dr. fernando j. bird-picó departamento de biología recinto ...academic.uprm.edu/~fbird/biol...

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



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



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



Tongue

Pharynx

Glottis

Larynx

Bolus offood

Epiglottisup

EsophagealsphinctercontractedEsophagus

To lungs To stomach

Trachea

Figure 41.10-1

Tongue

Pharynx

Glottis

Larynx

Bolus offood

Epiglottisup


To lungs To stomach

Trachea

Figure 41.10-2

Tongue

Pharynx

Glottis

Larynx

Bolus offood

Epiglottisup


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



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


Polysaccharides

Salivary amylase


Maltose

Stomach


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


Polysaccharides

Salivary amylase


Maltose

Pancreatic amylases

Disaccharides

Smallintestine(enzymesfrompancreas)

Stomach





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


Polysaccharides Disaccharides

Salivary amylase


Maltose

Pancreatic amylases

Disaccharides

Disaccharidases

Monosaccharides

Smallintestine(enzymesfromepithelium)

Smallintestine(enzymesfrompancreas)

Stomach


Figure 41.12-4


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



• 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



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



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

dr. fernando j. bird-picó departamento de biología recinto ...academic.uprm.edu/~fbird/biol...

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