Digestive System Flashcards

Functions of the Digestive System

• Digestion and absorption are the two primary functions of the digestive system.

Composition of the Digestive System

• Main components include mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

Accessory Organs

• Accessory organs outside the digestive tract include teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

GI Tract and Protection

• The GI tract protects the body from infection by absorbing essential nutrients, electrolytes, vitamins, and excreting waste.

Enteric Neurons

• Known as the "little brain," enteric neurons enable reflex actions, such as peristalsis, to facilitate movement of contents.

Interstitial Cells of Cajal

• These cells act as pacemakers, regulating the frequency and strength of muscle contractions in the GI tract.

Role of Salivary Glands

• Salivary glands produce saliva, which moistens the mouth, aids in carbohydrate breakdown, and lubricates food for swallowing.

Pancreas Functions

• The pancreas serves both endocrine (releasing hormones into the bloodstream) and exocrine (secreting digestive juices) functions to aid food digestion.

Bile Duct and Liver

• Bile duct carries bile from the gallbladder to the duodenum, while the liver processes nutrients and secretes bile crucial for fat digestion.

Structure of the Large Intestine

• Major function is absorbing water and transmitting waste. Taenia coli contracts to form haustra, which give the colon its segmented appearance.

Small Intestine Anatomy

• Divided into three segments: duodenum, jejunum, and ileum, where 90% of digestion and absorption takes place.

Special Features of the Small Intestine

• Circular folds (plicae) and finger-like projections (villi and microvilli) increase surface area for optimal nutrient absorption.

Disorders of the Digestive System

• Conditions like dyspepsia (indigestion), irritable bowel syndrome, and peptic ulcers affect digestive health and functionality.

Enteric Nervous System

• Functions independently of the central nervous system and is influenced by both parasympathetic and sympathetic branches.

Autonomic Nervous System Influence

• Parasympathetic stimulation increases GI motility and secretions, while sympathetic stimulation inhibits these actions.

Key Sphincters in the Digestive System

• The lower esophageal sphincter controls entry into the stomach, while the ileocecal valve regulates flow into the large intestine.

Gastric Structures and Secretions

• Unique cells in the stomach include parietal (HCl secretion), chief (pepsinogen), and G cells (gastrin production) for digestion.

Absorption of Nutrients

• Jejunum absorbs small nutrient particles; ileum focuses on vitamin B12 and bile salt absorption, enhancing overall nutrient intake.

Rectum and Anus Functions

• The rectum serves as a temporary storage site for feces, with internal and external anal sphincters regulating waste elimination.

Specialized Cells in the GI Tract

• Chief cells (secreting pepsinogen) and mucus-secreting cells are crucial for maintaining the digestive environment in the stomach.

Mesentery

• Structure attaching the large intestine to the posterior abdominal wall, providing support and vascular supply.

Acute Inflammation

• Peritonitis refers to the acute inflammation of the serous membrane lining the abdominal cavity and covering viscera.

Key Terms for Understanding

• Define dysphagia (difficulty swallowing), nausea (sickness with vomiting inclination), and anorexia (eating disorder focused on weight).

Test your knowledge on the functions and components of the digestive system with this comprehensive set of flashcards. Learn about the key organs and accessory structures involved in digestion and absorption. Perfect for biology students and anyone interested in human anatomy.