Absorption Assimilation Ingestion Mouth Pharynx Receiving Foregut Crop Conducting Storage Digestion Motility Midgut (stomach) Digestion (acidic) Secretions Hindgut Digestion (basic) Absorption Assimilation Storage of waste Defecation 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 Other inputs Salivary center in medulla Conditioned reflex + + Pressure receptors and chemoreceptors in mouth Autonomic nerves Simple reflex + Salivary glands Salivary secretion Fig. 14-6, p.622

Fig. 14-7, p.624

Esophagus Fundus Smooth muscle Gastroesophageal sphincter Body Stomach folds Pyloric sphincter Oxyntic mucosa Pyloric gland area Antrum Duodenum Fig. 14-8, p.627

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

Bile duct from liver Stomach Duodenum Hormones (insulin, glucagon) Blood Duct cells secrete aqueous NaHCO3 solution Acinar cells secrete digestive enzymes Endocrine portion of pancreas (islets of Langerhans) Exocrine portion of pancreas (acinar and duct cells) The glandular portions of the pancreas are grossly exaggerated. Fig. 14-12, p.638

+ Acid in duodenal lumen Fat and protein products in duodenal lumen Neutralizes Digests Secretin release from duodenal mucosa CCK release + (secretin carried by blood) (CCK carried by blood) Pancreatic duct cells Pancreatic acinar Secretion of aqueous NaHCO3 solution into duodenal lumen Secretion of pancreatic digestive enzymes into Fig. 14-13, p.640

Figure 14–14 Schematic representation of liver blood flow (mammal). Fig. 14-14, p.641

Figure 14–15 Anatomy of the mammalian liver. (a) Hepatic lobule Figure 14–15 Anatomy of the mammalian liver. (a) Hepatic lobule. (b) Wedge of a hepatic lobule. Fig. 14-15, p.642

Fig. 14-16, p.642

Lipid-soluble portion (derived from cholesterol) Negatively charged H2O-soluble portion (a carboxyl group at the end of a glycine or taurine chain) Small lipid (fat) droplet with bile salt molecules adsorbed on its surface Large fat droplet Through action of bile salts Lipid emulsion 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

External anal sphincter (skeletal muscle) Internal anal sphincter Transverse colon Haustra Taeniae coli Descending colon Ascending colon Ileocecal valve Figure 14–26 Anatomy of the large intestine (mammal, shown for a human). Appendix Sigmoid colon Cecum Rectum External anal sphincter (skeletal muscle) Internal anal sphincter (smooth muscle) Anal canal Fig. 14-26, p.657

Rumen Reticulum Omasum Abomasum To small intestine (b) Fig. 14-27b, p.661