The Respiratory System

1. The Respiratory System UEQ: How do we exchange oxygen to and carbon dioxide from the human body?

2. What is the respiratory system? • The system that • brings oxygen into the body and expels carbon dioxide out of the body. • ensures that during inspiration, or inhalation, air is brought from the atmosphere to the lungs by a series of cavities, tubes and openings. • ensures that during expiration, or exhalation, air is pushed out of the lungs into the atmosphere using the same structures.

3. THINK ABOUT IT: • WHAT ORGANS ARE APART OF THE UPPER RESPIRATORY TRACT? Major Organs Accessory Organs Nose Oral cavity , or mouth Nasal cavities Paranasal sinuses Pharynx, or throat

4. The Upper Respiratory Tract

5. The nose • Bone and cartilage support the nose internally • Two nostrils or nares • Air enters and leaves through here • Internal hairs guard nostrils • Prevents larger particles carried in air

6. The nasal cavities • Hollow space behind the nose • Divided into narrow canals separated from each other by cartilage and bone – nasal septum. • Nasal conchae • bones and bony processes that divide the cavity into passageways • Support the mucous membrane • Increases surface area • Pseudostratified ciliated columnar epithelium • Secretes mucous from goblet cells • Water evaporates from this lining moistening the air • Mucus traps debris coming in with the air • Lined with blood vessels • As air enters, heat from blood transfers to air and warms it • Adjusts air temp to body temp

7. Paranasal sinuses • Air filled spaces within the frontal, ethmoid, sphenoid and maxillary bones of the skull and opening into the nasal cavity. • Lined with mucous membranes – continuous with the lining of the nasal cavity • Reduce the weight of the skull • Resonance chambers that affect quality of voice

8. Pharynx, or Throat • Funnel shaped passage way that connects the nasal and oral cavities to the larynx • Passage way for food moving to esophagus, and air moving to the larynx • Helps to produce sound of speech • Has three parts: • Nasopharynx: where the nasal cavities open above the soft palate • Oropharynx: where the oral cavity opens • Laryngopharynx: area that opens up into the larynx

9. Pathway of air through the upper respiratory system. • REMEMBER!!!! Each time that you take a breath, there are three very important things that happen. 1. The air that you breathe in is cleaned by tiny hairs in your nose, trapping little bits of dirt and dust and germs that come in through your nose. 2. As you breathe, the air is made slightly wet. Your nose having damp passages does this. 3. The next thing that takes place when air enters your nose is that the air is warmed. This happens because the blood flows through the lining of the nose and gives off heat.

10. Snot and more.. Protecting us from harm • Snot: • "Snot", is just another word for mucus. When bits of stuff get stuck in your nose hairs, it’s the mucus or snot that surrounds the stuff and traps it. • Boogers: • Boogers are dried-up snot and dirty nose debris. • Encrusted mucus is filled with the junk that’s in the air you breathe - dust, pollen, germs, sand, fungi, smoke, small particles from outer space.

11. And now for the mucus model… Achoo…

12. Mucus model? – How does it compare to the real thing? • Model made up of gelatin (protein) and corn syrup (sugar) • Mucus is made mostly of sugars and protein. • The long, fine strings you could see inside your fake snot when you moved it around are protein strands. • These protein strands make snot sticky and capable of stretching

13. CHECK IT! Complete the questions for a stamp.. 

14. THINK ABOUT IT: • WHAT ORGANS ARE APART OF THE LOWER RESPIRATORY TRACT? Major Organs Accessory Organs Larynx, or voicebox Glottis Trachea, or windpipe epiglottis The bronchial tree Diaphragm The lungs

15. The Lower Respiratory System

16. Larynx, or voicebox • Cartilaginous structure that serves as a passageway for air between the pharynx and trachea. • A triangular box • top of the triangle is located to the front of the neck (Adam’s apple) • Framework of muscles and cartilage • Thyroid cartilage • Cricoid cartilage • Epiglottic cartilage • Houses the vocal cords • Allows for air in and out of the trachea • Prevents foreign objects entering into trachea

17. Vocal Cords • Vocal folds • Composed of muscle tissue and connective tissue • Covered with mucous membrane • False vocal cords • Upper folds • Do not produce sound • Muscle fibers help close airway when swallowing • True vocal cords • Muscle tissue and elastic fibers • Forced air between TVC causes them to vibrate and produce sound • Words = changing shapes of pharynx, oral cavity; and use of the tongue • Pitch= contracting or relaxing muscles that alter tension

18. Glottis • Opening between vocal cords • Durning normal breathing, relaxed vocal cords, the glottis opens • During swallowing/ eating, muscles around the false vocal cords contract, the glottis closes.

19. Epiglottis • A flap of soft tissue above the vocal cords • The larnyx will move upward against the epiglottis when swallowing to prevent food, water and saliva from entering the lungs.

20. The trachea, or windpipe • A tube that connects the larynx to the primary bronchi • Walls consist of connective tissue and smooth muscle • Reinforced by c-shaped cartilaginous rings • Prevents the trachea from collapsing • Lies anterior to the esophagus • Soft tissue that completes the c-rings, allow for esophagus to expand as food moves through • The outermost layer of the mucous membrane that lines the trachea is pseudostratified columnar epithelium with goblet cells. • Traps particles and moves it upwards to pharynx to be swallowed

21. The Bronchial Tree • Tubes that allow air to pass through, and are reinforced with cartilaginous rings, like the trachea. • Divided into the left and right primary bronchi, which lead into the lungs • Divison is located in the mediastinum, approximately at the level of the 5th thoracic vertebrae • Branch into the secondary bronchi • tertiary bronchi • keep dividing until they are about 1 mm in diameter • Bronchi that are 1 mm in diameter are called bronchioles • Terminal bronchioles • Respiratory bronchioles • Alveolar ducts • Alveolar sacs • Alveoli

22. The Lungs • Paired, cone-shaped organs • Separated by the mediastinum • Diaphragm and rib cage enclose them • Suspended by the bronchus and major blood vessels • Visceral pleura surrounds each lung • Continues to the parietal pleura which attaches and surounds the throacic cavity • Potential space between the pleura = pleural cavity • Filled with serous fluid • Reduces friciton of lungs moving against the thoracic cavity during breathing • Right lung has three lobes, the left lung only two – due to the heart pointing towards the left • Broken even further into lobules, which house bronchioles serving the alveoli

23. The Alveoli • Lungs have about 300 million alveoli • Each alveoli sac is surrounded by blood capillaries • Made up of simple squamous epithelium • This is the site where gas exchange happens

24. Be sure to complete the following • Your check it questions • The diagram at the back of the packet

25. WARM UP! • Why is it important for the capillaries from the cardiovascular system to be numerous and surround the alveoli? • When finished with the question, take a moment and breathe – notice what happens. Write it down.

26. Cardio/ Respiratory connection • Oxygen diffuses from alveolar walls and enters the blood.(where it can now go to other cells in the body) • Carbon Dioxide diffuses from the blood through the walls and enters the alveoli. (where it can be exhaled and released)

27. Alveoli Exchange of Gases: Using the picture below EXPLAIN the gas exchange process:

28. Why do the blood cells start blue and then turn red?

29. CHECK IT!

30. Breathing, or ventilation • Has two phases • Inspiration – moving air into the lungs • Expiration –moving air out of the lungs

31. Inspiration • Active phase of ventilation • In this phase the diaphragm and muscles of the ribcage contract – diaphragm moves downward and looks flattened • The volume of the thoracic cavity will increase, so does the lung volume • The pressure within the alveoli is less than the pressure outside in the atmosphere. There is a difference in pressure (or pressure gradient) and air will move into the body naturally.

32. Pressure and volume have an inverse relationship • Pressure inside the lungs and alveoli decrease, atmospheric pressure will push outside air into airways • During this time the pressure in the alveoli drops 2mmHg below atmospheric pressure • In response, atmospheric pressure forces air into the airways • The external intercostal muscles between ribs are stimulated and move the ribs and sternum upwards • Enlarges thoracic cavity even further • Internal pressure is further reduced; increases amount of air into the lungs

33. Water within the serous fluid found in between the visceral and parietal pleura creates an attraction between the pleura, and the membranes move upward during inspiration • This expands the lung in all directions. • Too much water in the alveolar sacs creates a surface tension that may collapse the alveoli. • Certain cells within the alveoli secrete a surfactant – lipids and proteins • Fills the alveolar air spaces – reducing the tendency to collaspe, especially when lung volumes are low • Makes it easier to inflate alveoli

34. Expiration • Passive phase of ventilation • Come from elastic recoil and surface tension • No effort is required for air to leave the body • Diaphragm and muscles of the ribcage relax – diaphragm looks cone shaped • Pressure within the alveoli increases to about 1mmHg above atmospheric pressure • Forces the air out of the lungs • The volume of the thoracic cavity will decrease, so does the lung volume

35. Maximum inspiration and forced expiration Maximum inspiration Forced expiration • Involves muscles of the back, chest, and neck • Thoracic cavity increases more than normal, for maximum lung capacity • Usually during exercise • Contraction of the ribcage muscles forces the ribcage to move downward and inward • Involves the abdominal muscles pushing against the abdominal organs which pushes against the diaphragm, pushing more out of the lungs • Usually during exercise, singing, playing an instrument, or blowing out a candle

36. CHECK IT! And then the activity.

37. Volumes of Air in the Lungs Warm UP: Are our lungs ever void of air? Why or why not?

38. Volumes of air within the lungs during ventilation • Why do we need to know this? • Knowing the amounts of air in the lungs and how it flows through the respiratory system helps to diagnose respiratory issues

39. Respiratory Air Volumes and Capacities • Spirometry is the test that measures air volumes in or out of the lungs. • Three distinct repiratory volumes can be measured: • Resting Tidal volume • Inspiratory reserve volume • Expiratory reserve volume • One inspiration + one expiration = respiratory cycle. • Air that enters of leaves during a respiratory cycle is the tidal volume

40. Respiratory cycle: One inspiration plus one expiriation. (Breathe in- breathe out) • Resting Tidal volume- the normal amount of air that enters the lungs and leaves the lungs during a respiratory cycle. • The average is about 500 milliliters of air per breath in and the same amount out.

41. During Tidal volume you do not use the total amount of space in your lungs! They only use about 75-80%

42. Inspiratory Reserve Volume: When you take a deep breath in to hold more air than a usual breath. “Forced inhalation”. • Expiratory Reserve Volume: Forced expiration. Expelling air beyond the tidal volume. Even after the most forceful exhale however you still have air left in your lungs. • This left over air is called the Residual Volume.

43. 4. 2. 1. 5. 3. 6.

44. Vital Capacity: Combining the tidal volume with both the inspiratory reserve volume and the expiratory reserve volume. • Total Lung Capacity: The vital capacity plus the residual volume. All the possible air that can come into or out of the lungs, including the air that never leaves the lungs.

46. Fill in the following table with the appropriate terms:

47. Respiratory centers and control of breathing… • Medullary respiratory center- controls both inspiration and expiration • Found within the pons and medulla oblongata • Medulla oblongata has two groups • Ventral respiratory group – controls basic rhythm • Dorsal respiratory group- controls the diaphragm

48. Factors that Affect breathingflow charts.. CHECK IT! • PP. 456- 458 • Create flow charts for the following factors that affect breathing • CO2 levels • O2 levels • Depth of breathing • Emotional upset • Holding your breath • Hyperventilation

49. Location: The alveoli Method: Diffusion How and why Gas Exchange happens:

50. Partial pressure: In a mixture of gases such as air or blood, each gas accounts for a portion of the total pressure the mixture produces. The amount of pressure each gas contributes is the partial pressure.