Gastro Intestinal System Flashcards
How long is the muscular tube that passes through thoracic and abdominopelvic cavities?
8 meters long from mouth to anus
Name the four layers within the muscular tube that are specialises in certain regions to perform functions?
Mucosa
Submucosa
Muscular layer
Serosa
What is the mucosa? Describe structure
(mucous membrane) Is underlying connective tissue and a small amount of smooth muscle. In some regions it is folded with projections that extend into lumen - this helps to increase absorption surface.
What does mucosa carry out?
Secretion and absorption and is in contact with food
What process is the function of the smooth muscle layer in the digestive system?
Mixing and propulsion
What process is the primary function of the mouth?
Ingestion
Which process is the primary functions of the villi of the small intestine?
Absorption
What accessory organ stores bile?
Gallbladder
What is the submucosa?
Loose connective tissue, nourishes surrounding tissues and carries away absorbed material
What does the submucosa contain?
glands, blood vessels, lymphatic vessels and nerves
What is the muscular layer? & what are its 2 constructed muscle tissue coats called?
It produces movement of the tube
1. circular fibres = on inner coat will cause contraction
2. longitudinal fibres = run length ways and cause shortening
What layer of the GI tract is composed of areolar connective tissue that binds the mucosa to the muscularis?
Submucosa
Why do emotions such as anger or fear slow digestion?
Bcos they stimulate the sympathetic nerves that supply the GI tract
What portion of the peritoneum is largely responsible for carrying blood and limp vessels to the intestines?
Mesocolon
What layer of the GI tract contains skeletal muscle?
Muscularis
What is the serosa layer?
Smooth tissue membrane - protects underlying tissues and secretes serous fluid so that there is free movement of abdominal organs against eachother
What is the peritoneum?
Largest serous membrane of the body - sheet of smooth tissue that lines your abdominopelvic cavity and surrounds your abdominal organs
What does the parietal peritoneum line?
Walls of abdominopelvic cavity
What does the visceral peritoneum cover?
The organs in cavity and is serosa
What is ascites?
Buildup of fluid in abdomen - often occurs as a result of cirrhosis, a liver disease
What organs are retroperitoneal?
Adrenal glands, kidneys, pancreas
What does retroperitoneal mean?
Where some organs lie on the posterior abdominal wall and are covered by peritoneum only on there anterior surfaces
What is NOT a function of the liver?
Storage of bilirubin
What structure regulates the flow of material into the colon?
Ileocecal sphincter
What is the mesentery?
Fold of membrane that attaches the intestine to the wall around the stomach area and holds it in place
What is the mesocolon?
A mesentery that attaches the colon to the posterior abdominal wall. Carries blood and lymphatic vessels to the intestines
What is NOT a primary function of the large intestine?
Regulation of blood glucose
What is mastication?
Chewing, crushing and breaking into smaller fragments - easier to move through digestive tract
Describe the process of ingestion?
Material enters the digestive tract via mouth - mouth starts the process of mechanical and chemical actions
What is pyloric stenosis & where does it occur?
Condition in infants that blocks food from entering small intestine. Happens in the pylorus valve (narrow opening between stomach and duodenum)
What is pancreatitis? & what can it be caused by?
Inflammation of the pancreas - heavy alcohol use
What is the enteric nervous system?
“brain of the gut”
What three organs are part of the enteric nerves system?
Gastrointestinal tract, pancreas and gall bladder
What is the parasympathetic nervous system?
network of nerves that relaxes our body after periods of stress or danger - also helps run life sustaining processes like digestion. PSS stimulation via the vagus nerve increases GI tract and motility
What is sympathetic nervous system?
Network of nerves that helps our body activate its ‘fight or flight’ response - this systems activity increases when we are stressed, in danger or physically active
What are salivary glands?
Within the mouth. They release saliva which keeps mouth and pharynx moist and clean.
Name the 3 salivary glands within the mouth?
- Parotid (watery texture)
- Submandibular
- sublingual
Both subs are mucous rich
What happens when food enters the mouth?
Secretion increases to lubricate and dissolve to begin chemical digestion
What is the oesophagus?
Secretes mucous, transports food
What is the pancreas?
organ in digestive and endocrine system - exocrine pancreas produces enzymes that help to digest food, particularly protein
What are some of the liver and gallbladder functions?
- Carbohydrate metabolism (glycogen - glucose)
- fat metabolism
Name the 3 regions of the small intestine
duodenum
jejunum
ileum
What is the role of bile?
Bile is fluid that is made and released by liver - it breaks down fats into fatty acids which can be taken into body from digestive tract
Where is bile stored?
The gallbladder
What is peristalsis?
Series of wave like muscle contractions that move food through the digestive tract
What is the illeocaecal sprincter?
Small opening with large nerve plexus between small and large intestine
What are the four regions of the large intestine?
Caecum
Colon
Rectum
Anal Canal
What is aerobic respiration?
Chemical process in which oxygen is used to make energy from carbon
What are amino acids?
These serve as building blocks of proteins. They are molecules that all loving things need to make protein
