absorption assimilation
DESCRIPTION
Four basic digestive processes Motility: muscular contractions within gut tube that mix and move forward the contents of the digestive tract Secretion: secretion of mucus, water, electrolytes, enzymes, Digestion: broken down structurally complex foodstuffes into smaller, absorbable units Absorption: transfer absorbable units from digestive tract lumen into the blood or hemolymph or body cavity.TRANSCRIPT
Motility
Storage of wasteDefecation
Secretions
IngestionMouthPharynx Receiving
Foregut
Crop
ConductingStorageDigestion
Midgut (stomach)Digestion (acidic)
Hindgut
Digestion (basic)Absorption
Assimilation
Fig. 14-1, p.613
Four basic digestive processes• Motility: muscular contractions within gut tube that
mix and move forward the contents of the digestive tract
• Secretion: secretion of mucus, water, electrolytes, enzymes,
• Digestion: broken down structurally complex foodstuffes into smaller, absorbable units
• Absorption: transfer absorbable units from digestive tract lumen into the blood or hemolymph or body cavity.
Fig. 14-2b, p.615
Fig. 14-2a, p.615
Table 14-1, p.616
Fig. 14-4, p.618
Cerebral cortex
Salivary centerin medulla
Autonomic nerves
Salivary glands
Other inputs
Salivary secretion
Pressure receptorsand chemoreceptors
in mouth
Conditioned reflex
+
+
Simplereflex
+
+
+
Fig. 14-6, p.622
Fig. 14-7, p.624
Fig. 14-8, p.627Duodenum
Smoothmuscle
FundusEsophagus
Gastroesophagealsphincter
Body
Stomachfolds
Oxynticmucosa
AntrumPyloricglandarea
Pyloricsphincter
Three main function of stomach• Store ingested food• Chemical digestion with HCl and enzymes• Produce chyme (a thick, liquid mixture)
Fig. 14-9, p.629
Table 14-2, p.629
Table 14-3, p.632
Fig. 14-10, p.633
Fig. 14-11, p.634
Table 14-4, p.635
p.636
Table 14-5, p.636
Fig. 14-12, p.638
Stomach
Blood
Hormones(insulin,glucagon)
The glandular portions ofthe pancreas are grosslyexaggerated.
Endocrine portionof pancreas(islets of Langerhans)
Exocrine portion of pancreas(acinar and duct cells)
Acinar cellssecrete digestiveenzymes
Duct cellssecrete aqueousNaHCO3 solution
Duodenum
Bile ductfrom liver
Acid induodenal
lumen
Fat and proteinproducts in
duodenal lumen
Secretin releasefrom duodenal
mucosa
CCK releasefrom duodenal
mucosa
Secretion of aqueousNaHCO3 solution into
duodenal lumen
Secretion ofpancreatic digestive
enzymes intoduodenal lumen
Pancreatic ductcells
Pancreatic acinarcells
(secretin carriedby blood)
(CCK carriedby blood)
Neutralizes Digests
+ +
Fig. 14-13, p.640
Fig. 14-14, p.641
Fig. 14-15, p.642
Fig. 14-16, p.642
Large fat droplet
Lipid emulsion
Small lipid (fat) droplet with bile salt moleculesadsorbed on its surface
Lipid-soluble portion(derived from cholesterol)
Negatively charged H2O-soluble portion (a carboxyl group at the end of a glycineor taurine chain)
Through action of bile salts
Fig. 14-17, p.644
Fig. 14-18, p.645
Fig. 14-19, p.646
Fig. 14-20, p.647
Table 14-6, p.649
Fig. 14-22, p.652
Fig. 14-23, p.653
Fig. 14-24, p.654
Table 14-7, p.655
Fig. 14-26, p.657
Transverse colon
Internal anal sphincter(smooth muscle)
Taeniae coli
Ileocecal valve
Ascending colon
RectumCecum Appendix
Anal canal
External anal sphincter(skeletal muscle)
Sigmoid colon
Descending colon
Haustra
Fig. 14-27b, p.661
Reticulum
(b)
To smallintestine
Rumen
Abomasum
Omasum