Classification of internal organs: INTERNAL ORGANS

viscera, splanchna

PARENCHYMALliver, kidney…

TUBULAROesophagus,

trachea GLANDS

TUBULAR(SIMPLE,

COMPOUND)

ALVEOLAR(SIMPLE,

COMPOUND)STROMA PARENCHYME

General plan of the structure of General plan of the structure of cavitas (tubular) organscavitas (tubular) organs::

• Mucose membrane (inner);

• Muscular layer (middle);

• Serous or adventitial (outer).

Mucous, muscular & serous layers Mucous, muscular & serous layers of the stomachof the stomach

Mucose membrane of the stomach.

The structure of the wall of different departments of the alimentary tube

The serous layer of the abdominal The serous layer of the abdominal cavity is the peritoneumcavity is the peritoneum

• It has two layers: visceral, covering internal organs & parietal, lying walls of the abdominal cavity.

The relation of organs with the The relation of organs with the peritoneumperitoneum

By the relation with the peritoneum all organs of the abdominal cavity are

grouped as: intraperitoneal, mesoperitoneal & extraperitoneal (or

retroperitoneal)

DEPARTMENTS OF THE ALIMENTARY DEPARTMENTS OF THE ALIMENTARY CANALCANAL

• Oral cavity, • pharynx, • esophagus, • stomach, • Small &• large intestine.

FUNCTIONS OF THE ALYMENTARY SFUNCTIONS OF THE ALYMENTARY SYYSTEMSTEM

• it provides storage,processing of ingest, and elimination of unabsorbed component (faeces)

• it secretes enzymes and lubricants which facilitate the passage of the ingest

• it absorbs nutrients and other materials and passes them into the body

• it propels material within it by muscular action• it has defensive, immunology properties• it houses microorganisms• its epithelial lining forms barrier between its

lumen and the true interior of the body.

Motor function:

л

Absorption function

Evacuation function

Internal organs develop from Internal organs develop from endoderm & mesodermendoderm & mesoderm

DEVELOPMENT OF THE DEVELOPMENT OF THE ALIMENTARY SYSTEMALIMENTARY SYSTEM

• Alimentary system is developed on 3-4th weeks of the development from the primitive gut, which is closed on the cranial and caudal ends

FORMATION OF THE ORAL AND FORMATION OF THE ORAL AND ANAL PITSANAL PITS

• They appear on the cranial and anal ends on the 1st month of embryonic development

• They form two layered membranes from ectoderm and endoderm: pharyngeal and anal

• They are broken till end of the 5th week of the development

Pharyndeal

membraneAnal membrane

entoderm

ectoderm

Viteline duct

su pe rio r, p ro xim a l ha lfo f de sce n d in g p ar t o f

d u od en um ,p a nc re as an d du c ts

b u cca l ca v i ty, p ha ryn x,o e sop ha g us , s to m a ch,

re sp ira to ry sys tem ,live r, ga llb la dde r,

F O R E G UT

re m a in ing d u od en um ,je ju nu m , i leum

ca e cu m , a pp e nd ix,a sce n d ing co lon

M ID G U T

d e scen d in g co lo n ,s igm oid c o lo n ,

re ctu m a nd an a l can a lto th e a na l v a lv es

H IN D G U T

P R I M I T I V E G U T

foregut midgut hindgut

Oral cavity

anus

BUCCAL CAVITY DERIVES FROM BOTH BUCCAL CAVITY DERIVES FROM BOTH ECTODERMAL AND ENDODERMAL ECTODERMAL AND ENDODERMAL

REGIONSREGIONS • The pharyngeal arches form

the mandibular and the maxillary prominences

• The opening of the stomodeum bounded cranially by the frontonasal prominence, caudally by the mandibular prominences and laterally by the maxillary prominences

ROTATION OF THE STOMACH AND FETAL GUTROTATION OF THE STOMACH AND FETAL GUT

• The stomach has two rotations. The first 90° clockwise, viewed from the cranial end, the second 90° clockwise about an anteroposterior axis, so its right surface becomes dorsal and its left ventral

• The proximal limb of the primary intestinal loop moves to the right and the distal limb to the left having already rotated through an angle of 90°

• Caecum may remains below the liver

• Rotation of organs on the left side is called situs viscerus inversus

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