Digestive Anatomy + Physiology Flashcards
what is hind gut fermentation
food goes through chemical/enzymatic breakdown before fermentation
what are the functions of the digestive tract
- extract nutrients from food
- eliminate residue
what is the foregut functions
- enzymatic digestion
- nutrient absorbtion
what are the teeths functions
- break up ingested fibre for coloic fermentation
what dysfunctions are caused by teeth
- excess fibre length
- choke increases
- colic can increase
- feed efficiency goes down
how many teeth do foles have
- 24 deciduous teeth
- 12 incisors
- 12 pre-molars
How many teeth do mature males have
40-42
2(I3/3 C1/1 P3or4(wolf)/ 3 M3/3)
how many teeth do mature females have
36-40 females
2(I3/3 C 0or1/0 P30r4/3 M3/3)
how can you tell the horses age through their teeth
- tooth eruption
- changing shape of occlusal surfaces
- change in angular profile of incisors
- general tooth wear (variable)
- disappearance of infundibulum cup (unreliable)
- 7 year old hook (unreliable)
- galvaynes groove (unreliable)
what changes can be seen in occlusal surface of the insisors
- newly emerged tooth is wider than is is deep
- 6 year old incisor is oval
- 9-12 year old incisor is round
- 14-17 year old incisor is triangular
- teeth over 20s are deeper than they are wide
what are some clinical signs of dental problems
- quidding
- inefficient chewing
- excessive salvation
- weight loss
- foul breath
- cheek sensitivity
- blood from mouth
- sinus infection
behavioural signs of dental problems
- inconsistent performance
- bit sensitivity
- head throwing
- lack of collection
- avoiding bit
- not stopping or turning
what is teeth floating
- upper arcade is wider than the lower arcade
- points are usually along cheek side of upper cheek teeth and lingual side of lower cheek teeth
- dentists shave down these points
what are sources of dental problems
pasture: incisors tear and cut grass, molars grind
stabling: little wear on incisors, contact between molars reduced
- abnormal mouth condition
what are salivary glands
- 99% water and 1% organic salts
- lubricant
- buffer
- stimulated by presence of food in mouth (scratching)
how does feed effect salivary glands
- hay absorbs 4x weight in salivia
- oats absorbs 1x weight in salivia
what common issues can arise from equine digestive tract
- reduction in salivia
- choke
- EGUS
- impaction
what is the esophagus
- peristaltically moves food and salivia from mouth to stomach
what can cause esophageal obstruction or choke
- large food bolus
- insufficient salivaia
- previous chokes
- poor dentition
what is equine gastric ulcer syndrome
- imbalance between exposure to acid and protective features of stomach
what causes EGUS
- stress
- transport
- emergy dense feeds
- confinment
- meal fed (horses are naturally grazers)
intense racing or exercise
what increases ulcers
- 7.6 fold increase = from cribbing and windsucking
- 3.9 increase = urban vs rural settings
- 1.1 fold = length of training time
- 3.4 fold increases on weight keepers or weight holders
how can fermentation damage mucosa
- at pH less then 4
- fermentation products inhibit Na transport functions of gastic mucosa
accumulates withn cells of stomach lining - water pulled into cells - mucosa damage
what is the small intestine
- 30% of total intestinal volume
- carbohydrases, proteases and bile salts secreted from the liver, pancrease and intestinal wall ( no gall bladder)
- contains 5-8% dry matter
what dysfunctions can occure in the small intestine
- obstruction = simple or strangulating
- high proximal or low distal
- proximal enterities
what is the cecum
- houses population of anaerobic lactate- utilizing lactobacilli and streptococci
- breakdown and absorbtion of fibrous carbs
- synthesis of protein, VFAs, b vitamins and vitamin k
what are cecum dysfunctions
- disruption of microbial populations
- ileocecal intussusception
can the cecum and colon change sizr
variable capacity in response to feed types
what is a colon
- 40-50% of intestinal tract capacity
- water absorbtion
- ventral colon 12% DM
- rectum 24% to 34% DM
- increases concentrates
- increase water loss
- absorbtion of products of breakdown of fibrous carbs
what are some obstructions in the colon
obstructions
impactions
enteroliths
lipomas
torion
displacement
entrapment
- diarrhea from toxins, infections and disease
