B5 The Respiratory System Review Flashcards
What are the stages in respiration?
- Breathing: involves inhalation and exhalation
- External respiration
- Internal respiration
- Cellular respiration
What is external respiration?
-Exchange of oxygen and carbon dioxide between the air and the blood
What is internal respiration?
-Exchange of oxygen and carbon dioxide between the body tissues and blood
What is cellular respiration?
-Series of energy releasing chemical reactions in the cells
-produces energy (ATP) for all cellular activities
Describe nasal passages
-Warms, moistens, and cleans incoming air
-cilia moves foreign particles into the nose and throat to be coughed or sneezed out
-mucous cleans air by trapping foreign particles
What is the pharynx?
-Air filled channel in the mouth
-2 openings branch into the esophagus (stomach) and the trachea (lungs)
Describe the larynx
-Voice box
-composed of 2 thin sheets of elastic ligaments called vocal cords
-vocal cords vibrate as air is forced from the lungs towards the pharynx
-different sounds are caused by a change in vocal cord tension
Describe the trachea
-Windpipe
-contain ciliated cells which produce mucous
-the mucous traps debris
-cilia sweep the debris from the windpipe
-the wall is supported by cartilage rings which keep the trachea open
Bronchi (bronchus singular)
-Contain cartilage rings
-bronchioles are smaller airway branches that don’t contain cartilaginous rings ~60 000
Describe Alveoli (alveolus singular)
-Tiny blind ended sacs ~300 million
-each alveolus is surrounded by capillaries
-gases diffuse between air and blood according to the concentration gradient (passive transport)
-single layer of cells permit rapid fade exchange
-during inhalation the alveoli are bulb shaped but during exhalation the sacs collapse
-to avoid sticking together there is a film of lipoprotein (non stick)
-allows alveoli to pop during inhalation
What is respiratory distress syndrome?
-Some new born babies do not produce enough lipoprotein
What is the pleural membrane?
-Lines the inner wall of the thoracic (chest) cavity
-filled with fluids that reduce friction between the lungs and the thoracic cavity
What is the diaphragm?
-A sheet of muscle that separates the organs of the thoracic cavity from those of the abdominal cavity
Where are intercostal muscles located?
-Found between the ribs and along the inside surface of the ribs
Describe inhalation
-Inspiration: breathing in
-begins when the external rib muscles and the diaphragm contract
-rib cage expands up and outward
-diaphragm flattens (down)
-increase in volume therefore the air pressure in the thoracic cavity decreases
-air moves with its pressure gradient (high to low pressure) from the environment to the lungs
Describe exhalation
-Expiration: breathing out
-begins when the diaphragm and the rib muscles relax
-reduces the volume of thoracic cavity
-lung volume decreases and air pressure increases
-air moves from lungs to environment
What is a Spirograph?
-Represents the amount of air that moves into and out of the lungs with each breath
What is tidal volume?
-Volume of air that is inhaled and exhaled in a normal breath
-average is 500 mL
What is inspiratory reserve volume?
-Additional volume of air that can be taken into the lungs beyond tidal inhalation
-average is 3000 mL
What is expiratory reserve volume?
-Additional volume of air that can be forced out the lungs beyond tidal volume
-average is 1200 mL
What is vital capacity?
-Total volume of gas that can be taken into and forced out the lungs
-average is 3000-5000 mL
-vital capacity = tidal volume + inspiratory reserve volume + expiratory reserve volume
What is residual volume?
-Amount of gas that remains in the lungs and respiratory system passageways even after full exhalation
-necessary so the lungs don’t collapse
What is Dalton’s law of partial pressure?
-Each gas in a mixture exerts it’s own pressure, which is proportional to the total value
-gases diffuse from an area of high partial pressure to areas of low partial pressure
What are external respirations?
-Gases exchanged between the alveoli and the blood in capillaries
What is inspiratory respiration?
-Occurs when oxygen and carbon dioxide are exchanged in the tissues
How is oxygen transported in the blood?
- By hemoglobin (99%)
- Dissolved in the blood
How is carbon dioxide transported in the blood?
- By hemoglobin (23%)
- Carried in plasma (7%)
- Dissolved in the blood as a bicarbonate ion (70%)
How does carbon dioxide get dissolved in the blood as a bicarbonate ion?
-Carbon dioxide combines with water to from carbonic acid
-carbonic acid breaks down and dissociates into a hydrogen ion and a bicarbonate ion (occurs in RBC)
-the hydrogen combines with hemoglobin
-the bicarbonate ion diffuses into the plasma
What are chemoreceptors?
-Specialized nerve receptors that are sensitive to specific chemicals
-2 are involved: oxygen chemoreceptors and carbon dioxide or acid chemoreceptors
-carbon dioxide are the most sensitive and the main regulators
Describe carbon dioxide chemoreceptors
-CO2 dissolves in the blood and forms an acid (carbonic acid)
-once CO2 accumulates the chemoreceptors are activated
-the medulla oblongata is then activated and relays messages to the diaphragm and ribs to begin breathing movements
-CO2 levels decrease and chemoreceptors are deactivated
Describe oxygen chemoreceptors
-Found in the carotid and aortic arteries
-detect low levels of O2
-work the same as CO2 receptors
-O2 levels increase with increases ventilation (breathing)
What is the medulla oblongata?
-Part of the brain stem, located at the base of the brain
-plays a crucial role in controlling vital functions such as heart rate, blood pressure, breathing and swallowing
