Exam 6 Class Compiled Flashcards
What is the function of the tongue in vertebrates?
Have taste buds, scraper rasping meet out of bones, manipulating and catching prey, grooming, vocalizations, vermonasal organ-smelling prey. allowing for a larger range of habitats adapting form wet to dry conditions
Describe the specializa0ons of shark, bird, snake, crocodile and ruminant mammal diges0ve systems compared to a generalized vertebrate diges0ve system.
generalized vertebrate digestive system: buccal cavity, pharynx, esophagus, stomach, small intestine, and large intestine
bird: croup and gizzard
snake: change size depending upon eating
crocodile: gizzard
ruminant: multiple
shark: spiral valves in small intestine, rectal gland
Compare and contrast the main arributes of the tongue and salivary glands in
vertebrates. Why was kera0niza0on of the tongue favored?
tongues usefull for terrestrial feeding and allowed adaptation to a larger range of habitats. Snakes (tongue used for smell), cat (grooming), and chameleons (grabbing prey) modified for different things Keratinizaiton fo the lingual epithelium have appear first in amniotes during adaption from wet conditions to dry or sea water conditions and it was favored because it allowed the animals to use it in a variety of conditions. Salivary galnds (present only on tongue in amphibians), reptiles, birds and mammals (tongue and oral cavity have salivary glands). primary digestion begins in buccal cavity with saliva having mucus, salts and amylase to break down starches
What are the main layers of the alimentary canal in vertebrates? What are the roles of each?
Alimentary canal has four layers:
mucosa (secretions to aid passage of food),
submucosa: autonomic nerves into alimentary canal
muscular externa- with longitudinal muscles. Muscle is necessary to push food down endoderm responsible for epithelial lying with inner lining is endoderm and the submucosa and muscularis externa from mesoderm
serosa: fibrous connective tissue most external layer, and mesentery.
Describe the main ways in which the alimentary canal can become specialized, and give an example of each.
Alimentary canal specialization
Alteration of food path/residence time Spiral valves increasing (shark), coiled length (fish), retrograde peristalsis (functional: some birds)
Canal extension: bird crops- espophageal bag (storage for food), cecum- intenstime out pocketing (appendix)
regional /differentiation- single intestine becomes small and large
rectal gland: eliminates excess salt ingested during feeding
pyloric ceca- fingerlike additional digestion and absorption
What are some feeding specializa0ons of snakes?
Snakes have specialized feeding mechanism. Teeth- grasping or piercing.
Tongue- prey location.
Venom gland- digestive enzymes break down prey immediately of soft tissues.
Digestion is faster and more efficient- clear prey faster to avoid interference with locomotion.
Trachea slips forward breathing as swallowing giant prey and jaw walking. Snakes that pierce kill prey far away and animals run away. Or they squeeze prey to break bones and “pre-chew” to swallow and speed up digestion. Snakes also down-regulate and upregulate components of their digestive system when fasting/feeding .
strangle prey and keep squeezing to break bones so that prey will be mushy.
Why may have coprophagy evolve?
eat own poop getting more stuff out of poop that u didnt get the first time partially broken down eat again and can access nutrients. Innoculate babies with the bacteria coming from parent digestive tract and then they will get it give pre-chewed food to get digestive bacteria.
Eat poop to hide from predators
Compare and contrast the process of mechanical and chemical digestion with
fermentation. What types of fermentation are there, and provide an example of each.
mechanical physically breaking down food and chemical digestion breaking down food via enzymes or proteins
fermenation- breaking down food or changing the product via bacteria or other microorganisms
hindgut fermentation- cecum horses rhinos
foregut fermentation- stomach cows and sloths
How does foregut fermentation occur in ruminants? What are the roles of the specialized stomach compartments in this group?
Fermentation chembers (vegetarian animals) sites where symbiotic microorgansism digest cellulose.
rumen- contain prokaryotes and protists that are able to digest cellulose fiber and produce proteins and fatty acids.
reticulum- separates coarse form fine materials
omasum- removes water, ammonia, separates fermenting (rumen) from acidic digestion (abomasum).
abomasum: digestion by enzymes before moving to small intestine produces HCl
Compare and contrast the functional roles of the pancreas and liver, and their histological architecture. When did these organs evolve?
liver - Found in all tetrapod. Produces bile (needed ot digest fat and absorb vitamins A, D, E, and K) and carry away wastes. sotoring vitamins and minerals and carbohydrates. Produces cholesterol and proteisn to carry fat thorugh body. Regulates amino acids in blood, stores iron, converts poisonious ammonia into urea, clears toxic substances regulates blood clotthing, produces immune factors and removes bacteria from blood.
liver lobe made of hepatocytes, ventral veins, portal veins, bile duct and hepatic arteries . sheets of hepatocytes separated by blood sinuses thorugh which courses venous blood returining from intestines and arterial blood form haptic artery .
pancreas - exocrine (produce something when traveling to duct duodenum amylase, lipase, and trypsin acini or acinar cells) and endocrine function (directly to blood insulin and glucagon via islets of langerham
pancreas- found in all vertebrates: empties trypsin (protein), amylase (carbohydrate), lipase (lipids) into the duodenum (exocrine) produces insulin and glucagon (endocrine). with exoxcrine secretory cells of pancreas and endocrine secretions islets of langerhans.
How come Koalas don’t die after eating a diet of Eucalyptus? or vultures that feed on rotting flesh?
Secondary plant compounds can accumulate and be bad for animals metabolism digestive system first line of defencse minizimg ba effect by diverting it to the liver.
Specialized salivary glands counteracting noxious toxins.
Lymphatic system lined up right along alimentary canal to pick up potential dangers.
Acidic enviornemnt of stomach kills many things so most bacteria and microorganisms die
Snake modified sodium channels so toxin doesnt affect these guys.
What are the functions of the urinary system?
eliminate waste products (ammonia), and regulate water and electrolyte balance
What is the difference between opistonephros and metanephros kidneys? Which
vertebrate groups have each type?
Three parts: pronephros (ancient not found in most modern vertebrates usually only found in embryos), mesonephros, and metanephros (posterior part of kidney amniotes).
Type of kidney- which region of nephric ridge are involved
ostinephros: fish and amphibians- mesonephros extends posteriorly into metanephros area without having metanephros. In many animals with opistonephric kidneys, the archinephric found anteriorly (ancient name for urinary duct) duct transports both sperm and urine
Amniotes: no pronephric tubule development. Mesonephros is replaced by metanephros, so amniotes have metanephric kidney.
How is urine made in a mammal?
renal artery branches into the glomerulus which comes in contact with the renal capsule forming the renal corpuscle where fluid electrolytes, and ammonia are exchanged with Intermediate region large region of loops with a lot of branching (loop of henle) ending in the nephrons tubule where urine is concentrated
Compare and contrast the three strategies for the removal of ammonia that have
evolved in different vertebrate groups.
In terrestrial animals ammonia cannot be eliminated through gills or skin.
eliminate either uric acid crystal (birds and reptiles produce feces and urates on top producing a small volume of urine)
urea-soluble in water (mammals, few amphibians and fish (elasmobranchs-shark)).
Fish living in freshwater eliminate the most dilute water eliminating ammonia
What is the primary funcAon of the bladder and which vertebrates have one?
Where does it derive from in fish vs. tetrapodes?
turtles and tuatara, amphibians and mammals have bladders with functions of urine storage, salt and water transport good moment away from predators and opotentially osmotic regulation role removal of water complementing role of kidney.
absent in birds and most lizards as well as most fish
Embryonic teleost two urinary ducts then have wide urinary duct to hold urine that then drain into the cloaca.
Amphibian and reptile urine that is produced drains into cloaca and then into urinary bladder which is an outpocketing of cloaca.
Mammals have evolved individual duct so urinary bladder seperated form digestive tract and ureters into bladder then out through the urethra.
derived form the urogenital sinus and the allantois
Describe how gonads become differentiated in males and females from an indifferent gonad.
Embryonic gonad development begins as genital ridge gives rise to an indifferent gonad with undifferentiated germ cell migrate form extra-embryonic endoderm to gential ridges and will form sperm or eggs.
if germ cells populate the medullar (deeper regions) of the sex cords a testis-inward is formed with primary sex cords only being testis. if germ cells populate the cortex region (peripheral regions) an ovary-outward is formed.with two sets of sex cords
What are the mechanisms of sex determination found in vertebrates? Draw the
sex ratio temperature curve for a turtle species whose sex raAo would be totally unaffected by climate change (going from 26-28 degrees). What would it look like in a species that would be very affected?
Sex determination mechanism are incredibly diverse in vertebrates
Mammals have xx/xy
Monotreme have multiple series of x chromosomes with platypus have 10 sex chromosomes
Reptiles and some fish: temperature at which eggs are incubated determines genes are activated for which sex hormones are produced
zz/zw system: male has homologous chromosomes and females (ZZ) have heterologous chromosomes (ZW) birds. Typically homogametic sex-defaults sex. In absence of testosterone in mammals you become a female. In absence of estrogen (in w chromosomes), in birds, you become a d male (default sex).
Frogs can ahve both sex determination mechanism by chromosomes
How do genital ducts become differentiated in males and females from the common ducts they start with?
Wollfian duct=mammal archnephric duct
archienphric duct- AKA pronephric duct/mesonephric duct, wolffian duct, opisthonephric duct, ductus deferens (vas defers). Female- wolfian ducts need testosterone to make testosterone and so wollfian ducts decay passively. In mamals, keep only wolffiat duct which connects to sperm transfer form testes to cloaca mulleran ducts regress and disapreear
mmullerian duct: oviduct
metanephric duct0 ureter
In females, mullaerian duct is conserved and become ovary duct with the wulffeian lost
Male testes produce testosterone and mullerian inhibiting hormone telling them to self-destruct active process embryonically
What are the funcAons of the Ovary? What are the main roles of the female hormones and where are they produced? How are mature Ovum produced?
Ovaries produce homrones make females into females produce progesterone and estrogne and mature ocytes.
Estrogen primarily producted in ovarian follicle (helps build yolk), and corpus leteum.
Progresterone produced in corpus leteum more of hormone that allows for pregnancy right after ovultation takes place to promote environemtn conducive to proegnancy and major changes like gettting ready to reproduces.
Primordal germ cells double number of chromomsomes and sit there in oogonium. Primary oocute in capusel with protective outside an secretion of estrogen as reproductive system gets on way will undergo first meiotic divison and one is destoryed then secondary oocyte splits again and second polar body is discarded ending up with mature ovum in follicle and when ovulation takes place follicle ruptures and ovum is released. Follicle forms corpus leteum continuting to secrete estrogen then will begin secrete progresterone if fertilized.
