Www.sciencea2z.com



Adela Genoves

G510 Life Science for Middle School Educators

Human Respiratory System Lesson

The respiratory system’s main job is to get oxygen into the body and remove carbons dioxide. All the cells found in the body require oxygen to release the energy needed to live. Cells need a continuous supply of air because the space in a cell is too small for storage of oxygen. Carbon dioxide is produced by cells as a byproduct of respiration and taken out of the body because it would be harmful to the body if retained. The lungs are the principal parts of the respiratory system. Once oxygen enters the lungs, this oxygen can enter the bloodstream.

[pic]

Respiratory System

Parts of the respiratory system are located in the head, neck, and chest. Air passages carry air (oxygen) to and from the lungs. Oxygen enters the nose then moves through the throat, larynx, trachea, and then into a bronchus which leads into the lungs.

Interesting Point: With every breath, more than 15 ounces of air is taken into the lungs.

Exchange of gases-- Once oxygen enters the nose it travels through the respiratory system where it is delivered to the capillaries which absorb the oxygen from the alveoli. Oxygen and carbon dioxide combine with the hemoglobin in red blood cells. Then they are circulated in the blood and are transported throughout the body. Arteries carry oxygen rich blood to the heart, where it is pumped to other regions of the body. Veins carry carbon dioxide and bring blood cells with little oxygen back into the lungs to deposit carbon dioxide into the lungs.

• Nose

The nose is the natural access route of air to the inside of the body.

• Pharynx

The pharynx is a passage located behind the nasal area and the mouth. It contains the crossroad between the respiratory systems and the digestive system because it pipes air to the larynx and food to the esophagus. The epiglottis is the flap that prevent food from going into the lungs when swallowing

• Larynx

The Larynx is also known as the voice box. It contains the vocal cords.

• Trachea

The Trachea, also known as the windpipe resembles a tube and carries air to between the Larynx and the Lungs. The lower part of the Trachea splits into two branches called Bronchi that enter the Lungs. The Trachea is supported from collapsing by pieces of cartilage that are shaped like the letter C. The Trachea also makes sticky mucus that traps dust and pathogens.

• Bronchus

The Bronchus grows out of the Trachea. The Bronchus divides into two Bronchi that lead into the right and the left Lung. The Bronchus continues divide into narrower branches called Bronchioles. This whole system resembles the branches of a leafless tree turned upside down.

• Bronchioles

Bronchioles stem from the Bronchi and are the smallest air passage of the bronchial tree. Each bronchiole ends in a cluster of alveoli.

• Alveoli

Alveoli are air sacs attached to the tips of Bronchioles that work to exchange gas in the lungs. Alveoli resemble a bunch of grapes attached to a stem. Alveoli are covered by capillaries, which pick-up Oxygen and carry it away from the lung and deliver Carbon dioxide back to the lungs and out of the body.

• Lungs

The lungs are two spongy organs housed inside the chest cavity and linked directly to the outside through the respiratory tracts. They perform the exchange of gases between the air and the blood. Each lung has a flattened base that rests against the diaphragm. The lungs are grooves by deep fissures that divide them into lobes. Each pulmonary lobe exchanges air and carbon dioxide by containing alveoli. In mammals and the more complex life forms, the two lungs are located in the chest on either side of the heart. Their principal function is to transport oxygen from the atmosphere into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere. This exchange of gases is accomplished in the mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs called alveoli.

• Capillaries

Capillaries are delicate vessels with fine walls that facilitate the exchange of gases between the blood and the tissues.

• Red Blood Cells

The main function of red blood cells, or erythrocytes, is transporting oxygen to the cells. Red blood cells contain a molecule called hemoglobin, to which oxygen binds until it reaches its destination.

• Thoraco-abdominal Diaphragm

The abdominal diaphragm is the term used to describe any of several large muscles, found in humans and other mammals, which separate two adjacent regions of the body. The most commonly known muscle of this class is the thoraco-abdominal diaphragm. In humans, the thoraco-abdominal diaphragm acts as a partition between the cavity of the chest and that of the abdomen. The chief muscle used in respiration, it is relaxed and dome-shaped during exhalation. During inhalation it contracts, pulling downward, and with the combined contraction of the chest muscles allows the chest cavity to expand. The thoraco-abdominal diaphragm is also subject to developmental defects, hernia, injury, displacement, and infection.

[pic]



What Protects the Lungs?

• The ribs surrounding the lungs provide the Lungs protection from physical damage. Alveolar macrophages, also known as dust cells surround and engulf (eat) infectious microorganisms and dust to stop them from interfering with the Oxygen and Carbon dioxide exchange (also known as gas exchange) inside the lungs.

• Thorax—The thorax is the part of the body between the neck and the abdomen. It contains the major portion of the organs of the respiratory system. The chest wall is responsible for protecting the heart and the lungs.

What controls Respiration?

Although humans can control their breathing for a short time, it is typically an involuntary function. Breathing is controlled by a respiration center located in the encephalic trunk. The respiratory center regulates the frequency and intensity of breathing air in.

Oxygen IN (Carbon dioxide OUT (Gas Exchange)

Blood picks-up Oxygen in the Lungs. As the blood circulates Oxygen through the capillary networks, Oxygen is swapped for Carbon dioxide. Oxygen and glucose (also known as sugar) are transferred from the blood into cells. Oxygen in cells is used to release energy. The waste products of releasing energy are Carbon dioxide and water. Carbon dioxide and water are transferred from the cell into the blood.

Lung Related Diseases

Asthma -- is a very common chronic disease involving the respiratory system in which the airways constrict, become inflamed, and are lined with excessive amounts of mucus, often in response to one or more triggers.[1] These episodes may be triggered by such things as exposure to an environmental stimulant such as an allergen, environmental tobacco smoke, cold or warm air, perfume, pet dander, moist air, exercise or exertion, or emotional stress. In children, the most common triggers are viral illnesses such as those that cause the common cold.[2] This airway narrowing causes symptoms such as wheezing, shortness of breath, chest tightness, and coughing. The airway constriction responds to bronchodilators. Between episodes, most patients feel well but can have mild symptoms and they may remain short of breath after exercise for longer periods of time than the unaffected individual. The symptoms of asthma, which can range from mild to life threatening, can usually, be controlled with a combination of drugs and environmental changes.

[pic]



Bronchitis – mean that the tubes that carry air to the lungs (the bronchial tubes) are inflamed and irritated. When this happens, the tubes swell and produce mucus. This makes you cough. Acute bronchitis is one type of bronchitis that comes on quickly and gets better after 2 to 3 weeks. Acute bronchitis is usually caused by a virus. A person gets acute bronchitis after having a cold or the flu. Acute bronchitis can also be caused by breathing in things that irritate the bronchial tubes, such as smoke. Symptoms of acute bronchitis are a cough that is dry and hacking at first. After a few days, the cough may bring up mucus. You may have a low fever and feel tired.



[pic]

Emphysema – is a long-term, progressive disease of the lung(s) and occurs when the alveolar walls are destroyed along with the capillary blood vessels that run within them. This lessens the total area within the lung where blood and air can come together, limiting the potential for oxygen and carbon dioxide transfer. The main cause of emphysema is smoking, which activates inflammatory cells in the lung. This inflammation causes; 1) swelling within the bronchioles, and 2) activation of enzymes called proteases which attack and destroy lung tissue (the alveolar wall structures). Emphysema is a progressive disease that usually appears in patients after 50 year of age. Symptoms for Emphysema include shortness of breath and wheezing.



[pic]



Science Standards Alignment

6th grade

• (6.2.LS.1) Describe the interactions between and among cells, tissues, organs and organ systems.

• (Scientific Inquiry 6.3.1) Based on observation and scientific knowledge and concepts propose hypotheses that can be examined through scientific investigation, design, and conduct an investigation that uses appropriate tools and techniques and collect relevant data.

7th grade

• (7.1.LS.1) Describe the function and relative complexity of cells, tissues, organs, and organ systems in organisms and explain that different body tissues and organs are made up of different kinds of cells.

• (Scientific Inquiry 6.3.1) Based on observation and scientific knowledge and concepts propose hypotheses that can be examined through scientific investigation, design, and conduct an investigation that uses appropriate tools and techniques and collect relevant data.

8th grade

• n/a

Lab 1:

Carbon dioxide OUT

Materials

• Distilled water

• Bromothymol blue

• Straws

• Timers

• Glass jars

STEP-by-STEP

• Fill glass jar half full with distilled water

• Add 5 drops of bromothymol blue

• Place straw in solution (water with bromothymol blue)

• EXHALE OUT, into the solution for 2 minutes

| |Water color after 2 minutes |Water color after 4 minutes |

|No running | | |

|Running in place for 5 min. | | |

Connections

The water will turn from light blue to green or yellow-green after exhaling into the solution. Bromothymol blue is an acid indicator that is blue in a basic solution. When the solution appears yellow, the solution is more acidic. Acid is a substance that tastes sour and neutralizes bases. A base is a substance that tastes bitter and neutralizes acids. The Carbon dioxide that is exhaled (breathed out) from the lungs will mix with water to from a weak acid called Carbonic acid. The Carbonic acid turn the bromothymol blue a green or yellow color. Exercise requires that muscle cells use carbohydrates for energy. The result of using Oxygen and carbohydrates to work is Carbon dioxide gas that needs to exit the body. After exercise, the body will produce more Carbon dioxide that will be present when exhaling. The bromothymol blue will turn color faster when breathing into the solution after some exercise.

Lab 2:

Breathing and the Diaphragm

Materials & Cost

• Scissors $ 3.00

• Rubber bands $ 0.59

• Clay $ 3.00

• Tape $ 2.00

• Balloon (small and large size) $ 1.00

• Plastic straws $ 1.00

• 3-way connectors $ 0.70

• Nails ------

• 2-liter soda bottles free

Total $11.00

Step-by-Step

• Cut off the bottom 3rd of the soda bottle

• Drill a hole in the soda cap with the nail

• Cut the end off of the large balloon

• Stick the straw in the opening of the small balloon. Secure with a rubber band.

• Put the straw with balloon through the hole in the cap. Screw the cap on the bottle.

• Use the clay to seal the straw in place

• Stretch the large balloon taut over the bottom opening. Use a rubber band to secure the balloon in place.

• Use tape to secure the balloon onto the bottle

• Pull down the bottom balloon

Connections

The small balloon inside will inflate when the large balloon is pulled down. The Diaphragm is a band of muscles located at the bottom of the chest cavity. When you inhale, the diaphragm contracts (becomes smaller), it flattens and pull downward. The volume of the chest cavity increases and the pressure inside it decreases. Because air pressure outside of the body is greater than the pressure inside the chest cavity, air rushed in through the mouth and nose. When exhaling, the Diaphragm releases and returns to its original shape. It decreases in volume and increases in pressure.

[pic]



Assessment 1:

Student writing-to-learn exercise based on building lungs activity

1. Beginning Idea – What are my questions?

2. Tests -- What did I do?

3. Observations -- What did I see?

4. Claims – What can I claim?

5. Evidence – How do I know? Why am I making these claims?

6. Reading – How do my ideas compare with other ideas?

7. Reflection -- How have my ideas changed?

Assessment 2:

The Human Respiratory System Quiz

Name ________________________________________________

Please circle the best answer.

1. What is the respiratory system’s main function?

a. To get oxygen into the body and remove carbons dioxide from the body

b. To get carbon dioxide into the body and remove oxygen from the body

c. To transport blood throughout the body

2. What function does the Trachea perform in the respiratory system?

a. It is the highway that carries air to between the Larynx and the Lungs.

b. It is inside the lungs and helps with exchanging oxygen and carbon dioxide.

c. It has nothing to do with the respiratory system.

3. Where is the Thorax?

a. It is part of the body between the neck and the abdomen

b. It is part of the body between the mouth and the larynx

c. It is the areas where oxygen and carbon dioxide are exchanged

4. What protects the heart and the lungs?

a. The chest wall and ribs

b. The epidermis

c. The system of capillaries

5. What is the chief muscle used in respiration?

a. Thoraco-abdominla diaphragm

b. The Heart

c. The Lungs

d. The mouth

6. What are Capillaries:

a. Capillaries are delicate vessels that facilitate the exchange of gases between the blood and the tissues.

b. Capillaries are the red blood cells that carry oxygen and carbon dioxide

c. Capillaries are organs in the body.

7. How are the lungs best described?

a. The lungs are hard organs that have nothing to do with respiration

b. The lungs are two spongy organs inside the thorax and linked to the respiratory tract.

c. The lungs are grooved by deep fissures and have a flattened base that rest against the diaphragm.

d. Both b. and c.

8. Label the parts in this diagram. [pic]

Image From:

1. Nose

2. Mouth

3. Larynx

4. Right Lung

5. Right Bronchi

6. Diaphragm

7. Pharynx

8. Trachea

9. Left Bronchus

10. Bronchioles

11. Alveoli

9. Please explain how Gas Exchange works.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

10. Please explain how the Thoraco-abdominal diaphragm behaves during respiration. ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

11. Please draw how Alveoli exchange oxygen and carbon dioxide with red blood cells in the capillaries.

| |

Main Components of Human Respiratory System

The Nose - Usually air will enter the respiratory system through the nostrils.  The nostrils then lead to open spaces in the nose called the nasal passages.  The nasal passages serve as a moistener, a filter, and to warm up the air before it reaches the lungs.  The hairs existing within the nostrils prevent various foreign particles from entering.  Different air passageways and the nasal passages are covered with a mucous membrane.  Many of the cells which produce the cells that make up the membrane contain cilia.  Others secrete a type a sticky fluid called mucus.  The mucus and cilia collect dust, bacteria, and other particles in the air.  The mucus also helps in moistening the air.  Under the mucous membrane there are a large number of capillaries.  The blood within these capillaries helps to warm the air as it passes through the nose.  The nose serves three purposes.  It warms, filters, and moistens the air before it reaches the lungs.  You will obviously lose these special advantages if you breathe through your mouth.

Pharynx and Larynx - Air travels from the nasal passages to the pharynx, or more commonly known as the throat. When the air leaves the pharynx it passes into the larynx, or the voice box.  The voice box is constructed mainly of cartilage, which is a flexible connective tissue.  The vocal chords are two pairs of membranes that are stretched across the inside of the larynx.  As the air is expired, the vocal chords vibrate.  Humans can control the vibrations of the vocal chords, which enables us to make sounds.  Food and liquids are blocked from entering the opening of the larynx by the epiglottis to prevent people from choking during swallowing.

Trachea - The larynx goes directly into the trachea or the windpipe.  The trachea is a tube approximately 12 centimeters in length and 2.5 centimeters wide.  The trachea is kept open by rings of cartilage within its walls.  Similar to the nasal passages, the trachea is covered with a ciliated mucous membrane.  Usually the cilia move mucus and trapped foreign matter to the pharynx.  After that, they leave the air passages and are normally swallowed.  The respiratory system cannot deal with tobacco smoke very keenly.  Smoking stops the cilia from moving.  Just one cigarette slows their motion for about 20 minutes.  The tobacco smoke increases the amount of mucus in the air passages.  When smokers cough, their body is attempting to dispose of the extra mucus.

Bronchi - Around the center of the chest, the trachea divides into two cartilage-ringed tubes called bronchi.  Also, this section of the respiratory system is lined with ciliated cells.  The bronchi enter the lungs and spread into a treelike fashion into smaller tubes called bronchial tubes.  

Bronchioles - The bronchial tubes divide and then subdivide.  By doing this their walls become thinner and have less and less cartilage.  Eventually, they become a tiny group of tubes called bronchioles.

Alveoli - Each bronchiole ends in a tiny air chamber that looks like a bunch of grapes.  Each chamber contains many cup-shaped cavities known as alveoli.  The walls of the alveoli, which are only about one cell thick, are the respiratory surface.  They are thin, moist, and are surrounded by several numbers of capillaries.  The exchange of oxygen and carbon dioxide between blood and air occurs through these walls.  The estimation is that lungs contain about 300 million alveoli. Their total surface area would be about 70 square meters.  That is 40 times the surface area of the skin.  Smoking makes it difficult for oxygen to be taken through the alveoli.  When the cigarette smoke is inhaled, about one-third of the particles will remain within the alveoli.  There are too many particles from smoking or from other sources of air pollution which can damage the walls in the alveoli.  This causes a certain tissue to form.  This tissue reduces the working area of the respiratory surface and leads to the disease called emphysema.

References

e.guides Human Body by Richard Walker. ISBN 0 7566 1009 5

Head to Toe Science by Jim Wiese. ISBN 0-471-33203-8

Insiders Human Body. ISBN 13





(anatomy)

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download