Regulation of Digestion and Feeding

Flashcards about digestion regulation, including nervous and endocrine systems, cells of the stomach, and phases of digestion.

Autonomic Nervous System

Branch of the nervous system that controls the viscera, with input from the digestive tract to centers in the hypothalamus and medulla.

Sympathetic Motor Neurons

Decreased secretions and motility are expected.

Parasympathetic Motor Neurons

Increased secretions and motility are expected.

Enteric Nervous System

A nerve network within the wall of the gastrointestinal tract that functions independently from the central nervous system.

G Cells

Located in the gastric glands, these cells secrete gastrin.

Gastrin

Promotes activity of the mucosa and muscularis, and closes the lower esophageal and pyloric sphincters.

Secretin and Cholecystokinin

Target cells include the pancreas, hepatocytes, gallbladder, and gastric mucosa cells.

Cephalic Phase

Digestive tract activities that occur before food enters the digestive tract.

Parietal Cells

Secrete protons (hydrogen ions) that come from hydrochloric acid

Chief Cells

Secrete pepsinogen, which quickly becomes pepsin in the acidic environment.

Gastric Phase

Begins when food enters the stomach, triggering distension and the entry of nutrient molecules.

Intestinal Phase

Begins when food enters the duodenum, triggering decreased motor commands to the stomach and increased motor commands to the small intestine.

Central Nervous System

Affects energy balance, body weight, and feeding behaviors; influenced by hormones, chemicals from muscle and adipose tissue, and neural inputs.

Hypothalamic Nuclei

Nuclei that receive input from the higher brain, emotional brain, hormonal input, and sensory input from the GI tract.

Leptin

Released predominantly by adipocytes based on triglyceride storage; influences food intake and energy expenditure.

Ghrelin

Associated with the initiation of feeding; levels drop following a meal and rise as the digestive tract empties.

Satiety

The point when you stop eating because you feel satisfied.

Cholecystokinin (CCK)

Stimulates the pancreas, liver, and gallbladder, and also contributes to the feeling of satisfaction, leading to the termination of a feeding session.