Digestive System 1

Question 1

What makes up the digestive system

Answer 1

Alimentary Canal
Accessory structures:
- teeth
- tongue
- glands
- liver
- gallbladder
- pancreas

Question 2

What are the functions of the Digestive system?

Answer 2

1. Ingestion
2. Propulsion
   (Peristalsis)
3. Swallowing
4. Digestion
   (Mechanical & Chemical)
5. Absorption
6. Defecation

Question 3

What is the Peritoneum?
What is the Mesentery?

Answer 3

Peritoneum= membrane of the alimentary canal
- serous membrane
- parietal & visceral layer
- produce serous fluid (lubrication)

Mesentery= Folds w/in the peritoneum

Question 4

What are the characteristics of the Mesentery?

Answer 4

1. Supports the organ
2. Free Movement (some level for organ)
3. supports NAVL
4. Most are Double Layered
   (except greater omentum)

Question 5

What are the different types of mesentery?
How many are there?
What organs do they go in between?

Answer 5

Types= Ventral & Dorsal
#: 5
Ventral= original from anterior wall
1. Falciform Ligament
- wraps around liver

Dorsal= anchor organ to the dorsal wall of the abdominal cavity

2. Lesser Omentum
   - branches off falciform ligament to act as a hammock for the stomach
3. Greater Omentum
   - creates a fatty apron
   - 4 layers
   -goes to the transverse colon

4.Transverse Mesocolon
- Loosely attached transverse colon from Rt to Lt side of the body
- trans. colon has some free movement to contract

5. Mesentery Proper
   - loosely anchors small intestine to the dorsal wall & together

Question 6

Retroperitoneal

Answer 6

Organs not surrounded in peritoneum & only has on the ventral surface

Primary:
- Kidney
- Duodenum
- Pancreas

Secondary:
-Ascending Colon
- Descending Colon
- Sigmoid Colon

Question 7

What are the 4 layers or the Alimentary Canal?

Answer 7

1) Mucosa
2) Submucosa
3) Muscularis Externa
4) Serosa/ Adventitiva
- serosa = visceral peritoneum ==>
- retroperitoneum = adventitia
- above diaphragm = adventitia

Question 8

What is the Mucosa & what are it’s parts?

Answer 8

Mucosa = Mucous Membrane

1. Epithelium Changes
   - abrasion = non-keratinized stratified squamous
   - no abrasion = non-ciliated simple columnar
2. Lamina Propria
   - basement membrane (areolar CT)
   - MALT (nodules)
3. Muscularis Mucosa (Interna)
   - contract to make Villi (villus)

Question 9

What is in the Submucosa & where is it located?

Answer 9

Submucosa is deep to the mucosa (outter)

• Connective Tissue
• Submucosal Glands
• Meissner’s Plexus
  –> network nerves that control the secreations of the glands in the submucosa & mucularis mucosa
• NAVL

Question 10

Muscularis Externa
Whats it made of?
Layers?
Anything else?

Answer 10

made of = Smooth Msl except upper esophagus & rectum => skeletal muscle

2 Layers:
1. Inner Circular
2. Outer Longitudinal

*Myenteric Plexus
- Muscles cause Plicae / Rugae to form

Question 11

Serosa

Where is it adventitia?

Answer 11

= Visceral Layer of the Peritoneum
- serosa of pig intestines used for sausages

Adventitia:
- esophagus
- retroperitoneal

Question 12

Enteric Nervous System

Answer 12

Brain of the Gut
- Meissner’s Plexus
- Myenteric Plexus
- don’t need CNS, digest w/ spinal cord injury