Digestive Processes
This process describes chewing and the physical breaking of food into smaller pieces in the mouth.
Mechanical digestion
This organ stores and mechanically breaks down food and mixes it with digestive juices after the mouth.
Stomach
Carbohydrates are broken down into this simple sugar that cells use for energy.
Glucose
This organ is responsible for filtering blood to remove waste and make urine.
Kidney
The tiny sacs in the lungs where oxygen enters the blood and carbon dioxide leaves the blood.
Alveoli
The name for the muscular contractions that push food through the digestive tract.
Peristalsis
This long, coiled organ is the main site of nutrient absorption.
Small intestine
Proteins are broken down into these smaller building blocks that the body uses to build and repair tissues.
Amino acids
The liquid waste product formed by the kidneys that contains urea and other dissolved wastes.
Urine
The name for the movement of air into and out of the lungs.
Breathing (ventilation)
The chemical process in the stomach that uses acid and enzymes to break proteins into smaller molecules is called _____.
Chemical/Gastric digestion
This accessory organ produces bile, which helps break down fats.
Liver
Fats are broken down into fatty acids and _____, which can be absorbed into the lymphatic system.
Glycerol
This structure stores urine until it is expelled from the body.
Urinary bladder
The process where oxygen moves from the alveoli into the blood and carbon dioxide moves from the blood into the alveoli.
Diffusion
The small intestine performs this two-part job: finishing digestion and _____ of nutrients into the bloodstream.
Absorption
The tube that connects the mouth to the stomach.
Esophagus
After absorption, nutrients first enter these tiny blood vessels in the villi before traveling to the liver.
Capillaries
Name two ways the body excretes wastes other than through urine.
Exhalation (lungs — carbon dioxide), sweating (skin), feces (large intestine). Any two.
The name of the muscle that contracts to expand the chest cavity and helps draw air into the lungs.
Diaphragm
Name the process by which large molecules like proteins and starches are split into smaller molecules by adding water and enzymes.
Hydrolysis
These small finger-like projections line the small intestine and increase the surface area for absorption.
Villi
The organ that processes absorbed nutrients, detoxifies chemicals, and stores certain nutrients before they circulate to the rest of the body.
Liver
Explain how the digestive and excretory systems work together to maintain homeostasis after a salty, protein-rich meal
Sample answer: The digestive system breaks down the salty, protein-rich meal and absorbs sodium, amino acids, and other nutrients into the blood. The kidneys filter the blood to remove excess salt and nitrogenous wastes (like urea) from protein metabolism, keeping blood composition and fluid balance stable.
Explain how oxygen concentration differences between air and blood cause oxygen to enter the blood (2–3 sentences).
Sample answer: Oxygen moves from areas of higher concentration (in the alveoli) to areas of lower concentration (in the blood) by diffusion across the thin respiratory membrane. The greater the difference in oxygen levels, the faster oxygen diffuses into the blood.