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The Respiratory System

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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.

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", 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… What you'll need: Boiling water (be careful with this) A cup Gelatin Corn syrup A teaspoon A fork Instructions: Fill half a cup with boiling water. Add three teaspoons of gelatin to the boiling water. Let it soften before stirring with a fork. Add a quarter of a cup of corn syrup. Stir the mixture again with your fork and look at the long strands of gunk that have formed. As the mixture cools slowly add more water, small amounts at a time.

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.. 

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 False vocal cords True vocal cords
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?


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
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
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 breathing flow charts.. CHECK IT!
PP Create flow charts for the following factors that affect breathing CO2 levels O2 levels Depth of breathing Emotional upset Holding your breath Hyperventilation

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

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.

51 Diffusion of Gases: When blood reaches the alveolus / lungs the blood is oxygen poor- it has depleted its oxygen source to the rest of the body and needs to “pick up more”.

52 Diffusion of Gases: Due to the pressure gradient, oxygen will move from the alveoli to the blood stream. In other words, there is more oxygen in the alveoli than the bloodstream, so oxygen will naturally move into the bloodstream.

53 So what about Carbon Dioxide?
Carbon dioxide will be or in the bloodstream. higher lower Carbon dioxide will or the bloodstream into the alveoli where it will be expelled out of the body. move into out of

54 Color and label the diagram


56 Factors affecting release of O2
Increase in CO2 concentration= increase in O2 release If blood Becomes acidic Temperate increases More O2 is released to skeletal muscle during physical activity; less O2 released to non active cells HYPOXIA – deficiency of O2 reaching tissues

57 GAS TRANSPORT - OXYGEN OXYHEMOGLOBIN HEMOGLOBIN PO2is high – oxygen dissolves in blood and combines with hemoglobin to form oxyhemoglobin Unstable bonding As PO2 decreases in the body, O2 is released from oxyhemoglobin O2 diffues across the membrane of cells to be used in cellular respiration 98% of oxygen in blood binds to hemoglobin a protein in red blood cells that carries oxygen


59 CO2 Transport Capillary blood gains CO2, as tissues have increased levels of PCO2 Transported in three ways to the lungs: Dissolved in plasma Bound to hemoglobin Bicarbonate ions Amount of CO2 dissolved in plasma dependent on its partial pressure Increased PCO2 = more CO2 in solution Only 7% of CO2 transports in this form

60 GAS TRANSPORT CO2 loosely bonds with hemoglobin = carbaminohemoglobin
Bicarbonate Ions CO2 loosely bonds with hemoglobin = carbaminohemoglobin Decomposes readily in regions of low PCO2 – releasing CO2 Only about 23% of the CO2 carried in the blood is formed in molecule, as this reaction happens slowly Most important CO2 transport mechanism CO2+ H2O => H2CO3 (carbonic acid) Occurs slowly in plasma Carbonic anhydrase speeds up reaction, releasing H+ and HCO3- (bicarbonate ions) Bicarbonate ions diffuse into the plasma – 70% of all CO2 in blood is transported this way

61 CO2 Transport Continued
Plasma release CO2 Dissolved CO2 diffuses into the alveoli (alveoli PCO2 is low Bicarbonate Ions Release CO2 As blood passes through the capillaries of the lungs At same time H+ and HCO3- combine to make H2CO3 under influence of carbonic anhydrase H2CO3 breaks down quickly to form CO2 and H2O CO2 then diffuses into the alveolus

62 CO2 Transport Continued
Carbaminohemoglobin release of CO2 As blood passes through the capillaries of the lungs Release of CO2 happens Will continue until PCO2 of blood and alveolar air are at equilibrium


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