GI Tract Flashcards
What is the function of the digestive system?
The digestive system digests food so that the body can absorb nutrients and excrete waste.
Identify the components of the GI Tract
Mouth, salivary glands, pancreas, small intestine, large intestine, stomach and anus
What are the 3 main functions of the tongue?
Allows food to be properly mixed with saliva
Moves food from mouth to oesophagus
Speech
What is the collective name given to the numerous small projections on the surface of the tongue used for grooming?
Papillae
What is the function of saliva?
Moisten the mouth
Lubrication for food to move
Soften food
Production pf amylase to break down carbohydrates
Describe the event of swallowing.
Stage 1 - Buccal Phase = tongue pushes food to back of mouth
Stage 2 - Pharyngeneal phase = involuntary signals block food from going down to lungs
Stage 3 - Oesophagal phase = food moves down oesophagus by muscle contractions and relaxing.
Identify the different regions of the stomach.
Cardia - end of oesophagus
Fundus - top
Body - main region
Pylorus - start of intestine
State the term used to describe the muscles contractions which move food down the oesophagus.
Peristalsis
What are rugrae
folds on the stomach lining which flatten when the stomach is full
What is meant by the term gastric?
Anything in relation to the stomach
Describe the function of mucus.
Protection of stomach lining
Describe the function of hydrochloric acid.
Keeps pH low to allow efficient function of pepsin
Describe the function of pepsinogen.
Produces pepsin
Describe the function of gastrin.
Stimulation of hydrochloric acid production.
Describe the function of lipase.
Breakdown of fat.
What is chyme?
The mixture of food, saliva and gastric secretions that leave the stomach
What is the function of goblet cells?
Mucus production.
Define vomitting.
A reflex act of expulsion of stomach contents through the oesophagus and mouth.
Identify the 3 regions of the small intestine.
Duodenum
Jejunum
Ileum
Describe what the duodenum of the small intestine is for.
Joins small intestine with the stomach.
Describe what the jejunum of the small intestine is for.
Absorbs nutrients from food stuffs that travel through the small intestine.
Describe what the ileum of the small intestine is for.
Connects small and large intestine.
List the 3 secretions of the small intestine.
Pancreatic juice
Bile
Intestinal juice
Identify the role the pancreas plays in the digestive system.
Produces pancreatic juice which neutralizes stomach acid
Identify the role of the liver and the gallbladder.
The liver produces bile and the gallbladder stores the bile.
Define the oesophagus.
Thin walled muscle which passes through diaphragm to reach stomach
Food travels from mouth to stomach through oesophagus
Define the role of the stomach.
Storage organ which breaks down food.
Describe the role of the large intestine
Digestion, defaecation, reflux control.
Identify the three salivary glands found in humans and state their location.
Parotid - posterior to pharynx
Submandibular - inferior to tongue
Subligual - inferior to submandibular gland.
Describe the 2 main constituents of bile.
Bile salts - involved in fat breakdown
Bile Pigments (bilirubin, biliverdin) - waste products from liver
List the functions of the liver.
Bile production Synthesis of proteins Breakdown of ammonia to urea Fat metabolism Storage of fat soluble vitamins Storage of iron
State the term used to describe the projections found along the inner lining of the small intestine.
Villi
What is the function of villi?
Absorption of small intestine contents
Describe the structure of a villus
Outer layer - absorptive cells
Inner layer - lymph capillary (lacteal) surrounded by blood capillaries
Describe the structure of the large intestine.
Caecum - first part of large intestine after small intestine
Ascending colon - up along small intestine
Transverse colon - over small intestine
Descending colon - down side of small intestine
Sigmoid colon - connects descending colon to rectum
Rectum - storage for fecal matter
Define chyle
Milky fluid containing digested fats which are absorbed by lacteals
What are lacteals?
Lymphatic capillaries found in villi
List the essential food stuffs humans require.
Protein Carbohydrates Fat Water Vitamins Mineral salts Water
