KIN 3304: Chapter 24 Respiration
20 Cards in this Set
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Primary function of lungs
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- gas exchange
- move air to/from lung surface
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Primary Bronchi
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-The trachea branches within the mediastinum, giving rise to the right and left
primary, or main, bronchi
-Each primary bronchus travels to a groove along the medial surface of its lung before branching further. This groove, the hilium, also provides access for entry to pulmonary ves…
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Right Lung vs. Left Lung
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- Right lung has three lobes: superior, middle, inferior
- R.L. is shorter than the left, the diaphragm rises on the right side to accommodate the mass of the liver
-L.L. has two lobes: superior, inferior
- L.L. is smaller than right lung, it accommodates the heart
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Pulmonary Bronchi
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The primary bronchi and their branches form the bronchial tree. Because the left and right bronchi are outside the lungs, they are called extrapulmonary bronchi. As the primary bronchi enter the lungs, they divide to form smaller passageways. Those branches are collectively called the int…
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Respiratory Bronchioles
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-Each terminal bronchiole delivers air to a single pulmonary lobule. Within the lobule, the terminal bronchiole branches to form several respiratory bronchioles; they deliver air to the exchange surfaces of the lungs
-The epithelial cells of the respiratory bronchioles and the smaller t…
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alveolar ducts and alveoli
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-Respiratory bronchioles are connected to individual alveoli and to multiple alve- oli along regions called alveolar ducts.
-These passageways end at alveolar sacs, common chambers connected to several individual alveoli
-An extensive network of capillaries is associated with each alve…
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The Alveolus and the Respiratory Membrane
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-The alveolar epithelium consists primarily of simple squamous epithelium. The squamous epithelial cells, called type I alveolar cells, are unusually thin and delicate. Type II alveolar cells, are scattered among the squamous cells.
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surfactant
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type II alveolar cells, are scattered among the squamous cells. These large cells produce an oily secretion containing a mixture of phospholipids. This secretion, termed surfactant, coats the inner surface of each alveolus and reduces surface tension in the fluid coating the alveolar surf…
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*Gas exchange
*will be on final
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Gas exchange occurs in areas where the basal laminae of the alveolar epithelium and adjacent capillaries have fused. In these areas the total distance separating the respiratory and circulatory systems is very small. Diffusion across this respiratory membrane proceeds very rapidly because…
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The Blood Supply to the Lungs
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-The respiratory-exchange surfaces receive blood from arteries of the pulmonary circuit
-Each lobule receives an arteriole and a venule, and a network of capillaries surrounds each alveolus directly beneath the respiratory membrane. In addition to providing a mechanism for gas exchange, …
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Angiotensin
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- peptide hormone, cause blood vessels to constrict
- affects BP
- also stimulates release of aldosterone ( promotes Na+ in the kidneys, thus B.P. goes up)
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angiotensin-converting enzyme
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- converts circulating angiotensin I to angiotensin II
- ACE found in high density in the lungs
-ACE inhibitors decrease angiotensin II production
- ACE inhibitors found in major drugs against hypertension
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Pleural Cavity
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The space between the pari- etal and visceral pleurae is called the pleural cavity. Each pleural cavity actually represents a potential space rather than an open chamber, for the parietal and visceral layers are usually in close contact. A small amount of pleural fluid is secreted by both…
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Pleurisy
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Inflammation of the pleurae, a condition called pleurisy, may cause the membranes to produce and secrete excess amounts of pleural fluid, or the in- flamed pleurae may adhere to one another, limiting relative movement. In either form of this disorder, breathing becomes difficult, and prom…
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Pulmonary Ventilation
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Pulmonary ventilation, or breathing, refers to the physical movement of air into and out of the bronchial tree. The function of pulmonary ventilation is to maintain adequate alveolar ventilation, the movement of air into and out of the alveoli. Alve- olar ventilation prevents the buildup …
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How do we breathe?
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- Air flows from areas of high pressure to lower pressure
- The lungs move due to pressure
- When there is negative pressure (<760 in the lungs), air moves in
- When there is positive pressure, air moves out ( exhalation)
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Skeletal Muscles involved in breathing: diaphragm
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-The diaphragm tenses and flattens as it contracts, and this increases the volume of the thoracic cavity. When the diaphragm relaxes, it arches upward and reduces the volume of the thoracic cavity.
-Air is drawn into the lungs when the volume of the thoracic cavity increases, and it i…
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External and internal intercostal muscles
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-The external intercostal muscles may assist in inspiration by elevating the ribs.
-The internal intercostal muscles depress the ribs and reduce the width of the thoracic cavity, thereby contributing to expiration.
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3 reflexes involved with respiration
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Mechanorecptor reflexes (respond to lung vol and changes in arterial blood pressure)
Chemoreceptor reflexes (respond to the changes in pH)
Protective reflexes (respond to physical injury or irritation of the respiratory tract)
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Changes to the respiratory system as you get older
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1) With increasing age, elastic tissue deteriorates throughout the body. The primary impact on the respiratory system is a reduction in the lungs’ ability to inflate and deflate.
2) Movements of the rib cage are restricted by arthritic changes in the rib articulations and by decre…
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KIN 3304: Diving Physiology