Small And Large Intestines Flashcards
What are the 3 segments the small intestine splits into
Duodenum
Jejunum
Ileum
What is the small intestine lined with
Glycocalyx
What are the 6 cells in the small intestine
Enterocytes
Goblet cells
Enteroendocrine cells
Paneth cells
Micro fold cells
Stem cells
What is the function of enterocyte cells
Express catabolic enzymes role in absorption
What do goblet cells do
Secrete mucus
What do enteroendocrine cells do
Gastrointestinal hormone secretion
Secretin, pancreozymin, enterglucagon
Sensory - synapsing with afferent nerves
What do paneth cells do
Synthesis of antimicrobial peptides regulates intestinal microflora
What do microfold cells do
Antigen presenting cells - present antigens to peyers patches
What do stem cells do
Self renew by dividing and differentiate into the specialised cells of the intestinal epithelium
What 3 factors decrease gastric emptying
High fat content
Low pH
Hypertonicity (high osmolarity)
What does bile do
Emulsifies fats assisting in their absorption
What is stimulated to release bile from the gall bladder into the duodenum
Stimulation of cholecystokinin
What is the pancreases endocrine function
Insulin and glucagon
What is the pancreases exocrine function
Pancreatic juices
What are the 4 pancreatic enzymes
A amylase
Lipase
Nucleases
Proteolytic enzymes e.g. proteases and peptidases
What are plicae circulares
Circular folds of mucosa evident in the jejunum
What does the ileum mainly absorb
Vitamin B12 and bile salts
Where are peyers patches found
Within lamina propria and submucosa
What is carboxypeptidase
A protease enzyme that hydrolyses (cleaves) a peptide bond specifically at the C-terminal of a protein or peptide
What is aminopeptidase
Cleaves peptide bonds at the amino terminal of a protein
What is lactose intolerance
Insufficient levels of lactose - enzyme which hydrolyses lactose to glucose and galactose
What are the 5 main functions of the large intestine
Reabsorption of water
Reabsorption of bile salts
Absorption of vitamins produced by bacteria
Compaction of intestinal contents to produce faeces
Storage of faeces prior to defaecation
Which intestine has a thinner wall
Large intestine
What is the large intestines walls made of
Small sacs called Haustra which permit expansion and elongation of the colon
What are the 3 section of the large intestine
Ascending
Transverse
Descending
What is the caecum
Very first part of the large intestine
What is the appendix thought to be involved in
Gut microbiota helping to replenish colon with microbiota if it becomes depleted during an immune reaction
What are the 3 synthesis of vitamins by intestinal bacteria
Vitamin K - clotting factors
Biotin - glucose metabolism
Pantothenic acid - vitamin B5
What does bacteria convert bilirubin to
Stercobilinogen - responsible for the pigmentation of faeces
What does bacteria in the the large intestine break down
Peptides in faeces and generate gases - ammonia and hydrogen sulphide
What does the anal canal contain
Small longitudinal folds
What is the anus lined with
Keratinised squamous epithelium
