Anatomy report about
The digestive system
In The Ruminant
The digestive system is composed of the :
(1) The Mouth
(2) The Esophagus
(3) The Stomach (and its compartment)
(4) The Intestine (and its division)
(5) The Accessory organs which is
** The Liver
** The Spleen
** The Pancreas
The Mouth
**It is divide to :
1-vestibule :
Is the cavity laying outside the teeth and the gum and
inside the lips and cheeks
2-mouth(oral) cavity :
Is bounded dorsally by the hard palate and ventrally by the
tongue and craniolateral by the dental arches and caudoventral
by the palatogloossal arch
**There is no incisor teeth in the upper jaws instead of it there is
the Dental pads
**The lips of the small ruminant are much more mobile than
those of the cattle.
The Tongue
**Is very large and it is have a transverse lingual fossa,which
food tends to collect
**It is have a several papilla :
(1) Filiform papilla:freely spread over the apex
While conical and flat lenticular papilla are present up on the
torus (the tongue root)
(2) Fungiform papilla: are scattered on the apex
(3) Vallate papilla : present in the torus (For taste )
**The oral floor below the apex of the tongue presence a fleshy
sublingual crancle of each side .
(4) Buccal papilla :its out the tongue and it is located in the upper
and lower jaws behind the dental pad and the incisor teeth
respectively (most prominent toward the corners of the mouth)
The Dentition Formula
The Temporary Teeth:
0-0–3
3-1–3
The Permanent Teeth:
0-0-3-3
3-1-3-3
Salivary Gland
**There are three major salivary gland
(1) The Parotid Gland :
It is continuously active and small,it lies ventral to
the ear along the caudal boarder of masseter m ,
where it partly covered the parotid lymph node, and it
is duct are palpated in the vascular notch in the
mandible
(2) The Mandibular Gland :
It is larger than the parotid gland and it produces
a mixed secretions but only when the animal is
feeding or remasticating,the gland extend in an arch
on the inner aspect of the lower jaw,the duct runs
below the oral mucusa to open by the sublingual
caruncle
Salivary Gland
(3)The Sublingual Gland :It has Two division:
1-The polystomatic part: it lies in the mouth floor lateral
to the tongue and drains though many small
openings beside the lingual frenulum
2-The monostomatic part: it compact,rostral has a
single duct opens with the mandibular Gland in the
sublingual caruncle.
The pharynx
**The pharynx is divided to :
(1) Nasopharynx
(2) Oropharynx
(3) Laryngopharynx
The Esophagus :
**Is a muscular tube leading from the mouth to the reticulum
and rumen.contraction of muscle causes feed boluses to be moved
down to the reticulum or up during the process of regurgitation and
rumination.
The stomach
**Its is composed of four chambers: rumen ,reticulum
,omasum , abomasum.
**The first three known as the forestomach, are
developed to cope with the complex CHO, and only
the last chamber is comparable in structure and
function to the simple stomach.
**The four chambers capacity are (60L) and its
percentage in :
*Large ruminants :
Rumen 80% , Reticulum 5%,, Omasum 8%,, and
Abomasum 7%.
*Small ruminants :
Rumen 75% , Reticulum 8%,,Omasum 4%,, and
Abomasum 13%
The rumen and reticulum
*The Rumen
extend from cardia to the pelvic inlet, and from the
abdominal roof to the floor, and form the left body
wall across the midline specially caudally and
ventrally where it may reach the lower right flank.
*The Reticulum
lies cranial to the rumen and mainly to the left of
the median plane, and it lies above the xephoid
process of the sternum.
**The rumen and reticulum communicate over the
ruminoreticular fold.
Ruminal Papilla
Reticular Papilla
The omasum
**It lies within the intra thoracic part of the
abdomen to the right of the midline and
between the rumen and reticulum to the left,
and the liver and body wall to the right.
**It is bilaterally flattened and displays along
convex border
**Most of it lies under cover of ribs 8-11.
The omasum
**The anterior is occupied by about 100
crescentic laminae that arise from the sides and
greater curvature and projects towards the
lesser curvature where there is a more open
passage (the omasul canal)
**The reticulo-omasul orifice is situated at the
upper end of the short cannel
** In
sheep and goats :
The omasum is relatively smaller
Omasal Folds
Abomasum
**It lies flexed upon the abdominal floor embracing the
lower pole of omasum from behind.
**It is divided by analogy with the simple stomach into
fundus and body.
**The narrower and more uniform distal limb constitutes
the pyloric part
***The abomasum does not usually come into contact
with the liver in adult cattle.
**The abomasum is lined by a pink slime-covered,
glandular mucosa which is in striking contrast to the
harsh lining of the fore stomach.
The omentum
**The attachment of the greater omentum begins dorsal
to the esophagus. The two serosal sheets of which it is
composed pass directly into the rumen but are so
widely separated that the immodestly post cardiac part
of the rumen roof is left bare.
**The lesser omentum arises from the visceral surface of
the liver between the porta and the esophageal
impression and passes to the region of the reticular
groove, the right place of omasum , and then along the
lesser curvature of the abomasum to the first part of
the duodenum which returns it to the liver.
The omentum
**The omental sheets enclose a space (omental
bursa is an important store of fat) which is
completely divided from the greater peritoneal
cavity except at the epiploic foramen (bursal
foramen) near the portal of the liver.
Digestive system of horse
Dental Formula
Temporary teeth:
=
I3C0P3M0
I3C0P3M0
Teeth
• Permanent teeth =36-42
=
I 3 C 1 (0) P 3 (4) M 3
I 3 C 1 (0) P 3 M 3
In the female horse , no canine teeth
- 1st premolar (wolf tooth); fail to developed, if
developed its vestigial.
The stomach
• B. Horse
–
–
–
–
–
2
simple composite stomach
Cardia
Fundus
Body
pylorus
1
5
3
4
The intestine
• Small intestine
– Duodenum
– Jejunum
– Ileum
• Large intestine
– Cecum
– Colon
– Rectum
Small intestine
• Proximal in most spices the principal organ of
digestion and absorption
• continuous three part
- Duodenum
- which is short and rather closely fixed in position
attached to abdominal roof by mesoduodenum
Jejunum and ileum
- Which are carried by the greater
mesentery
- Less closely fixed in position
Large intestine
• Distal large intestine
• Mush short and especially concerted with the
dehydration of food residue
• Comprises of three parts
- Cecum is the blind ending
- Colon
- Rectum
• Cecum - at junction of ileum and ascending colon
• huge, comma shaped in horse
- consists of a base, body and apex
• Colon contain three part
ascending
transverse
descending
• The rectum joins the short anal canal
10
3
6a
2
5
6b
4
6c
4
4
6
• Ascending colon - in horse, also called the great colon
- made up of:
a. right ventral colon - extends cranially on
right ventral floor to sternum
b. Sternal flexure - connection between
right and left ventral colons, curving
around apex of Cecum
c. left ventral colon extends caudally on
left ventral floor
10
3
6a
2
5
6b
4
6c
4
4
6
• Ascending colon (cont.)
- made up of:
d. Pelvic flexure- connection of left ventral
colon and left dorsal colon in left
paralumbar fossa
e. Left dorsal colon- continuation of pelvic
flexure cranially on top of the left ventral
colon against the left abdominal wall
10
3
6a
2
5
6b
4
6c
4
4
6
Ascending colon (cont.)
- made up of:
F . Diaphragmatic flexure connection of left dorsal colon and right
dorsal colon
G. Right dorsal colon- continuation
of diaphragmatic flexure caudally on top
of the right ventral colon against the
right abdominal wall
10
3
6a
2
5
6b
4
6c
4
4
6
• Transverse colon
– heads transverse right to left cranial to cranial
mesenteric artery
• descending colon
– heads caudal to left of cranial mesenteric artery
connects transverse colon with rectum
– also called small colon
10
7d
10
7c
7c
3
7e
3
2
5
7b
7a
4
2
5
7b
4
7a
4
4
VIII. Large Intestine
B. Horse
7
4
VIII. Large InHorse
7
4
Bovine intestine
The Omentum
• A double-layered connecting peritoneum
between the stomach and abdominal
organs or abdominal wall
1- Lesser omentum
– connect lesser curvature of the stomach and
first part of duodenum to the porta of the liver
• Gastrohepatic ligament
• Hepatoduodenal ligament
The Omentum
2- Greater omentum
– Connect the greater curvature of the
stomach to the dorsal abdominal wall
• Superficial leaf: extend from the stomach
caudally to pelvic inlet where it reflect and
returns cranially as the deep leaf
• Deep leaf attaches to the dorsal abdominal
wall and contains the left lobe of the
pancreas between its peritoneal layers
The omentum (bovine)
– The lesser omentum arises from the visceral
surface of the liver between the porta and the
esophageal impression and passes to the
region of the reticular groove, the right place of
omasum , and then along the lesser curvature
of the abomasum to the first part of the
duodenum
The omentum (bovine)
The greater omentum has two leaves as in the
other species:
• Superficial leaf arises from the left side of the rumen and deep
leaf arise from the right side of rumen.
– Both leaves extend ventrally and to the right, both
leaves ascend together along the right abdominal wall
to attach to the descending duodenum.
– Superficial leaf: attaches the greater curvature of the
abomasum and descending duodenum, it extends
along the ventral abdominal wall to the left side to
attach to the left longitudinal groove of the rumen.
– Deep leaf: extends from the right longitudinal groove of
the rumen to the descending duodenum
Omental bursa
• The omental sheets enclose a space
(omental bursa is an important store of fat.
– It is completely divided from the peritoneal
cavity except at the epiploic foramen (bursal
foramen) near the portal of the liver.