Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 1
Capítulo 41Sistema Digestivo
Dr. Fernando J. Bird-Picó
Departamento de Biología
Recinto Universitario de Mayagüez
Bulk Feeders
Suspension Feeders and Filter Feeders
Fluid FeedersBaleen
FecesCaterpillar
SubstrateFeeders
Figure 41.6
Retículo
Esófago
OmasoAbomaso
Intestino
Rumen1 2
34
Figura 41.18
Rumiantes Termita y Trychonympha
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 2
Tractos digestivosde acuerdoa la dieta
Figure 41.17
Digestión Intracelular
Figure 41.7
Mouth
Tentacles
Food
Epidermis Gastrodermis
Food particlesengulfed anddigested
Foodparticles brokendown
Digestiveenzymes released1
2
3
Digestión Extracelular
Canales Alimentarios
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 3
Figure 41.20
Transport ofglucose intobody cellsand storageof glucoseas glycogen
Breakdownof glycogenand releaseof glucoseinto blood
Homeostasis:70–110 mg glucose/100 mL blood
Stimulus:Blood glucose
level dropsbelow set point.
Pancreassecretesglucagon.
Stimulus:Blood glucose
level risesafter eating.
Pancreassecretesinsulin.
Tipos de dentición y dietas asociadas a los mismos
Figure 41.9
Liver
Salivaryglands
Gall-bladder
Esophagus
Pharynx
Oral cavity
Sphincter
Mouth
Stomach
Esophagus
Tongue
Pancreas
SmallintestineLargeintestine
RectumAnus
SphincterStomach
Duodenum ofsmall intestine
Pancreas
Schematic diagramAnusRectum
Largeintestine
SmallintestineLiver
Salivaryglands
Gall-bladder
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 4
Tongue
Pharynx
Glottis
Larynx
Bolus offood
Epiglottisup
EsophagealsphinctercontractedEsophagus
To lungs To stomach
Trachea
Figure 41.10-1
Tongue
Pharynx
Glottis
Larynx
Bolus offood
Epiglottisup
EsophagealsphinctercontractedEsophagus
To lungs To stomach
Trachea
Figure 41.10-2
Tongue
Pharynx
Glottis
Larynx
Bolus offood
Epiglottisup
EsophagealsphinctercontractedEsophagus
To lungs To stomach Relaxedmuscles
Contractedmuscles
Sphincterrelaxed
Stomach
Trachea
Figure 41.10-3
Gastric gland
Gastric pits oninterior surface
of stomach
Sphincter
Smallintestine
Epithelium
Mucous cell
Chief cell
Parietal cell
Chiefcell
Pepsinogen
Parietalcell
Pepsin
Folds ofepithelialtissue
Sphincter
Esophagus
Stomach
3
2
1
10 µµ µµ
m
HCl
H++++Cl−−−−
Figure 41.11
Secreciónde jugogástrico
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 5
DuodenoFigure 41.12-1
Carbohydrate digestion
Polysaccharides
Salivary amylase
Smallerpolysaccharides
Maltose
Oral cavity,pharynx,esophagus
Digestión Enzimática
Figure 41.12-2
Protein digestion
Small polypeptides
ProteinsPepsin
Carbohydrate digestion
Polysaccharides
Salivary amylase
Smallerpolysaccharides
Maltose
Stomach
Oral cavity,pharynx,esophagus
Digestión EnzimáticaFigure 41.12-3
Fat digestionNucleic acid digestion
Protein digestion
Fat (triglycerides)DNA, RNA
Nucleotides
Pancreaticnucleases
Pancreatic lipase
Glycerol, fatty acids,monoglyceridesSmall peptides
Pancreatic carboxypeptidase
Smallerpolypeptides
Pancreatic trypsin andchymotrypsin
Small polypeptides
ProteinsPepsin
Carbohydrate digestion
Polysaccharides
Salivary amylase
Smallerpolysaccharides
Maltose
Pancreatic amylases
Disaccharides
Smallintestine(enzymesfrompancreas)
Stomach
Oral cavity,pharynx,esophagus
Digestión Enzimática
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 6
Fat digestionNucleic acid digestion
Protein digestion
Fat (triglycerides)DNA, RNA
Nucleotides
Pancreaticnucleases
Pancreatic lipase
Glycerol, fatty acids,monoglycerides
Nucleotidases
Nucleosides
Nucleosidasesandphosphatases
Nitrogenous bases,sugars, phosphatesAmino acids
Dipeptidases, carboxy-peptidase, andaminopeptidase
Small peptides
Pancreatic carboxypeptidase
Smallerpolypeptides
Pancreatic trypsin andchymotrypsin
Small polypeptides
Proteins
Pepsin
Carbohydrate digestion
Polysaccharides Disaccharides
Salivary amylase
Smallerpolysaccharides
Maltose
Pancreatic amylases
Disaccharides
Disaccharidases
Monosaccharides
Smallintestine(enzymesfromepithelium)
Smallintestine(enzymesfrompancreas)
Stomach
Oral cavity,pharynx,esophagus
Figure 41.12-4
Digestión Enzimática
Digestión de
Proteínas
Figure 41.13
Vein carryingblood to liver
Muscle layers
Bloodcapillaries
Villi
Intestinal wall
Epithelialcells
Largecircularfolds
Key
Nutrientabsorption
VilliMicrovilli (brushborder) at apical(lumenal) surface
Epithelialcells
Lumen
Basalsurface
Lacteal
Lymphvessel
Vellosidades y microvellosidades
Figure 41.14LUMENOF SMALLINTESTINE
Triglycerides
Epithelialcell Fatty acids
Mono-glycerides
Triglycerides
Chylomicron
Phospho-lipids,
cholesterol,and proteins
Lacteal
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 7
• Bolo alimenticio: presiona pared estomacal: gastrina promueve secreción de jugo gástico
Figure 41.19a
• Acidez del quimo y presencia de amino ácidos y grasas: estimula duodeno. Secreción de colecistocinina(CCK) y secretina.
Figure 41.19b
• Si el quimo es rico en grasas, la CCK y secretina inhiben la peristalsis y secreción de jugo gástico en estómago: digestión más lenta
Secretinand CCK
Gastricjuices
3
KeyStimulationInhibition
++++−−−−
−−−−• Grelina: estimula apetito
• Leptina: producida en tejido adiposo; suprime apetito
• Péptido YY: producido en intestino delgado: suprime apetito, motilidad gástrica y secreción pancreática; aumenta absorción de agua y electrolitos en el cólon.
Apetito, hormonas y centro de saciedad
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 8
EXPERIMENT
Obese mouse with mutantob gene (left) next to wild-typemouse
RESULTSGenotype pairing
(red type indicatesmutant genes)
Average changein body mass (g)
of subject
8.3
38.7
8.2
−−−−14.9*
Paired with
ob++++ob++++ , db++++db++++ ob++++ob++++ , db++++db++++
ob ob, db++++db++++ ob ob, db++++db++++
ob ob, db++++db++++ ob++++ob++++, db++++db++++
ob ob, db++++db++++ ob++++ob++++, db db
Subject
*Due to pronounced weight loss and weakening, subje cts in this pairing werereweighed after less than eight weeks.
Figure 41.22
Leptina y obesidad Intestino grueso
Table 41.1
Biol 3052 - Sistema Digestivo 18/04/2016
Dr. Fernando J. Bird-Picó - 2016 9
Table 41.2
Minerales
Figure 41.UN01
Veins to heart
Mouth StomachEsophagus
Lymphatic system
Lipids
Absorbed food(except lipids)
Hepatic portal vein
Absorbedwater
Liver
Secretionsfrom salivaryglands
Secretionsfrom gastricglands
Small intestineSecretions from liver
Secretions from pancreasRectum
Anus
Largeintestine