Respiratory System - Mod 4 Flashcards
What is the general function of the respiratory tract?
It carries air to and from the lungs.
What is the function of the pleural membrane?
It is a double membrane that protects the lungs
What are the two layers of the pleural membrane?
Parietal pleura - superficial layer lining the walls of the thoracic cavity
Visceral pleura - thin layer directly covering the lungs
What is the function of pleural fluid, and where is it found?
Fluid found between the two layers of the pleural membrane, reducing friction between the layers to allow the lungs to slide smoothly over the thoracic wall.
What structures make up the upper respiratory tract?
The nasal cavity, pharynx, and their associated structures.
What separates the nasal cavity from the oral cavity?
The palate (hard and soft palate)
What are paranasal sinuses, and what is their function?
They are small, irregular air filled spaces lined with mucous membrane and function to lighten the skull and give the voice resonance.
What is the function of the mucosa lining the paranasal sinuses?
To warm and moisten the air.
What are the three parts of the pharynx?
Nasopharynx, oropharynx, and laryngopharynx.
What is the pharynx?
A muscular tube lined with mucosa membrane, joining the nasal and oral cavities to the esophagus and larynx.
The pharynx is the throat.
What is the general function of the tonsils?
They are part of the immune system that protects the body from infection.
What is tonsillitis?
Acute inflammation of the palatine tonsils
What are the three types of tonsils that are located in the pharynx?
The palatine tonsils, pharyngeal tonsils (adenoid), and lingual tonsils.
What structures make up the lower respiratory tract?
The larynx, bronchial tree, lungs, and their associated structures.
What is the larynx, and what is it made of?
The voice box, a cartilaginous structure composed of one thyroid, one cricoid, one epiglottis, and two arytenoid cartilages.
What is the function of the larynx?
Protects the airway, closes/seals the lower respiratory tract, and supports voice production.
What is the function of thyroid cartilage?
It houses and protects the vocal cords.
What is the function of the epiglottis during swallowing?
It moves downwards to block off the entrance to the larynx, ensuring food does not enter the airway.
What is the function of the arytenoid cartilages?
They tighten or slacken the vocal ligaments allowing us to change the pitch of our voice.
Where does the bronchial tree begin and end?
It originates beneath the larynx, as the trachea, and descends through the thorax, branching and ending as millions of alveolar sacs.
At what level does the trachea begin?
At C6, below the cricoid cartilage of the larynx.
What is the carina and what is its function?
A thick, incomplete cartilage ring between the two primary bronchi, where the trachea splits.
It functions to direct the air into each bronchi during respiration.
What are the alveoli and what do they contain?
They are air filled sacs rich in blood supply, and they contain surfactant and macrophages.
What is the function of the surfactant in the alveoli?
They prevent the alveoli from collapsing.
What is the function of the macrophages in the alveoli?
They phagocytose foreign particles and debris, killing bacteria that have entered the lungs and have been trapped on the moist walls.
At what level do the principal bronchi branch off the trachea, and where do they travel?
At T4, traveling to the lungs through the hilum.
How many secondary bronchi are there?
There is one for each lobe of the lungs: two left and three right.
How many tertiary bronchi are there in each lung?
There are ten in the right lung and eight in the left lung.
What are the bronchioles made of and what is their function?
Made of smooth muscle and a fibroelastic membrane (usually no cartilage), and they control the resistance to airflow and the distribution of air in the lungs.
How many lobes does each lung have?
The left lung has two lobes and the right lung has three lobes.
How do the lungs receive and send blood?
They receive deoxygenated blood from the pulmonary arteries and they send oxygenated blood away from the lungs to the heart through the pulmonary veins.
What do the bronchial arteries supply?
They supply oxygenated blood to the lung tissue.
What enters and exits the lungs at the hilum?
The principal bronchi, and the pulmonary and bronchial blood vessels.
What structure within the larynx is responsible for producing sound?
The vocal folds (vocal cords)
How is sound produced by the vocal folds?
By bringing the vocal folds together and driving air from the lungs through them, forcing them apart and to vibrate, producing sound.
What is the rima glottidis?
The space between the vocal cords.
What happens to the vocal folds during adduction?
They move together, closing the rima glottidis during voice production.
What happens to the vocal folds during abduction?
They move apart, opening the rima glottidis during inhalation.
What is the average vocal frequency in males?
About 120 Hz
What is the average vocal frequency in females?
About 200 Hz
What happens when the vocal folds lengthen?
The cricothyroid muscle contracts, stretching and lengthening the vocal folds, which increases the vibration frequency and raises the pitch of the voice.
What happens when the vocal folds shorten?
The thyroarytenoid muscle contracts, thickening and shortening the vocal folds, which decreases the vibration frequency and lowers the pitch of the voice.
What are the main muscles of ventilation?
The diaphragm and the intercostal muscles.
What is Boyle’s law?
A gas law which states that the pressure of a gas in a closed container is inversely proportional to the volume of the container:
- volume decrease = gas pressure increase
- volume increase = gas pressure decrease
What happens during inhalation?
- the lungs expand
- the pressure in the lungs decreases
- air flows towards the lower pressure in the lungs
What percent of air entering the lungs is the diaphragm and the external intercoastal muscles responsible for?
Diaphragm - 75%
External intercoastal muslces - 25%
What happens during exhalation?
- lung volume decreases
- pressure within the lungs increases
- air flows from the higher pressure in the lungs to the outside.
What happens to the air flow during forceful breathing?
The air flows out faster, due to increasing pressure in the lungs.
What three factors affect the ease of pulmonary ventilation?
Airway resistance, compliance of the lungs, and surface tension of alveolar fluid.
What is airway resistance?
The opposition of airflow in the respiratory system.
What is lung compliance?
The effort needed to stretch the lungs and thoracic cavity.
What is surface tension in the lungs?
The forces created between an air-fluid barrier.
What are non-respiratory air movements?
Air movements other than respiration, mostly involuntary reflexes but sometimes voluntary.
What causes hiccups?
Contraction of the diaphragm due to irritation of the phrenic nerve.
What is the purpose of coughing, and what triggers it?
A sudden and forceful expiration of air through the mouth caused by irritants in the pharynx or trachea. The purpose of coughing is to remove the irritant and prevent it from entering the lungs.
What is the purpose of sneezing, and what triggers it?
A sudden and forceful expiration of air through the nose caused by irritation of the nasal mucosa. The purpose of sneezing is to remove the irritant from the nasal cavity.
What is a yawn?
A deep inhalation and exhalation of air with the mouth wide open.
What is the air movement of a cry?
Inhalation followed by a series of short exhalations, often with tears, emotionally induced.
What is the air movement of a laugh?
Inhalation followed by a series of short exhalations, similar to crying, emotionally induced.
What are the four major pulmonary volumes?
Tidal volume, residual volume, expiratory reserve volume, and inspiratory reserve volume.
What is tidal volume?
The volume of air inhaled or exhaled with one normal breath.
What is residual volume?
The volume of air that remains in the alveoli after a forced expiration.
What is expiratory reserve volume?
The volume of air that can be forcefully expelled from the lungs after a normal expiration.
What is inspiratory reserve volume?
The additional volume of air you can inspire following a normal inspiration.
What make up the pulmonary capacities, and what are the four major capacities?
The relative sums of the pulmonary volumes make up the pulmonary capacities.
The four major pulmonary capacities are: inspiratory capacity, functional residual capacity, vital capacity, and total lung capacity.
Why do active cells require a constant supply of oxygen?
In order to produce energy to carry out cellular processes and release carbon dioxide as a waste product.
What is the function of the respiratory membrane?
It provides a large surface area and a thin, permeable, and moist surface where the gaseous exchange of oxygen and carbon dioxide take place.
What is the respiratory membrane made of, and what does it separate?
Composed of the cells that form the alveolar wall and the capillary wall, forming a barrier between the air in the lungs and the blood in the capillaries.
What governs gas exchange across the respiratory membrane?
Differences in partial pressure of oxygen and the partial pressure of carbon dioxide on either side of the respiratory membrane.
What is Daltons law?
A gas law that states, the total pressure of a mixture of gases equals the sum of the partial pressures of the individual gases in the mixture.
What is Henrys law?
A gas law that states, the quantity of a gas that will readily dissolve in a solution is proportional to the partial pressure of that gas and its solubility.
What is external respiration?
The exchange of oxygen and carbon dioxide between the air in the alveoli and the blood in the pulmonary circulation.
- Oxygen - lungs –> blood in pulmonary circle
- Carbon dioxide - blood –> lungs –> exhale from body
What is internal respiration?
The exchange of oxygen and carbon dioxide between the cells of the body and the blood in the systemic capillaries.
- Oxygen - blood –> tissues
- Carbon dioxide - tissues –> blood
How does hemoglobin contribute to oxygen transport?
Oxygen binds to the iron in hemoglobin and travels through the bloodstream to tissues throughout the body where the oxygen is released.
Hemoglobin is crucial for oxygen delivery to the bodys cells.
What is oxyhemoglobin?
it is formed when oxygen binds to hemoglobin.
What is deoxyhemoglobin?
the reduced form of oxyhemoglobin when oxygen dissociates.
What is the bohr effect?
A physiological phenomenon that describes how hemoglobin’s affinity for oxygen decreases when carbon dioxide levels increase or blood pH decreases.
What are the three ways carbon dioxide can be transported in the blood?
As bicarbonate ions (majority), carbaminohemoglobin, small percent is dissolved in blood plasma.
What occurs during the process of carbon dioxide transport?
carbon dioxide reacts with water and becomes carbonic acid, this then dissociates into hydrogen and bicarbonate ions.
The bicarbonate ions move into blood plasma and transported to the lungs to convert back to carbon dioxide and then exhaled.
What does carbonic anhydrase do?
It speeds up the reaction of carbon dioxide and water into carbonic acid, then into hydrogen and bicarbonate ions.
What is the chloride shift?
The exchange of ions between the blood plasma and red blood cells.
- Bicarbonate from RBC –> blood plasma
- Chloride from blood plasma –> RBC
What is the general function of the respiratory center?
It contros respiration by influencing the contraction and relaxation of the muscles of respiration.
What two parts of the brainstem control respiration?
The medulla oblongata and the pons.
What is the function of the medullary rythmicity area in the medulla oblongata?
It is responsible for sending inhibitory and stimulatory impulses to the muscles of respiration to regulate breathing rhythm.
What is the function of the pneumotaxic area in the pons?
- Transition between inspiration and expiration
- Transmits inhibitory nerve impulses to the inspiratory area
What is the function of the apneustic area in the pons?
- Transmits stimulatory impulses to inspiratory area
What is cortical control of respiration?
voluntary control of the respiration center, allowing us to alter our breathing pattern to suit certain situations, for example, while holding our breath underwater.
What are chemoreceptors and what do they do?
They monitor CO2, O2, and H+ levels in the blood and send information about varying levels of theses molecules to the respiratory center of the brain.
What are stretch receptors and what do they do?
They are in the lung and chest wall and respond to distension, preventing the lungs from over-inflamation.
What is the hering-breuer reflex?
A reflex that sends signals to the brain to prevent further inspiration when the lungs are full.
What are proprioceptors and what do they do?
They can help increase or decrease the rate of breathing in response to increased muscle and joint movement, for example during exercise.
