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12/2/2010
Maldigestion
Dr. H.Rustam Effendi YS,SpPD-KGEH
Divisi Gastroentero-Hepatologi Departemen Ilmu Penyakit
Dalam FKUSU/RSUP.H.Adam Malik-RSU Dr. Pirngadi Medan.
30-9-2010: Kelas A dan B
M
eso
lbg
Usus
colon
Anatomi saluran cerna
halus
Small bowel : 390-690 cm13-23ft.1ft=30cm)
• Duodenum ( 5%): 50 cm (1,5ft)
Ligamentum Treitz
• Jejunum
(35%): 160-280 cm (4-9ft),
•
( 60%): 240-420 cm (8-14 ft),
leum
Colon
: 150-180 cm (5-6 ft)
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Billiard tract obstruction caused by a gallstone in the
distal common bile duct.
Anatomy
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Proses Pencernaan
Gerakan saluran cerna.(Motilitas)
- smooth muscle constant low level of contraction (tone).
- mendorong (propulsive movements) dgn kecepatan berbeda.
- Mengaduk (mixing movements) isi sal cerna.
- Mencampur makanan dgn getah pencernaan.
- Memudahkan absorpsi nutrisi.
Sekresi :
- Kelenjar eksokrin getah pencernaan (enzim-enzim)
- Membutuhkan energi (transport aktif & sintesis)
- Getah pencernaan harus direabsorpsi ses. selesai digunakan
Pencernaan makanan : mekanikmemecah jadi ukuran kecil,
kimika(enzymatic hydrolysis)memecah jadi lebih sederhana.
(monomer, subunit), untuk memungkinkan absorpsi makanan.
Penyerapan : Transfer nutrisi hasil pencernaan dari lumen sal cerna ke dalam
pembuluh darah atau limfe.
Pembuangan (Tinja)
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FAKTOR ANATOMI DAN FISIOLOGI PENCERNAAN :
Area permukaan yang panjang & luas (12 jt /2 x 108 cm persegi)
- Mulut : gigi & lidah, amilase (hidrosisa)
- Lambung: - menggiling, mencampur, dan mendorong (<1mm)
- asam
Hidrolisa
- pepsin
- Hati dan saluran empedu : cairan empedu (hidrolisa)
- Pankreas : - amilase
- lipase
Hidrolisa
- tripsin
- Usus halus : - motilitas :
- gross motiliti (besar)
Hidrolisa & absorbsi
- Motilitas villi
FISIOLOGI
Saluran
Kantongan / penyimpanan
Pencernaan
Motilitas : - menggiling
- mendorong
- mencampur
Sekresi (enzim-enzim; air; asam)
Absorbsi (fold dan villi)
Eksresi (tinja)
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FUNGSI SALURAN CERNA :
1. AKOMODASI ( LAMBUNG )
2. PENCERNAAN
3. ABSORBSI
4. EKSKRESI ( BAB / DEFEKASI )
Fungsi Pencernaan
Two primary function
Digestion
Absorption of nutrients and water
Digestion
Mainly in duodenum – small intestine and
pancreatic enzymes
Bicarbonate from pancreas neutralizes acids
Mucous protects from acids
Bile emulsifies fats
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Mengunyah (mastication/chewing), berfungsi untuk :
Memecahkan & menghaluskan makanan memudahkan menelan
Mencampur makanan dgn saliva
Merangsang taste bud menikmati rasa makanan, salivasi; sekresi gaster, pankreas & empedu mempersiapkan tahap pencernaan selanjutnya
Fungsi Saliva :
salivary amylase
Mengandung lysozyme sebagai antibakteri.
Mengandung bikarbonat
Makanan sumber energi,diperlukan sel utk menghasilkan ATP. ATP perlu
utk kegiatan yg memerlukan energi : spt transport aktif, kontraksi, sintesis &
sekresi.
• Makanan juga berperan dalam:
a. sistem immune. b. sistem regulasi
c. regenerasi sel d. proses pertumbuhan & perkembangan
• Fungsi utama sistem pencernaan mentransfer nutrisi, air &elektrolit dari makanan ke dlm tbh dan berperan menjaga homeostasis.
food
Digested (GIT)
Biochemically Broken Down
Organic molecules
(smaller, simple)
Absorbed
(GIT)
cells
ECF
Circulatory system
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Control of Acid Secretion
May be considered as three separate phases.
1. Cephalic phase.
2. Gastric phase.
3. Intestinal phase.
1. CEPHALIC PHASE
Vagus nerve
Sight, smell or
thought of food
Parasympathetic activation
of gastric motility & gastric juice secretion
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2. GASTRIC PHASE
Food arrival causes
muscular reflexes &
gastrin secretion by G cells.
Gastrin
FOOD
GO
Gastrin stimulates secretion from both chief &
parietal cells.
3. INTESTINAL PHASE
Arrival of food in duodenum
triggers release of hormones
that inhibit gastric motility &
secretions.
Secretin &
Cholecystokinin (CCK)
Circulation
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Ggn. FUNGSI SALURAN CERNA DAN LOLOSNYA BAHAN2 GIZI KE
TINJA SERTA PENYEBABNYA.
PENYAKIT SISTEM SALURAN CERNA
GANGGUAN FUNGSI SALURAN CERNA
GANGGUAN FUNGSI PENCERNAAN
GANGGUAN FUNGSI ABSORBSI
LOLOS BAHAN GIZI KE TINJA (SINDROMA MALABSORBSI)
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Hormones & enzyme Important in
Small Intestine Digestive Activity
Secretin
Cholecyctokinin (CCK)
Enterokinase
Pancreatic enzymes
Lipase, Amylase, Peptidases, Trypsinogen, Trypsin
Hormones
Cholecystokinin – secretion stimulated by fat in
duodenum
Contraction of gall bladder
Pancreatic secretion of enzyme rich material
Secretin – secretion stimulated by low pH in
duodenum
Secretion of bile from the liver
Pancreatic secretion of HCO3- rich juice
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Digestive enzymes
Salivary amylase
Pepsin
Pancreatic enzymes:
Trypsin
Chymotrypsin
Carboxypeptidase
Nucleases
Pancreatic lipase
Pancreatic amylase
Intestinal enzymes:
Peptidases
Disaccharidases
Lipase
Nucleotidases
Digestion
Most occurs by hydrolysis reactions -
reactions that add water to break chemical
bonds
Enzymes involved:
amylase - breaks complex sugars to
disaccharides
lipases - breaks down lipids
proteases - breaks down proteins
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Small Intestine
Functions in digestion
CHO digestion resumes and is completed here
Protein digestion continues and completes here
Fat digestion is initiated and completed here
Also functions to absorb nutrients, fluids, and electrolytes
Divisions (@ 12 feet long total length)
duodenum = upper portion (@ 1 foot long) closest to
stomach
jejunum = middle section
ileum = lower section closest to large intestine
Small Intestine
Inner surface (epithelial layer) extensively folded
and covered with smaller folds (villi) and even
smaller folds (microvilli) increase surface area for
absorption to occur
Site of absorption of carbohydrates, lipids, amino
acids, calcium and iron in duodenum and jejunum
Bile salts, Vit B12, water, and electrolytes mainly in
ileum
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CHO Digestion in Small Intestine
Pancreatic amylase secreted into duodenum in
response to secretin
Is active in the intestine because the acidic chyme
is neutralized by HCO3- also secreted from
pancreas in response to secretin
Amylase converts complex CHOs to maltriose,
maltose, and short branched sugars
Fat Digestion in Small Intestine
Limited fat digestion occurs prior to sm. Intestine
Some lipases in saliva and gastric secretions
Lipase = enzyme important in fat digestion
Secreted into sm. intestine from pancreas in response to
secretin
breaks down triglycerides to free fatty acids and
monoglycerides
Activity is dependent upon the amount of surface area on
which it can work
Phospholipase A2 digests phospholipids
Bile is essential for proper fat digestion
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Digestion and Absorption of Lipids in
Small Intestine
Fats stimulate Intestine cell release of CCK
CCK triggers release of bile from gall bladder
Bile emulsifies fats
breaks large fat globules into smaller globules
does not actually break bonds between glycerol and
fatty acids
Increases surface area available for pancreatic
lipase to act
Protein Digestion in Small Intestine
Proteolytic enzymes are released (in inactive, zymogen
forms) from the pancreas in response to secretin
Trypsinogen = inactive precursor that is converted (by
enterokinase) to trypsin in the brush border of the
small intestine
Trypsin converts other zymogens to their active forms
Collectively, the proteolytic enzymes break proteins
and peptides into single amino acids, or di- and
tripeptides
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Penyebab gangguan Pencernaan :
1. Kelainan lambung (Reseksi lbg, Gastritis atrofi(HCl
menurun), Gastritis autoimmune, pernicious
anemia
2. Kelainan Pankreas : Insufisiensi pankreas, Cystic
fibrosis,
3. Penyakit parenkim hati,
4. Obstruksi saluran empedu,
5. Pertumbuhan bakteri berlebihan dalam usus halus.
6. Penyakit mukosa yang luas (celiac disease, Crohn
disease)
7. Infeksi, cacing, dll.
GANGGUAN PENCERNAAN
(MAL DIGESTION) :
Berkurangnya proses memecahkan makanan
( break down ↓ )
Berkurangnya proses hidrolisa bahan 2 gizi
(hidrolisis ↓)
Diare
Steatorrhoe
Penyulit (anemia, kemunduran tulang dll )
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Dr. Rustam Effendi YS, SpPD-KGEH
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