B23

Question 1

Caecum in the dog

Answer 1

small, and short, lookslike a little snail house

does not have a direct communiacation with the ileum

Question 2

Caecum in the pig

Answer 2

cylindrical ending blind sac, lies in the left half of the abdomen with its apex pointing caudoventrally

3 taenia and haustra:

• ventral is attached to the ileocaecal fold
• medialis
• lateralis

Question 3

Colon of the dog

Answer 3

Colon ascendens

• right side
• short

Colon transversum

• passes to the left
• between stomach and cranial mesenteric artery

Colon descendens

• left sided
• connected by duodenocolic fold to the ascending colon

Question 4

Colon ascendens in Sus

Answer 4

greatly elongated and coiled

ventral to the left kidney

Ansa spiralis coli

• gyri centripetales -2 taenia and haustra
• flexura centralis
• gyricentrifugales

Ansa distalis coli

Question 5

Colon transversum and descendens in sus

Answer 5

Colon transversum

• Right to left

colon descendens

• straight into the pelvic inlet

Question 6

Blood supply of the hindgut

• dog

Answer 6

• Caecum: A. caecalis (ex. a. ileocolica ex a mesenterica cranialis).
• Colon ascendens: R. colicus (ex. a. ileocolica) + a colica dextra (ex. cran. mesenteric a.).
• Colon transversus: A. colica media (ex. cran. mesenteric a.).
• Colon descendens: A. colica sinistra (ex caud. mesenteric a.) + a. colica media.
• Rectum: A. rectalis cranialis (ex caud. mesenteric a.).

Question 7

blood supply of hindgut

• pig

Answer 7

• Caecum: A. caecalis (from a. ileocolica).
• Colon ascendens:
  
  • Gyri centripetalis: R. colicus of a. ileocolica (ex. cran. mesenteric a.) → runs in wide coils in the colonic cone, giving off numerous vessels to the centripetal coils
  • Gyri centrifugalis: A. colica dextra (ex. cran. mesenteric a.) → coiled in narrow spirals as it passes ventrally to the colonic cone, gives off branches to those centrifugal coils, which are without sacculations.
    
    • The r. colicus and the a. colica dextra anastomose at the central flexure.
• Colon transversus: A. colica media (from cran. mesenteric a., common stem of origin with the a. colica dextra).
• Reaches the transverse colon where the latter is fused to the dorsal abdominal wall, and here the vessels form connections with the a. colica sinistra et dextra.
• Colon descendens: A. colica sinistra (from caud. mesenteric a.).
• Anastomoses with the a. colica media
• Rectum: A. rectalis cranialis (from caud. mesenteric a.).

Question 8

Rectum

Answer 8

pelvic part of the large intestine, terminates at canalis analis

suspended by mesorectum

caudal part lies in the retroperitoneal space

ampulla recti - enlargements of the terminal part, prominent in the horse

Question 9

Canalis analis

Answer 9

terminal part of the intestine

M. sphincter ani internus

• smooth muscle

Linea anorectalis

• separates the rectal mucosa and the anal canal

Linea anocutanea

• pigmented skin, surrounding the anus
• boundary between mucous membrane and skin

Gll. anales

M. sphincter ani externus

• striated muscle

Question 10

canalis analis in dogs

• mucosa division and glands

Answer 10

mucosa division

• columnar zone
• intermediate zone
• cutaneus zone - excretory ducts of anal sacs open here

sinus paranalis

• between the inner smooth and outer striated sphincter
• walls contains the anal sacs

gll. circumanales
* no ducts