UNT Test 4 Ch 23 ppt A
Basic Concepts of Regulating Digestive Activity: Digestive activity is provoked by a range of mechanical and chemical stimuli: Receptors located in walls of what?
GI tract organs
Digestive Processes: Mechanical breakdown: ______: local constriction of intestine that mixes food with digestive juices
Segmentation
Splanchnic circulation includes: Arteries that branch off aorta to serve digestive organs. Name these arteries:
Hepatic, splenic, and left gastric arteries Inferior and superior mesenteric arteries
Relationship of Digestive Organs to Peritoneum: Mesentery: does what?
Holds organs in place and also stores fat
Relationship of Digestive Organs to Peritoneum: Peritoneum: _____ _____: membrane that lines body wall
Parietal peritoneum
Digestive Processes: Propulsion: _____: major means of propulsion of food that involves alternating waves of contraction and relaxation
Peristalsis
____ ____: Fluid-filled space between two peritoneums
Peritoneal cavity
______: serous membranes of abdominal cavity
Peritoneum
_____: Inflammation of peritoneum
Peritonitis
Histology of the Alimentary Canal: ____: Consists of areolar connective tissue
Submucosa
Enteric nervous system: ____ nerve plexus: Regulates glands and smooth muscle in mucosa.
Submucosal
Enteric Nervous System: Enteric neurons make up bulk of two main interconnecting intrinsic nerve plexuses. Name them.
Submucosal nerve plexus Myenteric nerve plexus
Digestive Processes: Propulsion: movement of food through the alimentary canal, which includes: Swallowing Peristalsis
Swallowing Peristalsis
Enteric nervous system: Long reflexes: ____ system inhibits digestion
Sympathetic
Watch Video: Why This Matters
Watch Video: Why This Matters
Splanchnic circulation includes: Arteries that branch off:
aorta to serve digestive organs
Relationship of Digestive Organs to Peritoneum: Mesentery: Provides routes for:
blood vessels, lymphatics, and nerves
Relationship of Digestive Organs to Peritoneum: Mesentery: Extends from ____ ____ to digestive organs
body wall
Histology of the Alimentary Canal: Lamina propria: Rich supply of ____ located here
capillaries
Peritonitis Treatment:
debris removal and megadoses of antibiotics
Histology of the Alimentary Canal: Lamina propria: Also contains lymphoid follicles that help:
defend against microorganisms
Peritoneal cavity: Fluid lubricates ____ organs
mobile
Histology of the Alimentary Canal: Submucosa: Has abundant amount of elastic tissues that help organs to:
regain shape after storing large meal
Organs of the digestive system: Alimentary canal (gastrointestinal or GI tract or gut) Organs:
mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
Epithelium: Secretes ____.
mucus.
Histology of the Alimentary Canal: Lamina propria: Rich supply of capillaries located here. Needed for ___ and ____
nourishment and absorption
Relationship of Digestive Organs to Peritoneum: Retroperitoneal organs: Includes most of:
pancreas, duodenum, and parts of large intestine
Peritonitis: Can be caused by:
piercing abdominal wound, perforating ulcer, or ruptured appendix
Histology of the Alimentary Canal: Muscular externa: Muscle layer responsible for ___ and _____
segmentation and peristalsis
Enteric nervous system participates in both:
short and long reflex arcs
Organs of the digestive system fall into two groups:
1. Alimentary canal (gastrointestinal or GI tract or gut) 2. Accessory digestive organs
Three key concepts regulate GI activity:
1. Digestive activity is provoked by a range of mechanical and chemical stimuli 2. Effectors of digestive activity are smooth muscle and glands 3. Neurons (intrinsic and extrinsic) and hormones control digestive activity
Digestive Processes: Which process of the 6 essential activities involves: ______: eating.
1. Ingestion
Digestive Processes: Processing of food involves six essential activities:
1. Ingestion 2. Propulsion 3. Mechanical breakdown 4. Digestion 5. Absorption 6. Defecation
Mucosa: Functions: different layers perform one or all the listed functions:
1. Secretes mucus, digestive enzymes, and hormones 2. Absorbs end products of digestion 3. Protects against infectious disease
Digestive Processes: Which process of the 6 essential activities involves: _____: movement of food through the alimentary canal.
2. Propulsion
Digestive Processes: Which process of the 6 essential activities involves: ____ _____: includes chewing, mixing food with saliva, churning food in stomach, and segmentation.
3. Mechanical breakdown
Digestive Processes: Which process of the 6 essential activities involves: ______: series of catabolic steps that involves enzymes that break down complex food molecules into chemical building blocks.
4. Digestion
Digestive Processes: Which process of the 6 essential activities involves: _____: passage of digested fragments from lumen of GI tract into blood or lymph.
5. Absorption
Digestive Processes: Which process of the 6 essential activities involves: _____: elimination of indigestible substances via anus in form of feces.
6. Defecation
Organs of the digestive system: ___ ____: Continuous muscular tube that runs from the mouth to anus
Alimentary canal (gastrointestinal or GI tract or gut)
Histology of the Alimentary Canal: Submucosa: Contains what?
Contains blood and lymphatic vessels, lymphoid follicles, and submucosal nerve plexus that supply surrounding GI tract tissues
Splanchnic circulation includes: Hepatic portal circulation does what?
Delivers blood to liver for processing
Organs of the digestive system: ____ glands: produce secretions that help break down foodstuffs
Digestive
Alimentary canal (gastrointestinal or GI tract or gut) functions include:
Digests food: breaks down into smaller fragments Absorbs fragments through lining into blood
_____ : Simple columnar epithelium and mucus-secreting cells in most of tract
Epithelium
Mucosa: Made up of three sublayers:
Epithelium Lamina propria Muscularis mucosae
Gut brain is made up of enteric neurons that communicate extensively with each other. Major nerve supply to:
GI tract wall that controls motility.
Relationship of Digestive Organs to Peritoneum: ____ ____: organs that are located within the peritoneum
Intraperitoneal (peritoneal) organs
Peritonitis: what happens if it becomes widespread?
It becomes Dangerous and lethal
Histology of the Alimentary Canal: ____ ____: Made up of loose areolar connective tissue
Lamina propria
Learn Figure 23.1 "Alimentary canal and related accessory digestive organs"
Learn Figure 23.1 "Alimentary canal and related accessory digestive organs"
Learn Figure 23.3 "Peristalsis and segmentation"
Learn Figure 23.3 "Peristalsis and segmentation"
Learn Figure 23.4 "The peritoneum and the peritoneal cavity"
Learn Figure 23.4 "The peritoneum and the peritoneal cavity"
Learn Figure 23.5 "Basic structure of the alimentary canal"
Learn Figure 23.5 "Basic structure of the alimentary canal"
Learn Figure 23.6 "The enteric nervous system"
Learn Figure 23.6 "The enteric nervous system"
Learn Figure 23.7 "Neural reflex pathways initiated by stimuli inside or outside the gastrointestinal tract"
Learn Figure 23.7 "Neural reflex pathways initiated by stimuli inside or outside the gastrointestinal tract"
Enteric nervous system: ____ reflexes: respond to stimuli arising inside or outside of gut, such as from autonomic nervous system
Long
Histology of the Alimentary Canal: Lamina propria:Also contains lymphoid follicles that help defend against microorganisms. Follicles are part of:
MALT (mucosa-associated lymphoid tissue)
Relationship of Digestive Organs to Peritoneum: _____: double layer of peritoneum; layers are fused back to back
Mesentery
Epithelium: what is made up of epithelium?
Mouth, esophagus, and anus are made up of stratified squamous epithelium
_____: Tunic layer that lines lumen
Mucosa
All digestive organs have the same four basic layers, or tunics:
Mucosa Submucosa Muscularis externa Serosa
Histology of the Alimentary Canal: ____ ____: Muscle layer responsible for segmentation and peristalsis
Muscular externa
Histology of the Alimentary Canal: ____: Smooth muscle that produces local movements of mucosa
Muscular mucosae
Enteric nervous system: _____ nerve plexus: Controls GI tract motility.
Myenteric
Epithelium: Secretes mucus, which does what?
Protects digestive organs from enzymes Eases food passage
Histology of the Alimentary Canal: Serosa: _____ organs have both an adventitia and a serosa.
Retroperitoneal
Relationship of Digestive Organs to Peritoneum: _____ organs: located outside, or posterior to, the peritoneum
Retroperitoneal
Histology of the Alimentary Canal: _____: Outermost layer, which is made up of the visceral peritoneum
Serosa
Enteric nervous system: ___ reflexes: mediated by enteric nerve plexuses (gut brain); respond to stimuli in GI tract.
Short
Main functions of the digestive system:
Take in food Break it down into nutrient molecules Absorb molecules into the bloodstream Rid body of any indigestible remains
Organs of the digestive system: Accessory digestive organs:
Teeth Tongue Gallbladder Digestive glands * Salivary glands * Liver * Pancreas
Relationship of Digestive Organs to Peritoneum: Peritoneum: ____ peritoneum: membrane on external surface of most digestive organs
Visceral
Relationship of Digestive Organs to Peritoneum: Peritoneum: serous membranes of abdominal cavity that consists of:
Visceral peritoneum Parietal peritoneum
Understanding the process of digestion will help in properly assessing patients with digestive disorders such as ___ ___ and ____.
acid reflux and heartburn.
Histology of the Alimentary Canal: Serosa: Replaced by fibrous ____ in esophagus.
adventitia
Basic Concepts of Regulating Digestive Activity: Effectors of digestive activity are smooth muscle and glands: Reflexes can also activate or inhibit:
digestive glands that secrete digestive juices or hormones
Splanchnic circulation includes: Hepatic portal circulation - Drains nutrient-rich blood from:
digestive organs
Enteric nervous system: Long reflexes: Parasympathetic system enhances what?
digestive process
GI tract has its own nervous system, referred to as __ ___ ___.
enteric nervous system.
Gut brain is made up of ___ ____ that communicate extensively with each other.
enteric neurons
Epithelium: May secrete what?
enzymes and hormones (e.g., in stomach and small intestine)
Histology of the Alimentary Canal: Serosa: Replaced by fibrous adventitia in esophagus. Dense connective tissue that holds ____ to surrounding structures.
esophagus
enteric nervous system Also called the:
gut brain
Basic Concepts of Regulating Digestive Activity: Effectors of digestive activity are smooth muscle and glands: When stimulated, receptors:
initiate reflexes that stimulate smooth muscle to mix and move lumen contents
Histology of the Alimentary Canal: Muscular externa: Contains what layers?
inner circular muscle layer and outer longitudinal
Enteric Nervous System: Enteric neurons make up bulk of two main interconnecting ___ ___ ___.
intrinsic nerve plexuses
Peritonitis: Peritoneal coverings stick together, which helps:
localize infection.
Histology of the Alimentary Canal: Serosa: Formed from areolar connective tissue covered with ____ in most organs.
mesothelium (single layer of squamous epithelium)
Histology of the Alimentary Canal: Muscular externa: Contains inner circular muscle layer and outer longitudinal layers. Circular layer thickens in some areas to form ____.
sphincters
enteric nervous system Contains more neurons than ___ ____.
spinal cord
Basic Concepts of Regulating Digestive Activity: Digestive activity is provoked by a range of mechanical and chemical stimuli: Respond to:
stretch, changes in osmolarity and pH, and presence of substrate and end products of digestion.
All digestive organs have the same four basic layers, or ____
tunics