LIFESCI 2 Lecture Notes - Lecture 18: Lymphatic System, Cholecystokinin, Sodium Bicarbonate
Document Summary
Function of the digestive system: chemically beaks down food (large-sized molecules) we eat a. i. Large molecules can"t go through plasma membrane: absorbs the food to transfer it to cells b. i. Absorption: physical movement of food from digestive cavity, crossing digestive organs, into blood circulation b. i. 1. Can only refer to food being in the body once it"s in our circulation and can be absorbed by cells b. ii. Food can be used with oxygen to produce energy: goes through digestive cavity, to the body, food is just chemicals. Processes of digestive system: motility: movement of food through digestive organs through elementary canal a. i. Aided by gravity but occurs no matter what position body"s in a. i. 1. Peristalsis: constant involuntary rhythmic contraction of the smooth muscles gently drives food through the various digestive organs a. ii. Movement of food through digestive organs (canal) at an appropriate speed a. ii. 1. b. Occurs slowly because food is being a. ii. 2. processed. To promote digestion and mixing with enzymes a. ii. 2. b.
