Gastrointestinal tract part 1

2/15/2018 Prof.Dr.R.R.Deshpande 12/15/2018 Prof.Dr.R.R.Deshpande 1
GI Tract –Part 1
• Presented By –
• Prof.Dr.R.R.Deshpande (M.D in Ayurvdic
Medicine & M.D. in Ayurvedic Physiology)
• www.ayurvedicfriend.com
• Mobile – 922 68 10 630
• mailme.drrrdeshpande@rediffmail.com

Contents of PPT
• 5) Histology of Digestive Tract
• 6) Salivary glands
• 7) to 19) –Functions of Liver
• 21) Five Secretions & Five Movements
• 25) Functions of Salivary Gland
• 33) Functions of Gastric secretions
• 43) Functions of Pancreatic Sectretions
2/15/2018 Prof.Dr.R.R.Deshpande 2

Contents of PPT
• 53) Intestinal Juice –Enzymes
• 54) Functions of Large Intestine
• 58) Deglutition
• 65) Mastication
• 73) Movements of Stomach
• 80) Enteric Nervous system
• 90) Movements of small Intestine
• 102) Defecation Reflex
• 109) Stool

Histology of Digestive Tract
• From oesophagus onwards, the digestive tract
show 4 layers –
• 1) Serous layer (outermost)
• 2) Muscular layer consists of longitudinal &
circular muscle fibres
• 3) Sub mucous layer
• 4) Mucous layer.

Salivary Glands
• Salivary glands secrete saliva
• 1) Submaxillary (submandibular) glands --
open through Wharton duct at side of frenum of
tongue at the floor of the mouth
• 2) Parotid gland - open through stenson’s duct
to opposite the 2nd upper molar tooth,
• 3) Sublingual glands open through ducts of
Rivinus (10 - 12 ducts) at side of frenum of
tongue, at the floor of the mouth.

Functions of Liver - 1
• 1) In Connection With Blood & Circulation
• RBC formation, in foetal life
• RBC destruction in adult life
• Store house of blood & regulates blood volume
• Manufactures prothrombin & fibrinogen (
clotting factors)
• Mast cells form heparin & prevent intravascular
clotting

Functions of Liver -2
• 2) Related to activity of its R.E. system in
immune mechanism
• It transfers blood from portal to systemic
circulation
• Manufactures all plasma proteins
• Stores iron, haematinic factor Vit. B12 &
copper & thus helps in the formation of red cells
& haemoglobin
• Hepatic & portal circulation control

Functions of Liver – 3
• 3) Manufactures Bile
• Bile acids in conjugation with glycerin & taurine
form the compounds –
• Bile salts –
• Glycochloric acid &
• Taurocholic acid respectively
• Bile salts --- emulsification of fats

Functions of Liver -- 4
• 4) Relation With Carbohydrate Metabolism
• Converts non glucose monosaccharides into
glucose
• Converts lactic acid, pyruvic acid & glycerol
into glucose & also glycogen
• Stores carbohydrates in the form of glycogen
• Takes part in blood sugar regulation

• Manufactures fats from carbohydrates
etc
• Alchohol metabolism –
• The liver is the main seat of alcohol
metabolism
• The direct effect of alcohol may be
alcoholic fatty liver

Functions of Liver –6
• 5) Relation With Fat Metabolism
• It stores fat
• It helps in the oxidation of fat, releasing
energy in the form of A.T.P
• Site of synthesis of cholesterol from
acetate

• Synthesizes fats from carbohydrates &
proteins
• It is the seat of ketone body formation
• Unused free fatty acid (FFA) released
from fat depot is converted to
triglycerides & other lipids to meet energy
requirement

• In a carbohydrate deficiency, the fat
metabolism in the liver is increased & fat
is partially converted to glucose or
glycogen
• Fat soluble vitamins, eg. - A, D, E & K
are stored here

• 5) Relation With Protein Metabolism
• Synthesis of some amino acids takes place
here
• Plasma proteins are manufactured here
except immune globulin
• Main seat of urea & uric acid formation
• It is the seat of specific dynamic action of protein
• It is the seat of nitrogen metabolism

Functions of Liver --10
• 6) Hormone Metabolism
• Reduces the circulating adrenal cortical &
sex hormones by degradation &
conjugation
• Inactivation of insulin, glucageon, anti -
diuretic hormones (ADH) & anterior
pituitary tropic hormones etc. occur
here

• 7) Relation With Vitamins
• Manufactures prothrombin with the help of
vit. K
• It forms vit. A from carotene & stores vit. A &
D
• Chronic liver disease is always associated with
folic acid deficiency

• 8) Excretory Functions
• Certain heavy metals are temporarily
fixed by the liver cells, which are then
excreted in the bile
• Various toxins, bacteria & drugs are
excreted through bile
• Cholesterol & bile pigments are excreted
in the bile.

Functions of Liver - 13
• 9) Detoxicating & Protective Functions
• The liver is the site of detoxication of
different toxic substances either produced
in the body or taken along with food.
• 10) Takes Part In Heat Regulation
• The liver produces a large amount of heat
& takes part in heart regulation.

Complex to Simpler molecules
• In digestive system, due to action of different
enzymes & chemicals (Bile, HCL) complex
molecules break up & simpler molecules are
formed
• Carbohydrates → Glucose
• Protein → Amino acid
• Fats → Fatty acid & glycerol

5 Secretions & 5 Movements

1) Salivary secretions
• Parotid 20% Serous
• Sub mandibular 70% Mixed
• Sublingual 10% Mucus

Structure of Salivary glands

Salivary secretions
• 1) Salivary amylase (Ptyline)
• 2) Mucin
• 3) Na+, K+, HCO3-
• 4) Blood group antigen

Functions of Salivary Glands
• 1) Cleaning of oral cavity
• 2) Prevents caries, antiseptic action
(due to Lysozyme)
• 3) Alkaline medium & so Ca++ deposited
on teeth
• 4) Formation of bolus
• 5) Lubrication of bolus

• 6) Softening of food
• 7) Boiled starch.

• 8) Helps in speech
• 9) Taste perception
• 10) Neutralizes acidity in stomach
• 11) Water balance

Regulation of Salivary secretions
• Regulation = Nervous, hormonal
• Salivary gland is exception for above
rule. Only nervous regulation is done by
parasympathetic nerve
• 7th cranial nerve (facial) → sub
mandibular, sublingual
• 9th cranial nerve (glosso pharyngeal)
→ parotid

Saliva Secretions- Phases
• 1) Cephalic phase
• 2) Oral phase
• 3) Gastric phase

Saliva Secretions- Phases
• a) Cephalic phase - saliva increases after
thought of food or sight of food.
• b) Oral phase - It is most important. It is due to
contact of food with Taste buds. Signals pass to
brain from these Taste buds (Gustatory
pathway)
• c) Gastric phase - Presence of food in stomach
increases salivary secretions. After eating spicy
food, saliva increases, as a protective
mechanism

Gastric Secretion

Gastric Secretion
• 1) HCL / NaCl / KCl
• 2) Intrinsic factor (IF)
• 3) Pepsinogen
• 4) Mucin
• 5) Enzymes - Pepsinogen, Renin

Gastric Secretion - Functions
• 1) HCL - Antiseptic
• 2) Activation of pepsinogen
• 3) Provides acidic medium for action of
enzymes
• 4) Iron & calcium absorption

Gastric Secretion - Functions
• 2) Digestive
• c) Intrinsic factor is essential for absorption
of Vit B12 factor
• d) Mucin - Protects mucosa against
acidity

Regulation of Gastric Secretion

Gastric Secretion Phases
• 1) Cephalic
• 2) Gastric
• 3) Intestinal

Special Notes
• 4) Ferrous iron can only be absorbed &
this form is needed for hemoglobin
formation.
• Iron preparation is always given with
vitamin C (ascorbic acid) vitamin C keeps
iron in ferrous form.
• 5) Proteins that we eat are polypeptide
(amino acid linkage) Due to pepsin break
down of this linkage takes place

Special Notes
• 6) Mucin is alkaline & sticky. It forms the
buffer coat on gastric mucosa.
• In gastric mucosa rapid mitosis takes
place. Above facts prevent ulceration in
stomach (Peptic ulcer)
• 99% of ulcers occur in duodenum
because there is no protective
mechanism.

Special Notes
• 7) Presence of food & distention of
stomach causes afferent sensation.
Hence vagotomy is the surgical treatment
in peptic ulcer (afferent & efferent both
are cut)
• 8) In duodenum ulcers mid night pain is
common (i.e. after 2 ½ to 3 hr. after eating
pain starts. That means when food comes
in duodenum from stomach pain starts.)

Special Notes
• 9) HCl maintains appetite . Hence hyper
acidity patients eat frequently. In hyper
acidity patient gastric emptying time is also
shorter.
• 10) Gastric moments are affected by type
of food
• More acidic food - fast emptying time
• More carbohydrates or protein - faster emptying
time

Special Notes
• More fats - delayed emptying time
• (Reason - Due to fatty food CCK
hormone is stimulated. This hormone
inhibits gastrin, hence motility is
reduced.)

3) Pancreatic secretion
(Tubulo acinar gland)
• 1) Trypsinogen
• 2) Chymotrypsinogen
• 3) P. Amylase
• 4) P Lipase
• 5) Trypsin inhibitor
• 6) HCO3 / Na & K

Function- Pancreatic secretion

Note
• 1) Enterokinase enzyme is present in
Duodenum (intestinal juice)
• which converts inactive enzyme
(Trypsinogen) into active form Trypsin
• 2) In pancreas, enzymes are not in active
form - Due to trypsin inhibitor. Enzymes
get activated when they come in
duodenum

Note
• 3) When trypsin inhibitor is absent Auto
digestion of Pancrease takes place
• This condition is called as Acute
Pancreatitis
• This case is of acute abdomen. Patient
get severe stabbing pain in the epigastric
region, referred to back. Alcohol
consumption is predisposing factor

4) Bile secretion
• Bile is formed in Liver
• Stored in gall - bladder
• Through the bile duct it enters into
duodenum

Contents of Bile
• i) Bile salts (Sodium taurocolate,
Sodium glycolate)
• ii) Bile pigments (Bilirubin & Biliverdin)
• iii) Cholesterol (ester)
• iv) HCO- 3 (Na & K)

Function of Bile Salt
• Emulsification of fats (Big fat molecules
are broken down into smaller particles.)
Hence surface area increases, so action of
Lipase becomes easier)
• Note - In urine examination test for Bile
salt (Sulphur test) is based on this
information.

Control of bile secretion &
expulsion of bile from Gall bladder

Control of bile secretion
• Due to CCK hormone, Gall bladder
contraction increases
• Note - Bile does not contain any
enzyme
• 1) But still it is very necessary for fat
digestion (for action of Lipase enzyme) by
emulsification of fat

Bile & Gall Stones
• 2) Pathologically -
• Gall stones can cause Obstructive
jaundice
• Gall stones are common in fat, fertile,
female of forty complaining of flatulence
• (Remember as ‘ Five F’)

5) Intestinal Juice – Succus Entericus
Raw Enzyme Final Product
Maltose Maltase Glucose
Lactose Lactase Glucose
Sucrose Sucrase Glucose
Polypeptide or
Dipeptide
Erepsin Amino acid
Trigycerides Lipase FFA & Glycerol

Large intestinal functions
• 1) Absorption of water, electrolytes (Cl, HCO-
3)
• 2) Colonic bacteria - They synthesize Vit. B12 &
Vit. K.
• 3) Mucous – secreted by Goblet cells .
• Mucous is lubricant & avoids friction of faecal
matter with delicate mucosa of large intestine
• Mucous is sticky .So it collects undigested
particles together & helps in formation of faeces

Large intestinal functions
• Mucous is alkaline .So it neutralizes acids
which are produced by bacteria in large
intestine
• 4) Movements of large intestine push
undigested food ahead into the rectum &
given out by defecation reflex
• 5) Heavy metal salts can be excreted
through large intestine ,if there is
poisoning

Absorption
• Amino acids & glucose are absorbed
into blood capillaries
• Fatty acids are absorbed into lacteals
(Lymph vessels)

Movements of GI tract
• Deglutition
• 1) Process of swallowing of food
• 2) Phases
• i) Oral phase
• ii) Pharyngeal phase
• iii) Oesophageal phase.

Deglutition- i) Oral Phase
• Masticated food is mixed with saliva
• Bolus is pushed back to pharynx, by
movement of tongue
• This phase is voluntarily controlled by
muscle of tongue ---
• (Supplied by Hypoglossal nerve)

ii) Pharyngeal phase - Involuntary
• Events are
• a) Elevation of trachea
• b) Epiglottis falls on tracheal opening,
to close it
• c) Nasopharynx is closed by contraction of
muscle of soft palate.

ii) Pharyngeal phase - Involuntary
• d) Pharyngo - oesophageal sphincter
opens
•
• e) Vocal cords are approximated
•
• f) In all these events, respiration stops
temporarily (Deglutition Apnoea)

Deglutition - Control
• Reflex mechanism
• Presence of food in pharynx, stimulate touch
receptors
• Afferent impulses travel via 9th, 10th & 5th
cranial nerves to the brainstem
• Deglutition centre is situated in medulla.
Efferent impulses come through 9th, 10th & 11th
cranial nerves & bring about synchronized
events of this phase

iii) Deglutition - Oesophageal Phase
• Involuntary phase -- 2 components
• a) Primary peristalsis - due to activity of
pacemaker at pharyngo - oesophageal centre.
• b) Secondary peristalsis - presence of food
causes distension of oesophagus. Afferent
impulses travel via Vagus nerve. From Vagus
center efferent impulses come via Vagus nerve
& increase peristalsis.

Deglutition
• When food reaches cardiac sphincter, it
opens by receptive relaxation
• Food enters into stomach & sphincter
closes back
• This prevents regurgitation

Deglutition - Pathology
• 1)Dysphagia - Difficulty in deglution
• Main cause - Cancer of oesophagus. Also
occurs in ‘Achalasia cardia - when cardiac
sphincter is not relaxing properly
• 2)Regurgitation of food from nose or into
Trachea (Causing coughing reflex)
• This can happen if nerves are damaged near
pharynx - Pharyngeal phase cannot occur in
synchronized manner (eg. Diphtheria)

2) Mastication
• Definition - Process of grinding of food
under teeth
• Teeth functions –
• Incisors - To cut the food
• Molars & premolars - Mastication

Function of Mastication
• Big food particles are converted to small
particles
• Surface area increases & digestive
enzymes can act better.

Muscles of mastication
• 1) Temporalis - Originates from temporal
bone & is inserted on mandible. Fan
shaped muscle.
• 2) Masseter - Originates from maxillary
part of bone & is inserted on mandible.
• Functions - These muscles when contract
upward movement of jaw takes place
which helps in grinding

Muscles of mastication
• 3) Medial & lateral Pterygoid - Located
on inner side of mouth. Due to these
muscles side to side movement of jaw
occurs which helps in grinding
• All these muscles are supplied by -
Mandibular branch of „Trigeminal
nerve‟

Mastication Reflex
• This is stretch reflex
• Due to presence of food bolus in the
mouth jaw drops down. Stretch receptors
in the muscles of mastication are
stimulated
• Afferent impulses go through trigeminal
nerve - to its motor nucleus in pons

Mastication Reflex
• Efferent impulses again via mandibular
nerve give signals to the muscle to
contract. Jaw is elevated
• Process occurs again & again
automatically
• This process can also controlled
voluntarily, by motor cortex. We can
stop or start the act of mastication
voluntarily

Mastication -- Pathology
• Injury or pain or stiffness of TM joint -
movement of mastication suffers
• In Tetanus there is a spasm of muscles of
mastication - leading to „locked jaw‟ &
mastication reflex suffers

Mastication - Pathology
• If molars, premolars are in inadequate
number - i.e. in the old age → mastication
suffers
• If tongue is injured, mastication suffers
because for mastication, movements of
tongue are helpful to push the food under
teeth.

3) Movements of stomach
• 1) When food enters into stomach it
undergoesfood is stored receptive
relaxation. Then
• 2) Mixing waves & propulsive waves

3) Movements of stomach
• Mixing waves are initiated at rate of every
20 sec. & are due BER (Basic Electrical
Rhythm). This helps to mixed the food with
gastric juice.
• Then waves start moving down from
fundus to pylorus. They become powerful
which increases pressure of antral
contents.

Emptying of stomach
• Antral peristalsis (Pyloric pump) &
relaxation of pyloric sphincter, releases
gastric contents to duodenum
• In stomach food is stored for 2 to 2&1/2
hrs. It is called as “Gastric emptying
time”

Emptying of stomach
• It can be studied by „Barium Meal
examination -- BA swallow
• Waves of BER, become 5 to 6 times
powerful which push fluid food (Chyme)
towards pylorus. This is called „Pyloric
pump activity‟
• Emptying of stomach is proportionate to
the volume of food

Factors, which modify, gastric emptying
• Stomach factors
• Food in the stomach try to hasten gastric
emptying. Stimulation of vagus
increases pyloric pump activity & also
causes relaxation of sphincter
• Hormone gastrin also has the same
effect

• Duodenal factors
• With feed back inhibition, distention of
duodenum stimulates local nerve
plexuses, which inhibit gastric
emptying
• Duodenal hormones like GIP & CCK - PZ
cause inhibition of gastrin & inhibit gastric
emptying

• Fatty food -- Delays gastric emptying.
• Chilly food, Protein food has got quick
emptying effect
• In pyloric stenosis (which is a
complication of chronic duodenal ulcer)
Gastric emptying is delayed.

Enteric nervous system
• Nerve supply to Gastrointestinal Tract
• There are 2 types of Nerve supply
•
• 1) Intrinsic Nerve supply
• 2) Extrinsic Nerve supply

1) Intrinsic Nerve supply
• Enteric Nerve system is present within the
wall of Digestive tract from oesophagus to
anus
• Nerve fibers form 2 networks as
• i) Auerbach Plexus
• ii) Meissner Plexus.
• These plexuses contain stretch & chemo receptors
.Enteric Nervous system is controlled by Extrinsic
nerves.

1) Auerbach Plexus
• Called as Myenteric Nerve plexus
• It is present in between inner circular
muscle layer & outer longitudinal
muscle layer
• Main function is to regulate the
movements of GI Tract

1) Auerbach Plexus
• Some nerve fibres accelerate the
movements by secreting excitatory
neurotransmitter like Ach, Serotonin,
Substance P.
• Other fibres inhibit the GI motility by
secreting the inhibitory neurotransmitter
like vasoactive Intestinal Polypeptide
(VIP), Neurotensin, enkephalin

2) Meissner Nerve Plexus
• Called as sub mucous Nerve Plexus
• Present in between the muscular & sub
mucosal layer of GI Tract
• Function is to regulate secretory
functions of Digestive Tract

2) Extrinsic Nerve supply
• Both Sympathetic & Parasympathetic
divisions innervate the GI Tract

Sympathetic Nerve Fibres
• Preganglionic fibres arise from lateral
horns of spinal cord between 5th
thoracic & 2nd lumber segments
• They terminate in the celiac & mesenteric
ganglia

Sympathetic Nerve Fibres
• Sympathetic nerve fibres inhibit the
movements & decrease the secretions of
GI Tract
• This happens due to neurotransmitter
Noradrenaline .There is also constriction
of sphincters

Parasympathetic Nerve fibres
• They pass through some of cranial & sacral
nerves
• Nerve fibres to mouth & salivary glands pass
through facial & glossopharyngeal nerves
• Preganglionic parasympathetic nerve fibres to
oesophagus, stomach, small intestine & upper
part of large intestine pass through Vagus
nerve

Parasympathetic Nerve fibres
• Preganglionic fibres to lower part of large
intestine arise from 2nd ,3rd ,4th sacral
segments & pass through Pelvic nerve
• Parasympathetic nerve fibres
accelerate the movements & increase
the secretions of GI Tract, with
Neurotransmitter Ach.

Movements of small intestine
• Peristalsis - Definition
• Wave of relaxation, followed by wave of
contraction. This is the basic property of all
tubular structures
• In intestine it is more prominent due to
Myenteric plexus

Types of movement
• 1) Mixing movement - Only 1 segments
contracts & relaxes (Segmental peristalsis)
• Wave is not spreading to the next segment
• Food is mixed with digestive juices

Types of movement
• 2) Propulsive waves –
• Spread from one segment to another &
food is pushed ahead & ahead
• Speed = 5 to 6 hrs are required to reach
the food from duodenum to Caecum

Types of movement
• 3) Rush peristalsis –
• When irritation of mucosa, high segments
contracts & large quantity of food is
pushed ahead
• Structures lined by smooth muscle

Types of movement
• 4) Antiperistalsis –
• Normally wave of peristalsis - From oral to
rectal direction
• But when there is excessive irritation
(Gastro - enteritis, food poisoning,
obstruction) –
• Waves move in opposite direction,
leading to vomiting

Movements of Villi
• Due to movement of sub mucosa of
intestine thin coat of muscle contract due
to presence of food & distension of small
intestine
• Villi movement help in absorption
process

Role of ilio cecal valve
• It allows unidirectional movement of
food
• Contents of cecum cannot regurgitate
back

Causes of Peristalsis
• 1) Role of Nerves
• i) Role of Myenteric plexus (Intrinsic
supply)
• In muscularis layer of intestine this plexus
is present. Presence of food & distention
of intestine stimulate this plexus & they
send signal to smooth muscle -increasing
movement. This is called as local reflex/
myenteric reflex.

• ii) Role of sympathetic &
parasympathetic nerves (Extrinsic
supply)
• Parasympathetic nerves - increases the
peristalsis.
• Sympathetic nerves - decreases
peristalsis.

• iii) Role of Hormones
•
• CCKPZ, Gastrin, Serotonin etc.
hormones directly act on smooth muscle &
increase peristalsis

Functions of Peristalsis
• 1) Mixing of food with digestive juices.
• 2) Push the food on absorptive surfaces,
to facilitate absorption
• 3) Undigested food is pushed to large
intestine.
• 4) To increase the blood supply of
intestine.

Peristalsis - Pathology
• In cholera, food poisoning - peristalsis is
stimulated excessively - which causes
loose motion & dehydration
• Postoperatively or due to
anticholinergic drug (Tab Baralgan, Tab
Spasmindon) - Movements are reduced

Defecation Reflex
• Reflex of evacuation of Rectum
• Basically spinal reflex but influenced by
cortical areas
• Normally rectum is empty + external anal
sphincter is tonically closed
• When faecal matter accumulates in rectum
,wall is streached
• Stretch receptors in the wall are
stimulated2/15/2018 Prof.Dr.R.R.Deshpande 101

Defecation Reflex
• Impulses go via sensory nerves in spinal
cord & then to brain by ascending tracts
• Person is awarded of fullness of rectum
• Motor center is located in precentral
gyrus near the area of muscle thigh
• Motor signals come to spinal cord

Defecation Reflex
• Then via motor nerves & parasympathetic
nerves ,signals are given to rectum ,causing
it‟s contraction
• At the same time external anal sphincter relaxes
• Abdominal muscles also contract
• Pelvic diaphragm is elevated
• This help in complete evacuation of rectum

Defecation Reflex
• In child ,reflex is automatic & occurs at
spinal cord level ,because tracts are not
myelinated
• After the age of one & half year ,tracts
ate myelinated & child develops voluntary
control on defaecation

Defecation Reflex
• It is habituated in every person
•
• Taking of morning tea facilitates
defaecation in many
• In Spinal cord injuries voluntary control
may be lost on the act of defaecation (
Incontinence)

Faeces
• After the last stage of digestion, after
absorption of water solid or semisolid
waste part is formed which is called as
faeces
• Quantity - Roughly about 150 gm of solid
stool is passed in 24 hours.

Stool - Composition
• If vegetable course cereals & cellulose are excluded
from the diet, the faeces show a fairly constant
components as follows -
• 1) Water - 65 %
• 2) Solid - 35 %
• i) Ash - 15 % (Mainly, Ca, P4, Fe)
• ii) Ether soluble substances (Fat) - 15 %
• iii) Nitrogen - 5 %
• iv) Other - Desquamated epithelial cells, bacteria,
mucous, undigested & unabsorbed food.

Stool
• Reaction - Generally, neutral or acid.
• Colour - Due to the presence of Stercobilin,
derived from the bile pigments
• Odour - Mainly due to aromatic substances like
indole, skatole & also gases like H2S.
• Under normal condition about 500 cc of gas is
passed out per day.

Special notes
• Cellulose serves the important purpose of
increasing the bulk of stool
• Thus stimulating the movement of large
intestine

Faeces formation
• Last stage of digestion in the large
intestine
• The last stage of digestion occurs through
bacterial action & no enzymes are
secreted by the colon. Mucus is secreted
by the glands of the large intestine, but no
enzymes are secreted
• Chyme is prepared for elimination by the
action of bacteria

Faeces formation
• These bacteria ferment any remaining
carbohydrates & release hydrogen, CO2 &
methane gas. These gases contribute to
flatus (Gas) in the colon
• They also convert remaining proteins to
amino acids & breakdown the amino acids
into simpler substances that is indol,
skatole, hydrogen sulphide & fatty acids

Faeces formation
• Some of the Indol & Skatole is carried of
in the faeces & contributes to their odor
• The rest are absorbed & transported to the
liver where they are converted into less
toxic compounds & excreted in the urine
• Bacteria also decompose bilirubin into
simpler pigments (Stercobilinogen)
which gives faeces brown colour

Absorption & faeces formation
• By the time the chyme has remained into
large intestine for 3 - 10 Hr. It becomes
solid or semisolid as a result of absorption
of water & is known as faeces.
• Chemically faeces consist of water,
inorganic salts, sloughed of epithelial
cells from the mucosa of the GI tract,
bacteria, products of bacterial
decomposition & undigested part of food.

Physiology of defecation
• 1) Mass peristaltic movements push
faecal matter from sigmoid colon into the
rectum
• 2) The resulting distension of the rectal
wall stimulates pressure - sensitive
receptor initiating
• Reflex of defecation which results in
emptying of the rectum

Pathology
• 1) Diarrhoea - means frequent defecation of
liquid faeces, caused by increased motility of the
intestine. Since chyme passes too quickly
through the small intestine & faeces pass too
quickly through the large intestine. There is not
enough time for absorption.
• Vomiting & diarrhoea can result in dehydration
& electrolyte imbalance.
• 2) Constipation - means infrequent or difficult
defecation

Prof.Dr.R.R.Deshpande
• Sharing of Knowledge
• FOR
• Propagating Ayurved
2/15/2018 116Prof.Dr.R.R.Deshpande

Gastrointestinal tract part 1

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à Gastrointestinal tract part 1

Similaire à Gastrointestinal tract part 1 (20)

Plus de rajendra deshpande

Plus de rajendra deshpande (20)

Dernier

Dernier (20)

Gastrointestinal tract part 1