Chapter 43 Flashcards
(413 cards)
What is the length of the GI tract?
30 ft (9 m)
What are the four layers of the GI tract from inside to outside?
- Mucosa lining
- Submucosa connective tissue
- Muscle
- Serosa
What does the submucosa layer of the GI tract contain?
- Glands
- Blood vessels
- Lymph nodes
The GI tract extends
from the mouth to the anus.
What are the three smooth muscle layers in the GI tract?
The oblique (inner) layer, circular (middle) layer, and longitudinal (outer) layer.
What is the main function of the parasympathetic system in the GI tract?
Mainly excitatory, increasing peristalsis.
What is the main function of the sympathetic system in the GI tract?
Mainly inhibitory, decreasing peristalsis.
What does the enteric nervous system (ENS) regulate?
Motility and secretion along the entire GI tract.
What are the two networks that compose the enteric nervous system?
- Meissner plexus in the submucosa
- Auerbach (myenteric) plexus between the muscle layers.
What does the submucosal plexus control?
Secretion and is involved in many sensory functions.
What is the major nerve supply to the GI tract?
The myenteric plexus.
The enteric nervous system (ENS) functions
independently of the brain and spinal cord.
What is unique about the circulation in the GI system?
Venous blood drains into the portal vein, which perfuses the liver.
What arteries supply arterial blood to the GI tract?
- Celiac artery
- Superior mesenteric artery (SMA)
- Inferior mesenteric artery (IMA).
What is the nature of the omentum?
Hangs like an apron from the stomach to the intestines, containing fat and lymph nodes.
the main function of the GI system is to supply the body with nutrients. It does so by.
- Ingestion
- Digestion
- Absorption
- Elimination.
Ingestion is
The intake of food
What hormone released from the stomach mucosa stimulates appetite?
Ghrelin.
What factors stimulate appetite?
- Hypoglycemia
- An empty stomach
- Decrease in body temperature.
What is the role of leptin in appetite regulation?
Inhibits appetite.
What is deglutition?
The mechanical portion of swallowing
Which organs are involved in deglutition?
- Mouth
- Pharynx
- Esophagus
What are the components of the oral cavity?
- Lips
- Hard palate
- Soft palate
- Tongue
What is the primary function of the tongue?
Aids in swallowing and speech