Diversity in Nutrition

Cow, Human, Dog

Dentition

Teeth and Jaw structures and functions

Cow-Dentition

Dental/horny pad

Ruminant herbivores such as cows have no incisors or canine teeth in the upper jaw. Instead they have a dental pad against which the bottom incisors and underdeveloped canines cut through blades of long grass. The dental pad helps tear off the long grass. The space between the incisors and molars is called the diastema in which the canines would normally sit in other animals. The cow has well developed premolars and molars with complex ridges that act as a broad grinding surface allowing them to break down grass and plant material physically by chewing. Chewing leads to the plant matter having a greater surface area which makes for faster chemical digestion.

Cow-Facial Muscles

Masseter muscle

Temporalis Muscle

The cow’s tongue is a very useful muscle it is long and the cow uses it to wrap around long grass and pull it into it’s mouth. The cow has an under developed temporalis muscle; herbivores do not eat other consumers so do not need to hold/pin down other animals using their mouths. Cows do have a very large well developed masseter muscle because the cow does a lot of chewing to break down the plant matter they eat.

Human-DentitionThe human is a typical omnivore its set of teeth consisting of incisors, canines (eyeteeth), premolars and molars. Human incisors are spade like and are used for “biting” and “snipping” food. The human canines are very blunt and are used more like incisors. The premolars and molars are used to grind down food; especially plant matter so that food can be swallowed in smaller chunks and can be broken down further more efficiently in chemical digestion.

Human-Facial MusclesHumans have highly developed facial muscles we are able to move them side to side and forward to back, this aids in speech as well as physical digestion in the mouth. The temporalis muscle is reduced in size while the masseter muscle is quite developed and is a essential in allowing a human to chew. The human tongue aids in swallowing.

Dog-DentitionDogs are carnivorous and their teeth enable them to hold down prey and rip off chunks of flesh from the animals they eat. The dogs’ incisors are used to “bite off” things and appear more sharp and jagged then that of a human or cow. The dogs canines are highly developed, long and coned shaped used to hold, stab and kill prey. In carnivores the molars and premolars are adapted versions known as carnassials, they slice against each other acting like scissors and are used to for shearing flesh and bone.

Dog-Facial MusclesTemporalis Muscle

Masseter Muscle

The dog has a large temporalis muscle that allows it to clamp/snap down on living prey and to hold it in place. The dog has an under developed masseter muscle; chewing is not a necessity for a dog as its prey is high in nutrients and protein making it easy to break down chemically- physical digestion is therefore limited as its not really needed.

Survival

How do teeth and jaw structures allow each animal to survive in

their habitats

Cow The cows’ ideal habitat is high in plant life and grass. The cow consumes mainly grass the problem with this being that plant matter is not high in nutrients and it takes a long time to extract those nutrients from the plants because of the high quantity of cellulose in the plants cell walls. So to combat these problems the cow eats a lot of grass and plant matter and spends a very long time chewing this grass before it is swallowed and then re-chewing the grass as cud. The cow’s tongue and dental pad combined with its lower incisors speed up the amount of time it takes to cut/bite of blades of grass. The highly developed masseter muscle allows it to chew almost continuously and it’s molars grind down the plant matter speeding up the chemical digestion of the plants.

HumanThe food available to omnivores is diverse especially diverse to a human. Humans consume a wide variety of plant life and different animals and require a balance of the different nutrients found in each. Human’s need to be capable of ingesting and physically digesting both plant life and animals in order to live healthily and survive. To the this humans have teeth which are capable of biting, chewing and grinding down tough plant matter and biting large bits of meat into smaller chunks that we are able to swallow. Our masseter muscle allows us to chew the plant matter and our temporalis muscle enables us to make strong quick biting motions to bite right through meat.

DogDogs are carnivorous and need to catch and eat other animals in order to survive. The animals they consume are high in nutrients but the problem for carnivores is that they often waste a lot of energy finding, stalking and catching their prey. To aid in catching its prey the dog’s large temporalis muscle allows it to clamp down on a living animal the dogs large canines pinning the prey in place. The dogs sharp carnassials shear smaller chunks of meat off they prey allowing it to be swallowed and chemically digested in the stomach.

Bibliography• Slide three images: http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/cowpage.html• Slide four images: http://en.wikibooks.org/wiki/Image:Anatomy_and_physiology_of_animals_Sheeps_skull.jpg• Slide five images: http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/humanpage.html• Slide six images: http://www.parkchambersdental.co.uk/images/tmj.jpg• Slide seven images: http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/dogpage.html• Slide eight images: http://en.wikibooks.org/wiki/Image:Anatomy_and_physiology_of_animals_Dogs_skull.jpg• Slide ten images: http://www.vet.ed.ac.uk/dhhps/images/Cow%20Photos/cow%20grazing.jpg• Slide eleven images: http://www.theage.com.au/ffximage/2008/01/18/supermarket_lead_narrowweb__300x406,0.jpg• Slide twelve images: http://www.dogwoodfarmonline.com/dogsheep1.jpg

http://www.alpinelabradoodles.com/images/newpics/labradoodle-nephewlg.jpg

Useful websites: • http://en.wikibooks.org/wiki/Anatomy_and_Physiology_of_Animals/The_Gut_and_Digestion• http://www.vivo.colostate.edu/hbooks/pathphys/digestion/index.html

Useful books:• Biozone: Year 12 biology 2008