Large animal GI tract anatomy (Struc) Flashcards
ORAL CAVITY IN LARGE ANIMALS
- like in small animals it has two segments: ? vestibule, oral ? proper
- in horses the ? palate (6) is very long;
- it hangs down before the epiglottis (11);
- its free margin is closely applied to the tongue;
- in ? – the upper ? teeth lacks;
- at the level of the inner face of the lips and cheeks- ? papillae (3);
ORAL CAVITY IN LARGE ANIMALS
- like in small animals it has two segments: oral vestibule, oral cavity proper
- in horses the soft palate (6) is very long;
- it hangs down before the epiglottis (11);
- its free margin is closely applied to the tongue;
- in ruminants – the upper incisor teeth lacks;
- at the level of the inner face of the lips and cheeks- buccal papillae (3);
The tongue
In horses
* is ?;
* is ? at its apex;
* its upper surface is covered with delicate ? papillae that confer a ? texture;
* ? papillae (10);
* ? papillae (9);
* ? papillae (11);
The tongue
In horses
* is long;
* is spatulate at its apex;
* its upper surface is covered with delicate filliform papillae that confer a velvetlike texture;
* vallate papillae (10);
* foliate papillae (9);
* fungiform papillae (11);
TONGUE
In ruminants
* the caudal part is raised, and form the ? ? (3);
* rostral- ? fossa (arrowhead);
* the dorsal aspect of the tongue is strongly ?;
- Filiform papillae (b)- are ?;
- Fungiform papillae (c)- along the ? of the apex and body and scattered between the ? papillae;
- Vallate papillae (f, g)- 8-21 in cattle on each side;
- Foliate papillae – are absent in ruminants !!!
- Lenticular and conical papillae (e) – cover the lingual torus in ruminant;
TONGUE
In ruminants
* the caudal part is raised, and form the lingual torus (3);
* rostral- lingual fossa (arrowhead);
* the dorsal aspect of the tongue is strongly keratinized;
- Filiform papillae (b)- are keratinized;
- Fungiform papillae (c)- along the edges of the apex and body and scattered between the filiform papillae;
- Vallate papillae (f, g)- 8-21 in cattle on each side (pink ones in pic)
- FOLIATE PAPILLAE – are ABSENT in ruminants !!!
- Lenticular and conical papillae (e) – cover the lingual torus in ruminant;
DENTITION
Brachydont type
? crowns, well-developed ?, and an obvious division between the crown and root (carnivores / humans)
Hypsodont type
?-crowned teeth and enamel extend deep to the ? line, providing extra material for future ? and ?. (Ruminants / Equine)
DENTITION
Brachydont type
short crowns, well-developed roots, and an obvious division between the crown and root (carnivores / humans)
Hypsodont type
high-crowned teeth and enamel extend deep to the gum line, providing extra material for future wear and tear. (Ruminants / Equine)
Dentition: Divide mouth into 4 quadrants
DENTAL FORMULA IN HORSES
3 - 1 - 3(4) - 3/ 3-1-3-3
incisors, canine, premolar, molar
Diastema: the wide ? that separates the ? from the cheek teeth; may be interrupted by the canine tooth.
Triadan numbering system
(see pic)
note: in small animals its until 110 and 210 however in large animals its until 111 and 211 same as the lower ones
(recall in small animals -> 3 - 1 - 4 - 2 / 3 - 1 - 4 - 3 so there’s lesser number of premolars in large animals and upper of large animal has 1 more molar as compared to small)
Dentition: Divide mouth into 4 quadrants
DENTAL FORMULA IN HORSES
3 - 1 - 3(4) - 3/ 3-1-3-3
incisors, canine, premolar, molar
Diastema: the wide gap that separates the incisor from the cheek teeth; may be interrupted by the canine tooth.
Triadan numbering system
(see pic)
note: in small animals its until 110 and 210 however in large animals its until 111 and 211 same as the lower ones
wolf tooth
-is a component of the ? dentition;
-is the first ? (?1);
-often fails to ?;
-almost invariably confined to the ? jaw;
-it is without ? significance;
-it is easily ?.
wolf tooth
-is a component of the permanent dentition;
-is the first premolar (P1);
-often fails to devleop;
-almost invariably confined to the upper jaw;
-it is without functional significance;
-it is easily extracted.
dental formula in cattles
0-0-3-3/3-1-3-3
- absence of ? and ? teeth in the upper jaw
- the assimilation of the canines to the incisors in the lower jaw;
- the fourth or corner incisor; -> “what does he mean by that”
- upper and lower first premolar teeth fail to develop (that’s why in small animals there 4 premolar teeth on lower and upper jaw and only 3 in large animals)
The upper incisors are replaced by the ? ? (2). It is specific for both, large and small ruminant.
dental formula in cattles
0-0-3-3/3-1-3-3
- absence of canine and incisor teeth in the upper jaw
- the assimilation of the canines to the incisors in the lower jaw;
- the fourth or corner incisor; -> “what does he mean by that”
- upper and lower first premolar teeth fail to develop (that’s why in small animals there 4 premolar teeth on lower and upper jaw and only 3 in large animals)
The upper incisors are replaced by the dental pad (2). It is specific for both, large and small ruminant.
EQUINE STOMACH
Simple stomach;
It has a ? size, in relation to the animal and to the volume of fodder consumed;
The interior is divided in two areas;
Non-? part of the stomach, is covered by squamous epithelium and the ? part covered by ? ?;
The border between these parts - ? ? (4).
The ** ? ** is well developed- is responsible for the horse’s inability to eructate or vomit;
? ? and ? segment of the stomach can be parasitized by ? larvae.
EQUINE STOMACH
Simple stomach;
It has a small size, in relation to the animal and to the volume of fodder consumed;
The interior is divided in two areas;
Non-glandular part of the stomach, is covered by squamous epithelium and the glandular part covered by glandular mucosa;
The border between these parts - margo plicatus (4).
The ** cardiac sphincter ** is well developed- is responsible for the horse’s inability to eructate or vomit;
margo plicatus and pyloric segment of the stomach can be parasitized by botfly larvae.
BOVINE STOMACH
Is composed of four chambers:
rumen (4);
reticulum (1);
omasum (2) ;
abomasum (3);
The rumen, reticulum, and omasum- are known as ? while ? is the known as the real stomach
The rumen (4)
* It is a huge ? chamber;
* placed on the ? side of the ? cavity;
* it extends from * ? * to the * ? *;
* it continues with the reticulum-> ?-reticular orifice.
* the left and right longitudinal groves- divides rumen in ? ruminal sac and ? ruminal sac.
BOVINE STOMACH
Is composed of four chambers:
rumen (4);
reticulum (1);
omasum (2) ;
abomasum (3);
The rumen, reticulum, and omasum- are known as forestomach while abomassum is the known as the real stomach
The rumen (4)
* It is a huge fermentation chamber;
* placed on the left side (flipped on the image) of the abdominal cavity;
* it extends from *cardia * to the * pelvic inlet *;
* it continues with the reticulum-> rumino-reticular orifice.
* the left and right longitudinal groves- divides rumen in dorsal ruminal sac and ventral ruminal sac.
The reticulum (1)
- it is the second ?;
- placed on the right or left? side of the ? cavity;
- cranially is bordered by ? muscle;
- caudally is bordered by the ?;
- communicates with the ? (rumino-reticular orifice) and with the ? (reticulo-omasal orifice).
- the reticular mucosa has a ? appearance;
The reticulum (1)
- it is the second forestomach;
- placed on the left side of the abdominal cavity;
- cranially is bordered by diaphragm muscle;
- caudally is bordered by the rumen;
- communicates with the rumen (rumino-reticular orifice) and with the omasum (reticulo-omasal orifice).
- the reticular mucosa has a honeycomb appearance;
Stomach
The omasum (2)
* it is the ? forestomach;
* placed on the ? side of the ? cavity;
* It is ? in shape;
* It has two curvatures: ? curvature and ? curvature;
* communicates with the reticulum (** ?-? orifice **) and with the abomasum ( ** ? orifice **);
* It is under cover of the ?th – 11th ribs.
Stomach
The omasum (2)
* it is the third forestomach;
* placed on the left side of the abdominal cavity;
* It is spherical in shape;
* It has two curvatures: greater curvature and lesser curvature;
* communicates with the reticulum (** reticulo-omasal orifice **) and with the abomasum ( ** omasoabomasal orifice **);
* It is under cover of the 8th – 11th ribs.
The abomasum (3)
- it is the ? compartment of the bovine stomach;
- of the 4 compartments, the Abomasum resembles the ? stomach most closely.
- placed on the ? side of the abdominal cavity;
- it looks like an ? sac;
- it is in direct contact with the abdominal floor;
- it has three segments: ?, ?, and ? part.
- all three segments are covered by ? mucosa
- it continues with the ?.
The abomasum (3)
- it is the last compartment of the bovine stomach;
- of the 4 compartments, the Abomasum resembles the monogastric stomach most closely.
- placed on the right side of the abdominal cavity;
- it looks like an elongated sac;
- it is in direct contact with the abdominal floor;
- it has three segments: fundus, body and pyloric part.
- all three segments are covered by glandular mucosa
- it continues with the duodenum
pic:
cecum is horse is comma-shaped and is huge
LARGE INTESTINE IN HORSES
The cecum
- is the first segment of the ? intestine;
- placed on the ? side of the abdomen;
-it occupies the ? flank region;
- it is a ?-shaped organ;
- *** it has three segments: ?, ? and a ? blind ?;
- it presents #? teniae coli.
- It has tow orifices: ? orifice (close to last part of small intestine DJ”I”) and ? orifice
LARGE INTESTINE IN HORSES
The cecum
- is the first segment of the large intestine;
- placed on the right side of the abdomen;
-it occupies the right flank region;
- it is a comma-shaped organ;
- *** it has three segments: base, body and a ventral blind apex;
- it presents #4 teniae coli.
- It has tow orifices: ileocecal orifice and cecoclic orifice
The large intestine in horses
The colon
- It has three segments: ? colon, ? and
? colon;
The ascending and the transverse – ? colon; The ? colon is known as the small colon;
** The ascending colon has #? parallel limbs and #? flexures
Right ventral colon (RVC)
Ventral diaphragmatic flexure (VDF)
Left ventral colon (LVC)
Pelvic flexure (PF)
Left dorsal colon (LDC)
Dorsal diaphragmatic flexure (DDF)
Right dorsal colon (RDC) **
The large intestine in horses
The colon
- It has three segments: ascending colon, transverse and descending colon;
The ascending and the transverse – large colon; The small colon is known as the small colon;
** The ascending colon has #4 parallel limbs and #3 flexures