GI Flashcards
What is the formula to gauge horse age by deciduous incisor teeth?
Middle appears at 6 days
Second at 6 weeks
Third at 6 months
What is the difference in shape between deciduous/milk incisors and permanent incisors in horses?
What is the formula to gauge horse age by adult incisor teeth?
Middle: 2.5 years
Second: 3.5 years
Third: 4.5 years
What are canine teeth also known as in horses?
Tushes
Canine teeth are present in only what type of horses?
Male
The cardia sits at what rib on the horse?
Rib 11
The stomach sits between which ribs on the horse?
Rib 9-15
Where is the nephrosplenic/ Reno splenic ligament located?
Between spleen and left kidney
(Is a continuation of gastrosplenic ligament)
Digestion in the horse occurs in which 2 broad regions?
Foregut (stomach & SI)
& hindgut
What are the 2 types of carbohydrates?
structural (cellulose)
non-structural (starch)
Name 3 carbohydrares that can by hydrolyzed to sugars in the equine SI
fructose, glucose, starch
Name 1 carbohydrates that CANNOT be hydrolyzed to sugar in the equine SI and instead need bacterial fermentation
cellulose
Equine saliva is high in what two elements?
Ca & Cl
Does horse saliva contain digestive enzymes?
no
What is the scientific term for swallowing?
degluttination
What are the 3 phases of swallowing?
oral, pharyngeal, oesophageal
What is a peristaltic wave?
Muscular contraction that send food down esophageal tube
What does quidding mean? [equine]
dropping food while chewing
What structure can be loosely classified as the “fill line” in horse stomachs?
margo plicatus
What are 2 intrinsic inciting substances to horse stomach lining?
HCL & pepsin
What is the most significant protective factor of stomach glandular mucosa?
bicarbonate-rich mucus layer
What are 2 ways that a horse’s constant eating can protect the stomach mucosa?
1- bicarbonate-rich mucus layer is produced by constant eating, and protects glandular mucosa
2- fibrous mat can be formed, protecting acid splashes from reaching non-glandular region
What sphincter of the horse closes after gastric distention?
lower oesophageal/cardiac sphincter
The horse has a lower capability to digest starch due to low levels of __________________
pancreatic amylase
Absorption of glucose takes place in what organ?
SI
Glucose and fructose enter an enterocyte through which 2 transporters?
SGLT1 & GLUT 5
Glucose and fructose exit an enterocyte through which transporter?
GLUT 2
What substance aids in the digestion of triacylglycerols?
gastric lipase
What do triacylglycerols turn into after partial digestion by gastric lipase?
diacylglycerols & free fatty acids
What is 1? 2? 3?
1: proteases
2: lipase
3: amylase
Equine GIT is able to gradually adapt to a high ______ diet by increasing __________ expression
CHO
SGLT1
Does the equine LI have mucosal enzymes?
no
What are the 3 VFAs produced in the equine LI?
Which is the most predominate?
Acetate (predominate)
butyrate
propionate
What 3 gasses are found in the equine LI?
CO2, hydrogen, methane
Can the large intestine digest starch and sugar?
yes- but only VERY little
VFA production stimulates the movement of _________ into the lumen
water
___________ buffering prevents mucosal damage in the lumen
bicarbonate
Which VFA is an energy source for epithelial cells?
butyrate
Which VFA is an energy source for peripheral tissues?
acetate
Which VFA is used in the liver as a precursor to gluconeogenesis?
propionate
Which VFA supressed mucosal inflammation?
butyrate
In what organ does “hindgut fermentation” take place in a horse?
LI
What are the 6 layers of the GI wall?
serosa
longitudinal smooth muscle
circular smooth muscle
submucosa
mucosa
villi
lumen(inside)