View
84
Download
2
Category
Tags:
Preview:
DESCRIPTION
Human Digestion. Human digestion (General plan). Organs of the GI tract. Accessory digestive organs. Chemical digestion is aided by enzymes. Protein digestion. Fat digestion. Nucleic acid digestion. Carbohydrate digestion. Oral cavity, pharynx, esophagus. Polysaccharides - PowerPoint PPT Presentation
Citation preview
Accessory digestive organs
Organs of the GI tract
Oral cavity,pharynx,esophagus
Carbohydrate digestion
Polysaccharides(starch, glycogen)
Disaccharides(sucrose, lactose)
Salivary amylase
Smaller polysaccharides,maltose
Stomach
Protein digestion Nucleic acid digestion Fat digestion
ProteinsPepsin
Small polypeptides
Lumen of small intes-tine
Polysaccharides
Pancreatic amylases
Maltose and otherdisaccharides
Epitheliumof smallintestine(brushborder)
Disaccharidases
Monosaccharides
Polypeptides
Pancreatic trypsin and chymotrypsin (These proteases cleave bonds adjacent to certain amino acids.)
Smallerpolypeptides
Pancreatic carboxypeptidase
Amino acids
Small peptides
Dipeptidases, carboxypeptidase, and aminopeptidase (These proteases split off one amino acid at a time, working from opposite ends of a polypeptide.)
Amino acids
DNA, RNA
Pancreaticnucleases
Nucleotides
Nucleotidases
NucleosidesNucleosidasesandphosphatases
Nitrogenous bases,sugars, phosphates
Fat globules (Insoluble inwater, fats aggregate asglobules.)
Bile salts
Fat droplets (A coating ofbile salts prevents small drop-lets from coalescing intolarger globules, increasingexposure to lipase.)
Pancreatic lipase
Glycerol, fattyacids, glycerides
Chewing, peristalsis
Churning, mixing
Peristalsis, mixing
Large intestine Resident bacteria in the colon digest material in chyme.
Vitamin-K and some B-complex vitamins are released by these bacteria.
Composition of the adult human body
Oral cavity,pharynx,esophagus
Carbohydrate digestion
Polysaccharides(starch, glycogen)
Disaccharides(sucrose, lactose)
Salivary amylase
Smaller polysaccharides,maltose
Stomach
Protein digestion Nucleic acid digestion Fat digestion
ProteinsPepsin
Small polypeptides
Lumen of small intes-tine
Polysaccharides
Pancreatic amylases
Maltose and otherdisaccharides
Epitheliumof smallintestine(brushborder)
Disaccharidases
Monosaccharides
Polypeptides
Pancreatic trypsin and chymotrypsin (These proteases cleave bonds adjacent to certain amino acids.)
Smallerpolypeptides
Pancreatic carboxypeptidase
Amino acids
Small peptides
Dipeptidases, carboxypeptidase, and aminopeptidase (These proteases split off one amino acid at a time, working from opposite ends of a polypeptide.)
Amino acids
DNA, RNA
Pancreaticnucleases
Nucleotides
Nucleotidases
NucleosidesNucleosidasesandphosphatases
Nitrogenous bases,sugars, phosphates
Fat globules (Insoluble inwater, fats aggregate asglobules.)
Bile salts
Fat droplets (A coating ofbile salts prevents small drop-lets from coalescing intolarger globules, increasingexposure to lipase.)
Pancreatic lipase
Glycerol, fattyacids, glycerides
Chewing, peristalsis
Churning, mixing
Peristalsis, mixing
Large intestine Resident bacteria in the colon digest material in chyme.
Vitamin-K and some B-complex vitamins are released by these bacteria.
Salivary glands◦ Produce saliva
Mostly water Some enzymes
Salivary amylase Lysozyme
Mucus or mucin
Teeth◦ Mechanical digestion◦ Different teeth
Different functions Fit omnivore diet
Tongue
Swallowing: from mouth to stomach
Oral cavity,pharynx,esophagus
Carbohydrate digestion
Polysaccharides(starch, glycogen)
Disaccharides(sucrose, lactose)
Salivary amylase
Smaller polysaccharides,maltose
Stomach
Protein digestion Nucleic acid digestion Fat digestion
ProteinsPepsin
Small polypeptides
Lumen of small intes-tine
Polysaccharides
Pancreatic amylases
Maltose and otherdisaccharides
Epitheliumof smallintestine(brushborder)
Disaccharidases
Monosaccharides
Polypeptides
Pancreatic trypsin and chymotrypsin (These proteases cleave bonds adjacent to certain amino acids.)
Smallerpolypeptides
Pancreatic carboxypeptidase
Amino acids
Small peptides
Dipeptidases, carboxypeptidase, and aminopeptidase (These proteases split off one amino acid at a time, working from opposite ends of a polypeptide.)
Amino acids
DNA, RNA
Pancreaticnucleases
Nucleotides
Nucleotidases
NucleosidesNucleosidasesandphosphatases
Nitrogenous bases,sugars, phosphates
Fat globules (Insoluble inwater, fats aggregate asglobules.)
Bile salts
Fat droplets (A coating ofbile salts prevents small drop-lets from coalescing intolarger globules, increasingexposure to lipase.)
Pancreatic lipase
Glycerol, fattyacids, glycerides
Chewing, peristalsis
Churning, mixing
Peristalsis, mixing
Large intestine Resident bacteria in the colon digest material in chyme.
Vitamin-K and some B-complex vitamins are released by these bacteria.
Muscular sac◦ Churns & mixes food
Gastric glands◦ Parietal cells HCl,
intrinsic factor◦ Goblet cells mucus◦ Chief cells
pepsinogen, weak gastric lipase
◦ Gastrin Hormone Controls gastric juices
Comes out as chyme (2-6 hours)
Pepsin (active enzyme)
HCl
Parietal cellChief cell
Stomach
Folds of epithelial tissue
Esophagus
Pyloric sphincter
Epithelium
Pepsinogen
3
2
1
Interior surface of stomach.- Highly folded - Dotted with pits
Gastric gland. -Secrete gastric juice-Three types of cells
Mucus cells
Chief cells- Pepsinogen
Parietal cells - Secrete HCl
1 Pepsinogen and HCI secreted into lumen
2 HCl convertspepsinogen to pepsin
3 Pepsin activatesmore pepsinogen
5 µ
m
Small intestine
Cardiac orifice
Liver Secretes bile (stored in gall bladder) Components: Bile
salts & bile pigments
Emulsifies fats
Gallbladder Stores, concentrates,
and releases bile into duodenum
Cystic duct + hepatic duct = common bile duct
Stimulated by the hormone cholecystokinin (CCK)
Exocrine function Acinar cells secrete
pancreatic juice◦ Amylase◦ Lipase◦ Trypsin◦ Chymotrypsin◦ Carboxypeptidase◦ Nuclease◦ NaHCO3
-
Secretin and cholecystokinin (CCK) fr intestinal wall stimulates PJ production
Oral cavity,pharynx,esophagus
Carbohydrate digestion
Polysaccharides(starch, glycogen)
Disaccharides(sucrose, lactose)
Salivary amylase
Smaller polysaccharides,maltose
Stomach
Protein digestion Nucleic acid digestion Fat digestion
ProteinsPepsin
Small polypeptides
Lumen of small intes-tine
Polysaccharides
Pancreatic amylases
Maltose and otherdisaccharides
Epitheliumof smallintestine(brushborder)
Disaccharidases
Monosaccharides
Polypeptides
Pancreatic trypsin and chymotrypsin (These proteases cleave bonds adjacent to certain amino acids.)
Smallerpolypeptides
Pancreatic carboxypeptidase
Amino acids
Small peptides
Dipeptidases, carboxypeptidase, and aminopeptidase (These proteases split off one amino acid at a time, working from opposite ends of a polypeptide.)
Amino acids
DNA, RNA
Pancreaticnucleases
Nucleotides
Nucleotidases
NucleosidesNucleosidasesandphosphatases
Nitrogenous bases,sugars, phosphates
Fat globules (Insoluble inwater, fats aggregate asglobules.)
Bile salts
Fat droplets (A coating ofbile salts prevents small drop-lets from coalescing intolarger globules, increasingexposure to lipase.)
Pancreatic lipase
Glycerol, fattyacids, glycerides
Chewing, peristalsis
Churning, mixing
Peristalsis, mixing
Large intestine Resident bacteria in the colon digest material in chyme.
Vitamin-K and some B-complex vitamins are released by these bacteria.
Enteropeptidase
Completes digestion of nutrients in chyme
Absorbs products of digestion
Receives enzymes from pancreas and gall bladder
Lumen, villi, lacteal, microvilli, intestinal glands
Watery fluid, digestive enzymes on microvilli: disaccharidase, dipeptidase, nucleotidases
25 cm
1-2 m
2 m
Liver
Bile
Acid chyme
Stomach
Pancreatic juice
Pancreas
Intestinaljuice
Duodenum of small intestine
Gall-bladder
Oral cavity,pharynx,esophagus
Carbohydrate digestion
Polysaccharides(starch, glycogen)
Disaccharides(sucrose, lactose)
Salivary amylase
Smaller polysaccharides,maltose
Stomach
Protein digestion Nucleic acid digestion Fat digestion
ProteinsPepsin
Small polypeptides
Lumen of small intes-tine
Polysaccharides
Pancreatic amylases
Maltose and otherdisaccharides
Epitheliumof smallintestine(brushborder)
Disaccharidases
Monosaccharides
Polypeptides
Pancreatic trypsin and chymotrypsin (These proteases cleave bonds adjacent to certain amino acids.)
Smallerpolypeptides
Pancreatic carboxypeptidase
Amino acids
Small peptides
Dipeptidases, carboxypeptidase, and aminopeptidase (These proteases split off one amino acid at a time, working from opposite ends of a polypeptide.)
Amino acids
DNA, RNA
Pancreaticnucleases
Nucleotides
Nucleotidases
NucleosidesNucleosidasesandphosphatases
Nitrogenous bases,sugars, phosphates
Fat globules (Insoluble inwater, fats aggregate asglobules.)
Bile salts
Fat droplets (A coating ofbile salts prevents small drop-lets from coalescing intolarger globules, increasingexposure to lipase.)
Pancreatic lipase
Glycerol, fattyacids, glycerides
Chewing, peristalsis
Churning, mixing
Peristalsis, mixing
Large intestine Resident bacteria in the colon digest material in chyme.
Vitamin-K and some B-complex vitamins are released by these bacteria.
Areas of Colon◦ Cecum ◦ Rectum ◦ Terminates at anus
Absorption of water and electrolytes
Concentration & elimination of solids
Home for bacteria that produce biotin, folic acid, vitamin K, several B-vitamins, gases
Name Source Stimulant Target Organ Function
Stomach GastrinPyloric mucosa
Partially-digested food
Gastric glandsSecretion of gastric juice
Intestinal Gastrin
Intestinal mucosa
Stomach
SecretinAcidity of
chymePancreas and
liverSecretion of PJ rich in
HCO3- and bile production
Cholecystokinin (CCK)
Fats or combination of acids and
fats
Pancreas and gallbladder
(Sphincter of Oddi in CBD)
Secretion of PJ, bile from gallbladder, opening of
SO
EnterocrininAcidity of
chymeDuodenum
Secretion of intestinal juice
Enterogastrone or Gastric Inhibitory
Peptide (GIP)
Fats StomachInhibits secretion of
gastric juice and decreases gastric motility
Liver
Gall-bladder
CCK
Entero-gastrone
Gastrin
Stomach
Pancreas
Secretin
CCK
Duodenum
Key
Stimulation
Inhibition
Recommended