Chapter 23 Digestive System Video 1

Anatomy

greater omentum. -drapes over the transverse colon and anterior coils of the small intestine • contains many lymph nodes •The large amount of adipose tissue

Anatomy

-peritoneum contains large folds -five major peritoneal folds: •greater omentum •falciform ligament •lesser omentum •mesentery •mesocolon

Digestive System

Accessory digestive organs •Teeth, tongue, gallbladder(TTG) •Digestive glands(salivary glands)

Anatomy Overview

-peritoneum -it wraps around most abdominopelvic organs. visceral peritoneum forms the "serosa" of the alimentary canal covers other intra-abdominal organs. continues around the abdominal wall as the parietal peritoneum.

GI Tract Regulatory Mechanisms

1.Mechanoreceptors and chemoreceptors -Monitoring stretch of the digestive system -Osmolarity(conc of solutes in a fluid); as you consume food you increase osmolarity and pH is going to be altered -Detecting substrate (presences of proteins, changes in ph)- chemoreceptors -Presence of substrates- causing changes in ph, osmolarity and stretch -Initiate reflexes •digestive glands (secretion) •Stimulate smooth muscle to contract

GI Tract Regulatory Mechanisms

2.Intrinsic(inside) and extrinsic(outside) controls -Short reflexes - enteric(digestion) nerve plexus (network of nerves) -Long reflexes respond to stimuli inside or outside GI tract; •CNS centers and autonomic nerves -Hormones

Anatomy

Organs in the retroperitoneal space include: The kidneys and ureters Most of the pancreas The adrenal glands The aorta and inferior vena cava

Peristalsis

contractions of smooth muscles that provide the force that moves food through the esophagus toward the stomach

Anatomy

mesentery (of the small intestine) and mesocolon (of the large intestine) attach the bowel to the posterior abdominal wall, Keeps the intestines in place as muscular contractions occur

Segmentation

squeeze on both sides

Peritoneum and Peritoneal Cavity

•Mesentery - double layer of peritoneum -Routes for blood vessels, lymphatics, and nerves -Holds organs in place; stores fat •Intraperitoneal (peritoneal) organs surrounded by peritoneum - •Retroperitoneal(being behind) organs posterior to the peritoneum -Only partially covered by peritoneum

Peritoneum and Peritoneal Cavity

•Peritoneum - serous membrane of abdominal cavity -Visceral peritoneum - covering the organ -Parietal peritoneum - lining the cavity •Peritoneal cavity- subset of the abdominal pelvic cavity

Homeostatic Imbalance

•Peritonitis -Inflammation of peritoneum -Dangerous and lethal if widespread -Treated with debris removal and antibiotics

Digestive Processes

•Six essential activities 1.Ingestion- putting food in the body 2.Propulsion- moving food through the body via smooth muscles 3.Mechanical breakdown- making the food smaller 4.Digestion- break things down into smaller molecules using enzymes and acids 5.Absorption 6.Defecation- get rid of

Digestive System

•Two groups of organs 1. Alimentary canal (GI tract)- any part of the digestive system that directly touches food •Digests food and absorbs fragments •Mouth, •pharynx, •esophagus, •stomach, •small intestine and large intestine

Anatomy

•lesser omentum suspends the stomach and duodenum from the inferior edge of the liver. -forms a pathway for blood vessels to enter the liver, - contains the common bile duct.