The structure of the gut wall

• how many tissue layers does the gut wall consist of?

  throughout its length, the gut wall consists of 4 tissue layers surrounding a cavity, the lumen of the gut
• what are the proportions of the different layers of the gut wall like?

  they vary, depending on the function of the part of the gut
• what is the outermost layer of the gut wall called?

  the serosa
• what is the serosa like (the outermost layer of the gut wall)?

  • its a tough connective tissue, protecting the gut wall
  • the gut moves while processing food and the serosa reduces friction with other abdominal organs
• what is the muscle in the gut wall like?

  the muscle comprises of 2 layers in different directions, the inner circular muscles and the outer longitudinal muscles
• what is the function of the muscle in the gut wall?

  • they make coordinated waves of contractions, peristalsis
  • behind the ball of food, circular muscles contract and longitudinal muscles relax, pushing the food along
• what is the submucosa?

  its connective tissue containing blood and lymph vessels
• what does the submucosa do?

  its a connective tissue containing blood and lymph vessels, which remove absorbed products of digestion, and nerves that coordinate peristalsis
• what is the innermost layer of the gut wall called?

  the mucosa
• what is the mucosa?

  its the innermost layer of the gut wall and lines the gut wall
• what is the mucosa like?

  • its epithelium secretes mucus, lubricating and protecting the mucosa
  • in some regions of the gut, it secretes digestive juices and in others, absorbs digested food
• what is this an image of?

  a generalised structure of the gut wall