PHARMACY PROGRAM
NOVEMBER 2012
REV. PROF. A.S. AYETTEY
OBJECTIVES
 BE ABLE TO RECOGNIZE DIFFERENT PARTS OF THE
DIGESTIVE SYSTEM (mouth, esophagus, stomach,
duodenum, jejenum, ileum, large bowel, anal canal)
 BE ABLE TO RECOGNIZE THE FUNCTIONAL DESIGN
OF THE DIGESTIVE SYSTEM
 BE ABLE TO RECOGNIZE THE FUNCTIONAL ROLE
OF DIFFERENT PARTS OF THE DIGESTIVE SYSTEM
 BE ABLE TO WORK OUT CLINICAL PROBLEMS IN
THE DIGESTIVE SYSTEM BASED ON YOUR
KNOWLEDGE OF ITS FUNCTIONS
PARTS OF THE DIGESTIVE SYSTEM
 THE ORAL (buccal) CAVITY
 TEETH (mastication, defensive)
 TONGUE (aid in swallowing by rolling food, taste, sensory functionhot and cold receptors)
 PALATE (also has taste fibres, and aids in rolling food)
 SALIVARY GLANDS
 THE ORO-PHARYNX (immediately behind the oral cavity)
 THE ESOPHAGUS (10 INCHES; 25CM)
 THE STOMACH (digestion of proteins)
 DUODENUM – 10 INCHES; 25 CM
 LIVER
 GALL BLADDER
 PANCREAS
 JEJENUM 8 FEET; 2.5 METERS [absorption takes place mainly in the
jejenum]
 ILEUM – 12 FEET; 3.6 METERS
 LARGE BOWEL – 5 FEET; 1.5 METERS [absorption of water and
electrolytes and concentrate the waste into solid mass]
THE ROLE OF THE ORAL CAVITY 1
 TEETH
 MASTICATION
 TO SOFTEN FOOD
 SPEECH
 TONGUE
 TASTE
 GENERAL SENSATION
 DEGLUTITION - swallowing
 SPEECH
 PALATE
 TASTE
 DEGLUTITION
ROLE OF ORAL CAVITY 2
 SALIVARY GLANDS
 PAROTID GLANDS
 SUBMANDIBULAR GLANDS
 SUBLINGUAL GLANDS
 FUNCTIONS OF SALIVARY GLANDS
 LUBRICATION/MOISTEN FOOD
 SECRETION OF SALIVARY AMYLASE (STARCH TO
GLUCOSE)
 SECRETION OF LYSOSYMES - ANTIBACTERIAL
 RELEASE OF ANTIBODIES – IMMUNOGLOBULIN A
TO PROTECT THE MUCOSA
FUNCTIONS OF THE STOMACH
 RECEPTACLE FOR FOOD AND FLUIDS
 CAPACITY 2-4 LITRES
 PROTEIN DIGESTION
 PEPSINOGEN TO PEPSIN (pH 1-2)
 ABSORPTION OF WATER AND ELECTROLYTES
 ABSORPTION OF LIPID SOLUBLE SUBSTANCES
 ALCOHOL
 SOME DRUGS SUCH AS ASPIRIN
 CAFFEINE
 PRODUCTION OF INTRINSIC FACTOR
 ROLE IN ABSORPTION OF VITAMIN B12
 PROPULSION OF FOOD INTO DUODENUM
GASTRIC SECRETIONS
 GASTRIC JUICE AND CONTENTS
 HYDROCHLORIC ACID (PARIETAL CELLS)


ACTIVATES PEPSINOGEN SECRETION
INACTIVATES INGESTED BACTERIA
 MUCUS (LUBRICATION AND PROTECTION)
 PEPSINOGEN (ENZYME)
 PEPSIN (INITIATION OF PROTEIN DIGESTION)
 GASTRIN (HORMONE)
 STIMULATES SECRETION OF ACID
 INCREASES GASTRIC MOTILITY
 INTRINSIC FACTOR (GLYCO-PROTEIN)
 FOR ABSORPTION OF VITAMIN B12 IN THE ILEUM (without
intrinsic factor there cannot be vit. B12 absorption)
FUNCTIONS OF THE DUODENUM
 RECEIVES FOOD-chyme (rich in lipids, starch, amino





acids) FROM STOMACH
REGULATES FOOD ENTRY FROM STOMACH
SECRETES HORMONES
COMPLETES PROCESSES OF DIGESTION OF
PROTEINS AND CARBOHYDRATES
BEGINS THE PROCESS OF ABSORPTION
IRON ABSORPTION OCCURS PRIMARILY HERE
DUODENAL GLAND SECRETIONS
 BRUNNERS GLANDS
 MUCUS RICH ALKALINE SECRETION
 DEACTIVATES PEPSINOGEN
 PROTECTS DUODENUM FROM GASTRIC SECRETIONS
 HORMONES
 SECRETIN


STIMULATES BICARBONATE SECRETION FROM THE LIVER AND PANCREAS
TO REGULATE pH
TRIGGERS INSULIN SECRETION TO REGULATE GLUCOSE
 CHOLECYSTOKININ
 PEPTIDE HORMONE
 RESPONSIBLE FOR DIGESTION OF FAT
 CONTRIBUTES TO DIGESTION OF PROTEINS
 UROGASTRONE
 INHIBITS SECRETION OF ACID AND PEPSINOGEN
FUNCTIONS OF THE PANCREAS
 EXOCRINE FUNCTIONS
 PRODUCING DIGESTIVE JUICES THAT CONTAIN




ALKALINE FLUID (BICARBONATES)
CHYMOTRYPSIN (BREAKDOWN OF PROTEINS AND
POLYPEPTIDES)
LIPASE (HYDROLYSIS OF LIPIDS)
AMYLASE (DIGESTION OF STARCH ends in the duodenum).
 ENDOCRINE FUNCTIONS – HORMONE PRODUCTION
 INSULIN (LOWERS BLOOD GLUCOSE LEVEL)
 GLUCAGON (INCREASES BLOOD SUGAR LEVEL)
 SOMATOSTATIN (INHIBITS RELEASE OF GROWTH
HORMONE AND THYROID STIMULATING HORMONE)
FUNCTIONS OF THE LIVER
 PLASMA PROTEINS – ALBUMIN, GLOBULIN,
FIBRINOGEN(blood clotting)
 GLUCOSE METABOLISM(can mobilise glucose when level is
low)
 DEAMINATION (removal of amine group) OF AMINO ACIDS –
TO FORM UREA(to be excreted in the kidneys)
 CONVERSION OF AMMONIA TO UREA
 FORMATION OF BLOOD CLOTTING FACTORS –




I(FIBRINOGEN) II (PROTHROMBIN), IV, V, VI, VII
PROTEIN AND LIPID SYNTHESIS/CHOLESTEROL (abt 25%)
STORAGE OF GLUCOSE, IRON AND VITAMINS A,D,E,K AND
B12
BREAKDOWN OF HAEMOGLOBIN TO IRON AND BILE
DETOXIFICATION/METABOLISM OF DRUGS
THE GALL BLADDER





ATTACHED TO THE LIVER
RECEIVES BILE SECRETED BY THE LIVER
STORES BILE
CONCENTRATES BILE
SECRETES BILE FOR FAT DIGESTION
 THROUGH THE COMMON BILE DUCT
 INTO THE DUODENUM
 ASSOCIATED WITH CLINICAL PROBLEMS
 GALL STONES
 GALL BLADDER INFECTIONS
 CANCER OF THE GALL BLADDER
FUNCTIONS OF THE JEJUNUM AND ILEUM
 FUNCTIONS OF JEJENUM
 ABSORPTION OF PRODUCTS OF DIGESTION



GLUCOSE
AMINO ACIDS
FATTY ACIDS
 ABSORPTION OF WATER SOLUBLE VITAMINS – THE B SERIES &
VITAMIN C (EXCEPT B12)
 ABSORPTION OF REMAINING IRON
 ABSORPTION OF SODIUM
 FUNCTIONS OF THE ILEUM
 ABSORPTION OF B12 (AIDED BY INTRINSIC FACTOR)
 FAT SOLUBLE VITAMINS – A;D;K & E
 BILE SALTS ABSORPTION
 WATER
 IMMUNOLOGIC FUNCTIONS (PEYERS PATCHES) – bacteria that
must have escaped the GIT are destroyed by lymphocytes present in
the Peyers patches in the ileum especially at the ileo-caecal junction.
FUNCTIONS OF THE LARGE BOWEL
 STORAGE OF WASTE MATTER
 ABSORPTION OF WATER
 ABSORPTION OF ELECTROLYTES
 FORMATION OF FAECES
 ABSORPTION OF SOME VITAMINS SUCH AS VIT K
 PROPULSION OF WASTE MATERIAL TO THE ANUS
 DEFAECATION