Download Digestive system

Digestive system
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Parts of digestive system
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Introduction
Development of digestive system 
The digestive system develops from the endoderm develops the 
epithelial lining of digestive system, from mesoderm the
muscular layer of the wall of the digestive system develops,
during developments of embryo and at the cephalic (cranial)
part formed sub cephalic pouch and at the caudal area ,sub
caudal pouch ,these two parts form the primitive gut which
divided into three parts:
a-the forgut: from which develops the mouth, esophagus and 
pharynx.
b-the mid gut: from which develops the liver, pancreas and 
intestine.
c-the hind gut: from which develops the large intestine. 
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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1-Mouth:
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Extend from lips to the pharynx
Its bounded :
Cranially …..by the lips
Laterally ….by the cheeks
Dorsally ….by the hard palats
Ventrally ….tongue ,lateralsides of tongue ,under the tip of the tongue
Caudally …oropharynx(formed by the soft palate and root of the tongue .
The mouth cavity is divided by the teeth and alveolar processes into:
1- oral cavity proper:
Is the space which isbounded within the teeth.
`Vestibule :
Is the space external to the teeth and alveolar process ,closed by the two lips and cheeks
dividedinto :
A- labial vestibule :the space between the lips and incisor .
B- buccal vestibule: the space between the cheek and premolar and molar teeth
**proper mouth cavity connect with vestibule by spaes between the teeth
**behind upper incisors present papilla called (incisive papilla ) has two opening of incisive
ducts which connect between the oral cavity and nasal cavity (vomernasal organ). Except
in the horse th incisive ducts closed from the oral cavity .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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A-Lips (labia oris):
 They are two musculo embranous folds which surround the
surface of the mouth .lips connect to each other on each side
of the mouth by the angles of the mouth . each lips have two
surface :
 External surface : coverd by skin and contain tactile hair ( lips
may used as a actile organs )
 Internal surface : lind by mucosa membrane having papillae
which that opening of labial glands
 **the upper lip more movable than the lower lip in the (
horse , ovine and carnivores) …..more movable than in the
bovine and pig .
 **the upper lip in ovine (sheep& goat ) and carnivores have
median furrow called phitrum ,while in bovine have
nasolabial plate ( middle part of skin lip is modified .
 ** the lower lip have round prominence called chin (
menttum)
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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B-Teeth
Teeth: 
A simple teeth consist of 
*Crown .which project from the alveolr 
*Root .continned within the alvealur 
*Neck. the area betweenthe crown and the root 
*Pulp cavity . the interior of teeth containing soft 
material and including vessels and nerves which
pass through formamen at the apex of the root
**the teeth of domestic mammals is classified as : 
*Heterodont :since there are several groups of teeth 
each possessing certain characterstics adapted to
specific function incisor cut .caninesseize and tear ,
premolars and molars shred or in most cases grind
the food .
*Diphyodont : in that they passess a temparay set of 
teeth whick rupts early in life replaced by a
permanent set
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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C-Check:
it is formed the lateral wall of the mouth cavith ( bucaal 
vestibule ).
Extend from the angles of the mouth to the 
pterygomandibular fold .
The caudal part of cheeks contained the master muscle . 
Its formed form : 
Skin , muscular layer ( buccnator m,zygomtic and buccal m ( 
dorsal &ventral )
Mucosa membrane of the mouth: 
*in the ruminants : 
The buccal mucosa membrane covered with cornfields conical 
papilla called (conical papilla)
While in horse and carnivores smooth buccal m.m. 
*buccal gland lie between the mucosa and muscle or between 
the buccal muscle
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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D-gum
In the ruminant the gum in the region of upper 
incisors is modified to become (dental pad ) .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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E-hard palate :
Its formed the roof of the mouth 
cavity and bounded laterally and
cranially by the upper alveolar with
soft palate Incisive maxilla and
palatine bone
*.
*Mucosa (of mouth cavity ) 
**in the horse the mucosa of hard 
palate contained venous plexus .
**hard palate divided into two equal 
parts by median palatine raphe as
shallow groove usually but in dog as
crest
**transverse palatine ridges lies on 
each side of palatine .
** in the horse these ridges reach to 
the soft palate while in the other
animals the caudal part of hard
palate is smooth .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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F-Tongue
Its muscular membranous movable organ located on the floor of the 
mouth cavity between the rami of the mandible .
It's contained straight muscle +C.T+adipose tissue + glands and covered 
by thick mucosa .
Its supported caudally by the hyoid bone . 
Divided into ; 
Root : the caudal part attached with hyoid bone , soft palate and the 
pharynx , only the dorsal surface is free . the root of tongue converge
ventrally toward the base of epiglottis .
Body ( corpus ) the middle part ( largest one ) have three surfaces : 
Dorsal surface (dorsum lingae) 
Lateral surface that rounded cranially . 
Ventral surface its attached to the geniohyoideus m. and mylohyoideus 
m.
Apex : the free part have dorsal and ventral surface ,two borders . 
The ventral surface of the apex connect with floor oral cavity by median 
fold called frenulum lingae .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Function of the tongue :

For intake of solid and liquid 
food .
Its important tactial organ ( 
test the food) .
Cleaing the skin ,hiar . 
Its important in the 
mastication and deqlutition .
Selective the food either 
mechanically or chemically (
tast bude ) .
Paly arole in infting . 

Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Structure of the tongue
Intrinsic muscles :nformed the main substance of 
the tongue . they are longitudinal , vertical and
transverse direction .the glands present between
the muscle fiber called lingual gland .
*Mucous memberane : 
M.m of ventral and lateral surface of tongue 
issmooth , while dorsal surface (m.m) is thick spcially
in (bovine and cat ).
m.m .having two type of papillae: 
a- mechanical papillae

Conical. 
** filiform 
*Lenticular. 
Gustatory papillae : 
* fungiform. 
*Vallate. 
*Foliate 

Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Blood supply of the tongue: 
1-lingual artery . from external carotid artery. 
2- sublingual branch . from lingofascia trunk . 
Nerve supply of the tongue : 
1- lingual nerve . from trigeminal nerve . 
2- glossopharyngeal n. 
3- chordatympani n. from the fascial n . 
4- hypoglossal n . 
Muscles of tongue:

1-interinsic muscles of the tongue . or call proper intrinsic m.m 
of tongue .
2- extrinsic muscle of the tongue ……include : 
Genio glossus m
hypoglossus m.
styloglossus 
m.}fix the tongue with the mandible and with hyoid bone .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Fixation of the tongue
 1- tongue attached caudally with lingual process of
hyoid bone .
 2- reflection of m.m from gum .
 3- by the frenulum .
 4- attached with soft palate by palatoglossal arch .
 5- extrinsic muscle of the tongue .
 6- muscle of hyoid bone .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Soft palate :
Musclomembranous fld separates the mouth cavity 
from the pharynx except during the swallowing . soft
palate divides the cranial pharynx into oropharynx and
naso pharynx .cranial end is attached with hard palate ,
while the caudal end is free near the base of epiglottis .
In the horse the soft palate is large or long 15 cm. and 
caudal end of its always near the base of epiglottis
except in swallowing make the cranial aspect of
epiglottis close above the dorsal aspect of the soft
palate , so that the horse seems unable to breath by the
mouth and vomiting .
&&& on each side there is thick fold from the soft palate 
attached with the tongue and pharynx forming
palatoglossal arch and palatopharyngeal
arches .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Soft palate consist of :
 Oral mucus memberane .
 Thick layer of palatine glang .
 Apeneurosis.
 Muscular layer ( palatine m.)
 Pharyngeal surface m.m continous with the nasal m.m
 Muscle of soft palate :
 Palatine m.
 Tensor velli palatine .
 Levator velli palatine .
Arteries: lingufacial trunk and maxillary artery. 
Nerves: trigeminal, vagus and glossapharyngeal 
nerve.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Pharynx:
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 Is the funnel or conical shape musculo membranous organ,
connect between oral cavity and esophagus. Also between nasal
cavity and larynx .
 Its bounded :
 Laterally by ………pterygiod m. 2- stylohyoideus m 3- palatine
m.
 Ventrally by….. the larynx and esophagus .
 Dorsally by ……the base of cranium ..
 Cranial part of the pharynx divided by soft palate :
 Into
 a- dorsal passage (nasopharynx).
 b- Ventral passage (oropharynx).
 Caudal part of the pharynx .its narrow called (laryngopharynx).
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Muscle of the pharynx :
 They are paired arrangement and all of them acts as
constrict of the pharyngeal cavity except one muscle
called stylopharyngeal acts as dilator of pharynx
 There are two groups:
 Constrictor m.m. : divided into
 Cranial group or rostral (pterygopharyngeus
,palatopharryngeus , rostral stylopharyngeus ,
hyopharyngeous )
 Caudal group (thyropharyngeus , cricopharyngeus )
Dilator muscle : include only one muscle the caudal 
stylopharyngeus
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Lymphatic organs of the pharynx :
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Tonsils:
1-longual tonsil.
3- tonsil of soft palate
2-palatine tonsil.
4- paraepiglottic tonsil
5-pharyngeal tonsil 6- tubal tonsil .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Esophagus:
 Its musculomembranous tube connect the pharynx to
the stomach , and it’s the continuation of
laryngophrynx.
 Its divided according to their location into:
 Cervical part :

Is the long part situated between longus colli
muscle and the muscle which parallel to ventral
surface of cervical vertebra , dorsal to the trachea .
 Near the thoracic inlet its convert from median
position dorsal to left side of trachea .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Organs near the esophagus in the
neck:
 Common carotid artery .
 Internal jugular vein .
 Trachral duct and cervical lymph node .
 Cartilages of larynx.
 Vagosympathetic trunk.
 Caudal laryngeal n .
Thymus gland 
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Thoracic part
 Start on the thoracic inlet after that returned
to the first position above the dorsal surface
of the trachea .
 Continuous caudally across dorsal
mediastinum and then above the bifurcation
of trachea and the a cross the aortic arch (
righ sid caudally to the base of the heart pass
) between the lungs pass near the thoracic
aorta ( ventral sid ) also the dorsal and ventral
branch of vagus .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Abdominal part :
 Short part about (1) inch the esophagus across or
penetrated the diaphragm through esophageal hiatus
and then end to cardiac region of the stomach.
 The thickness of esophagus wall gradually increase
from cranial to the caudal , and this is clear in the
horse , while in the ruminant not clear .
 The shape of the (diameter ) in the horse stellate or
cleft . the lumen of esophagus is closed by deep
longituduinal folds when its empty .
 * the muscular layer in the ruminants its usually
striated along the esophagus , while in the horse only
(2/3 cranially ) striated and the third smooth muscle .
dep. Anat .Hist.& Emb.
Dr.waleed J.A.
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Stomach :
It’s a large dilation of
alimentary canal , located
directly caudal to the liver
and part of it contacts the
and between esophagus
and duodenum ..its stores
of food temporary and
digested chemically ( renin,
pepsin ,Hcl .) secreted from
the glands in wall of the
stomach .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Classification of the stomach:
1-According to the number of cavities: 
A-monolocular stomach: it is contains one cavity like 
in dog, horse, pig and all animals except ruminants.
B-multilocular stomach: it is contain many cavities like 
in ruminants (ox, goats and sheep).
2-according to the mucous membrane lining (inner 
lining):
A-simple stomach: it lines by one kind of mucous 
membrane (glandular mucosa), covered by simple
columnar epithelium like dog, cat and man.
B-compound stomach: it lines by glandular and non 
glandular mucosa like in ruminants, pig and horse.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Single stomach ( or monolocular )
 Single stomach ( or monolocular ) :
 The opening of stomach toward esophagus called cardiac
opening , while the opening to ward the duodenum ( pyloric
opening ) .
 General feature :
 Cardia : near to the cardiac opening .
 Pylorus : part near to the pyloric opening .
 The shape of stomach like J shape .
 Contained greater and lesser curvatures .
 Have two surfaces …..parietal surface ___attached to
diaphragm .

….visceral surface ___viscera .
 Stomach cavity divided into three parts :
 Fundus ___near to the cardiac region .
 Pyloric antrum ___near to the pyloric region .
 Body between a&b
 In the horse the stomach characteristic by presense of
Dr.waleed J.A. dep. Anat .Hist.& Emb.
enlargement dilation in the fundus called 26
saccus cecus ..
Fixation of stomach
 Pressure of adjacent organs .
 Gastro phrenic ligament .
 Lesser omentum ___hepato gastric ligament .

___hepato duodenal ligament .
 Gastro splenic ligament .
 Gastro pancreatic fold .
 Greater omentum .
Esophagus & duodenum 
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Multilocular stomach :
Ruminant stomach :
Rumen (left side )
Reticulum (cranially towards the head ,)
Omasum ( right side ) ,
Abomasum ( ventrally ) but the proximal
part of its lie under rumen , reticulum
and omasum .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Rumen :
Rumen :
Occupied large part of abdominal cavity
extend from diaphragm to the pelvic inlet
on the left side , and extend into the right
when the rumen filed .
Rumen has two surface (partial surface (
left side ) ___diaphragm 7floor of
abdominal cavity .) visceral surface ( right
side ) __ liver ,intestine , omasum ,
abomasum ) .
Also has two curvatures dorsal curvature
__ diaphragm ,roof of abdominal )
( ventral curvature __ on the floor of
abdomen ).
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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External feature of rumen:
 Blind sac : formed by dorsal and ventral sacs
caudally .

In small ruminants (ventral caudal
blind sac ), longer than the (dorsal caudal
blind sac ) .
 Coronary groove : from the caudal end of
longitudinal groove .
 Insula ruminanlis : formed by (right
longitudinal groove with right accessory
groove .
 Dorsal and ventral sacs extend cranially to
form cranial sac of rumen and ruminal recess.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Internal features of the rumen:

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Has a pillar instead of groove .
Also :
Intra ruminal opening surrounded by :
Cranial transverse pillar , caudal transvers pillar ,
right longitudinal pillar , left longitudinal pillar .
 Ruminal mucosa :has ruminal papillae large ,faunal
shape or tongue shape about (1cm ) length .
 ** well developed , large and long ventral sac when
compere with dorsal which short , due to the
presence of food and fluid in the ventral sac .
 Cardiac orifice.
 Rumino –reticulum orifice .
 ** esophageal opened in stomach between the
rumen and reticulum .
 ** cranial sac of rumen has important role in
regurgitation its mean ( rumination ) .31
Dr.waleed J.A. dep. Anat .Hist.& Emb.
Reticulum :
 Reticulum :
 Situated between the rumen and diaphragm at level
of (6-9) ribs about (1-2) from the heart. has oval
rounded shape pressed cranially and caudally .
 Rumino-reticular groove , rumino-reticular fold .
 Inner surface have shape like (honey comb) having
small papillae .
 Opening :a- rumino reticular orifice . b- reticuloomasum orifice .
 **gastric groove :well developed in the stomach of
the ruminants ,extend from cardiac region pass
through the reticulum , omasum and finished in the
abomasum .
 Divided into 3 parts reticular part ,omasal part ,
abomasal part ).
 Its important physiologically in the infant animal the
gastric groove it's become a duct conduct the milk
from cardiac rigion to abomasum directly .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Omasum :
 Its dome like located on the right surface of
rumen caudal to reticulum connect with
reticulum by reticulo-omasum orifice , connect
with abomasum by omaso-abomasum orifice .
 Internal surface of omasum :
 It have or filled by parallel fine laminae
different in size or length called omasal
laminae , originated from the wall of omasum
and the free ends of them extend to the
omasal canal .
 Between these lamina its present recesses
called ( interlaminar recesses) .
 **number of laminae:
Dr.waleed
Bovine=90-130,
sheep =72-80, goat
= 80-88.
J.A. dep. Anat .Hist.& Emb.
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Abomasum:
 Abomasum:
 It’s the glandular stomach of the ruminate located
on the right surface of the rumen . its have greater
and lesser curvatures .
 Consist of : fundus ,body , pyloric part ( as
monolocular stomach ).
 ** mucosa of abomasum divided into:
 Region of proper gastric gland , include ( fundus ,
body ) , the color is red and its arranged as spiral
fold .
 Region of pyloric gland , the color is lighter than
the first one contained of irregular folds .
** pyloric sphincter not developed in the 
ruminants so the pyloric orifice controlled by the
toyus pyloricus
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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** Blood supply of stomach :
 Celiac artery : arise from abdominal aorta , which innervate the
stomach , liver , spleen and pancreas .
 It divided into :3 branches
 Left gastric artery ……a-pancreatic branch.

b- esophageal branch.

c- parietal branch.

d- visceral branch .
 Hepatic artery :……..a-pancreatic branch .

b-right gastric artery .

c- gastero duodenal artery .
 Splenic artery :………a- pancreatic branch .

b-splenic b.

C-short gastric a.

D- Left gastric epiploic a .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Intestine:
 Intestine:
 Extend from pyloric region of stomach to
the anus.
 Divided into:
 Small intestine (duodenum, jejunum, ileum).
 Large intestine (cecum, colon, rectum)

Horse
It's about 70feet
Cattle
130 feet
Sheep
80 feet
dog
5 time the body length of animal
pig
time
the body
Dr.waleed
J.A. dep. Anat15
.Hist.&
Emb.
length of animal
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Small intestine:
 Duodenum: consist of .
 Cranial part: pass above lateral surface of the liver ,formed sigmoid loop(s- shape) in the
horse ,ruminants and pig .
 Attached with liver by hapitoduodnal ligaments , contained ampulla of vatter or
hepatopancreatic ampulla ,clear in the horse surrounded by audi sphincter with the
pancreatic duct and bile duct open on it .
 Accessory pancreatic duct opened on the papilla lie opposite the opening pancreatic
duct . the cranial duodenum end in cranial flexure .
 Descending duodenum: directed caudally to ward right kidney and formed caudal flexure
behind the kidney.
 Ascending duodenum: directed cranially attached with duodeno-jejunum flexure and
descending and ascending formed U-shape which contain pancreas.
 Duodenum connect descending colon by duodeno-colic fold, its considered the end of
duodenum and begin of jejunum .
2- Mesoduodenum short per tonal fold connect the duodenum with the liver and dorsal 
ascending colon .
3- Bile duct and pancreatic duct together in horse ,dog and small ruminants , while in 
bovine each opened on papillae separated from the other .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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2- jejunum 
Longest part of small intestine about 90% of total 
length of its have long mesentery ,and its empty in
dead animal .
3- Ileum:

The last small part of small intestine have thick wall. 
Connect with the cecum by ileo-cecal fold.
Ileal opening: 
Ruminants ….ileo-cecocolic opeing . 
Horse …..1- ileo-cecal opening 2- ceco- colic 
opening .
**end of ileum near (cecum with colon ) 
surrounded by sphincter muscle in most animals
except horse its absent .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Large intestine:
Cecum
 In the horse:
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Comma shape.
Located in right abdominal cavity.
Have base, body and apex.
Have four band (longitudinal muscular bands (dorsal ,ventral ,right and left bands ) .
Have two openings ( ileo-cecal opening , ceco-colic opening ) .
Dorsal and ventral curvature.
In the carnivores:
In the cat ……very short .while in the dog ….. longer than the cat .
The shape spiral .
Dose not have bands and sacculation .
Has ileo-cecocolic opening .
In the ruminants:
Blind tube like.
Has one opening ( ileoceco colic ) orifice .
When it's filled extend to pelvic cavity.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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Colon :
Ascending, transvers, descending colon) .

(


** Colon of carnivores similar to colon of man .
** Transvers colon similar in all domestic animal .
 Ascending colon:
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In horse formed 4 parts continuous to each other and 3 flexures.
Right ventral colon start from lesser curvature of cecum end in xphoid cartilage formed sternal flexure and
continuous with ,
Left dorsal colon directed caudally to reach pelvic inlet formed pelvic flexure and then continuous with,
Left dorsal colon directed toward the diaphragm formed diaphragmatic flexure and then,
Right dorsal colon to connect with the transvers colon ,
1-right and left ventral colon and sternal flexure have ( 4 bands and sacculation ) .
2-Pelivc flexure has (one band without sac)
Left dorsal colon have 2 bands.
Diaphragmatic flexure have 3 bands ,
Right dorsal colon has 4 bands.
Transvers and descending colon have 2 bands.
Ascending colon in ruminants: formed from
Ansia proximal.
Centripetal turns or gyri .
Ansa centralis .
Centrifugal turns or gyri .
Ansia distalis .
The colon of ruminants does not have bands and sacculation.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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 Rectum :
 The terminal part of intestine start from the end of descending colon to anal
canal.
 Consist of:
 Peritoneal part ( attached part formed mesorectum ) .
 Retroperitoneal (formed final dilation called rectal ampulla.
 Mesorectum (peritoneal fold) formed from ( sacro-rectal ppouch (male) ,
recto-vaginal pouch (female ) recto-pubic pouch .

 Anal canal :
 The line which separated between rectum and anus called white line or
anorectal line.
 Also present a line called ( anocutaneaus line ) and this important in dog and
cat . the cutaneous zone contained two opening lead to the anal sacs which
sourrounded by among of gland .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
41
Anus :
 Surrounded by two sphincter muscles (external and internal
muscle) .from the 1st there coccygeal vertebra the lavetor ani
muscle originated , and then extend ventrally towerd the anal
opening , when its reach the anus opening its divided into two
lateral parts passes a rounded to the anus above the sphincter
muscles .then passes ventrally to the anus and combined or
united again to form retractor peni muscle .
 The line which separated between the rectum and anus called
white line or ano rectal line .
 The pouches associated or near to this region (rectum and anal
canal ) .
 An cutaneous line is important in the dog and cat .the
cutaneous zone contained two opening lead to the anal sacs
which surrounded by amoung of gland .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
42
Dr.waleed J.A. dep. Anat .Hist.& Emb.
43
Accessory glands :
salivary
glands
the extramural glands (glands outside the wall of the digestive

system)
It is special tissue of epithelium originated from oral ectoderm and 
produce saliva which is a mixture of serous and mucous fluids
produced by salivary glands.
Functions of saliva: 
1-lubrication and moisten the alimentary canal to help in: 
A-swallowing of food.
B-cleaning the mouth.
C-keeping the 
mouth moist . D-it is important for taste.
2-secreting enzymes like: amylase, lipase and in pig secret the ptyalin 
which is concern primarily in hydrolysis of starch.
3-production of hormones like protein, epidermal growth hormone 
and nerve growth hormone.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
44
Functions of saliva
4-it has special function in fur-bearing 
animals like cat and rat by hitting it with
saliva, in response to heat, because it is
lead some cool as sweating.
5-perform defense mechanism as in 
snake (venom glands), modified buccal
glands.
6-in birds help in holding the nest. 
Dr.waleed J.A. dep. Anat .Hist.& Emb.
45
Classifications of salivary glands:
1-According to size: 
A-major salivary glands: large masses of glandular 
tissue include: parotid, mandibular and sublingual
glands.
B-minor salivary glands: small seromucous units, 
presents in the sub mucosa of the oral cavity, they
named according to location (labial, buccal, lingual
and palatine).
2-According to the number of excretory ducts: 
A-monostomatic: This has only one excretory duct 
(parotid, mandibular)
B-polystomatic: which has large number of excretory 
ducts e.g.: sublingual, all the minor salivary glands.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
46
Dr.waleed J.A. dep. Anat .Hist.& Emb.
47
parotid salivary gland
It's purely serous in most species except 
in dog, it is situated check in the space
caudal to the ramus of the mandible
.obtain its name from its relationship to
the ear. The parotid duct arises from the
continues of numerous small excretory
ducts .its empty into the buccal
vestibule opened opposite to the third
upper premolar tooth .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
48
B- Mandibular salivary gland:
Its produce a mixed mucous and serous 
secretion, generally smaller than the
parotid gland, it's more compact and is
placed close to the angle of the jaw. This
gland also drains by a single large duct
that rums ventral to the mucus
membrane of the floor of the mouth,
close to the frenulum of the tongue to
open on the sublingual canal .
Dr.waleed J.A. dep. Anat .Hist.& Emb.
49
C- Sublingual salivary gland :
 It's situated beneath the mucus membrane of the mouth,
between the base of the tongue and the ramus of mandible. In
all species except the horse there are two glands:
 Monostomatic sublingual gland: (absent in horse) has only one
excretory duct , the major sublingual duct .
 Polystomatic sublingual gland: consist of fairly large number of
small individual glandular lobes and thus opened by several
ducts into the lateral sublingual recess .
 2-minor salivary gland: are morphologically and functionally
similar to the major salivary glands.
 Minor salivary glands are mixed (mucoserous) glands.
 minor salivary glands named according to their location (labial
,buccal, molar , palatine and zygomatic )
Dr.waleed J.A. dep. Anat .Hist.& Emb.
50
2- Liver :
2- Liver :
The largest gland of the body .the color
depend on the amount of the blood
which present in it , species , age and the
nature of the food .in the horse , bovine
and ovine it red brown ,and it became
brown after hemorrhage .
In the dog, cat it always red brown, but
in fatty animal and infants (brown
yellowish ) .and starvation animals ( dark
red brown ) .
** situated on the ventral surface of the
diaphragm.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
51
** have two surfaces:
 Diaphragmatic surface or parietal
surface.
 Visceral surface.
 Diaphragmatic surface: contained
groove of caudal vena cava passes
through it caudal vena cava and
number of hepatic veins.
 Visceral surface: contained portal
fissure or hepatic portal depression
dorsal to the middle of the liver, the
hepatic portal vein, hepatic artery and
hepatic nervous plexus passed through
it .
From this fissure (hepatic portal) the 
Dr.waleed J.A. dep. Anat .Hist.& Emb.
52
hepatic
duct and hepatic lymph nodes
Liver lobes :
 The liver of carnivores is typical in the number of
lobes as below .
 Right lobe (lateral, medial) .
 Left lobe (lateral , medial ) .
 Middle lobe (quadrate lobe, caudate lobe ……acaudate process b- mammillary process ) .
 In the horse:
 Right lobe (undivided).
 Left lobe (divided) .
 Quadrate and caudate lobes are present but the
mammillary process of caudate lobe is absent.

 In the ruminants:
 Right and left lobes are undivided, and present other
lobes .
 In the pig:
 Same of liver of dog but the mammillary process of
Dr.waleed
J.A. dep. Anat
.Hist.&
53
caudate
lobe
is Emb.
absent .
Ligaments of liver :
 Lesser omentum (hepatogastric lig. ,
hepatoduodenal lig.).
 Coronary lig .
 Falciform lig .
 Round lig .
 Right and left triangular lig .
 Hepato renal lig .

Dr.waleed J.A. dep. Anat .Hist.& Emb.
54
table show comparative of liver
between different species
Lobes
Carnivores
Ruminants
Horse
Pig
Left lobe
+
+
+
+
Lt.lateral
+
-
+
+
Lt.med.
+
-
+
+
Quadrate
+
+
+
+
Right lobe
+
+
+
+
Rt. Med
+
-
-
+
Rt.lat
+
-
-
+
Caudate lobe
+
+
+
+
Caudate process
+
+
+
+
Papillary
process
+
55
+
-
-
Dr.waleed J.A. dep. Anat .Hist.& Emb.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
56
3-Pancrease
Its lobulated gland U shape act as
exocrine producing enzyme from acini (
lipase )
and endocrine releasing hormones from
islet of Langerhans ( insulin , glucagon ) .
Its formed form:
Body: against the cranial part of
duodenum.
Right lobe: extend from body to
descending.
Left lobe: extend from body to the
stomach.
right and left lobe approximate equal in
the carnivores .
In the ruminants (left one wide, right
one long
. .Hist.& Emb.
Dr.waleed
J.A. dep.)Anat
57
In horse left one long, right one short ) .
Pancreatic duct:
In horse and dog there are, (main. major
pancreatic duct, accessory .miner
pancreatic duct) .
In bovine: there is only miner pancreatic
duct .
Ovine and feline: there is only major
pancreatic duct.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
58
Serous Membrane Cavities
— are lined by serous
membrane
— are normally empty
(except for microscopic
cells and a film of fluid)
— function to preclude
adhesions among organs,
thereby allowing organs to
move
Freely relative to one
another.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
59
A serous membrane
 consists of a single layer of flattened mesothelial cells applied
to the
 surface of a thin layer of collagenous tissue that attaches to
underlying end thoracic/transversalis fascia.
 The mesothelium of the serous membrane forms the lining of a
closed serous membrane cavity.
 Serous membrane lining the wall of a serous cavity is
designated parietal while that covering viscera is called visceral.
Connecting serous membrane runs between parietal and
visceral components.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
60
Peritoneum
 The peritoneal cavity is found within the abdominal & pelvic
body cavities.
 Connecting peritoneum forms:
 — mesentery
 — ligament.
 Pleura
 Two pleural cavities (separated by mediastinum) are found
within the thoracic cavity.
 Parietal pleura are further subdivided into:
 — Costal pleura
 — Diaphragmatic pleura
 — Mediastinal pleura & — pleural cupula.
 Connecting pleura forms the pulmonary ligament.
 Visceral pleura are also called pulmonary pleura.
Dr.waleed J.A. dep. Anat .Hist.& Emb.
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
Thank you for 
listening
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