(2) Stomach (Ventriculus, Gaster)

Digestive system part.

In stomach, there is 2 general types of mucosa, which ones?

In stomach, there is 2 general types of mucosa, which ones?

1. glandular mucosa which contains glands

2. non-glandular mucosa without glands

The 2 types of stomach ?

1. simple stomach - one single compartment

   • a) glandular stomach in car

   • b) stomach with composite lining in su + eq. (has glandular and non-glandular mucosa)

2. complex stomach - 4 compartments

what do we in general describe on simple stomach? which species is this?

• 2 facies: facies parietalis (in contact with diaphragm and liver) and facies visceralis (in contact with surrounding organs)

• curvatura ventriculi major (1)

• curvatura ventriculi minor (2)

• incisura angularis (3) (at level, which stomach is sharply bent)

• corpus ventriculi (4)

• fundus ventriculi (5)

• incisura cardiaca (6)

• pars cardiaca (7) with ostium cardiacum (8) (opening to the esophageus)

• pars pylorica (9) with ostium pyloricum (10) - continuing into duodenum

  • pars pylorica can be divided into antrum pyloricum and the narrower canalis pyloricus.

  • torus pyloricus formed in ru + su - closing the pylorus.

  • m. sphincter pylori - formed by circular layer of muscle coat.

• sulcus ventriculi - along interior of curvatura ventriculi minor, fro cardia to pylorus.

Species: carnivores, cat stomach. Simple and glandular. Lies on left side of abd. cavity, only pars pylorica to the right. Non-glandular area is only on cardia.

What type of stomach do the ruminants have?

1. complex stomach with 4 compartments

   • first 3 lined up with non-glandular mucosa (pars non-glandularis), known as the forestomach (proventriculus) which includes the rumen, reticulum and omasum.

   • The fourth compartment, abomasum is the glandular part (pars glandularis). It has a capacity of 110 - 235 L in bovine and 19-38 L in small ruminants.

complex stomach - ruminant, structures on left side.

1. sulcus ruminoreticularis (with ostium ruminoreticulum)

   • In between the rumen and reticulum.

2. Reticulum

3. Abomasum

4. sulcus cranialis

5. sulcus caudalis

6. saccus dorsalis

7. correspond to the pilae ruminis on the inner surface of rumen. Together on the inside, it has papillae ruminis surrounding them.

8. sulcus coronaris dorsalis

9. sulcus longitudinale sinister

10. saccus ventralis

11. sulcus coronaris cventralis

12. saccus ceccus caudoventralis

13. saccus seccus caudodorsalis

complex stomach of ruminant - right side.

1. saccus ceccus caudodorsalis - separated by coronary grooves

2. sulcus caudalis

3. sulcus coronarius dorsalis

4. sulcus accessorius dexter

5. rumen - laterally compressed sac in the left half of abdominal cavity, from diagram to the pelvic inlet.

6. Insula ruminis - island of rumen, which is formed by sulcus longitudinale dexter and the sulcus accessorius dexter.

7. sulcus longitudinale dexter - right long groove, longitudinally on facies visceralis and parietalis

8. saccus ventralis

9. sulcus coronarius ventralis

10. saccus seccus caudoventralis

11. facies visceralis

12. curvatura dorsalis

13. facies parietalis

14. curvatura ventralis (towards abd. floor)

15. reticulum

16. abomasum

17. omasum

18. sulcus cranialis

19. sulcus ruminoreticularis - between rumen and reticulum, the ostium ruminoreticularis structure is here.

what do we describe in stomach of pig?

• simple stomach with composite lining, lying on left side, only pars pylorica is on the right.

• fundus of stomach → diverticulum ventriculi (lines with glandular mucosa)

• nonglandular area surrounds the ostium cardiaca.

• pylorus forms → torus pyloricus

What do we describe in stomach of a horse?

• Simple stomach with composite lining and small. Lies more left, pars pylorica to the right.

• (1) fundus → saccus cecus ventriculi (blind sac)

• (2) margo plicatus - irregular raised ridge where the glandular and non-glandular mucosa meets.

  • non-glandular lines the saccus cecus ventriculi

the stomachs of ruminant, these are?

1. rumen

2. reticulum

3. omasum

4. abomasum

Showing the forestomachs - proventriculus.

Rumen structures?

1. plicae ruminis

2. papillae ruminis

Rumen - in left half, from diaphragm to pelvic inlet. We describe facies parietalis, towards diaphragm, left abd. wall + spleen and facies visceralis - towards omasum, abomasum, intestine + pancreas.

• curvatura dorsalis et ventralis

Structures of reticulum? (3)

Reticulum - spherical, to the left, bw. diaphragm + rumen. Has facies diaphragmatica et visceralis.

1. crista reticuli - formed by non-glandular mucosa

2. cellulae reticuli

3. on the crests and cells there are small papillae reticuli.

The reticulum communicates with omasum through the ostium reticulo-omasicum.

Structures of omasum?

Omasum - lies bw. ventral sac of rumen + right abdominal

• curvatura omasi + basis omasi is described, facies parietalis et visceralis.

• laminae omasi (1) (several omasal folds)

• papillae omasi (2)

Omasum communicates with abomasum by means of ostium omasoabomasicum, closed by vela abomasica.

structures of abomasum?

We describe: (2) fundus abomasi, (1) corpus abomasi, facies parietalis et visceralis, curvatura major et minor.

3. plicae spirales abomasi

4. sulcus abomasi - gastric grooves of ruminant stomach, including also of the others: sulcus omasi, sulcus reticuli. → important in young as these folds and convert into a tube for the milk to pass through, directly to abomasum.

Abomasum is lined with glandular mucosa, said to be true stomach.

2nd flashcard of abomasum structures (same)

1. plicae spirales (internally)

2. fundus abomasi (cranial blind end, seen on the ventral part in the dried stomach structure)

3. curvatura minor (seen dorsally, towards omasum)

4. curvatura major (seen ventrally)

5. facies parietalis (towards rumen and omasum)

6. facies visceralis (towards abdominal floor)

7. corpus abomasi

2nd flashcard on structures of omasum (same)

1. ostium reticulo-omasicum (between reticulum and omasum)

2. laminae omasi (the folds)

3. papillae omasi (covers the folds, by epithelium)

4. ostium omaso-abomasicum (between omasum and abomasum, which is closed by vela abomasica, by 2 muscular folds)

- other structures: curvatura omasi (seen at the top, towards the reticulum on dried structure) and basis omasi (ventrally seen at the tip of the dried stomach structure).

2nd flashcard on reticulum structures (same)

Position: spherical shaped, lies to the left, between diaphragm and rumen.

1. cellulae reticuli (honey comb-structure)

2. cristae reticuli (forms the cellulae reticuli, it is by non-glandular mucosa)

3. papillae reticuli (on the cellulae and cristae reticuli)

4. ostium reticulo-omasicum

5. omasum

6. facies visceralis (towards rumen)

7. fascies diaphragmatica (towards other organs)

8. rumen

2nd flashcard on rumen structures (same)

Position: laterally compressed sac in left half of abdominal cavity, from diaphragm to pelvic inlet.

1. Pilae ruminis (shown both externally and internally)

2. papillae ruminis (by mucous tunic, looks like small corny threads)

3. ostium ruminoreticulare (the opening between rumen and reticulum)

- other structures are curvatura major et minor, facies visceralis (left) and facies parietalis (right, towards reticulum)

Describe the structure of the gastric wall.

General - corresponding to the one of esophageus. Consisting of layers (from outside to inside):

1. tunica serosa

2. tunica muscularis - with m. sphincter cardiae

3. tunica mucosa

   • subdivides into glandular and non-glandular part.

   • glandular forms folds, surface is divided by sulci gastrici into raised areae gastricae. The glandular part is divided into three regions based on species.

   • gastric glands: gll. cardiacae, gll. gastricae propriae, gll. pyloricae (regions)