الرحيم الرحمن الله بسمThe oral region:

It includes the oral cavity, teeth, gingivae, tongue, palate, and region of palatine tonsil.

Oral cavity:

Limitation:

The roof of the oral cavity consists of the hard and soft palates.

The floor of the oral cavity formed mainly of soft tissues, which include a muscular diaphragm and tongue.

The lateral walls are the cheeks.

Teeth:

Teeth vasculature:

The superior alveolar artery a branch of the maxillary artery supplies the maxillary teeth.

The inferior alveolar artery a branch of the maxillary artery supplies the mandibular teeth.

Alveolar veins with the same names.

Teeth innervation:

The superior alveolar nerve a branch of maxillary nerve (CV2) supplies the maxillary teeth.

The inferior alveolar nerve a branch of mandibular nerve (CV3) supplies the mandibular teeth.

Both of them form a dental plexus.

Note: there is important relationship between the lingual nerve and the 3rd molar tooth, therefore caution is taken to avoid injuring this nerve during their extraction.

Palate:

Vasculature:

Greater palatine + lesser palatine arteries (both of them branches of descending palatine artery)

The veins of the palate are tributaries of the pterygoid venous plexus.

Innervation:

The sensory nerves of the palate are branches of the maxillary nerve (CNV2) that branch from pterygopalatine ganglion.

Note: the soft palatine consists of 5 muscles:

Tensor veli palatini

Levator veli palatini

Palatoglossus

Palatopharyngeus

Musculus uvulae

All of them are innervated by the pharyngeal branch of the vagus nerve, Except the first one (tensor veli palatini muscle which is innervated by a medial pterygoid nerve, a branch of mandibular verve CNV3.

Tongue:

It is a mass of muscles that is mostly covered by mucous membrane.

A. Extrinsic muscles of the tongue:Genioglossus, hyoglossus, styloglossus, and Palatoglossus.

B. Intrinsic muscles of the tongue:The superior and inferior longitudinal, transverse, and vertical muscles.

Innervation:

All muscles of the tongue are innervated by Hypoglossal nerve CN XII, Except Palatoglossus muscle which innervated by vagus nerve CN X.

For general sensation (touch and temp.):

The anterior 2/3 of the tongue is supplied by the lingual nerve, a branch of CN V3.

The posterior 1/3 of the tongue is supplied by the lingual branch of glossopharyngeal nerve CN IX.

For special sensation (taste):

The anterior 2/3 of the tongue is supplied by the chorda tympani nerve, a branch of CN VII.

The posterior 1/3 of the tongue is supplied by the lingual branch of glossopharyngeal nerve CN IX.

Vasculature:

By lingual artery, a branch of external carotid artery.

The pharynx:

It is the superior expanded part of alimentary system posterior to the nasal and oral cavities.

It is widest (approximately 5 cm) opposite the hyoid.

and narrowest (approximately 1.5 cm) at its inferior end.

It is divided into 3 parts:

Nasopharynx: posterior to the nose and superior to the soft palate. Oropharynx: posterior to the mouth. Laryngopharynx: posterior to the larynx.

Vasculature:

by a tonsillar artery, a branch of facial artery.

and the venous drainage is obtained by the large external palatine artery.

Innervation:

The nerve supply to the pharynx (motor and most of sensory) derived from pharyngeal plexus of nerves.

The esophagus:

It is a muscular tube that is continuous with the pharynx and runs in the thorax through the superior and posterior mediastinum.

Limitation: it begins at the cricoids cartilage (C6) and ends at gastroesophageal (GE) Junction, the esophagus pierce the diaphragm to form the esophageal hiatus (T10).

General features:

The esophagus constitutes the primary posterior relationship of the base of the heart.

The upper third of the muscularis externa of the esophagus consists of skeletal muscles only.

The middle third of the muscularis externa of the esophagus consists of both skeletal and smooth muscles.

The lower or distal third of the muscularis externa of the esophagus consists of smooth muscles only.

The overall length is 23-25 cm. From incisor teeth the GE junction is 38-43 cm.

Constrictions:

There are 5 constrictions of the esophagus along its course:

1. At the junction of the pharynx and esophagus.2. At the aortic arch.3. At the tracheal bifurcation (vertebral level T4) where the left main

bronchus crosses the esophagus.4. At the left atrium [ السريريات قسم في .[يتبع5. At esophageal hiatus [ األمراض قسم في .[يتبع

Sphincters:

1. The upper esophageal sphincter (UES) [composed of skeletal muscles]

Separates the pharynx from the esophagus.

Composed of opening muscles and closing muscles

A. Opening muscles: Thyrohyoid muscle + Geniohyoid muscleB. Closing muscles: Inferior pharyngeal constrictor muscle +

cricopharyngeus muscle.

2. The lower esophageal sphincter (LES) [composed of smooth muscles]Separates the esophagus from the stomach. [ األمراض قسم في [يتبع

Arterial supply: It involves many arteries:

Esophageal arteries arise from thoracic aorta. Bronchial arteries. Ascending branches of the left gastric artery in the abdomen.

Venous drainage:

Small vessels returning > the Azygos + Hemiazygos veins > systemic venous blood.

Esophageal branches > left gastric vein > portal venous blood

Innervation:The esophagus is innervated by:

Esophageal nerve plexus, formed by vagal trunks. Thoracic sympathetic trunks via greater splanchnic nerves. Periarterial plexus around the left gastric and inferior phrenic arteries.

The stomach:

It is divided into 4 parts:

1. Cardia: is near GE junction.2. Fundus: is above the GE junction.3. Body: is between the fundus and antrum.4. Pylorus: is the distal part of the stomach and is divided into the pyloric

antrum (wide part) and pyloric canal (narrow part). The pyloric orifice is surrounded by the pyloric sphincter.

Arterial supply:

Anastomosis formed along the lesser curvature by the right and left gastric arteries.

Anastomosis formed along the greater curvature by the right and left gastro-omental (gastro-epiploic) arteries.

The fundus and upper body receive blood from the short and posterior gastric arteries (branches of the splenic artery).

Venous drainage:

The gastric veins parallel the arteries in position and course, and all of them eventially lead to portal venous blood.

Innervation:

A. Parasympathetic innervation:Is derived from anterior and posterior vagal trunks, which are the continuation of the left and right vagi nerves respectively.[note: the posterior vagal trunk is larger the the anterior one]

B. Sympathetic innervation:By the greater splanchnic nerves; the sympathetic fibers come from T6-T9 spinal segments > through the greater splanchnic nerves > distribute to the stomach around the gastric and the gastro-omental arteries.

Duodenum:

The duodenum has a C-shaped course around the head of the pancreasse, Is the first, shortest and widest part of the small intestine, Begins at the pylorus and ends at the duodenojejunal junction, the dupdenum is divided into:

1. Superior part (first part):

Horizontal

The first 2 cm of the superior part (duodenal bulb) is intraperitoneal and therefore has a mesentery and is mobile, while The remaining distal 3 cm is retroperitoneal.

It begins at the gastroduodenal junction, which is marked by prepyloric vein.

Lies anterolateral to the body of L1.

It is overlapped by the liver and gallbladder.

The lesser omentum is attached superiorly to it while the greater

omentum is attached inferiorly.

2. Descending part (second part):

Runs inferiorly along L2, 3.

Curves around the head of pancreas.

Lies to the right and parallel to the IVC.

The bile and pancreatic ducts unite to form the hepatopancreatic

duct which enters the posteromedial wall of the 2nd part.

3. Horizontal part (third part):

Runs horizontally to the left.

Crosses the IVC and aorta anteriorly at L3.

Crosses the SMA, SMV and the root of the mesentery of the

jejunum and ileum posteriorly at L3.

Superiorly is the head of pancreas and the uncinate process.

Posteriorly it is separated from the vertebral column by the right

psoas major, IVC, aorta and the right testicular or ovarian vessels.

4. Ascending part (fourth part):

Begins at the left of L3 then rises superiorly until it reaches the

pancreas.

Then it curves anteriorly to join the jejunum at the

duodenojejunal junction.

The duodenojejunal junction is supported by the attachment of a

muscle called the ligament of Treitz.

Contraction of the ligament of Treitz widens the angle of the

flexure, facilitating movement of the intestinal contents.

Blood supply:

a. Duodenal Arteries: arise from the celiac trunk, supply the proximal

part of the duodenum, and the SMA, supply the distal part of the

duodenum.

b. Pancreaticoduodenal Arteries: lie in the curve between the

duodenum and the head of pancreas.

c. The Duodenal Veins: follow the arteries and drain into the portal

vein via the SMV and splenic vein.

Nerve Supply:

Nerves of the duodenum derive from the vagus and sympathetic

nerves through the celiac and superior mesenteric plexuses.

Spleen

Facts:

o Is the largest lymphatic organ

o A mobile organ

o Purple in color

o Varies in size and weight

o Contains large quantities of blood

o Located intraperatoneally in the left upper quadrant

o Entirely surrounded by peritoneum except at the hilum

o Left 9th, 10th and 11th ribs are posterior to it

o The diaphragm and the costodiaphragmatic recesses separate the

spleen from the ribs

o It rests on the left colic flexure

Relations of the spleen:

o Anteriorly is the stomach

o Posteriorly is the left part of the diaphragm

o Inferiorly is the left colic flexure

o Medially is the left kidney

Blood Supply:

o Splenic artery: a branch of the celiac trunk which divide into five

or more branches that enter the hilum

o Splenic vein: comes from the hilum then joins with IMV and runs

posterior to the pancreas. Then it unites with the SMV at the level

of the neck of pancreas to form the portal vein

Nerve Supply:

o Spleen nerves derive from the celiac trunk and move along the

arteries (splenic), they act as vasomotor.