Intro to Digestive System Flashcards
Flashcards and notes from part 1A of UMICH ANAT 403 UNIT $
Digestive system
a muscular tube open at both ends with attached accessory structures
- 2 parts
Gastrointestinal Tract
Also known as the alimentary canal
- Part of the digestive system
- extracts valuable carbs from food and secretes waste
Contains:
Oral cavity, pharynx (oro and laryngo), esophagus, stomach, small intestine, large intestine
Accessory Digestive Organs
-Part of the digestive system
-most found in abdominopelvic cavity
Contains:
(1)teeth, tongue, salivary glands
- associated with oral cavity, mechanically and chemically breaks down food in the oral cavity
(2) gall bladder, liver, pancreas
- associated with small intestine, further chemical breakdown
Layers of the GI Tract
- Mucosa Layer (superficial innermost)
- Submucosal Layer
- Muscularis Layer
- Serosa Layer (deep outermost)
Mucosa Layer
innermost layer, associated with the lumen of the large intestine
- glands of the submucosa empty into the lumen of the mucosa layer
3 LAYERS:
- Epithelial: lumen
- Lamina Propria: specialized connective tissue layer
- Muscularis Mucosae
Submucosal Layer
Contains glands and is a specialized connective tissue layer
- submucosal plexus of nerves
Muscularis Layer
2 Layers:
- Circular: inner
- Longitudinal: outer
In between the two layers is the Myenteric plexus of nerves (nervous tissue)
Serosal Layer
2 Layers:
- Epithelium
- Areolar Connective Tissue
Peritoneum
Double-layer serous membrane that covers some of the digestive system structures
2 Layers:
- Parietal Layer: outside layer, can be specialized layers. Lines the abdominopelvic wall and folds back on itself forming a double membrane called Mesentery
- Visceral Layer: Lines the abdominal organs within the peritoneum
Mesentery
Two layers of peritoneum through which nerves, blood vessels, and lymphatics travel to and from an organ. Specialized layer of parietal pleura
- where the parietal peritoneum touch
FUNCTIONS:
- supports the intestines
- prevents intestinal twisting
- stores fat
- pathway for blood vessels and nerves
How do organs make their way to the peritoneum sac?
Organs do not push into the peritoneal cavity, but they do push the peritoneum and try to get to where the sac is.
Peritoneal Cavity
contains serous fluid for lubrication of peritoneal surfaces
“The” Mesentery
anchors jejunum and ileum to the posterior abdominal wall, and is a specific portion of the overall mesentery
-associated with the small intestine
Peritoneal Ligament
two layers of the peritoneum that connect an organ to the body wall or another organ
Omentum
Two layers of the peritoneum that connect the stomach to another organ
Greater Omentum
Connects the greater curvature of the stomach and the transverse colon (Gastrocolic ligament)
- overgrowth and fusion lead to a 4-layer structure
- protects the small intestine
Lesser Omentum
Connects the liver to the lesser curvature of the stomach (hepatogastric ligament) and to the duodenum (hepatoduodenal ligament)
Intraperitoneal
Viscera invested in the visceral peritoneum
Retroperitoneal
Viscera posterior to the parietal peritoneum
- either didn’t push into the sac or did and lost the attached layer
SAD PUCKER
- Suprarenal Glands (Adrenal)
- Aorta
- Duodenum (2nd and 3rd parts)
- Pancreas
- Ureters
- Colon (ascending and descending)
- Kidneys
- Esophagus
- Rectum
Secondary Retroperitoneal
Originally intraperitoneal organs that became fixed to the posterior abdominal wall during development. now retroperitoneal because the parietal peritoneal was lost as they moved to the posterior abdominal wall
+ Fusion (Toldt’s) Fascia
- Duodenum (2nd and 3rd parts)
- Pancreas
- Colon (ascending and descending)
Peritonitis
Acute inflammation of the peritoneum
- sac has serosal fluid in it to allow movement and reduce inflammation as things move past eachother
- possible for bacteria and microbes to get into the sac
CAUSE:
- contamination by infectious microbes during surgery or from rupture of abdominal organs
