movement of air into and out of the lungs so that the gases there are continuously changed and refreshed. (commonly=breathing).
Movement of oxygen from the lungs to the blood and of carbon dioxide from the blood to the lungs.
Transport of respiratory gases
transport of oxygen from the lungs to the tissue cells of the body, and of carbon dioxide from the tissue cells to the lungs. The transport is accomplished by the cardiovascular system using blood as the transporting fluid.
Movement of oxygen from blood to the tissue cells and of carbon dioxide from the tissue cells to blood.
The actual use of oxygen and production of carbon dioxide by tissue cells. The cornerstone of all energy-producing chemical reactions in the body.
Respiratory system includes..
the nose, nasal cavity, and paranasal sinuses (pharynx, larynx, trachea, bronchi, lungs).
the actual site of gas exchange, is composed of respiratory bronchioles, alveolar ducts, and alveoli, all microscopic structures.
includes all other respiratory passageways, which provide fairly rigid conduits for air to reach the gas exchange sites. Also cleanse, humidify and warms incoming air.
Jutting external portion is supported by bone and cartilage. Internal nasal cavity is divided by midline nasal septum and lined with mucosa. Produces mucus, filters, warms, and moistens incoming air; resonance chamber of speech.
Mucosa lined, air filled cavities in cranial bones surrounding nasal cavity. Functions like the nose, also lighten skull.
Passageway connecting nasal cavity to larynx and oral cavity to esophagus. Three subdivisions: nasopharynx, oropharynx, and laryngopharynx. Passageway for air and food.
Connects pharynx to trachea. Has framework of cartilage and dense connective tissue. Opening (glottis) can be closed by epiglottis or vocal folds. Air passageway, prevents food from entering lower respiratory tract. Houses vocal folds (or true vocal folds) and is the voice production.
Houses tonsils (lymphoid tissue masses involved in protection against pathogens. Facilitates exposure of immune system to inhaled antigens.
Flexible tube running from larynx and dividing inferiorly into two main bronchi walls contain C-shaped cartilages that are incomplete posteriorly where connected by trachealis muscle. Air passageway, cleans, warms, and moistens incoming air.
Consists of right and left main bronchi, which subdivide within the lungs to form lobar and segmental bronchi and bronchioles. Bronchiolar walls lack cartilage but contain complete layer of smooth muscle. Constriction of this muscle impedes expiration. Air passageways connecting trachea with alveoli; cleans, warms and moistens incoming air.
Microscopic chambers at termini of bronchi tree. Walls of simple squamous epithelium are underlain by thin basement membrane. External surfaces are intimately associated with pulmonary capillaries. Main sites of gas exchange and produce surfactant. Reduces surface tension: helps prevent lung collapse.
Paired composite organs that flank mediastinum in thorax. Composed primarily of alveoli and respiratory passageways. Stroma is fibrous and elastic connective tissue, allowing lungs to recoil passively during expiration. House respiratory passages smaller than the main bronchi.
Serous membranes. Parietal pleura lines thoracic cavity, visceral pleura covers external lung surfaces. Produce lubricating fluid and compartmentalize lungs.
pseudostratified ciliated columnar epithelium, containing scattered goblet cells that rests on a lamina propria richly supplied with mucous and serous glands.
help empty the rectum and can also splint (stabilize) the body trunk when one lifts a heavy load.
the open posterior parts of the cartilage rings, which abut the esophagus, are connected by smooth muscle fibers and by soft connective tissue.
The last tracheal cartilage is expanded and a spar of cartilages, projects posteriorly from its inner face, marking the point where the trachea branches into the two main bronchi.
a procedure in which air in the victims lungs is used to "pop out", or expel, an obstructing piece of food has saved many people from becoming victims of cafe coronaries.
Bronchial or Bronchial tree
the site where conducting zone structures give way to respiratory zone structures.
Irregular plates of cartilages, Mucosal epithelium thins as it changes from psuedostratified columnar to columnar and then to cuboidal in the terminal bronchioles. Mucus producing cells are absent. Amount of smooth muscle increases as passageways become smaller.
Type I cells
The walls of the alveoli are composed primarily of a single layer of squamous epithelial cells; surrounded by a flimsy basement membrane. 15xs thinner than tissue paper.
Type II cells
Scattered amid the type I squamous cells that form the major part of the alveolar wall are cuboidal. Secrete a fluid containing a detergent like substance, called surfactant.
Each lobe contains a number of these pyramid shaped segments; separated from one another by connective tissue septa. Each is served by its own artery and vein and recieves air from an individual segmental bronchus.
Systemic venous blood that is oxygenated in the lungs is delivered by these, which lie anterior to the main bronchi.
Freshly oxygenated blood is conveyed from the respiratory zones of the lungs to the heart by these.
The lungs are innervated by parasympathetic and sympathetic motor fibers, and visceral sensory fibers. These nerve fibers enter each lung through this plexus on the lung root and run along the bronchial tubes and blood vessels in the lungs.
Parasympathetic vs. Sympathetic.
Parasympathetic fibers constrict the air tubes, whereas the sympathetic nervous system dilates them.
Atmospheric pressure (Patm)
the pressure exerted by the air (gases) surrounding the body. At sea level = 760 mm Hg. Respiratory pressures are always described relative to this.
Intrapulmonary pressure (Ppul)
The pressure in the alveoli. Rises and falls with the phases of breathing, but it eventually equalizes with the atmospheric pressure.
Intrapleural pressure (Pip)
The pressure in the pleural cavity, also fluctuates with breathing phases, but is always about 4mm Hg less than Ppul. That is Pip is always negative relative to Ppul.
How negative intrapleural pressure is est.
Because of lungs elasticity, they always assume the smallest size possible and naturally recoil. The molecules of the fluid lining the alveoli attract each other and this produces surface tension that constantly acts to draw the alveoli to their smallest possible dimension.
the difference between the intrapulmonary and intrapleural pressure (Ppul-Pip) that keeps the air spaces of lungs open or phrased another way. Keeps lungs from collapsing.
The relationship between pressure and volume of a gas. At constant temp, the pressure of a gas varies inversely with its volume. (P1V1=P2V2)
the diaphragm and external intercostal muscles. The diaphragm contracts and flattens out which increases thoracic cavity dimension. Contraction of the intercostal muscles lift the rib cage and pulls the sternum superiorly, which expands the diameter of the thorax.
In healthy individuals, depends more on lung elasticity then on muscle contraction. As inspiratory muscles relax, the rib cage descends and the lungs recoil.
an active process produced by contraction of the abdominal wall muscles, primarily the oblique transversus muscles.
At any gas-liquid boundary, the molecules of the liquid are more strongly attracted to each other than to the gas molecules. This unequal attraction produces a state of tension at the liquid surface.
Inspiratory reserve volume (IRV)
The amount of air that can be inspired forcibly beyond the tidal volume (2100 to 3200 ml).
Expiratory reserve volume (ERV)
The amount of air-normally 1000-1200 ml that can be evacuated from the lungs after a tidal expiration.
Residual volume (RV)
Even after the most strenuous expiration about 1200 ml of air remains in the lungs, which helps to keep the alveoli patent (open) and to prevent lung collapse.
include inspiratory capacity, functional capacity, vital capacity, and total lung capacity. Always consists of two or more lung volumes.
Inspiratory capacity (IC)
the total amount of air that can be inspired after a tidal expiration, so it the sum of TV and IRV.
Functional residual capacity (FRC)
represents the amount of air remaining in the lungs after a tidal expiration and is the combined RV and ERV.
The total amount of exchangeable air. Its the sum of TV, IRV, and ERV. In healthy young males, VC is approx. 4800 ml.
Total lung capacity (TLC)
The sum of all lung volumes and its normally around 6000 ml. Tend to be smaller in women than in men because of women's smaller size.
Anatomical dead space
Some of the inspired air fills the conducting respiratory passageways and never contributes to gas exchange in the alveoli. Typically amounts to about 150 ml. A healthy young adult is equal to 1 ml per pound of body weight.
The total amount of gas that flows into or out of the respiratory tract for one minute.
Forced Vital capacity (FVC)
measures the amount of gas expelled when a subject takes a deep breath and then forcefully exhales maximally and as rapidly as possible.
Alveolar ventilation rate (AVR)
A much better index of effective ventilation opposed to minute ventilation. Takes into account the volume of air wasted in the dead space and measures the flow of fresh gases in and out of the alveoli during a particular time interval.
Dalton's law of partial pressure
States that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture. Further, the pressure exerted by each gas its partial pressure is directly proportional to the percentage of that gas in the mixture.
when a gas is in contact with a liquid, that gas will dissolve in the liquid in proportion to its partial pressure.
Carried in the blood in two ways; bound to hemoglobin within red blood cells and dissolved into plasma. O2 is poorly soluble in water, so only about 1.5% is transported in the dissolve form.
Carbon Dioxide Transport
From the tissue cells to the lungs in three forms. Dissolved in plasma, chemically bound to hemoglobin, and as bicarbonate ion in plasma.
Sensors responding to the changing levels of CO2, O2 and H found in two major body locations. Central= located throughout the brain stem, including the ventrolateral medulla and peripheral= found in the aortic arch and carotid arteries.
Respiratory during Exercise
Geared towards both intensity and duration of exercise, working muscles consume a ton of O2 and produce large amounts of CO2.