2 The Respiratory System Respiration: The exchange of oxygen & carbon dioxide between an organism & its external environment.The respiratory system supplies oxygen to cells & removes carbon dioxide.
3 Components of Respiration Breathing (Ventilation)External RespirationInternal RespirationCellular Respiration
4 Breathing (Ventilation) Inhalation: Oxygen is taken in from the external environment.Exhalation: Carbon dioxide is removed from the internal environment.
5 External Respiration Gas exchange between the alveoli & blood. Oxygen diffuses into the alveoli & carbon dioxide diffuses out.The alveoli must be moist to allow for diffusion.The blood carries the oxygen from the lungs to the body cells.
7 Internal Respiration Gas exchange between the blood &the body cells. Oxygen diffuses out of the blood & carbon dioxide diffuses in.Allows cellular respiration to occur.
8 Cellular Respiration Occurs in the mitochondria of every cell. Cells produce energy (ATP) when glucose is broken down in the presence of oxygen.Byproducts include carbon dioxide & water
9 Anatomy of the Respiratory System Analogous to an upside-down tree.Components:NoseNasal & oral cavitiesPharynxLarynxTracheaBronchi & bronchiolesAlveoliRespiratory Basics - Learning Activity - Flash Player Installation
10 The Upper Respiratory Tract NoseStructure: Two nostrils separated by cartilage and soft boneFunctions: Air that is breathed in through the nose is:Warmed by heat in the capillaries in the noseDampened when it passes over the mucus lining of the noseCleaned by cilia that sweep dirt into the mucusFiltered by hairs that remove large particles
11 Pharynx (throat) Structure: a muscular tube Function: the pharynx is necessaryfor:a) breathing: the pharynx connectsthe 2 nasal passages to the larynxwhich leads to the tracheab) maintaining air pressure: the Eustachain tube is found in the middle ear and opens into the pharynx and is able to equalize the pressure inside the ear to atmospheric pressurec) Swallowing: during swallowing, the soft palate rises to block the opening to the nose. A small flap of cartilage, the epiglottis, slides closed to cover the entrance to the trachea.
12 Larynx Structure: -the first part of the trachea - contains tightly stretched cords (vocal cords)- while breathing they lie against the wall, while speaking they move forwardFunction: forcing air over them causes the cords to vibrate and allows us to speakthe loudness is determined by how hard we breathe outthe pitch is determined by how tight the cords arethe quality is determined by amplifiers (mouth, nose, lungs)N.B. Men have longer vocal cords therefore their voices are lower
13 TracheaStructure: a 10 cm tube extending from the larynx to the branches of the bronchiAll breathing tubes are held open by C-shaped rings of cartilage that prevent the tubes from collapsingFunction: passage wayfor air
14 The Lower Respiratory Tract BronchiStructure: the base of the trachea divides into 2 tubes called bronchi-one bronchus goes into the left lung and one to the right lung-inside the lungs, the bronchi branch out into smaller tubes called bronchioles which spread all over the lungsFunction: passageway for air
15 AlveoliStructure: inside of our two lungs are 300 million air sacs called alveoli, found in clusters at the ends of bronchioles (allows more surface area)- each alveolus is surrounded by blood capillaries- each alveolus is covered in a film of moistureFunction: the oxygen in the air that enters the alveoli during inhalation dissolves in the moisture and diffuses into the capillaries- the O2 is absorbed by molecules of hemoglobin, a pigment in red blood cells, and transported to the heart.- CO2 dissolved in water, passes from the capillaries into the alveoli to be breathed outTherefore, this process is called gas exchange, and the two systems involved are the alveoli and the capillaries.
17 Lungs Structure: 2 large spongy organs that fill nearly the entire thoraciccavity (chest)- the left lung is slightly smaller(2 lobes) b/c the heart sits on it,whereas the right lung has 3 lobes- the lungs contain the bronchi, bronchioles, alveoli, and capillaries- enveloped in layers of tissue called pleuraFunction: expand and contract to fill up with gas
18 Structure: a membrane (sac) that covers the lungs PleuraStructure: a membrane (sac) that covers the lungs- between the pleura and the lungs is a fluid that acts as a lubricantFunction: applies pressure equally to all parts of the lungs allowing inhalation and exhalationAnimation: The Pleural Membranes
19 Pleurisy: Inflammation of the pleura that causes when you take a breath or cough; the smooth lining of the lungs becomes roughPleural effusion: fluid collecting aroundthe lungs; resultingfrom TB infections
20 How is O2 taken up?Oxygen diffuses to the cells of the capillaries, to the blood plasma, and then across the cell membranes of red blood cellsIn the red blood cells, the oxygen forms a bond with hemoglobin.Hemoglobin + O2 oxyhemoglobin (HbO2 -)The red blood cells circulate rapidly in the bloodstream transporting oxygen to all body cells. (A very small amount of dissolved O2 is carried in blood plasma)
21 How is CO2 removed?Diffusion from cells to the blood ~ 9% is held in the plasmaAbout 27% attaches to hemoglobin and is carried by RBCs to lungs64% combines with water to form bicarbonate (HCO3) and hydrogen ions (H+)CO2 + H2O H2CO3H2CO3 H+ + HCO3
22 Hydrogen ions are very reactive and can be fatal in high concentrations therefore they must be removedThe H+ is taken up by oxyhemoglobin. When this happens, the oxygen is released by the oxyhemoglobin and goes into the cells to be used for cellular respiration.The H+ then react with HCO3 releasing CO2 and H2O which are both released by the lungs.Respiratory system | Flash simulation, Animation, Illustration, Picture, Diagram