Physiology- Digestion Part 1

Digestive system

What body system has functions of ingestion, mechanical processing, digestion, secretion, absorption, and excretion

GI tract

What are these organs a part of: Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

Accessory organs

What are these organs a part of: Teeth, tongue, glandular organs, salivary, liver, and pancreas

Monogastric

Animals that contain a single, true stomach

Ruminants

Animals that have multiple compartments to their stomach, with a large fermentative compartment called the rumen

Mucosa, submucosa, muscularis externa, serosa

What are the four major layers of the GI tract wall?

Digestive epithelium

Part of the mucosa, stratified squamous epithelium and simple columnar epithelium

Lamina propria

Part of mucosa, layer of areolar tissue, contains blood vessels, nerve endings, etc.

Rugae

Longitudinal folds in the mucosa, that disappear as tract fills

Plicae

Circular folds of the mucosa, permanent transverse folds

Mucosa

What layer of digestive tract has rugae, plicae, villi, and microvilli for absorption

Submucosa

Layer of dense irregular connective tissue that surrounds muscularis, contains large blood and lymphatic vessels

Muscularis externa

Layer of smooth muscle cells with an inner and outer layer, has essential role in mechanical processing and movement

Serosa

Layer of the digestive tract that is a serous membrane

Peristalsis

Circular muscle contracts, wavelike movement, propel digestive tract contents

Segmentation

Periodic circular muscle contractions, occur in adjacent sites, mixes digestive tract contents

Short reflexes

Part of neural mechanism with sensory, interneurons, and motor neurons on myenteric plexus, helps local peristalsis

Long reflexes

Part of neural mechanism, involves interneurons and motor neurons, controls large-scale peristaltic waves

Hormonal mechanism

Part of the digestive tract with 18 hormones, affects every aspect of digestive function

Local mechanisms

Part of digestive tract, has local factors that affect adjacent cells within a small segment of the tract

Oral cavity

What part of GI tract analyzes food, mechanical, lubrication, and initiates digestion of carbs and lipids

Salivary glands

Which part of GI tract, has three pairs of glands that act as a lubricant

Parotid glands

Salivary gland that is the largest, produces watery saliva containing amylase

Submandibular glands

Part of salivary glands that secretes a mixture of buffers, glycoproteins, and amylase

Sublingual glands

Part of salivary glands that is the smallest, produces a watery, mucous secretion that acts as a buffer, lubricant, lingual lipase

Monogastric stomach

Which organ functions are bulk storage of ingested food, mechanical breakdown, disruption of chemical bonds

Chyme

Ingested food + secretions of stomach, highly acidic

Cardia

Region of stomach, opening from the esophagus

Fundus

Region of stomach, distensible blind pouch

Body

Region of stomach, central portion of the stomach

Pyloric antrum

Region of stomach, lower part of the stomach

Pylorus

Region of stomach, muscular sphincter that guards exit