Body Systems and Homeostasis 2 Nutrient Extraction and Excretion -the digestive system allows for nutrient extraction from food and the excretory system allows for excretion of non-gaseous waste -it is made of the digestive tract and other accessory organs 1. digestive tract: a muscular tube that food travels through 2. accessory organs: help break down food

Digestive Tract Path of the digestive tract: mouth  esophagus  stomach  small intestine  large intestine -as food travels through the digestive tract, it continually broken down -the mouth breaks food down into smaller pieces -the stomach continues to break down those pieces

Digestive Tract -chemical digestion mostly occurs through the help of enzymes -there are digestive enzymes throughout the digestive tract found in the mouth, stomach, and intestines -enzymes and acid are secretions produced by: -salivary glands (amylase in saliva) -stomach (hydrochloric acid) -pancreas (lipase, amylase) -liver (bile, protease)

Digestive Tract -food travels from the stomach to the small intestines where 90% of absorption occurs -lining of the small intestines has villi and lots of blood vessels for absorption of nutrients which are taken to cells through the circulatory system

Digestive Tract -the large intestines is where water is absorbed and feces is compacted for excretion -the end of the digestive tract is the rectum and anus which requires a strong muscle contraction for excretion

Body Systems and Homeostasis 2 -non-gaseous waste is carried leaves the cells via the circulatory system and brought to the kidneys and eventually excreted out -one common waste product is nitrogen from the breakdown of amino acids which produces ammonia (toxic) and is converted water-soluble urea

Body Systems and Homeostasis 2

Compare and Contrast Compare how homeostasis works with the respiratory system and the circulatory system with how homeostasis works with the respiratory system and the digestive system: Respiratory & Circulatory Digestive & Circulatory