Flashcards in Anatomy and Physiology of Digestion Deck (17)
How has domestication led to a change in eating habits?
- horses are now fed small, concentrated meals
- this means they are not constantly consuming forage, as they have been naturally designed to do
In the field: 60% eating, 20% standing, 10% lying, 10% other
In the stable: 15% eating, 65% standing, 15% lying, 5% other activities
What are the percentage components of the horse's GIT?
The stomach makes up 8% of the GIT, 30% the S/I and 62% the hindgut.
Digestion is the process through which food is broken down
Absorption is the transportation of food that has been digested into the bloodstream
What does the food journey involve?
- the food enters the horse
- the food is broken down (digestion)
- the food being transported through the GIT and digested further
- the food being absorbed as it is transported through the GIT
- the food being metabolised into energy
- the food being excreted as waste when all the nutrients have been removed
Where does all energy come from?
From the sun; all horses do is convert it.
Describe the horse's head and dentition
- have teeth that are well adapted to a lignified, fibrous diet
- the mandible (lower jaw) moved forward when the head is at ground level
- have a very strong, highly motile, sensitive upper lip
- incisors bite and molars chew
- have upper and lower incisors used for closely grazing
Saliva is a colourless liquid produced by the paratoid, mandibular and sublingual glands. It is aids chewing and acts as a lubricant for digestion. Acts as a buffer for gastric juices as it is slightly alkali
Composition: 99% water, bicarbonate and NaCl. pH of 7
What are the components of the foregut?
From the mouth, down the oesophagus, into the stomach and to the end of the small intestine
What are the components of the hindgut?
The large intestine (the caecum and the large and small colon) anus.
On average, how many jaw movements are there when eating concentrates compared with forage?
1kg concentrates = 1000 jaw movements
1kg forage = 3000 jawmovements
1kg concentrates = 6500 jaw movements
1kg forage = 22500 jaw movements
Describe the horse's stomach
- has a capacity of 8l
- secretes 25l a day
- has a transit time of 2-6 hours
- has 4 regions - the oesophagal, cardiac, fundic and pyloric regions
What are the three regions of the horse's stomach?
Cardiac region (small in horses), the fundic region (main region, pH of about 5.4), pyloric region (pH of about 2)
What are the three parts of the small intestine?
The duodenum, jejunum, ilieum
What are the 4 secretions that come from the small intestine?
- duodenal juice (neutralzes things coming in)
- pancreatic juice (very enzyme rich)
- bile - breaks down large lumps of fat into small ones
- succus entericus
Describe the horse's hindgut
Very sensitive to change. Has a pH of 7. Celluose, hemicellulose and pectins are transformed into VFA. Anything not digested in the small intestine is digested here.