HAP 4 SEMESTER 2 BPHARMACY AS PER PCI SYLLABUS

1. SEM 2
DIGESTIVE SYSTEM

2.  The digestive system consists of a group of organs that break down the food we eat into
smaller molecules that can be used by body cells.
 Two groups of organs compose the digestive system
 Gastrointestinal (GI) tract and
 Accessory digestive organs.
 G I Tract is a continuous tube that extends from the mouth to the anus through the thoracic
and abdominopelvic cavities.
 Organs of the gastrointestinal tract include the mouth, most of the pharynx, esophagus,
stomach, small intestine, and large intestine.
 Accessory digestive organs include the teeth, tongue, salivary glands, liver, gallbladder, and
pancreas.

4.  Functions of the Digestive System
 1. Ingestion: taking food into mouth.
 2. Secretion: release of water, acid, buffers, and enzymes
into lumen of GI tract.
 3. Mixing and propulsion: churning and movement of food
through GI tract.
 4. Digestion: mechanical and chemical breakdown of food.
 5. Absorption: passage of digested products from GI tract
into blood and lymph.
 6. Defecation: elimination of feces from GI tract.

6. Layers of the GI Tract

8. Mucosa
 The innermost layer of the digestive tract has specialized epithelial cells supported by an
underlying connective tissue layer called the lamina propria.
 The lamina propria contains blood vessels, nerves, lymphoid tissue and glands that support the
mucosa
 Beneath the lamina propria is the muscular is mucosa. This comprises layers of smooth muscle
which can contract to change the shape of the lumen.
Submucosa
 The submucosa surrounds the muscular is mucosa and consists of fat, fibrous connective tissue
and larger vessels and nerves. At its outer margin there is a specialized nerve plexus called the
submucosal plexus or Meissner plexus. This supplies the mucosa and submucosa.
Muscular is externa
 This smooth muscle layer has inner circular and outer longitudinal layers of muscle fibers
Neural innervations control the contraction of these muscles and hence the mechanical breakdown
and peristalsis of the food within the lumen
Serosa/mesentery
 The outer layer of the GIT is formed by fat and another layer of epithelial cells called
mesothelium

9.  The peritoneum is the largest serous membrane of the body; it consists of a
layer of simple squamous epithelium (mesothelium) with an underlying
supporting layer of areolar connective tissue.
 The peritoneum is divided into the parietal peritoneum, which lines the wall
of the abdominal cavity, and the visceral peritoneum, which covers some of
the organs in the cavity and is their serosa
 The slim space containing lubricating serous fluid that is between the parietal
and visceral portions of the peritoneum is called the peritoneal cavity.
 There are five major peritoneal folds: the greater omentum, falciform liga-
ment, lesser omentum, mesentery, and mesocolon:

10.  Stomach
 The stomach is a J-shaped enlargement of the GI tract directly inferior to the
diaphragm in the abdomen.
 The stomach connects the esophagus to the duodenum, the first part of the
small intestine
Functions of the Stomach
1. Mixes saliva, food, and gastric juice to form chyme.
2. Serves as reservoir for food before release into small intestine.
3. Secretes gastric juice, which contains HCl (kills bacteria and denatures
proteins), pepsin (begins the digestion of proteins), intrinsic factor (aids
absorption of vitamin B12), and gastric lipase (aids digestion of triglycerides).
4. Secretes gastrin into blood.

11. Retrospective validation

12.  Anatomy of the Stomach:
 The stomach has four main regions: the cardia, fundus, body, and pyloric part
 The cardia surrounds the opening of the esophagus into the stomach.
 The rounded portion superior to and to the left of the cardia is the fundus .
 Inferior to the fundus is the large central portion of the stomach, the body.
 The pyloric part is divisible into three regions. The first region, the pyloric antrum, connects
to the body of the stomach.
 The second region, the pyloric canal, leads to the third region, the pylorus which in turn
connects to the duodenum.
 When the stomach is empty, the mucosa lies in large folds, or rugae ,that can be seen with
the unaided eye. The pylorus communicates with the duodenum of the small intestine via a
smooth muscle sphincter called the pyloric sphincter (valve).
 The concave medial border of the stomach is called the lesser curvature; the convex lateral
border is called the greater curvature.

17.  Pepsin Enzyme:
 Pepsin enzyme is a proteolytic enzyme produced by the gastric glands and
functions in
 protein digestion. This enzyme is produced as an inactive zymogen, namely
pepsinogen, which is then activated by gastric acid into pepsin
 Functions Of Pepsin Enzymes In Humans:
• Protein Breakdown
 The main function of the pepsin enzyme is to break down proteins into smaller,
 digestible fragments by the body. This enzyme acts on the peptide bonds in
 proteins to form peptides and amino acids.
• Activation of other enzymes
 The enzyme pepsin can also activate other protein-digesting enzymes such as
 trypsin and chymotrypsin which are produced by the pancreas.

18. • Improved Nutrient Absorption
 Pepsin helps in the breakdown of proteins so that the nutrients in food can be
 absorbed more effectively and quickly by the body.
• Inhibition of Bacterial Growth
 The enzyme pepsin helps inhibit the growth of bacteria present in food. This
helps
 prevent infection in the digestive tract
• Improved Nutrient Absorption
 Pepsin helps in the breakdown of proteins so that the nutrients in food can be
 absorbed more effectively and quickly by the body.
• Inhibition of Bacterial Growth
 The enzyme pepsin helps inhibit the growth of bacteria present in food. This
helps
 prevent infection in the digestive tract

21.  Small Intestine :
 Anatomy of the small intestine.
 (a) Regions of the small intestine are the duodenum,
jejunum, and ileum.
 (b) Circular folds increase the surface area for
digestion and absorption in the small intestine.

22.  Anatomy of the small intestine:
 Divided into three regions
 Duodenum : shortest region, and is retroperitoneal. It starts at the pyloric
sphincter in the form of a C-shaped tube that extends about 25 cm (10 in.)
until it merges with the jejunum.
 Jejunum : long and extends to the ileum.
 Ileum : The final and longest region of the small intestine joins the large
intestine at a smooth muscle sphincter called the ileocecal sphincter
 Layers: mucosa, submucosa, muscularis, and serosa
 The epithelial layer :
 Absorptive cells : enzymes that digest food and possess micro-villi that absorb
nutrients in small intestinal chyme.
 Cells lining the crevices form the intestinal glands and secrete intestinal juice
contain paneth cells and enteroendocrine cells.
Paneth cells : secrete lysozyme,
Enteroendocrine cells : S cells, CCK cells, and K cells, secrete secretin, -tin),
cholecysto-kinin (CCK), glucose-dependent insulino-tropic peptide (GIP)

23. Functions of the Small Intestine
1. Segmentations mix chyme with digestive juices and
bring food into
contact with mucosa for absorption; peristalsis propels
chyme through
small intestine.
2. Completes digestion of carbohydrates, proteins, and
lipids; begins and
completes digestion of nucleic acids.
3. Absorbs about 90% of nutrients and water that pass
through digestive
system.

24.  Large Intestine:
Functions of the Large Intestine
1. Haustral churning, peristalsis, and
mass peristalsis drive contents of
colon into rectum.
2. Bacteria in large intestine convert
proteins to amino acids, break down
amino acids, and produce some B
vitamins and vitamin K.
3. Absorption of some water, ions, and
vitamins.
4. Formation of feces.
5. Defecation (emptying rectum).

25.  Anatomy of the Large Intestine:
 The large intestine which is about 1.5 m (5 ft ) long and 6.5 cm (2.5 in.) in
diameter in living humans and cadavers, extends from the ileum to the anus.
 The opening from the ileum into the large intestine is guarded by a fold of
mucous membrane called the ileocecal sphincter
 Hanging inferior to the ileocecal valve is the cecum, a small pouch about 6
cm
 Attached to the cecum is a twisted,coiled tube, measuring about 8 cm (3 in.)
in length, called the appendix
 Mesoappendix attaches the appendix to the inferior part of the mesentery of
the ileum.
 The open end of the cecum merges with a long tube called the colon which is
divided into ascending, transverse, descend-ing, and sigmoid portions.
 The rectum is about 15 cm (6 in.) in length and lies anterior to the sacrum
and coccyx.

27.  The wall of the large intestine contains the typical four layers found in the
rest of the GI tract: mucosa, submucosa, muscularis, and serosa.
 The epithelium contains mostly absorptive and goblet cells
 The absorptive cells function primarily in water absorption; the goblet cells
secrete mucus that lubricates the passage of the colonic contents.
 More absorption occurs in the small intestine than in the large intestine.
 The submucosa of the large intestine consists of areolar connective tissue.
 The muscularis consists of an external layer of longitudinal smooth muscle
and an internal layer of circular smooth muscle.

28.  Salivary Glands:
 Gland that releases a secretion called saliva into the oral
cavity.
 labial, buccal, and palatal
 Glands in the lips, cheeks, and palate, respectively, and
lingual glands in the tongue, all of which make a small
contribution to saliva.
 Parotid, submandibular, and sublingual glands
 Parotid glands: secretes saliva into the oral cavity via a
parotid duct
 Submandibular glands are found in the floor of the mouth
 The sublingual glands are beneath the tongue and superior to
the submandibular glands.
 Lesser sublingual ducts, open into the floor of the mouth in
the oral cavity proper.

29.  Function:
 The primary function of these glands is to produce saliva,
this helps maintain the moisture in the mouth and other
parts of the digestive tract.
 The glands release the saliva into the oral cavity and is
responsible for lubricating the passage that foods go
through from the oropharynx to the oesophagus then finally
the stomach.

30.  Pancreas
Anatomy of the Liver

31.  Anatomy of the Pancreas:
 The pancreas consists of a head, a body, and a tail and is usually connected to
the duodenum of the small intestine by two ducts
 Pancreatic juices are secreted by exocrine cells to small intestine
 The pancreatic duct, or duct of Wirsung, is the larger of the two ducts.
 Pancreatic duct joins the common bile duct from the liver and gallbladder
and enters the duo-denum as a dilated common duct called the
hepatopancreatic ampulla or ampulla of Vater
 Ampulla opens on an elevation of the duodenal mucosa known as the major
duodenal papilla.
 The passage of pancreatic juice and bile through the hepatopancreatic
ampulla into the duodenum of the small intestine is regulated by a mass of
smooth muscle surrounding the ampulla known as the sphincter of the
hepatopancreatic ampulla, or sphincter of Oddi

32.  FUNCTIONS:
 Pancreatic juice buffers acidic gastric juice in chyme,
 stops the action of pepsin from the stomach,
 creates the proper pH for digestion in the small intestine,
 and participates in the digestion of carbohydrates, proteins, triglycerides, and
nucleic acids.

33.  Anatomy of the Liver:
 The liver is divided into two principal lobes—a large right lobe and
a smaller left lobe—by the falciform ligament, a fold of the
mesentery

34.  Liver is composed of several components:
 Hepatocytes, Bile canaliculi, Hepatic sinusoids
 Together, a bile duct, branch of the hepatic artery, and branch of the hepatic
vein are referred to as a portal triad
 Hepatic lobule, Portal lobule, Hepatic acinus
 1. Hepatocytes are the major functional cells of the liver and perform a wide
array of meta-bolic, secretory, and endocrine functions. Hepatocytes form
complex three-dimensional arrangements called hepatic laminae, hepatocytes
secrete bile.
 2. Bile canaliculi: are highly permeable blood capillaries between rows of
hepatocytes that receive oxygenated blood from branches of the hepatic
artery and nutrient-rich deoxygenated blood from branches of the hepatic
portal vein.
 3. Hepatic sinusoids: are highly permeable blood capillaries between rows of
hepatocytes that receive oxygenated blood from branches of the hepatic
artery and nutrient-rich deoxygenated blood from branches of the hepatic
portal vein.

35.  DIGESTION AND ABSORPTION OF NUTRIENTS
 Digestion of carbohydrates:

36.  Digestion of Proteins:

37.  Digestion of Fats:

40.  Gastrointestinal Disorders:
 Inflammatory Bowel Disease (IBD):
 IBD is a group of chronic inflammatory conditions that affect the gastrointestinal
tract. The two main types of IBD are Crohn's disease and ulcerative colitis.
 Gastroesophageal Reflux Disease (GERD): GERD is a condition in which stomach
acid backs up into the esophagus, causing heartburn and other symptoms.
 Irritable Bowel Syndrome (IBS): IBS is a common disorder that affects the large
intestine. It is characterized by abdominal pain, bloating, constipation, and
diarrhea.
 Peptic Ulcer Disease (PUD): PUD is a condition in which sores develop in the lining
of the stomach or duodenum (the first part of the small intestine).
 Diverticulitis: Diverticulitis is a condition in which small pouches (diverticula) in
the lining of the large intestine become inflamed.

41.  3.BMR The Basal Metabolic Rate
 (BMR) is the energy required by an awake individual during physical,
emotional and digestive rest.
 It is the minimum amount of energy required to maintain life or sustain vital
functions like the working of the heart, circulation, brain function,
respiration, etc.
 The metabolic rate during sleep is less than BMR. Basal metabolic energy
required to support the basic processes of life, including circulation,
respiration, temperature maintenance, etc.
 It excludes digestion and voluntary activities. BMR constitutes the largest
proportion (2/3) of a person’s daily expenditure

42.  FACTORS THAT AFFECT BMR
 Age – BMR higher in youth. Lean body mass declines with age; physical
activity can offset this effect.
 Height – tall people have larger surface area.
 Growth – children & pregnant women have higher BMR’s
 Body composition – more lean tissue, higher BMR
 Fever – raises BMR
 Stress
 Environmental temperature
 Fasting/starvation, lowers BMR
 Malnutrition, lowers BMR
 Thyroxine – regulates BMR

43.  Normal Value for BMR Since
 BMR is affected by body surface area, it is usually expressed in kilocalories
per hour/square meter of body surface.
 Body surface area is calculated using the formula A = W 0.425 × H 0.725 ×
71.84 A = area in sq cm, H = height in centimeters and W = weight in
kilograms.
 The BMR is then calculated from the values of oxygen consumption, calorific
value and surface area.
 NORMAL VALUE FOR BMR For adult men normal value for BMR is 34-37
kcal/square meter/hour, and For adult women, 30-35 kcal/Sq.m./hour.
 For easier calculations, BMR for an adult is fixed as 24 kcal/ kg body
weight/day.

44.  CREATINE PHOSPHATE
 Phosphocreatine, also known as creatine phosphate (CP) or PCr (Pcr), is a
phosphorylated creatine molecule that serves as a rapidly mobilizable reserve
of highenergy phosphates in skeletal muscle, myocardium and the brain to
recycle adenosine triphosphate, the energy currency of the cell.
 Creatine is synthesized by the liver, pancreas and kidneys.
 It is synthesized from glycine, the guanido group of arginine and the methyl
group from S-adenosylmethionine.
 It is transported across the membranes of muscle and nerve cells by a specific
transporter system.
 The enzyme creatine kinase catalyzes the phosphorylation of creatine to CP