Digestive, Respiratory, & Cardiovascular Systems Test

The process by which food and drink are broken down into smaller molecules so that the body can use them to build and nourish cells and provide energy. It involves: Mixing of food (mouth and stomach churning) Movement of food (digestive tract) Chemical breakdown of large molecules into smaller (mouth, stomach, small intestine)

Mechanical and Chemical

Mouth Pharynx Esophagus Stomach Small intestine Large intestine/colon Rectum Anus

teeth tongue salivary glands liver gallbladder pancreas

1) Teeth physically tear the food you eat apart into smaller pieces while your salivary glands secrete saliva and begin the chemical breakdown of food in your mouth. It moistens the food so it can be turned into a food bolus positioned by your throat and swallowed. 2) Food is swallowed using peristalsis down the pharynx to the esophagus. The esophagus connects the throat to the stomach. 3) Where the esophagus and stomach join, there is a valve to separate the organs. When food nears the valve, it opens, then closes again. 4) The stomach stores, mixes, and empties the food it was given. 5) The pancreas delivers pancreatic juice into the small intestine that breaks down starch, facts, proteins, and nucleic acids. The liver secretes bile to help the breakdown of fat. 6) The small intestine contains villi which contain microvilli that absorb the nutrients from food and drink consumed. The nutrients flow into your blood stream. 7) The waste (undigested food and older cells) shed from the intestinal lining and move into the large intestine where it absorbs the water left. 8) The feces is stored in the rectum until it is expelled through the anus.

The involuntary wave-like motion of the throat/pharynx that helps push the food bolus down the esophagus.

villi are tiny finger-like sponges. They are covered in microvilli, even smaller finger-like sponges. They absorb huge amounts of nutrients due to their shape and unique structure.

Produce digestive juices in the stomach.

Stores the excess bile secreted from the liver.

To obtain O2 so that it can be transported to each body cell and be used during cellular respiration. To remove CO2 as a waste product from each body cell as a result of cellular respiration.

The release of energy (ATP) resulting from the breakdown of glucose.

The exchange of gases between the atmosphere and the lungs (organ).

The exchange of gases between the blood cells and the lung cells (cellular).

Cilia line the nasal tract, fluttering and catching toxins so that we don’t breathe them in, filtering our air. Smokers cilia will become paralyzed and die over time.

Nose -> nasal cavity -> pharynx -> larynx -> Trachea -> Left and right bronchus -> bronchioles -> alveoli

to warm the air you breathe in

The throat

The top part of the trachea that houses the vocal cords

In the lungs.

The diaphragm is a flat sheet that lays across the whole body. It rests in an upward curved position and when it contracts, it flattens in a way that allows the lungs to expand, and air to come in.

You are not just sucking air in. When the diaphragm contracts, it causes the chat cavity to enlarge. As the volume increases, the pressure inside decreases, causing the air to flow in to equalize the pressure change.

1) Each alveolus is surrounded by oxygen poor capillaries. The alveoli are filled with oxygen rich air. 2) CO2 from the blood diffuses into the alveoli to be exhaled. 3) The O2 in the alveoli diffuses into capillaries where it will be transported to the rest of the body cells.

CO2 gas. Breathing is involuntary and controlled by our brain. The brain knows when we need oxygen due to carbon dioxide receptors. When carbon dioxide dissolves in the blood, it forms carbonic acid. Because it is so unstable, it splits into H ions and bicarbonate ions. The H ions decrease the pH of the blood which signals the carbon dioxide receptors to respond by breathing.

Bronchitis Pneumonia Emphysema Asthma