Respiratory System

What is it? The human respiratory system is a series of organs that are responsible for taking in oxygen and getting rid of carbon dioxide The main organs of the respiratory system are the lungs The lungs are where the exchange of oxygen and carbon dioxide takes place The respiratory system also includes the nose, throat, voice box, and windpipe

What does it do? The job of the respiratory system is to make sure that oxygen is taken into the body and that carbon dioxide leaves the body Inhalation is when air is breathed into the lungs Exhalation is when air it breathed out of the lungs

Oxygen Oxygen is the most important gas for keeping us alive because our body cells need it for energy and growth Oxygen is found in the air that we breathe It is abbreviated a O2 The body takes in oxygen every time we take a breath!

Carbon Dioxide Carbon dioxide is the waste gas that is produced when carbon is combined with oxygen as part of the body’s energy-making processes. It is also known as CO2 Carbon dioxide is released from our bodies every time we exhale. Plants take in the carbon dioxide that we release and use it in photosynthesis in which they release oxygen! Talk about good recycling!

Interesting Facts Each day we breathe about 20,000 times The average rate of breathing depends upon age: Newborn 40 times a minute when awake, 20-40 times a minute when sleeping Adults 12-16 times a breaths a minute when resting, about 45 breaths a minute when exercising Breathing is automatic, we don’t have to think about it After about four minutes without oxygen, brain cells begin dying, which can lead to brain damage and death

Parts of the Respiratory System Lungs: the main organs of the respiratory system Oxygen is taken into the body and carbon dioxide is breathed out Trachea (or windpipe): filters the air that we breath and branches into the bronchi Bronchi: two air tubes that branch off of the trachea and carry air into our lungs Diaphragm: dome-shaped muscle at the bottom of the lungs that contracts when you breathe in and expands when you breathe out

Respiration The term for the exchange of oxygen from the environment for carbon dioxide from the body’s cells. If the air you breathe is dirty, your respiratory system filters out foreign matter that enter the nose and mouth These pollutants are breathed out, coughed out, destroyed by digestive juices, or eaten by macrophages (a type of blood cell) Cilia (tiny hairs) are found in the nasal passageways and also work to trap dust and other particles that enter in the nose.

Pathway of Air When we breathe in, oxygen enters the nose or mouth and passes into the sinuses (hollow spaces in the skull) The sinuses regulate the temperature and humidity of the air that we breathe The trachea, or windpipe, filters the air that is inhaled

Pathway The trachea branches into the bronchi, which are two tubes that carry air into each lung The bronchial tubes are lined with cilia (tiny hairs) The cilia move back and forth, carrying mucus up and out Mucus collects dust, germs, and other matter that has invaded the lungs The mucus is expelled when we sneeze, cough, spit, or swallow

Pathway The bronchial tubes lead to the lobes of the lungs The right lung has 3 lobes, and the left lung has 2 lobes The left lung is smaller to allow room for the heart Within the lung, the bronchi branch into even smaller tubes called bronchioles Bronchioles (thin as a hair strand) end in tiny air sacs called alveoli Lobes are filled with these small, spongy sacs called alveoli The exchange of oxygen and carbon dioxide occurs in the alveoli

Pathway The alveolar walls are extremely thin and composed of a single layer of tissues and tiny blood vessels called pulmonary capillaries Blood passes through the capillaries and the pulmonary artery carries blood containing carbon dioxide to the air sacs, where gas moves from the blood to the air Oxygenated blood goes to the heart through the pulmonary vein and is pumped throughout the body

Hemoglobin A molecule in red blood cells that picks up oxygen in the blood stream

Diaphragm When we breathe in, the diaphragm moves downward toward the abdomen, and the rib muscles pull the ribs upward and outward This enlarges the chest cavity to make room for the oxygen When we breathe out, the diaphragm moves upward and the chest cavity is forced to get smaller, pushing the gases in the lungs up and out

Yawning When you’re sleepy, the lungs don’t take in enough oxygen from the air This causes a shortage of oxygen in our bodies The brain senses the shortage of oxygen and sends a message that causes you to a take a long deep breath or a YAWN!!!

Sneezing Sneezing is like a cough from the upper breathing passages It is your body’s way of removing an irritant from the sensitive mucous membranes of the nose Dust, pollen, pepper, or even a cold blast of air can make you sneeze

Hiccups Hiccups are the sudden movements of the diaphragm They are involuntary movements The diaphragm becomes irritated from things like eating too fast and causes the movements to occur

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