Ruminants+-+Giraffes

=Ruminants - Giraffes=

Pre-Small Intestine (Group 4 - Kayla R)
//__Mouth/Teeth:__// Prehension of giraffes is completed by using their tongues. They are lacking upper incisors, but have 24 molars in the back of their mouths to help in the start of physical digestion. The dental plate is located where the incisors would normally be and is used, along with the tongue and an excessive amount of saliva to create a bolus (ball of feed for deglutition). The saliva also carries salivary amylase which begins the breakdown of starches.

//__Esophagus:__// The esophagus in a giraffe can complete two way peristalsis. This gives them the ability to regurgitate their food in the form of cud. Cud is then re-chewed and re-swallowed.

__//Stomach://__ The stomach of a giraffe is made up of 4 parts- reticulum, rumen, omasum, and abomasum. Being a ruminant, the giraffe also has a special reticular/esophageal groove.

//Reticulo-Rumen:// The function of this area is to store, moisten, and physically break down the food. Physical breakdown happens how? Microbes--what do they do, what byproducts do they produce?

//Omasum:// This area of the stomach controls the passage rate of food particles by size. Water absorption

//Abomasum:// This is considered to be the "true" stomach, this is where the first extensive digestion takes place. Here, Peptic cells secrete pepsinogen. When pepsinogen is combined with HCl and protein peptin pepsin (an active enzyme) is formed and along with HCl begins the chemical breakdown of proteins. Physical digestion is also present through the mixing and churning.

//Reticular/Esophageal Groove:// This is a special tube that closes of when in the presence of suckling and milk protein (may be triggered by other things as well, but it is still unknown). By having a closed tube it allows for the milk to bypass the rumen and enter directly into the omasum. It is normally found in young animals.

Large Intestine and Post Large Intestine (Group 4 - Emily N)
Large Intestine – made up of the Cecum, Colon, and Rectum. Cecum – The blind pouch at the junction of the small and large intestines. Microbial digestion of fibrous carbohydrates, synthesis of B and K-vitamins, and the production of Volatile Fatty Acids by microbes take place in the cecum. VFAs are used for energy and are absorbed through the cecal wall. Colon – A giraffe’s colon (ascending) is part of a large distal fermentation chamber that is vital for their survival when they are browsing. The colon is made up of cuboidal and goblet cells, which secrete mucous. It has the same roles as the cecum, but has a slower rate of passage of material. Microbial digestion, VFA synthesis, and B and K-vitamin synthesis take place in the colon as well. The colon also is the site for water reabsorption and the concentration of feces. Rectum – The last part of the gastrointestinal tract where the undigested material is formed into feces, which is made up of unabsorbed feedstuffs, dead bacteria, sloughed cells, and fluid.

Anus –The last part of alimentary tract that controls the exit of feces. In a giraffe’s case, the feces is similar to that of goat droppings.