopted as jaw fulcrum in some taxa).
Where did human gills go?
Human embryo had arches becoming the different bones such as the stapes and styloid ligament, alisphenoid, malleus and inches and remnants of meckel’s cartilage.
important patterns to remember: how the bones of the first and second arch became bones of the middle ear in mammals, and that posterior branchial arches became laryngeal cartilages in tetrapods, while the third and fourth arches contribute ot the hyoid. Palquadrate to quadrate epiperterygoid to incus alipsheoind
Hypobranchial to body of hyoid
rest of branchial arches become part of laryngeal and thyroid cartilage
What is the phylogeny of splanchocranium?
backbones of gill arches become specializations used for trachea and articulating start of vertebrae starting to move bones out of jaw and have formation of hyoid apparatus developed in mammals. cartilage and meckel’s don’t see bits of splanchnocranium just see full cranium.
What is chondrocranium or neurocranium?
overlies and supports brain, cartilage (elasmobranchs), or ossifies into endochondral bone, forms form mesenchyme next to notochord, supports sensory organs, in most vertebrate is primary embryonic scaffold, and there is a role for vertebrae for occipital formation in cranium. Ethnosphonid and occipital are two main divisions. occipital arch and ethmoid plate other important part.
What is the structure of the skull in a shark?
skeleton and blue is chondrocranium (top covering protecting brain and sensory organs- part of occipital bones and rest from vertebrae ), ethmoid and sphenoid bones internal through planes are a scaffold large part derived from splanchnocranium
What is ethmoid?
ossified in fish and unossified in everyone else except mammals for turbinates associated with becoming endothermic
What dermatocranium?
outermost casing of brain by dermal bones, intramembranous ossification vs. endochondral bone (chondrocranium), arose from bone armor of integument and sank inward to associate with chondrocranium and encase splanchnocranium first found in ostracoderms and placoderms. arose originally from bony armor in sank inward and became closely associated with chondrocranium.
What are dermal bones?
dermal bones divided into different series depending upon where they are located with facial series on the front and face, premaxilla (lost in humans), maxilla, and nasal
What are orbital bones?
whole bunch of bones. temporal series made out of series of bones in reptiles humans just have one temporal bone but a whole bunch in crocs.
wWhat are vault series?
roof what makes the roof of the skull with frontal, parietal, and then post=paratal with pair bones humans lost post=parietal and fused frontal keeping two parietal making skull stronger with less articulations and protecting massive brain in huans.
What is the structure of a jaw bone?
entire lower jaw is a single bone with all of it becoming one bone.
What is the occipital made of?
occipital mostly chondrocranium, some dermatocranium.
What are the three bones?
three bones composite bones, temporal bone has bits of chondrocranium, dermatocranium, splanchnocranium (through ear bones and styloid process- bone coming down on skull)
What is the sphenoid?
Sphenoid- splanchnocranium chondrocranium, and dermatocranium.
What is the structure of a shark jaw?
sharks hyomandibula attaches lower jaw to rest of jaw
What are kinetic skulls and who has them?
many skulls are kinetic skulls (ancient fish, teleosts, squamates, birds, and early therapsids) having lateral movements of upper jaw and these bones rotate with multiple points of rotation, and rapid change of jaw size and configuration.
What are akinetic skulls and who has them?
akinetic (modern amphibians, turtles, crocodiles, and mammals)- has no movement between upper jaw and braincase, suckling and chewing using specialized teeth.
what is jaw suspension evolution?
maxilla fused to braincase, meckle’s cartilag encased by dermal bone, and suspensorium formed by hyodmandibular and quadrate
What is suction feeding apparatus?
rapid extension of the buccal acavity hyoid apparatus forms a struts pushes premaxilla out creating suction sucking prey in
What are the structure of alligator jaws?
alligators, jaws attaches to braincase through quadrate attached to lower jaw in back by articular bone. stapes- retile have stapes, with the stapes the only ear ossicle in the alligator as in all non-mammalian vertebreates it is long and thing and attaches to small disc-shaped tympaum on prootic depe within external acoustic meatus
What is the structure of the malls jaw?
In mammals, the en:re upper jaw is incorporated into the braincase. The lower jaw is made en:rely of the dentary bone, which is also a dermal bone
What are the structures of the ear and where did they come from?
Stapes: was there first (Hyoid) Incus: Middle (Quadrate) Malleus: Most external (Ar:cular).
The incus is on top of the malleus because the quadrate is on top of the auricular
What is the structure of the snake?
quadrate bone not rigidily attached cn jaw walk because skull is so atricultural.
What does the embryo armadillo show?
embryonic armadillo shows formation of three middle ear bones form mandibular arch
How did skulls develop?
from anapsid skull lacking finestra we go to a diapsid skull and fro diapsid two openings posterior to orbit forming temporal arches of the squamosal and ost orbital bone but these have been highly modified in many groups seeing such as anapsid turtles, modified diapsid in snake (greatly reduced skull because of kinetics for allowing to swallow prey losing bones and openingins merged with orbital space of skull, lizard (same thing previously) and bird (keep bones nd merging of ausual with orbiaal spice with giant hole).
What are synapsid skulls?
synapsids mammals with single opening posterior to the orbital space and the whole can often be merged and separate like some of earlier synapsids.
What is the skull like in an alligator?
alligator- superior and inferior temperoal fenestral
What is the skull like in a lizard?
lizard incomplete merging with eye
What is the skull like in a snake?
snake an dbard is one big hole bones smaller and lighter or lost entirely. at least lower boundary of inferior temporal fossa (infratemporal arch) lost. in many snakes fossae difficult to distinguish as such because of loss of so much of surrounding skeleton.
What are th human skulls made of?
Humans have three composite bones: occipital, parietal, sphenoid bone and have multiple bones that go into them.
sphenoid bone- center of skull and how are other bones attached to sphenoid bones
What are condyles?
in occiptal bone attaching to vertebral column and attaches to vertebrae through condyles. different types of vertebrates have different condyls, single occipital condyel located ventral to foramen magnum (spinal cord contacts the brain). with salamander, frog and humans having to condyles and attached and raised structure from occipital bone with divit but not always varying in shape dependent upon attachement to head. bird, crocodile and fish ahve 1 condyle.
What are the importance of fenestra in animals?
fenestra may allow for attachmet of strong jaw muscles and fenestra made by process of contact of two bones sygmatic and temperoral to form process and by having kidn of opening can actually have strong muscular attachment making jaw function (temporalis muscle) attaching all the way up to sagittal crest at top of head very distinguishable male trait of sexual dimoprhism the larger the crest the more powerful the jaw. temporalis muscle attach at superior suture of temporal bone and fenestra allow for muscle ot go thorugh and attac strongly to skull.
What was jaw attachment in primitive amniotes?
primitive amniote- anapsid skull with temporal muscles running from neurocranium to the lower jaw.
What was jaw attachment in therapsids?
sharing with some of primitive models alowing for expanded jaw muscle attachment. with branching of muscle attaching to dermatocranium and neurocranium wrapping around both.
What was jaw attachment in malls?
mammals muscles through fenestra nad attaching outside of the skull alowing for expanded jaw muscle attachment.
What is sound?
sound is a pressure wave caused by vibration: frequency or pitch: how close those waves are,
why is sound important for animals?
Intensity and how loud with most animals have a middle ear and an inner ear, sometimes an ear canal to change this mechanical energy into electric impulses understood by the brain with femlaes liking males to make low frequency osund making it hard to make that sound as a small animal prefferring something bigger and greater seperation between those waves. whales too big cant vibrate fast off such a large distance.
What is the structure of the inner ear?
malleus in contact with eardrum communicating sound to incus and sound to stapes hitting inner ear and that is transmitting informaiton in direct contact with inner ear. most animals have a middle and inner ear and very few have an ear canal. when stapes hitting inner membrane amplifying sound having ability to hear wider rane of frequencies because of bones and the structure
What is fish hearing like?
not all fish have same morphology, fish can have as many as 3 systems for hearing: lateral line (can sense surroundings using hair cells), swim bladder (attached ot inner ear, transmit sound through little bones with ossicles aging fish, internal hearing with a heavy otholit (accelerometer telling how fast going) or ear stone acts as an accerometer, and semi=circular canals. since fish can move in 3 dimensions (X,Y, and Z axis) their semi-cicular canals are more complex than in terrestrial mmamls to help them orient with an inner ear (sacculus) similar to those of tetrapods. sound passes form water through fish to inner ear complicated canals
What is tetrapod hearing?
with terrestriality, new echanisms were needed to bring sound energy from air to inner ear: fluid resists being set into motion by air (.1% transfer) with the middle ear gathering and concentrating airbrone virations from tympanum toward fluid-filled inner ear. They act as a lever system, transform air waves into fluid waves, and amplifying sound becaus elittle bones are much smaller than receptive tympanum.
What is hearing like in reptiles?
reptiles: one bone with sound and stapes touching tympanum sending vibrations to little ear. stapes called columella in all but synapsids,
What is hearing like in meals?
sound hits tympanum vibration transferring sound through little bones into inner ear. pinna is a therian innovation- ear connecting sound to one area sound gathering devices. with a transition to a three ear bone functional conflict between chewing and hearing. before: sound passes via articular-quadrates stapes to inner ear. after: with chewing, stronger jaws conflicted with hearing role and jaw transferred to dentary/squamosal while articular/quadrate specialize. the inner ear is full of fluid lined with hair cells, similar to those of lateral line that responds to movement of fluid when fibers are excited making particular region of calculating vibration like strings on guitar throughout cocclear
Why are teeth important?
eeth critical in vertebrate evolution allowing animals to become specialized predators taking advantage of prey and food items.
What is teeth in sharks like?
elasmobranchs/ sharks derived fro placoid scales directly in other groups no longer coming from placoid.
What are the two main parts of teeth?
teeth have crown- part of tooth emerging from gum-line, and root is part of teeth below jawline with varying depths having multiple or single roots.
What are the inner structures of teeth?
roots have pulp cavity-innermost part of tooth, cementum attach teeth to gum-line, canal going into each of roots of tooth full of blood and nerves as they are alive.
on crown can have one cusp or multiple cusps with molar in back have multiple teeth. covering on outside of teeth is enamel or epidermis the hardest substance in the body depositing before tooth comes out. dentin right below enamal deposited throughout lie of individual made of dermis and is harder than bone but not as hard as enamel.
What is the development of teeth?
how do teeth grow, lamina, placode, dental mesenchyme (neural crest cells) in in bud differentiation into dermal papilla with formation of cap (lose cap when erupt) and enamel epithelium being deposited secondary to deposit in cracks and spaces.
What is mammals tooth development like?
mammalian tooth development. epidermis produced enamel organs producing ameloblasts and secreting enamels. dermis [produces dermal papilla cells from neural crest make papilla, produces odontoblasts, secreting dentin and bone defines socket.
How do we classify teeth?
teeth classifications homodont vs. heterodont, polyphyodont vs. diphyodont, thecodont vs. acrodont vs. pleurodont (how many teeth attached).
What are homodonts and heterodonts?
homodont- unicuspid snake (each tooth one cusp) same kind of teeth throughout jaws. tricuspid (mutltiple cusps). heterodont- different types of teeth
What is a polyphyodont vs. a diphyodont?
polyphyodont- many sets of sharks. vs. diphyodont with 2 sets (milk teeth deciduous, and permannt teeth) special with rodents and lagomorphs teeth continuously grow resharpening when eating .
What are the specialized teeth of mammals?
specialized teeth of mammals with uneven enamel and dentin create self-sharpening teeth with wear, hyposodont teeth rotate into jaw as previous teeth wear out (conveyor belt)- six sets of teeth dying of starvation because can’t chew up and grind food.
