What are the two main divisions of the respiratory tract?
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Upper respiratory tract (上呼吸道) and lower respiratory tract (下呼吸道).
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What are the two main divisions of the respiratory tract?
Upper respiratory tract (上呼吸道) and lower respiratory tract (下呼吸道).
What is the mucociliary escalator?
A mechanism where cilia in the trachea and airways beat upward to carry mucus and trapped contaminants into the pharynx.
How do tears reach the nasal cavities?
Through the nasolacrimal canals.
What is the primary function of the larynx?
It serves as a cartilaginous passageway for air between the pharynx and trachea.
What is the primary function of the respiratory tract?
To cleanse, warm, and moisten the air from the nose to the lungs.
What role does lysozyme play in the respiratory tract?
It helps to kill bacteria in the mucus.
What are the two portions of the palate?
The hard palate and the soft palate.
What type of blood does the pulmonary vein carry?
Oxygen-rich blood.
What muscle primarily drives inhalation?
The diaphragm.
Where is the concentration of carbon dioxide higher during external respiration?
In the blood.
What encloses the lungs?
A double layer of serous membrane called the pleurae.
Which process involves oxygen entering the blood?
External respiration.
What are paranasal sinuses?
Air-filled spaces that reduce the weight of the skull and act as resonating chambers for the voice.
What shape are the lungs?
Paired, cone-shaped organs.
What type of blood does the pulmonary artery carry?
Oxygen-poor blood.
What structures are found in each lobule?
A bronchiole and pulmonary arteries/arterioles/capillaries serving many alveoli.
What color is used to represent oxygen-poor blood?
Blue.
How does the respiratory system help regulate blood pH?
By altering the bicarbonate/carbonic acid buffer system through breathing.
What bones form the structure of the nose?
Maxilla and palatine bones.
What is the term for hemoglobin combined with oxygen?
Oxyhemoglobin.
What is the primary function of the mechanism of breathing?
To facilitate the exchange of oxygen and carbon dioxide in the body.
What is released oxygen referred to as?
Deoxyhemoglobin.
What happens to the lungs when the respiratory muscles expand the thorax?
The lungs passively expand.
What happens to the mucus after it is moved by the cilia?
It is either swallowed or expelled through coughing.
What percentage of oxygen is transported in the plasma?
2-3%.
What is the nature of intrapleural pressure compared to atmospheric pressure?
It is less than atmospheric pressure.
What do the intercostal nerves stimulate?
The external intercostal muscles to contract.
What is the role of the lubricating serous fluid?
It creates surface tension between the pleural layers, allowing them to cling together.
What is the process of breathing out called?
Expiration or exhalation.
What is the function of the visceral pleura?
It adheres to the surface of the lung.
What are the smaller divisions of each lobe called?
Lobules.
Which process involves carbon dioxide being released from the blood?
Internal respiration.
Where does gas exchange occur during internal respiration?
Between the blood in systemic capillaries and the tissue fluid.
What happens during hypoventilation?
Increased CO2 leads to decreased pH, resulting in acidosis (pH less than 7.35).
What happens to the thoracic cavity during inhalation?
It expands, decreasing pressure and allowing air to flow in.
What keeps the trachea open?
About twenty C-shaped cartilaginous rings.
What is the function of the mucociliary escalator?
Epithelial cilia sweep mucus produced by goblet cells.
What is the primary method of carbon dioxide transport in the blood?
Most combines with water to form carbonic acid (60%).
What is pulmonary ventilation?
The entrance and exit of air into and out of the lungs.
What are the three parts of the pharynx?
Nasopharynx, Oropharynx, Laryngopharynx.
Where are odor receptors located in the nose?
In the olfactory epithelium.
Where does gas exchange occur during external respiration?
Between the alveolar air and the pulmonary capillary blood.
What is external respiration?
The process of gas exchange between the atmosphere and the blood in the lungs.
What is the mucociliary escalator?
A defense mechanism in the trachea that helps clear mucus and trapped particles.
Where do the lungs lie?
Within the sealed-off thoracic cavity.
What is the normal range of ventilations per minute for adults?
12 - 20 ventilations per minute.
What two layers make up the respiratory membrane?
Alveolar epithelium and capillary endothelium.
What role do alveoli play in gas exchange?
Alveoli are the tiny air sacs in the lungs where gas exchange occurs.
What determines the loudness of a voice?
The amplitude of the vibrations of the vocal cords.
What happens to the respiratory rate and depth during exercise?
They increase due to rising levels of carbon dioxide and hydrogen ions.
What is the surface area of the respiratory membrane?
50 - 70 m².
What is the chemical reaction associated with hypoventilation?
↑CO2 + H2O → ↑H2CO3 → ↑H+ + HCO3-.
What happens when a person cries?
It produces a runny nose.
What role does mucus play in the trachea?
It traps dust, pathogens, and other particles to prevent them from entering the lungs.
What is internal respiration?
The exchange of gases in the tissues.
What is the primary purpose of external respiration?
To supply oxygen to the blood and remove carbon dioxide.
How is oxygen primarily transported in the blood?
Bound to hemoglobin in red blood cells.
What occurs to the external intercostal muscles during expiration?
They relax, causing the rib cage to move down and in.
How much carbon dioxide combines with the protein portion of hemoglobin?
30% (forming carbaminohemoglobin).
What role does intrapleural pressure play in the lungs?
It helps to keep the lungs inflated.
How many secondary bronchi are there for the right lung?
Three, corresponding to its three lobes.
What extends from the pharynx to the alveoli of the lungs?
A continuous column of air.
What is the process of breathing in called?
Inspiration or inhalation.
What is the shape of the pharynx?
Funnel-shaped passageway.
What role do tonsils play in the pharynx?
They contain lymphocytes that protect against inhaled pathogens.
How does air enter the respiratory system?
Through the nostrils.
What lines the nasal cavities?
A mucous membrane.
What is the primary function of the nose?
To facilitate breathing and sense of smell.
What happens to the pressure in the thoracic cavity during forced expiration?
It increases.
How many lobes does the right lung have?
3 lobes.
How many lobes does the left lung have?
2 lobes.
In which direction does carbon dioxide diffuse during external respiration?
From the blood in the pulmonary capillaries to the alveoli.
How does the mucociliary escalator function?
Cilia on epithelial cells move mucus upwards towards the pharynx.
What is gas transport in the context of respiration?
The process by which oxygen and carbon dioxide are carried in the blood between the lungs and tissues.
What does the parietal pleura line?
The inside of the thoracic cavity.
What is expiration/exhalation in the context of ventilation?
Usually the passive phase of ventilation, requiring no muscular effort.
What supports the vocal cords in the larynx?
Elastic ligaments.
What is tidal volume?
The volume of air exchanged during normal, relaxed breathing, about 500 mL.
What percentage of carbon dioxide is transported as bicarbonate in the blood?
About 70%.
What is the maximum inspiratory effort?
The maximum expansion of the lungs.
What does the trachea divide into?
The right and left primary bronchi.
What happens to oxygen during cellular respiration?
Cells continually consume O2, causing it to diffuse from the blood into the tissue fluid.
What occurs during hyperventilation?
Decreased CO2 leads to increased pH, resulting in alkalosis (pH greater than 7.45).
What separates the nasal cavities from the oral cavity?
The palate.
What separates the two nasal cavities?
A septum made of bone and cartilage.
How is air conducted toward the lungs during inhalation?
By a series of cavities, tubes, and openings.
What does a spirogram display?
The measurements recorded by a spirometer.
What does the pharynx connect?
The nasal and oral cavities to the larynx.
What shape does the larynx resemble?
A triangular box.
Why does the left lung have fewer lobes than the right lung?
To allow room for the heart.
What is the primary function of the respiratory membrane?
Facilitates rapid gas exchange.
What color is used to represent oxygen-rich blood?
Red.
What is the primary gas exchanged in the lungs?
Oxygen is taken in, and carbon dioxide is expelled.
What is vital capacity?
The maximum volume of air that can be inhaled plus the maximum volume of air that can be exhaled.
What happens to red blood cells in the capillaries of the respiratory membrane?
They are pressed up against the narrow capillary wall with little plasma present.
What surrounds the alveolar sac?
Extensive pulmonary capillaries.
How does the structure of the respiratory membrane facilitate gas exchange?
By having a large surface area and being extremely thin.
What happens to respiration when only the medulla is functioning?
Respiration becomes short, irregular, and gasping.
Which muscles contract during inhalation?
External intercostal muscles (外肋間肌).
What do secondary bronchi divide into?
Tertiary bronchi.
What lines each alveolus?
An extremely thin layer of water-based tissue fluid.
What are bronchioles?
The smallest conducting airways with no cartilage support.
What is the primary function of the respiratory system?
To facilitate gas exchange between the body and the environment.
What are the main structures involved in the respiratory system?
Nose, pharynx, larynx, trachea, bronchi, and lungs.
What is external respiration?
The exchange of gases between air and blood.
How is air conducted away from the lungs during exhalation?
By a series of cavities, tubes, and openings.
What is the only external portion of the respiratory system?
The Nose.
What activities can lead to forced expiration?
Heavy exercise, singing, blowing air into a trumpet, or blowing out birthday candles.
Which muscles contract to force the rib cage downward and inward during forced expiration?
Internal intercostal muscles.
What is internal respiration?
The exchange of gases between the blood and the body's tissues.
What regulates voice pitch?
The tension on the vocal cords and the opening of the glottis.
What is the primary function of the nasal cavity (鼻腔)?
To filter, warm, and humidify the air we breathe.
What does the respiratory center respond to in terms of chemical input?
Levels of carbon dioxide and hydrogen ions.
What nerve carries impulses to the diaphragm?
The phrenic nerve.
How is sound produced in the larynx?
When air is expelled past the vocal cords through the glottis, causing them to vibrate.
Where are chemoreceptors located that monitor blood oxygen levels?
In the carotid arteries and aorta.
Why is oxygen not very soluble in water?
Oxygen has low solubility in water.
Which brain areas provide nervous input for ventilation control?
Cerebral cortex, limbic system, hypothalamus, and other brain centers.
What causes the lungs to recoil during expiration?
The elastic tissue in the lung walls and slight alveolar surface tension.
What is the concentration of carbon dioxide in the tissue fluid compared to the blood?
Higher concentration in the tissue fluid.
What occurs during the soundest stage of sleep regarding ventilation?
Ventilation decreases.
What is residual volume?
The amount of air remaining in the lungs after a forced expiration, about 1,000 mL.
How does gas exchange occur in the alveoli?
Across moist cellular membranes.
What happens to carbonic acid in the blood?
It splits into CO2 and H2O, and CO2 diffuses into the alveoli.
What is inspiratory reserve volume?
The amount of air that can be inhaled after a normal inhalation.
How does the respiratory system contribute to homeostasis?
By regulating the levels of oxygen and carbon dioxide in the blood.
What is external respiration?
The exchange of gases in the lungs.
In which direction does oxygen diffuse during external respiration?
From the alveoli into the blood.
How do abdominal wall muscles contribute to forced expiration?
They push on the abdominal organs and compress upward against the diaphragm.
Where is the Adam's apple located?
At the anterior neck.
What is gas exchange?
The process of oxygen and carbon dioxide moving between the lungs and the bloodstream.
What factors increase the amount of oxygen released by oxyhemoglobin?
Increased blood carbon dioxide, acidity, and temperature.
What creates intrapleural pressure?
The surface tension between the visceral and parietal pleura.
What physical changes occur in the larynx during puberty?
The growth of the larynx and vocal cords is faster in males, leading to a more prominent Adam's apple and deeper voices.
What influences the control of ventilation?
Nervous input and chemical input.
What is the function of the epiglottis?
It prevents food from entering the larynx.
What are the chemoreceptors in the carotid arteries called?
Carotid bodies.
What occurs during exhalation?
The diaphragm relaxes, the thoracic cavity decreases in volume, and air is expelled.
What happens to the diaphragm during inhalation?
It contracts and flattens.
What are the chemoreceptors in the aorta called?
Aortic bodies.
What is the chemical reaction associated with hyperventilation?
↓CO2 + H2O → ↓H2CO3 → ↓H+ + HCO3-.
What does the trachea allow for in relation to the esophagus?
Expansion of the esophagus.
How is air warmed in the respiratory tract?
By warm blood flowing through blood vessels close to the airway surface.
What is the function of the scalene muscles during inspiration?
They assist in expanding the thoracic cavity during maximum inspiratory effort.
What do bronchioles lead to?
Air sacs called alveoli.
What are paranasal sinuses?
Air-filled spaces surrounding the nasal cavity.
What moistens the air in the respiratory tract?
The mucous membrane.
What is a spirometer?
An instrument that records the volume of air exchanged during breathing.
What percentage of oxygen is transported by hemoglobin in red blood cells?
97-98%.
What type of epithelium is found in the nasal cavity for smell?
Olfactory epithelium.
What structures are housed within the larynx?
The vocal cords.
What are the two main phases of breathing?
Inhalation and exhalation.
Which part of the brain controls ventilation?
The medulla oblongata and pons.
How thick is the respiratory membrane?
Extremely thin.
Where is the trachea located in relation to the esophagus?
Anterior to the esophagus.
What type of fluid do the pleurae produce?
A lubricating serous fluid.
What happens to the volume of the thoracic cavity during expiration?
It decreases, leading to lung recoil.
What is the major function of the respiratory system?
Gas exchange, allowing oxygen to enter the blood and carbon dioxide to exit into the air.
What is the term for normal, quiet breathing?
Eupnea.
What type of cartilage is the epiglottis made of?
Flat elastic cartilage.
What is the result of maximum inspiratory effort?
It allows more air to be inspired.
What is the chemical reaction for carbon dioxide combining with water?
CO2 + H2O → H2CO3.
What is expiratory reserve volume?
The volume of air that can be forcibly exhaled after normal expiration, about 1,200 mL.
What role do the erector spinae muscles play in breathing?
They assist in maximum inspiratory effort by helping expand the thoracic cavity.
What is dead air space?
The portion of tidal volume that does not reach the alveoli, about 30% of the tidal volume.
What type of epithelium do bronchioles possess?
Ciliated epithelium.
What is the function of the pharynx?
It serves as a passageway for both food and air.
What do bronchi divide into?
Smaller bronchioles (細支氣管).
What is the primary function of the respiratory system?
To facilitate gas exchange, primarily oxygen and carbon dioxide.
What role do alveoli play in the respiratory system?
They are the sites of gas exchange between air and blood.
How does tension on the vocal cords affect pitch?
Greater tension and a narrower glottis result in a higher pitch.
What are the primary gases involved in gas transport?
Oxygen (O2) and carbon dioxide (CO2).
What does the trachea connect?
The larynx to the primary bronchi.
What happens to the diaphragm during expiration?
It relaxes and resumes its dome shape.
How is oxygen transported in the blood?
Oxygen is primarily transported bound to hemoglobin in red blood cells.
What percentage of carbon dioxide is transported as a dissolved gas in blood plasma and red blood cells?
10%.
What is the primary purpose of internal respiration?
To provide oxygen to tissues and remove carbon dioxide from them.
What is the role of the pulmonary artery and arteriole?
To carry oxygen-poor blood to the lungs.
What is the active phase of ventilation called?
Inspiration/Inhalation (吸氣).
What factors affect the efficiency of gas exchange?
Surface area, concentration gradients, and the thickness of the alveolar membrane.
What is the role of the pulmonary vein and venule?
To carry oxygen-rich blood from the lungs.
What is the significance of partial pressure in gas transport?
Partial pressure gradients drive the diffusion of gases in and out of the blood.
How many secondary bronchi are there for the left lung?
Two, allowing room for the heart.
What gases are exchanged in the alveoli?
Oxygen enters and carbon dioxide exits the bloodstream.
What happens to carbon dioxide during internal respiration?
It diffuses from the tissue fluid into the blood.
Which chest muscle aids in maximum inspiratory effort?
Pectoralis minor.
What helps lung tissue return to its resting position when exhaling?
The attractive force created by the fluid’s surface tension.
How does air flow during inhalation?
From an area of higher pressure (atmospheric pressure) to an area of lower pressure (within the lungs).
What is the concentration of oxygen in the blood compared to the tissues?
Higher concentration in the blood.
What happens to air during inhalation?
Air passes through the bronchial tree to the alveoli.
What are respiratory volumes?
The different amounts of air that can be inhaled or exhaled during breathing.
What does carbonic acid dissociate into?
Hydrogen ions (H+) and bicarbonate ions (HCO3-).
Which enzyme catalyzes the reaction of carbon dioxide and water to form carbonic acid?
Carbonic anhydrase.
Why do the lungs increase in volume during inhalation?
Because the lung adheres to the wall of the thoracic cavity.
What is the function of the nasal conchae?
To increase the surface area for moistening and warming inhaled air.
What does the transport of gases involve?
Transporting gases to and from the lungs and the tissues.
What is internal respiration?
The exchange of gases between blood and tissue fluid.
What role does the plasma play in gas transport?
It carries dissolved gases, including a small amount of oxygen and carbon dioxide.
How does maximum inspiratory effort affect the thoracic cavity?
It helps increase the size of the thoracic cavity larger than normal.
What volumes contribute to vital capacity?
Tidal volume, inspiratory reserve volume, and expiratory reserve volume.
What happens to intrapulmonary pressure during expiration?
It increases as lung volume decreases.
Why can both acidosis and alkalosis be fatal?
Because they interfere with cell enzyme functions.
What supports tertiary bronchi?
Smaller plates of cartilage.
What is the chloride shift?
The exchange of bicarbonate ions for chloride ions to maintain electrical balance.
What do the stretch receptors in the lungs produce when stimulated?
Inhibitory nerve signals that prevent further nerve signals from the respiratory center.
How do the pleural layers help the lungs?
They hold the lungs open against the chest wall.
How does the body regulate the rate of breathing?
Through the respiratory center in the brain, which responds to carbon dioxide levels.
What is inspiratory reserve volume?
The volume of air that can be inhaled beyond the tidal volume, about 3,000 mL.
Which muscles are involved in maximum inspiratory effort?
Accessory muscles of respiration, including the erector spinae, pectoralis minor, scalene, and sternocleidomastoid muscles.
What is tidal volume?
The amount of air inhaled or exhaled during normal breathing.
What is vital capacity?
The maximum amount of air a person can exhale after a maximum inhalation.
Which neck muscles are involved in maximum inspiratory effort?
Scalene and sternocleidomastoid muscles.
What is the primary muscle involved in breathing?
The diaphragm (橫隔膜).
What occurs between the air in the alveoli and the blood in the capillaries?
Gas exchange.
What occurs when oxygen concentration decreases?
Chemoreceptors communicate with the respiratory center, increasing the rate and depth of breathing.
What stimulates the stretch receptors in the lungs?
Increased inspiratory depth.
What is total lung capacity?
The total volume of air the lungs can hold, including all respiratory volumes.
What occurs in the alveoli?
Exchange of oxygen for carbon dioxide.
What is the role of the larynx (聲門)?
To produce sound and protect the trachea against food aspiration.
What effect does smoking have on the trachea?
It destroys the cilia of the mucociliary escalator.
What are the main branches of the trachea called?
Bronchi (支氣管).
What movement occurs in the rib cage during inhalation?
It moves upward (向上) and outward (向外).
What happens to the thoracic cavity volume during inhalation?
It increases.
What are dust cells?
White blood cells that defend against debris or pathogens inhaled.
What is the primary function of the lungs (肺)?
To facilitate gas exchange between air and blood.
What happens to respiration when a person is angry or frightened?
It increases, leading to hyperpnea (faster-than-normal respiration).
What is carbon dioxide in relation to cellular respiration?
An end product of cellular respiration.
Why does air flow out of the lungs during expiration?
Because intrapulmonary pressure becomes greater than atmospheric pressure.
What is the Hering-Breuer reflex?
A reflex that prevents overexpansion of the lungs.
What is residual volume?
The amount of air remaining in the lungs after a forced exhalation.
What is the role of surfactant in the alveoli?
It lowers surface tension to prevent the alveoli from completely collapsing.
What is expiratory reserve volume?
The amount of air that can be forcibly exhaled after a normal exhalation.
What happens to the air pressure within the alveoli during inhalation?
It decreases (intrapulmonary pressure).
What is the mechanism of breathing?
The process by which air is inhaled and exhaled from the lungs.
What are the key processes involved in gas exchange?
The transfer of oxygen and carbon dioxide between the lungs and the bloodstream.
How is oxygen transported in the body?
Primarily through hemoglobin in red blood cells.
What are the main components of the respiratory system?
Nose, pharynx, larynx, trachea, bronchi, and lungs.
What role does the diaphragm play in breathing?
It contracts and relaxes to help draw air into and push air out of the lungs.
What is the significance of the alveoli in the respiratory system?
They are the sites of gas exchange in the lungs.
What is the primary function of the respiratory system?
To facilitate gas exchange and transport oxygen to the body.
How does the diaphragm contribute to breathing?
It contracts and relaxes to change the volume of the thoracic cavity, facilitating inhalation and exhalation.
What is the function of the trachea (氣管)?
To provide a clear airway for air to enter and exit the lungs.
What does the pharynx (咽) connect?
It connects the nasal cavity and mouth to the larynx and esophagus.
Why are respiratory events necessary?
To provide oxygen for and remove carbon dioxide waste from cellular respiration to produce ATP.
What is the significance of the pleurae in the lungs?
They provide a lubricated surface for lung expansion and contraction.
How is air cleansed in the respiratory tract?
By nasal hairs, cilia, and mucus.
