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Unit 3 respiratory system and gas exchange(3)

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Mahlatse Mokoena
Mahlatse Mokoena

The document describes the process of respiration in terrestrial vertebrates. It involves 3 main steps: 1) ventilation of the lungs through inspiration and expiration, 2) external respiration which is the gas exchange between air in the lungs and blood, and 3) internal respiration where gases are exchanged between blood and body tissues. Oxygen is transported via hemoglobin in red blood cells to tissues for cellular respiration while carbon dioxide is transported back to the lungs, mostly as bicarbonate ions in plasma. The lungs and respiratory tract feature adaptations for effective gas exchange including an extensive surface area in the alveoli.

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Unit 3 respiratory system and gas exchange(3)
Sequence of events that results in gas exchange. In terrestrial vertebrates it includes 3 steps: 1. Ventilation: Inspiration and expiration. 2. External respiration: Gas exchange between air (in lungs) and blood. Blood then transport Oxygen to the body tissue cells. 3. Internal respiration: Gas exchange between blood and tissue fluid. Blood then transports carbon dioxide to the lungs.
External respiration Internal respiration oxygenCarbon dioxide oxygen Carbon dioxide Alveoli filled with air (gas) Body cells surrounded by tissue fluid Blood part of circulatory system contain red pigment hemoglobin, to transport gasses Gas exhange surface must be: Moist Thin Large in relation of size of body Process: Diffusion of gasses (oxygen and carbon dioxide
Is the process whereby an organism uses oxygen and food to produce energy (ATP) and 2 by products e.g. water and carbon dioxide Glucose + O2 ATP + H2O + CO2 Therefore gaseous exchange is necessary to get oxygen for cellular respiration.
Consists of: 1. Nose 2. Air passages: Pharynx Trachea Bronchus Bronchioles 3. Lungs Alveoli
Nose has a nasal cavity that leads to the pharynx. Nasal cavity is lined with cilia and hairs and goblet cells that make mucus (anti- septic and moisten air) filter the air dust, pollen and other foreign material sticks to it. 3 x turbinate bones divide the nasal cavity into 4 passages This enlarges the surface of the nasal cavity For warming, cleaning and moisten of air. Several surface blood vessels help to warm air.
Pharynx pass air form nose to trachea via larynx. Trachea: long, straight tube kept open by C-shaped cartilage rings. Trachea lined with cilia and goblet cells (mucus production) traps foreign particles
CILIA (SEM) TRACHEAL LINING
Trachea divides in a right and left bronchus consist of C-shaped cartilage rings and lined with goblet cells (mucus) Bronchi branch in lung to form bronchioles branch further and cartilage rings disappears lead air to air sacs of lung. Bronchiole Left bronchus long, branch in 2 Right bronchus-short Branch in 3
Right lung (3 lobes - shorter) and left lung (2 lobes longer, narrow) Spongy, elastic pink organ. Consists of several air sacs called alveoli. Alveoli are grouped together and form the endings of the bronchioles.
Lined with single layer squamous epithelial cells Thin easy diffusion of gas. Alveoli is surrounded by a network of blood capillaries gasses diffuse into and out of blood. Alveoli is lined with moist layer oxygen dissolves in moisture and diffuses through alveoli wall into blood capillary.
SEM TEM Alveoli Pulmonary artery (Deoxygenated blood) Pulmonary vein (Oxygenated blood) Diaphragm Bronchiole Bronchus Trachea Pharynx Turbinate bones
INSPIRATION INSPIRATION EXPIRATION EXPIRATION Diaphragm contracts (moves down) Diaphragm relaxes (moves up) Rib cage expands as rib muscles contract Rib cage gets smaller as rib muscles relax Air inhaled Air exhaled When pressure in lungs decrease air rush in When pressure in lungs increase air is pushed out
Air moves in and out of the body via the same route. All terrestrial vertebrates do this except for birds. The lungs are not completely emptied during each breathing cycle. The air entering mixes with used air remaining in the lungs.
A spyrometer can be used to determine how much air enters the lungs. Your lungs has a volume of +/- 5 liters. During a normal breath, only 0.5 liters of air is exchanged This air is known as tidal volume. During forced breathing, as much as 3.5 liters of air can be exchanged, this is known as vital capacity. (The fitter you are, the higher your vital capacity.) +/- 1.5 liters of air always remains in the lungs this air is known as residual air/volume.
Unit 3 respiratory system and gas exchange(3)
Normal breathing rate for adults: 12 20 ventilations per minute. Respiratory Center in the Medulla Oblongata of the brain controls breathing. The respiratory center send impulses through the phrenic nerve to the diaphragm and through the intercostal nerve to the intercostal muscles to either contract or relax. (Contract during inspiration and relax during expiration)
Brain Respiratory center automatically regulates breathing Intercostal nerves stimulate the intercostal muscles Intercostal muscles Pheric nerve stimulates the diaphragm Diaphragm
EXTERNAL RESPIRATION INTERNAL RESPIRATION Gas exchange between air in lungs and blood Movement driven by diffusion gradient. ( [] to []) Gasses exerts pressure, the amount of pressure each gas exerts is called partial pressure (PO2 and PCO2 ) Gas exchange between blood and tissue fluid Movement driven by diffusion gradient. ( [] to []) Gasses exerts pressure, the amount of pressure each gas exerts is called partial pressure (PO2 and PCO2 )
If PO2 differs across a membrane oxygen will diffuse from a high to a low pressure. If PCO2 differs across a membrane carbon dioxide will diffuse from a high to a low pressure. During inspiration the alveoli fills with air higher PO2 and lower PCO2 than blood. Oxygen diffuse from alveoli into blood and carbon dioxide diffuse from blood into alveoli.
When blood reaches the tissue, cellular respiration in cells causes the tissue fluid to have a lower PO2 and a higher PCO2 than the blood. Thus oxygen diffuse from a high pressure in the blood to a low pressure in the tissue fluid and eventually in the tissue cells. Carbon dioxide diffuse from a high pressure in the tissue fluid to a low pressure in the blood.
Unit 3 respiratory system and gas exchange(3)
Most oxygen is transported by hemoglobin (red pigment protein in erythrocytes). Oxygen combines with hemoglobin to form oxyhemoglobin. Hb + O2 = HbO2 Hemoglobin Oxygen Oxyhemoglobin A small amount of oxygen is transported in solution in the blood plasma.
Each red blood cell carries 250 million Hb molecules = 1 Billion Oxygen molecules Consist of 4 polypeptide chains (protein 2 alpha and 2 beta). Each chain is associated with a heme group. Each heme group contains an iron atom. Iron binds with oxygen.
Most CO2 is transported as bicarbonate ions (HCO3 -) HOW? FIRST CO2 binds with water to form carbonic acid (H2CO3) CO2 + H2O = H2CO3 Then carbonic acid dissociates to form hydrogen and bicarbonate ions. H2CO3 = H+ + HCO3 -
A small amount of carbon dioxide is transported by the Hemoglobin molecules in the form of carbaminohemoglobin (HbCO2). CO2 + Hb = HbCO2 The higher the amount of hydrogen ions in the blood the lower the pH. Therefor hydrogen ions bond with the globin part of Hb to keep the pH normal in the blood.
The following lower respiratory tract disorders are caused by exposure to infectious pathogens and / or polluted air, including tobacco smoke. Pneumonia Pulmonary Fibrosis Pulmonary Tuberculosis Emphysema Bronchitis Asthma
Bacteria streptococcus can cause pneumonia Alveoli fill with pus and fluid making gas exchange difficult X-ray of a patient with pneumonia
Fibrous connective tissue builds up in lungs, reducing their elasticity and Oxygen diffusion.
Caused by a bacillus bacterium
Alveoli burst and fuse into enlarged air spaces. Surface area for gas exchange is reduced.
Airways are inflamed due to infection (acute) or due to an irritant (Chronic). Coughing brings up mucus and pus.
Airways are inflamed due to irritation and bronchioles constrict due to muscle spasms
Smoking causes almost 90% of all lung cancers and is also a major cause of emphysema. Healthy normal lung of a non- smoker Lung of a smoker
Lung with large tumors causing lung cancer

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Unit 3 respiratory system and gas exchange(3)

  • 2. Sequence of events that results in gas exchange. In terrestrial vertebrates it includes 3 steps: 1. Ventilation: Inspiration and expiration. 2. External respiration: Gas exchange between air (in lungs) and blood. Blood then transport Oxygen to the body tissue cells. 3. Internal respiration: Gas exchange between blood and tissue fluid. Blood then transports carbon dioxide to the lungs.
  • 3. External respiration Internal respiration oxygenCarbon dioxide oxygen Carbon dioxide Alveoli filled with air (gas) Body cells surrounded by tissue fluid Blood part of circulatory system contain red pigment hemoglobin, to transport gasses Gas exhange surface must be: Moist Thin Large in relation of size of body Process: Diffusion of gasses (oxygen and carbon dioxide
  • 4. Is the process whereby an organism uses oxygen and food to produce energy (ATP) and 2 by products e.g. water and carbon dioxide Glucose + O2 ATP + H2O + CO2 Therefore gaseous exchange is necessary to get oxygen for cellular respiration.
  • 5. Consists of: 1. Nose 2. Air passages: Pharynx Trachea Bronchus Bronchioles 3. Lungs Alveoli
  • 6. Nose has a nasal cavity that leads to the pharynx. Nasal cavity is lined with cilia and hairs and goblet cells that make mucus (anti- septic and moisten air) filter the air dust, pollen and other foreign material sticks to it. 3 x turbinate bones divide the nasal cavity into 4 passages This enlarges the surface of the nasal cavity For warming, cleaning and moisten of air. Several surface blood vessels help to warm air.
  • 7. Pharynx pass air form nose to trachea via larynx. Trachea: long, straight tube kept open by C-shaped cartilage rings. Trachea lined with cilia and goblet cells (mucus production) traps foreign particles
  • 9. Trachea divides in a right and left bronchus consist of C-shaped cartilage rings and lined with goblet cells (mucus) Bronchi branch in lung to form bronchioles branch further and cartilage rings disappears lead air to air sacs of lung. Bronchiole Left bronchus long, branch in 2 Right bronchus-short Branch in 3
  • 10. Right lung (3 lobes - shorter) and left lung (2 lobes longer, narrow) Spongy, elastic pink organ. Consists of several air sacs called alveoli. Alveoli are grouped together and form the endings of the bronchioles.
  • 11. Lined with single layer squamous epithelial cells Thin easy diffusion of gas. Alveoli is surrounded by a network of blood capillaries gasses diffuse into and out of blood. Alveoli is lined with moist layer oxygen dissolves in moisture and diffuses through alveoli wall into blood capillary.
  • 13. INSPIRATION INSPIRATION EXPIRATION EXPIRATION Diaphragm contracts (moves down) Diaphragm relaxes (moves up) Rib cage expands as rib muscles contract Rib cage gets smaller as rib muscles relax Air inhaled Air exhaled When pressure in lungs decrease air rush in When pressure in lungs increase air is pushed out
  • 14. Air moves in and out of the body via the same route. All terrestrial vertebrates do this except for birds. The lungs are not completely emptied during each breathing cycle. The air entering mixes with used air remaining in the lungs.
  • 15. A spyrometer can be used to determine how much air enters the lungs. Your lungs has a volume of +/- 5 liters. During a normal breath, only 0.5 liters of air is exchanged This air is known as tidal volume. During forced breathing, as much as 3.5 liters of air can be exchanged, this is known as vital capacity. (The fitter you are, the higher your vital capacity.) +/- 1.5 liters of air always remains in the lungs this air is known as residual air/volume.
  • 17. Normal breathing rate for adults: 12 20 ventilations per minute. Respiratory Center in the Medulla Oblongata of the brain controls breathing. The respiratory center send impulses through the phrenic nerve to the diaphragm and through the intercostal nerve to the intercostal muscles to either contract or relax. (Contract during inspiration and relax during expiration)
  • 18. Brain Respiratory center automatically regulates breathing Intercostal nerves stimulate the intercostal muscles Intercostal muscles Pheric nerve stimulates the diaphragm Diaphragm
  • 19. EXTERNAL RESPIRATION INTERNAL RESPIRATION Gas exchange between air in lungs and blood Movement driven by diffusion gradient. ( [] to []) Gasses exerts pressure, the amount of pressure each gas exerts is called partial pressure (PO2 and PCO2 ) Gas exchange between blood and tissue fluid Movement driven by diffusion gradient. ( [] to []) Gasses exerts pressure, the amount of pressure each gas exerts is called partial pressure (PO2 and PCO2 )
  • 20. If PO2 differs across a membrane oxygen will diffuse from a high to a low pressure. If PCO2 differs across a membrane carbon dioxide will diffuse from a high to a low pressure. During inspiration the alveoli fills with air higher PO2 and lower PCO2 than blood. Oxygen diffuse from alveoli into blood and carbon dioxide diffuse from blood into alveoli.
  • 21. When blood reaches the tissue, cellular respiration in cells causes the tissue fluid to have a lower PO2 and a higher PCO2 than the blood. Thus oxygen diffuse from a high pressure in the blood to a low pressure in the tissue fluid and eventually in the tissue cells. Carbon dioxide diffuse from a high pressure in the tissue fluid to a low pressure in the blood.
  • 23. Most oxygen is transported by hemoglobin (red pigment protein in erythrocytes). Oxygen combines with hemoglobin to form oxyhemoglobin. Hb + O2 = HbO2 Hemoglobin Oxygen Oxyhemoglobin A small amount of oxygen is transported in solution in the blood plasma.
  • 24. Each red blood cell carries 250 million Hb molecules = 1 Billion Oxygen molecules Consist of 4 polypeptide chains (protein 2 alpha and 2 beta). Each chain is associated with a heme group. Each heme group contains an iron atom. Iron binds with oxygen.
  • 25. Most CO2 is transported as bicarbonate ions (HCO3 -) HOW? FIRST CO2 binds with water to form carbonic acid (H2CO3) CO2 + H2O = H2CO3 Then carbonic acid dissociates to form hydrogen and bicarbonate ions. H2CO3 = H+ + HCO3 -
  • 26. A small amount of carbon dioxide is transported by the Hemoglobin molecules in the form of carbaminohemoglobin (HbCO2). CO2 + Hb = HbCO2 The higher the amount of hydrogen ions in the blood the lower the pH. Therefor hydrogen ions bond with the globin part of Hb to keep the pH normal in the blood.
  • 27. The following lower respiratory tract disorders are caused by exposure to infectious pathogens and / or polluted air, including tobacco smoke. Pneumonia Pulmonary Fibrosis Pulmonary Tuberculosis Emphysema Bronchitis Asthma
  • 28. Bacteria streptococcus can cause pneumonia Alveoli fill with pus and fluid making gas exchange difficult X-ray of a patient with pneumonia
  • 29. Fibrous connective tissue builds up in lungs, reducing their elasticity and Oxygen diffusion.
  • 30. Caused by a bacillus bacterium
  • 31. Alveoli burst and fuse into enlarged air spaces. Surface area for gas exchange is reduced.
  • 32. Airways are inflamed due to infection (acute) or due to an irritant (Chronic). Coughing brings up mucus and pus.
  • 33. Airways are inflamed due to irritation and bronchioles constrict due to muscle spasms
  • 34. Smoking causes almost 90% of all lung cancers and is also a major cause of emphysema. Healthy normal lung of a non- smoker Lung of a smoker
  • 35. Lung with large tumors causing lung cancer