Transcript DIGESTIVE SYSTEM

DIGESTIVE SYSTEM`
DIGESTIVE PROCESSES
• INGESTION
• MOVING FOOD ALONG GI TRACT
• MECHANICAL PREPARATION FOR
DIGESTION
• CHEMICAL DIGESTION
• ABSORPTION
• ELIMINATION
EMBRYONIC
DEVELOPMENT
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ECTODERM
FOREGUT
HINDGUT
MIDGUT
STOMODEUM
PROCTODEUM
DERIVATIVES OF
DIGESTIVE SYSTEM
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GI TRACT
THYROID
PARATHYROID
SALIVARY GLANDS
LIVER
GALLBLADDER
PANCREAS
DIGESTIVE ANATOMY
MUCOUS MEMBRANE
MUCOUS MEMBRANES
ORGANS
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ORAL CAVITY
PHARYNX
ESOPHAGUS
STOMACH
SMALL INTESTINE
LARGE INTESTINE
MOUTH
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HARD PALATE
SOFT PALATE
UVULA
GLOSSOPALATINE ARCHES
PARYNGOPALATINE ARCHES
FAUCES
ORAL VESTIBULE
ORAL VESTIBULE
LIPS
HARD AND SOFT PALATE
OROPHARYNX
TONGUE
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FLOOR OF MOUTH
EXTRINSIC MUSCLES
INTRINSIC MUSCLE
PAPILLAE
PAPILLAE
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FILIFORM
FUNGIFORM
VALLATE
TASTE BUDS FOUND ON FUNGIFORM
AND VALLATE
FILIFORM PAPILLAE
FUNGIFORM PAPILLAE
VALLATE PAPILLAE
LINGUAL TONSILS
• FORMS POSTERIOR DORSAL
SURFACE
• LYMPH NODULES
LINGUAL FRENULUM
• CONNECTS TONGUE VENTRALLY
TEETH
• GOMPHOSES IN ALVEOLI
• GINGIVIVAE
STRATIFIED SQUAMOUS EPITHELIUM
• PERIDONTAL LIGAMENT
ANATOMY OF THE TOOTH
• DENTIN COVERED BY ENAMEL
• ANCHORED TO PERIDONAL
LIGAMENT BY CEMENTUM
PARTS OF
TOOTH
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CROWN
NECK
ROOT
PULP CAVITY
ROOT CANAL
APICAL FORAMEN
TYPES OF TEETH
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INCISORS
CUSPIDS
BICUSPIDS
MOLARS
DECIDIOUS TEETH
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20 TEETH
COME AT REGULAR INTERVALS
START AT SIX MONTHS
USUALLY ALL IN BY 2 1/2 YEARS
PERMANENT TEETH
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32 TEETH
APPEAR AT ABOUT 6 YEARS
STOPS AT ABOUT 17 YEARS
SOMETIME BETWEEN 17 AND 25
WISDOM TEETH MAY COME IN
SALIVARY GLANDS
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BUCCAL GLANDS
PAROTID GLANDS
SUBMANDIBULAR GLANDS
SUBLINGUAL GLANDS
PAROTID GLAND
SUBMANDIBULAR GLAND
SUBLINGUAL SALIVARY
GLANDS
PHARYNX
• NASOPHARYNX
• OROPHARYNX
• LARYNGOPHARYNX
MESENTERIES
LAYERS OF THE
GASTROINTESTINAL WALL
FOUR LAYERS
TUNICA MUSOSA
TUNICA SUBMUCOSA
TUNICA MUSCULARIS
TUNICA SEROSA OR ADVENTITIA
TUNICA MUCOSA
• EPITHELIAL LAYER
• LAMINA PROPIRA
• MUSCULARIS MUCOSAE
EPITHELIAL LAYER
• STRATIFIED SQUAMOUS IN MOUTH
ESOPHAGUS AND ANUS
• REST IS SIMPLE COLUMNAR
LAMINA PROPIRA
• LOOSE CONNECTIVE TISSUE
CONTAINS BLOOD VESSELS, LYMPH
NODULES AND SMALL GLANDS
• PHARYNX -- TONSILS
• SMALL INTESTINE -- PEYERS
PATCHES
• APPENDIX -- LYMPH NODULES
MUSCULARIS MUCOSAE
TUNICA SUBMUCOSA
• THICK LAYER OF EITHER DENSE OR
LOOSE CONNECTIVE TISSUE
• CONTAINS BLOOD VESSELS,
LYMPHATIC VESSELS, NERVES, AND
SOMETIMES GLANDS
TUNICA MUSCULARIS
• DOUBLE LAYER OF MUSCLE IN MOST
AREAS
• INNER LAYER
ARRANGED CIRCULARLY
• OUTER LAYER
ARRANGED LONGITUDINALLY
• THICKENED AREAS OF INNER LAYER
FORMS SPHINCTERS
MUSCLES FOUND IN
MUSCULARIS
• SKELETAL --- UPPER PART OF
ESOPHAGUS AND EXTERNAL ANAL
SPHINCTER
• SMOOTH -- REST OF TRACT
TUNICA SEROSA OR
ADVENTITIA
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OUTER MOST TUNIC
CONNECTIVE TISSUE
ESOPHAGUS -- ADVENTITIA
ABDOMINAL CAVITY COMPONENTS-- SEROSA
NERVE PLEXUSES AND
REFLEX PATHWAYS
• SUBMUCOSAL PLEXUS --TUNICA
SUBMUCOSA
• MYENTERIC PLEXUS --BETWEEN
CIRCULAR AND LONGITUDINAL
LAYERS OF TUNICA MUSCLUARIS
• SUBSEROUS PLEXUS -- TUNICA
SEROSA
• COORDINATE MUCH OF ACTIVITY OF
GI TRACT
GANGLIA FOUND IN GI TRACT
• AUERBACH’S/MYENTERIC PLEXUS
– AUTONOMIC GANGLIA ARE FOUND IN THE
TUNICA MUSCULARIS
• MEISSNER’S/SUBMUCOSAL PLEXUS
– AUTONOMIC GANGLIA FOUND IN TUNICA
SUBMUCOSA
REFLEX PATHWAYS
• SHORT REFLEXES
• LONG REFLEXES
SHORT REFLEXES
• SIGNALS ORIGINATE FROM
RECEPTORS IN WALL OF GI TRACT
• TRANSMITTED BY INTRINSIC NERVE
PLEXUS TO EFFECTOR CELLS
• ALL ELEMENTS ARE FOUND IN WALL
OF GI TRACT
LONG REFLEXES
• SIGNALS ORIGINATE IN RECEPTORS
IN GI TRACT
• TRANSMITTED BY AFFERENT
NEURONS TO CNS
• AUTONOMIC NEURONS (VAGUS)
CARRY CNS INPUT TO INTRINSIC
NERVE PLEXUSES AND EFFECTOR
CELLS
ESOPHAGUS
• LONG MUSCULAR
TUBE
• POSTERIOR TO
TRACHEA
• PASSES THROUGH
MEDIASTINUM
• PASSES THROUGH
ESOPHAGEAL
HIATUS
• PERISTALSIS
MOVES FOOD
THROUGH
STOMACH
• LEFT OF MID
PLANE
• BLOW
DIAPHRAGM
• CARIDAC ORIFICE
• PYLORIC
SPHINCTER
ANATOMY OF STOMACH
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LESSER CURVATURE
GREATER CURVATURE
LESSER OMENTUM
GREATER OMENTUM
FUNDUS
BODY
PYLORIC REGION
PYLORIC ANTRUM AND CANAL
• RUGAE
STOMACH RUGAE
PYLORIC SPHINCTER
MODIFICATIONS OF
STOMACH MUCOSA
• GASTRIC GLANDS IN LAMINA
PROPIRA
• GASTRIC PITS
TRANSITION FROM STOMACH
TO DUODENUM
TYPES OF GLANDS
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FUNDIC GLANDS
GASTRIC GLANDS PROPER
CARDIAC GLANDS
PYLORIC GLANDS
ENTEROENDOCRINE CELLS
FUNDIC AND GASTRIC
GLANDS PROPER
• MUCOUS NECK CELLS
• PARIETAL (OXYNTIC ) CELLS
• ZYMOGENIC (CHIEF) CELLS
PARIETAL AND CHIEF CELLS
MUCOUS NECK CELLS
• SECRETE MUCOUS
• LOCATED NEAR GASTRIC PITS
PARIETAL CELLS
• OXYNTIC CELLS
• SECRETES HCL
ZYMOGENIC CELLS
• CHIEF CELLS
• SECRETES PEPSINOGEN
CHIEF CELLS
CARDIAC AND PYLORIC
GLANDS
• SECRETE MAINLY MUCOUS
ENTEROENDOCRINE CELLS
• GASTRIN
• SEROTONIN
• HISTAMINE
MODIFICATIONS OF TUNICA
MUSCULARIS
• OBLIQUE MUSCLE LAYER
• ALLOWS STRONG CONTRACTIONS
TO MIX FOOD WITH DIGESTIVE
ENZYMES
SMALL INTESTINES
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LONGEST PORTION OF GI TRACT
6 METERS LONG
MOST CONVOLUTED
LINED WITH SIMPLE COLUMNAR
EPITHELIUM
• SPECIALIZED TO ABSORB
NUTRIENTS
• WHERE MOST ABSORPTION OCCURS
REGIONS OF SMALL
INTESTINE
• DUODENUM
• JEJUNUM
• ILEUM
DUODENUM
• HEPATOPANCREATIC AMPULLA
(AMPULLA OF VATER)
• DUODENAL PAPILLA
• HEPATOPANCREATIC SPHINCTER
(SPHINCTER OF ODDI)
• DUODENUM IS RETROPERITONEAL
• 25 CM
SUBMUCOSA OF DUODENUM
TUNICA MUSCULARIS OF
THE DUODENUM
DUODENOJEJUNAL JUNCTION
JEJUNUM
• 2.5 METERS
• SUSPENDED BY MESENTERY
ILEUM
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3.5 METERS
ILEOCECAL VALVE
ILEOCECAL SPHINCTER
SUSPENDED BY MESENTERY
ILEUM
MODIFICATIONS OF THE
SMALL INTESTINE WALL
• OCCUR IN TUNICA MUCOSA AND
TUNICA SUBMUCOSA
• PLICAE CIRCULARES
• VILLI
PLICAE CIRCULARES
• CIRCULAR SHELF LIKE FOLDS
• INCREASE SURFACE AREA
• HELP MIX FOOD WITH ENZYMES
VILLI
• MUCOSAL PROJECTIONS INTO
LUMEN
• COVERED BY SIMPLE COLUMNAR
EPITHELIUM
• CONTAINS A LYMPHATIC CAPILLARY
CALLED A LACTEAL
DISTENDED LACTEALS
EPITHELIAL CELLS THAT
COVER THE VILLI
• GOBLET CELLS --- MUCUS
• ABSORPTIVE CELLS --- ABSORPTION
AND DIGESTION
• ENTEROENDOCRINE CELLS -- IN
DUODENUM--CCK, SECRETIN AND
OTHERS
ENTEROENDOCRINE CELLS
INTESTINAL GLANDS
• CRYPTS OF LIEBERKUHN
• BETWEEN BASES OF VILLI
PANETH CELLS
• NOT ENTEROENDOCRINE
• SECRETE ANTIBACTERIAL
PRODUCTS
PEYER’S PATCHES
• IN SUBMUCOSA
• AGGREGATION OF LYMPHATIC
NODULES
LARGE INTESTINE
• 1.5 M LONG
• EXTENDS FROM
ILEOCECAL VALVE TO
ANUS
• NAMED FOR DIAMETER
• SIMPLE COLUMNAR
EPITHELIUM
• MICROVILLI
• ABSORPTIVE AND
GOBLET CELLS
• FEW ENZYMES
PRODUCED
ANATOMY OF THE LARGE
INTESTINE
• CECUM
• VERIFORM
APPENDIX
• ASCENDING
COLON
• RIGHT COLIC
(HEPATIC)
FLEXURE
• TRANSVERSE
COLON
• LEFT COLIC
(SPLENIC
FLEXURE)
• DESCENDING
COLON
• SIGMOID COLON
• RECTUM
• ANUS
CECUM
• BLIND POUCH
• RECEIVES THE CONTENTS OF THE
ILEUM
TYPICAL HISTOLOGY OF
THE COLON
VERIFORM APPENDIX
• NARROW BLIND TUBE
• EXTENDS DOWNWARD FROM CECUM
• NUMEROUS LYMPHATIC NODULES
ASCENDING COLON
• EXTENDS UPWARD
• TIGHTLY ATTACHED TO POSTERIOR
WALL OF ABDOMEN
• RETROPERITONEAL
RIGHT COLIC FLEXURE
• HEPATIC FLEXURE
• JUST BELOW LIVER
• BENDS TO THE LEFT
TRANSVERSE COLON
• PASSES ACROSS ABDOMINAL CAVITY
• SUPENDED BY MESOCOLON
LEFT COLIC FLEXURE
• SPLENIC FLEXURE
• BENDS DOWNWARD
DESCENDING COLON
• RETROPERITONEAL
• DESCENDS TO LEFT PELVIC BRIM
SIGMOID COLON
• CURVES TO MIDPLANE TO FORM AN
S SHAPED SIGMOID COLON
TUNICS OF THE COLON
TUNICA MUCOSA
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INTESTINAL GLANDS
MUCOUS CELLS
NO VILLI
PLICAE SEMILUNARE (SEMILUNAR
FOLDS)
TUNICA MUSCULARIS
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TAENIAE COLI
3 BANDS OF SMOOTH MUSCLE
RUNS LENGTH OF COLON
FORMS POUCHES CALLED HAUSTRA
EPIPLOIC APPENDAGES
• FAT FILLED FOLDS OF PERITONEUM
HAUSTRA
RECTUM
• IN FRONT OF SACRUM
• SAME STRUCTURE AS COLON
EXCEPT NO TAENIAE COLI
• FEMALE
MALE RECTUM
ANAL-RECTAL JUNCTION
MUCOUS CUTANEOUS JUNCTIONS
ANAL CANAL
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LAST 3-4 CM OF COLON
BELOW PELVIC DIAPHRAGM
NOT IN ABDOMINOPELVIC CAVITY
MALE ANAL CANAL
ANATOMY OF ANAL CANAL
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ANAL COLUMNS
ANAL SINUSES
ANAL VALVES
INTERNAL AND EXTERNAL ANAL
SPHINCTERS
INTERNAL ANAL
SPHINCTER
• SMOOTH MUSCLE
EXTERNAL ANAL SPHINCTER
• SKELETAL MUSCLE
• FEMALE
ACCESSORY DIGESTIVE
ORGANS
• LOCATED OUTSIDE THE GI TRACT
• IMPORTANT FOR DIGESTION OF
FOOD
• CARRIED BY DUCTS
• DERIVED FROM ENDODERM ALSO
PANCREAS
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EXOCRINE AND ENDOCRINE GLAND
RETROPERITONEAL
HEAD
BODY
TAIL
HEAD OF PANCREAS
BODY OF PANCREAS
TAIL OF PANCREAS
MICROSCOPIC ANATOMY
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RESEMBLE SALIVARY GLANDS
ACINI
SINGLE SET OF PYRAMIDAL CELLS
ACTIVELY SECRETE ZYMOGEN
GRANULES
• INACTIVE DIGESTIVE ENZYMES
PANCREATIC SECRETIONS
• HORMONES
• PANCREATIC JUICE
PANCREATIC SECRETIONS
• EXOCRINE
TRANSPORT TO GI TRACT
• PANCREATIC DUCT (DUCT OF
WIRSUNG)
• COMMON BILE DUCT
• ACCESSORY PANCREATIC DUCT
(DUCT OF SANTORINI)
ENDOCRINE SECRETIONS
• ISLETS OF LANGERHAN
• EXOCYTOSIS
• DIFFUSION INTO BLOOD STREAM
HEAD OF PANCREAS
PANCREAS
AUTONOMIC GANGLION IN
PANCREAS
ISLETS OF LANGERHANS
PANCREATIC ACINI
PANCREATIC ACINI
LIVER
• LARGE ORGAN
• MANY IMPORTANT FUNCTIONS
CAUDATE LOBE
QUADRATE LOBE
LEFT LOBE
RIGHT LOBE
FALCIFORM LIGAMENT
LIGAMENTUM TERES
CORONARY LIGAMENT
LIGAMENTUM VENOSUM
BARE AREA
LESSER OMENTUM
ATTACHES IT TO STOMACH
BLOOD SUPPLY
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TWO BLOOD SUPPLIES
1500 ML OF BLOOD PER MINUTE
HEPATIC PORTAL VEIN
SYSTEMIC CIRCULATION
SYSTEMATIC BLOOD
SUPPLY
• 400 ML IN HEPATIC ARTERY
• BRANCHES OFF AORTA
• OXYGENATED BLOOD
HEPATIC ARTERY
HEPATIC PORTAL VEIN
• VENOUS BLOOD
• DEOXYGENATED
• NUTRIENT RICH BLOOD FROM
DIGESTIVE TRACT, PANCREAS AND
SPLEEN
• 1100 ML PER MINUTE
HEPATIC PORTAL VEIN
UNIQUENESS OF HEPATIC
CIRCULATION
• BOTH SYSTEMIC ARTERIE AND
HEPATIC PORTAL VEIN EMPTY INTO
SAME SINUSOIDS
• MEANS THERE IS A MIXTURE OF
ARTERIAL AND VENOUS BLOOD
• EMPTY INTO HEPATIC VEIN AND
INTO INFERIOR VENA CAVA
STRUCTURE OF THE LIVER
LIVER CORDS OR PLATES
• MADE UP OF ROWS OR SHEETS OF
HEPATOCYTES
LIVER LOBULES
• TINY HEXAGONAL COMPARTMENTS
LIVER LOBULES
PORTAL CANALS
• PORTA HEPATIS
HEPATIC TRIAD
CLASSIC LOBULE
CENTRAL VEIN
LIVER STROMA
HEPATOCYTE
LIVER SINUSOIDS
• LINED WITH ENDOTHELIUM
• HIGHLY PERMEABLE
PERISINUSOIDAL SPACE
• SPACE OF DISSE
• SEPARATES THE ENDOTHIAL LINING
FROM HEPATOCYTES
• MICROVILLI EXTEN INTO SPACE
STELLATE MACROPHAGES
• KUPPFER CELLS
• EXTENSIONS EXTEND INTO
SINUSOIDS
• ACTIVE PHAGOCYTES THAT REMOVE
BACTERIA AND FOREIGN CELLS
CELLS LINING SINUSOIDS
BILE CANALICULI
• LOCATED BETWEEN HEPATOCYTES
• CARRY BILE TO BILE DUCTS
LOCATED AT PERIPHERY OF LOBULES
• TRAVELS IN OPPOSITE DIRECTION OF
BLOOD
• BILE DUCTS JOIN TOGETHER TO
FORM HEPATIC DUCT
GLYCOGEN IN THE LIVER
GALL BLADDER
• SMALL SAC ON INFERIOR SURFACE
OF LIVER
• COLUMNAR EPITHELIUM
• STORAGE SITE FOR BILE
• SERVICED BY CYSTIC DUCT
HEPATOPANCREATIC
SPHINCTER
• CONTROLS FATE OF BILE
COMMON BILE DUCT
• HEPATIC DUCT AND CYSTIC DUCT
GREATER DUODENAL PAPILLAE
LESSER DUODENAL
PAPILLAE
COMMON BILE DUCT