Exam 2 Class Compiled Flashcards
Integument: Which germinal layers do epithelium and connective tissue arise from? Then what germinal layers are involved in the forma5on of integument?
mesoderm- forming dermis and connective tissue (neural crest cells)
ectoderm- external layer in skin cells of epidermis
epithelium- come from all three mostly ectoderm
Integument: Compare the general characteristics of epithelium and connective tissue.
epithelium- arising from ectoderm, mesoderm, and endoderm it is typically resting on a basal layer, highly organized tissue, functioning as a covering and lining- simple epithelium and has little extracellular matrix
Connective tissue- functiosn to hold things together with a lot of extracellular matrix loosely associated with eachother except adipose tissue with close fit. ECM determines physical properties of connective tissue arise from mesoderm and neural crest cells.
Integument: What are the functions of the integument?
immune protection secreting antibiotics keeps organism barrier thermoregulation protection from mechanial abrasion gas exchange (for some species) synthesizing vitamin D interacting with external world (sensory) Uv protection Dessication
Integument: Which integument structures arise only from the epidermis? Only from
the dermis? The interac5on of both?
Epidermis- baleen, claws, nails horns, and beaks
Dermis- formal dermal bones (osteoderms and reptiles, and spiny echidna)
Epidermis/Dermis- interacting resulting in teeth, denticles, fish scales, hair, mammary glands, feather
Integument: Label the general layers of the epidermis and state their function.
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S. corneum (differentiates into specialized structure to better interact with the environment dead cells creating claws and hooves),
S. lucidium (layer of clear dead cells
S. granulosum (bind intermediate keratin filaments together)
S. spinosum (synthesizing fibrilar proteins, known as cytokeratin, which build up within the cells which allow for strong connections to form between adjacent keratinocytes)
S. basal. (stem cells of epidermis, have melanocytes (pigment-producing cells), Langerhans cells (immune cells), and Merkel cells (touch receptors))
Integument: Compare the main characteristics of the skin of amphioxus, lamprey, shark
and teleost fish.
amphioxus- columnar or cuboidal epidermis resting on basal lamina. collagen plies of dermis regularly patterned (alternating) giving shape and structure of material properties have epidermis, dermis, and myomere
lamprey- develop stratified epidermis with mucus surface layer
shark- placoid scales from dermis
teleost fish- thick non-overlapping bone with ganoin and the development of elasmoid scales. Fish skin alive- not keratiinized. covered with mucus resisting infection, increase laminar flow (hydrodynamic surface increasing drag), ecasion of predators (release stuff distateful to eat), toxic components.
Integument: How does the stratum compactum contribute to hydrodynamics?
in sharks: highly organized stratum compactum plays role in streamlining aquatic animals thorugh orientation of collagen plies.
in fish: highly orznized stratum compact with collagen plies resists stretching without wrinkling
Integument: What are the types of scales found in fish and what are their main
characteris5cs?
placoid- chdornicthyes (shark and ray)- dermal origin reducing drag in water.
ganoid scales- thick, nonoverlapping bone covered with ganoin. dont pierce epidermis, covered by mucus highly organized stratum compactum with collagen plies to wrinkling
teleoist (elasmoid) only non-calcified lamellar bone, lack enamel, dentine and vascular bone used to age fish with two varieties: cycloid and ctenoid
Integument: How does the skin of an amphibian differ from that of a fish? Can you label the different layers of integument?
amphibian- loss of dermal scales, little keratinization (alpha keratin) but stratum corneum protects from abrasion and retains moisture. with cutaneous respiration and capillary beds in epidermis and dermis containing as respiration. poison and mucous gland
Fish skin alive- not keratiinized. covered with mucus resisting infection, increase laminar flow (hydrodynamic surface increasing drag), ecasion of predators (release stuff distateful to eat), toxic componentmucus secreting glands, club cells to warn other fish of predators
Mammals: Describe the changes from an ectotherm ancestor to an endotherm mammal.
we developed from pelycosaur which had enlarged neural spines supporting large sail on back allowing the animal to dissipate heat functioning as an ectotherm and then becoming a better predator by warming up faster, adapting to temperature were ancestor to
therapsids (contain cynodonts and mammals)- believed to be warm blooded and the transition into endotherms with some fossils illustrating fur or modifying epithelium and layer of fat under skin which were the ancestor to
cynodonts- had turbinates warming up air before it is coming into body suggesting endothermic which were the ancestor to then mammals
Mammals: What are the characteris5cs of the main evolu5onary radia5ons that led to modern mammals (pelycosaurs, therapsids, and cynodonts), can you compare some of their traits to rep5les?.
reptile: lower jaw many bones, hinge at back, undifferentiated teeth
pelicosaurs had enlarged canines spines with a stronger arched palate (stiff spine slow and not agile allowing them to breathe as they walk and run) many had neural spines on cervical and dorsal vertebrae which supported a large sail on back. appears to dissipate heat so functions as ectotherm warming up faster becoming effective predators warming up faster and lumbar after prey much stronger palate and canines being carnivorous and herbivorous perhaps due to some changes of diet. ancestors gave rise to therapsids
therapsids-
primitive: cervical ribs, number of bones in digits, large b=pubis, lumbar ribs, reptilian tail
derived: more upright posture, ilium expanded. modifications of lower jaw with a reduced number of bones and hinge is farther forward as an adaptation to chew food have canines, stiff spine longer legs better locomotion and move around better may have been warm blooded and transtiion into endotherms because some fossil records indicate structure of fur or modifying epithetlial structure and a layer of fat under the skin.
cynodonts-
primitive: cervical ribs and intercentra atlas/axis complex jaw joint,
derived: pineal foramen lost, teeth modifed for slicing powerful jaws for more chewing, complete secondary palate- bony: dividing food from air thing under tongue, turbinates-series of membranes ossified incresing surface area of olfactory epithelium and function of warming up air before coming into body and taking heat away from air you are breathing out, and lumbar ribs reduced (locomotion and breathing) and shorter tail 2 occipital condyles
Mammals: • What were the two major ex5nc5on events that affected mammalian diversity?
hypotehses for radiation of mammals was because dinosaurs came extinct opening up niches for very little tiny group of mammals. The extinction at end of permian had permian extinction of (pelycosaurs and therapsids) that were exinct and vast majority becoming extinct perhaps movement of continents, comet shower or asteroid.
Mammals:What are three main characteris5cs of extant mammals and what are some synapomorphies of the three main groups of extant mammals? (Monotremes, marsupials and eutherian mammals?)
fur, three middle ear bones, and nursing
monotreme- no nipples nurse young, lay eggs, teeth as young but not older walk like reptile single opening for everything, 2 oviducts only left is active double headed penis
marsupials- give birth to live underdeveloped young which they carry in pouch for a short pregnancy and very long lactation. double horn uterus and vagina and penis, sped up maturation of brain and facial structure temporary placenta
eutherian- placental mammals, precocial and altricial longer pregnancy shorter and penis bone.
Mammals: Why might humans have such large yet altricial babies compared with other primates?
the brains are to big to have precocial and the weaning is too costly energetically so they have them large to maximize chances and then have articial so others and family can help take care of whilehey have more young. pelvic space hypothesis- babies born prematurely because of brain size pelvis literally stretches
babies weaning faster in lactation alone in three years because of social structure (wanting to have well developed brain to understand) with alloparental carea nd extended groups long term pair bones with males but lots of extended family members and cooperative care of young shortening interbirth interval and producing much faster. orangutan- low reproductive output and long reproductive care.
Mammals: How is the olfactory system different from the vomeronasal system? How are they similar?
olfactory- tightly impacted to epithelium close and short nerve. chemoreceptors not sensing different chemicals and translating to brain
specizlied from nasal chamber and factory epithetlium deeply connected to olfactory bone located in front of palage and sense particular smells
similarity sense outside smells
vomeronasal organ-in amphibians and reptiles sense pheromones from other individuals with only stapes independent of olfactory and nerves only allowing them to sense very narrow range of things
