Horses Flashcards
What teeth in the horse are hypsodont, brachydont?
Hypsodont: incisors, premolars, molars
Brachydont: canines
What is the dental formula of an adult horse?
2 (I 3/3 C 1/1 P3(4 - wolf tooth)/ 3 M 3/3) = 40 (42)
What is the deciduous formula of a horse?
2 (i 3/3 c 0/0 p 3/3) = 24
Describe why horses are obligate nasal breathers?
When the mouth is ‘resting’, the soft palate sits below the epiglottis, allowing only air to travel through the nose
What are the extensive tonsils that are located in the pharynx and root of the tongue?
Diffuse follicular
What % of the oesophagus is skeletal/ smooth muscle, also include if its caudal/ cranial.
Cranial 60-70% is skeletal
What is the saccus caecus/
Enlarged fundus of the stomach
What angle does the oesophagus enter the stomach enter, comment on the cardiac sphincter.
Abdominal oesophagus enters obliquely, the cardiac sphincter is well developed -> cannot vomit
What approximate percentage of the horse stomach is covered by non-glandular mucosa? what does this mean for gastric ulcers?
~50%, gastric ulcers are commonly found here
What is the border of the non-glandular and glandular mucosa in the stomach called?
Margo plicatus
What organ is a major site for bacterial fermentation? where does it sit in the horses abdominal cavity?
Caecum, and fills much of the RHS
Where can a horse be auscultated for sand colic?
Xiphisternum
How many taeniae are located in the caecum
4, dividing into 4 rows of haustra (or sacculations)
What structure separates the haustra?
Deep semilunar folds
What structure does the dorsal and ventral band attach to?
Dorsal band: ileocaecal fold
Ventral band: caecocolic fold
Describe how the ileocaecocolic junction is different in the horse.
The ileocaecal (ileum caecum) orifice and the caecocolic (caecum colon) orifice both open into the lesser curvature of the base of the caecum, meaning the ingesta must pass through the caecum as the ileum is not directly connected to the colon
How large (approx.) is the ascending + descending part of the colon?
3-5m
Which part of the colon is U-shaped and is double on itself in another U-shape?
ascending colon
Name the seven parts of the ascending colon
Right ventral colon, sternal flexure, left ventral colon, pelvic flexure, left dorsal colon, diaphragmatic flexure, right dorsal colon
What happens to the diameter in the transverse colon, following the ascending colon?
Decreases abruptly (to 7-10cm)
What structure supports the descending colon?
Descending mesocolon
Explain how the faecal balls are formed in the descending colon.
The deep sacculations in descending colon (caused by 2 wide and prominent taeniae) divide the contents into balls
Name 3 structures or cells in the small intestine (and location if relevant) that contribute to secretions or health.
Brunner’s glands: secrete mucin (entire length of duodenum)
Crypts of lierberkuhn which contains paneth cells (to keep microbial population in check)
