dentition Flashcards
dogs and sheep
what does carnivore and herbivore mean
carnivore=eats meat
herbivore=eats plants/grass
what is the dentition of a dog designed for
gripping prey, cutting and tearing meat off bones and for crushing bones
how long is the gut for carnivores
short, as protein is easily digested
name the 5 types of teeth in a dog
incisors, canines, carnassials, molars, premolars
describe the shape of the incisors and their function
chisel shaped and sharp, used for stripping flesh from bones
describe the shape of the canines and their function
large and pointed, used to kill and grip the prey and tear the flesh
describe the shape of the carnassial teeth and their function
they fit together when the mouth is closed, work like a pair of scissors and slice the flesh and crush bones
describe the shape of the molars and premolars and their function
strong pointed cusps, cutting meat
describe features of a dog’s jaw
the lower jaw can only move vertically, not horizontally = prevents dislocation of the joint due to the struggling movement of the prey – jaw muscles are very powerful, enabling a bite strong enough to crack bones
what is the dentition of a sheep designed for
cutting off the grass from the plant when grazing and for grinding the grass efficiently to smash the cellulose cell walls (therefore releasing the digestible plant cell contents)
describe the shape of the incisors and their function
sharp and chisel shaped (bite against a horny pad on the upper jaw) = enables the vegetation to be cut off the plants during feeding
what is the space between the horny pad and the upper premolars called
the diastema (characteristic of herbivorous mammals)
what does the diastema allow
manipulation of the food by the tongue
what behaviour of sheep allows then to look around frequently while feeding
they fill the diastema with extra grass during feeding and then can stop feeding until the grass is chewed and swallowed
describe the shape of the molars and their function
large, interlocking (WM arrangement) are strengthened with ridges of cement which also help to prevent edges of the teeth being chipped away by abrasive food – to grind the tough plant material
describe features of a sheep’s jaw
the lower jaw moves horizontally during chewing (circular motion to grind the grass) = effectively breaks open the cellulose walls of plant cells
what’s the benefit of the root cavities of sheep premolars and molars remaining open for their entire life
good blood supply is maintained to the teeth which can therefore grow throughout life (useful as they get worn down by grinding)
