ANATOMY OF DIGESTIVE
SYSTEM
BMS 231:
2015/2016
DR SOBIA IKRAM
DR AQEELA BANO
DR SADIA FARHAN
Table of Contents
1. Objectives for this lesson
2. Function of the Digestive system and the organs involved and
Anatomyof the Layers and Membranes of the gut.
3. Gross Anatomy and functions of the Oral cavity, Esophagus
4. Gross Anatomy and functions of the Stomach , Small Intestine
and Large Intestine.
5. External Anatomy and Functions of the Liver, Gall Bladder and
Pancreas
Objectives
When you finish this lesson, you should be able to
• Describe the Functions of the Digestive system and the process
of Digestion Involved.
• Name the Layers and Membranes of the gut .
• Identify the Location, External Anatomy and Function of the
Oral cavity, Esophagus, Stomach, Small Intestine, Large
Intestine.
• Identify the Location, External Anatomy and Function of the
Liver, Gall Bladder and Pancreas.
• Understand the Interaction and Importance of all the organs
working together in the Digestive system.
DIGESTIVE SYSTEM
Digestive system is responsible for breaking
down of food into small absorbable
nutrients to get energy for all body
functioning.
It consist of
1. MUSCULAR HOLLOW TUBE (THE DIGESTIVE
TRACT)
2. ACESSORY ORGANS.
Functions Of Digestive system
• ingestion
• mechanical digestion
• chemical and enzymatic digestion
• secretion
• absorption
• compaction
• excretion and elimination
Functions Of Digestive system
Peritoneum - serous membrane lining the abdominal cavity
is called peritoneum.
Mesenteries - double sheets of peritoneum are called
Mesentery
1. Greater omentum
2. Lesser omentum
3. Mesentery proper
4. Mesocolon
Oral Cavity
• Also called buccal cavity
• Hard and soft palates - forms
roof of mouth
• Tongue - skeletal muscle
• Salivary glands - three pairs
• Teeth
Three pairs of Salivary Glands
1. Parotid gland
2. Submandibular gland
below the mandible
3. Sublingual gland -below the
tongue
ESOPHAGUS
 Esophagus is a tube like structure.
 It is usually 25 cm in adults but variations are
present.
 It has three parts anatomically
1. Cervical
2. Thoracic
3. Abdominal
ESOPHAGUS
Esophagus has two sphincters
1. Upper – present at the level of pharynx.
2. Lower - present at the level where esophagus enters
the stomach.
These sphincters are important as they prevent the reflux
of food in backward direction.
ESOPHAGUS
Gross Anatomy of the Stomach
Lesser curvature
Greater curvature
Cardia
Fundus
Body
Antrum
Pylorus
Rugae
GROSS ANATOMY OF STOMACH
CORONAL SECTION OF STOMACH
GROSS ANATOMY OF STOMACH
There are two sphincters of
the stomach
1.
First at the junction of
esophagus with stomach at
the level of cardia
called cardiac sphincter or
lower esophageal sphincter.
2. Second at the junction of
stomach with duodenum at
the level of pylorus called
pyloric sphincter.
Gross anatomy of small intestine
Small intestine is the longest part
of digestive system.
1. Duodenum :(short, 12 inches)
fixed shape & position.
2. Jejunum :(2.5 m long)
Most of digestion happens in
the jejunum.
3. Ileum :(longest part of small
intestine 3.5 m)
Regions of Large Intestine
Caecum
is the pocket like part at the proximal
end of the large intestine with appendix.
Colon
Ascending colon
on right side of the abdomen.
Transverse colon
horizontal portion of the large intestine.
Descending colon
On left side of the abdomen.
Sigmoid colon
S shaped bend near terminal end of the
large intestine.
Fig 25-1
Rectum
Rectum
Terminal end of large intestine ending at the anus - it has
internal involuntary sphincter and external voluntary
sphincters.
Liver
 Largest organ that is present
on the under surface of
diaphragm on right side of
abdomen.
 It has four lobes
1. Right and left main lobes.
2. Caudate and quadrate lobes on
the inferior surface.
FUNCTIONS OF LIVER
Metabolic Functions
1. Synthesis of Bile
2. Breakdown of Fats
3. Other functions – storage of vitamin A,D,B12,..
Excretion of waste products from bloodstream into bile
Vascular – storage of blood
ANATOMY OF GALL BLADDER
1.
2.
3.
4.
Pear-shaped sac.
30-50 ml capacity for bile storage.
Located on the inferior surface of the liver.
Gives off cystic duct that join with common
hepatic duct to make common bile duct, it put
the bile secretions into duodenum.
ANATOMY OF PANCREAS
1.
Gland with both exocrine and
endocrine functions.
2.
15-25 cm long approximately.
3.
Location: retro-peritoneum, 2nd
lumbar vertebral level
4.
Parts of pancreas: head, neck, body ,
tail and uncinate process.
ANATOMY OF PANCREAS
SECRETIONS OF PANCREAS

Alpha cells produce glucagon.

Beta cells produce insulin.

Delta cells produce somatostatin