Flashcards in 15 - Respiratory System Deck (119):
The term respiration covers a broad array of processes. Which?
1. Ventilation, or breathing, which is the movement of air into and out of the lungs.
2. The exchange of oxygen and carbon dioxide between the air in the lungs and the blood.
3. The transport of oxygen and carbondioxide in the blood.
4. The exchange of oxygen and cabondioxide between the blood and the tissues. (Cellular respiration)
In addition to the important functions of gas-exchange, at least 4. other important functions are performed by the respiratory system. Which?
1. Regulation of blood pH
2. Voice production
4. Innate immunity.
The respiratiory system is divided into two parts.
The upper respiratory tracts and the lower respiratiory tract.
Which structures are associated with the upper respiratory tract?
The external nose, the nasal cavity and the pharynx.
Which structures are associated with the lower respiratory tract?
The larynx, the trachea, the bronchi, and the lungs.
The oral cavity is a part of which system?
It is usually considered a part of the digestive system, and not a respiratory system component.
What are the nares?
The nares are the external openings of the nose. Popularly known as nostrils.
What are the choanae?
The choanae are the openings in the nasal cavity that lead to the pharynx.
What is the nasal septum?
The nasal septum is a partition dividing the nasal cavity into right and left parts.
What is the hard palate?
The hard palate forms the floor of the nasal cavity, separating the nasal cavity from the oral cavity.
What are the conchae?
The conchae are the three bony ridges on the lateral walls on each side of the nasal cavity. The conchae increase the surface area of the nasal cavity and cause air to churn, so that it can be cleansed, humidified and warmed.
What are the paranasal sinuses?
The paranasal sinuses are air-filled spaces within bone. The paranasal sinuses open into the nasal cavity and are lined with a mucuous membrane. They produce mucus, and influence the quality of the voice by acting as resonating chambers.
What are the nasolacrimal ducts?
The ducts that carry tears. Also open onto the nasal cavity.
What is the photic sneeze reflex?
The phenomenon in which people (17-25% of all humans) sneeze when stimulated by exposure to bright light.
Please try to mention as many nasal cavity structures as possible.
- Paranasal sinuses
- Nasolacrimal ducts
- Nasal septum
- Hard palate
What is the pharynx?
The pharynx (throat) is the common passageway for both the respiratory and digestive system.
We can divide the pharynx into three regions. Which?
The nasopharynx, the oropharynx, and the laryngopharynx.
Where does food in the pharynx go?
To the esophagus.
Where does the air in the pharynx go?
To the Larynx.
Describe the location of the nasopharynx in medical directional terms related to
1. The pharynx
2. The soft palate
3. The choanae
1. It is the superior part of the pharynx.
2. It is located superior to the soft palate
3. It is located posterior to the choanae.
What is the uvula?
The uvula is the posterior extension of the soft palate.
What are the auditory tubes, and where do they open to?
The auditory tubes are the air-filled openings in which the ossicles are found. This tube ends in the nasopharynx.
What is one of the main functions of the soft palate?
It can close off the nasopharynx, which is does during swallowing.
Describe the location of the oropharynx.
It extends from the uvula to the epiglottis.
What is the lingual tonsil?
The lingual tonsil is located on the surface posterior part of the tongue.
Describe the location of the laryngopharynx.
It passes posterior to the larynx and extends from the tip of the epiglottis to the esophagus.
What is the epiglottis?
Epiglottis, en slimhinnekledd buet plate av elastisk brusk som stikker opp bak tungen. Fortil er den festet til innsiden av skjoldbrusken. På hver side har den en kraftig slimhinnefold (plica aryepiglottica). Slik dekker den reflektorisk inngangen til strupehodet når man svelger, slik at ikke mat og drikke kommer ned i luftrøret.
Describe the location of the larynx.
The larynx is located in the anterior throat and extends from the base of the tongue to the trachea.
The larynx has how many cartilages?
Nine cartilages connected to one another by muscles and ligamends.
How many of the cartilages in the larynx are paired?
Six of them form three pairs.
How many of the cartilages in the larynx are unpaired? What are their names?
Three of them are unpaired. The thyroid cartilage (Adam's Apple), cricoid cartilage, epiglottis.
What is the norwegian translation of cartilage?
Two pairs of ligaments extend from the posterior surface of the thyroid cartilage to the paired cartilage. Which?
The vestibular folds (false vocal cords), and the vocal folds (true vocal cords).
What is the trachea?
It is a membranous tube attached to the larynx. It begins immediately inferior to the cricoid cartilage, and projects through the mediastinum and divides into the right and left primary bronchi. The esophagus lies immediately posterior to the trachea.
Describe the structure of the trachea.
C-shaped cartilages form the anterior and lateral sides of the trachea. The posterior wall of the trachea has no cartilage and consists of a ligamentous membrane and smooth muscle.
What muscles (no names needed) contract during the cough reflex?
The smooth muscles on the posterior wall of the trachea.
What type of tissue lines the trachea?
The trachea is lined with pseudostratified columnar epitehelium, which contains numerous cilia and goblet cells. The cilia propell mucus produced by the goblet cells, as well as foreign particles embedded in the mucus, out of the trachea, trough the larynx and into the pharynx, from which they are swallowed.
What is a goblet cell?
A goblet cell is a glandular, modified simple columnar epithelial cell whose function is to secrete gel-forming mucins, the major components of mucus.
What can happen to the trachea if subjected to constant long-term irritation by cigarette smoke?
It can cause the tracheal epithelium to change to stratified squamous epithelium, which has no cilia. Mucus is therefore not removed, and becomes a place for microorganisms to grow - respiratory infections.
What is the Heimlich maneuver?
A sudden application of pressure to the abdomen, which forces air up the trachea. The person who performs the maneuver stands behind the victim with his or her arms under the victim's arms and this or her hands over the victim's abdomen between the navel and the rib cage. With one hand formed into a fist, the other hand suddenly pulls the fist towards the abdomen with an accompanying upward motion.
Where are the brochi?
The brochi extend form the trachea to the lungs.
Describe the tissues that line the bronchi.
Like the trachea, the main bronchi are lined with pseudostratified ciliated columnar epithelium and are supported by C-shaped pieces of cartilage.
The lungs have an unequal amount of lobes. How many do they have?
The right lung has three lobes, called superior, middle and inferior lobes. The left lung has two lobes, called the superior and inferior lobes.
Can you give names to the tracheobronchial tree from bronchus to..
Each main bronchus divides into lobar bronchi as they enter their respective lungs. The lobar bronchi in turn give rise to segmental bronchi. The bronchi continue to branch many times, finally giving rise to bronchioles. The bronchioles also subdivide numerous times to give rise to terminal bronchioles, which then subdivide into respiratory bronchioles.
Where are the alveoli?
The alveolis are small air sacs that protrude out from the alveolar ducts.
How many alveoli are there in the lungs?
Broadly describe the regional differences in tissue wall in the lungs.
As the air passageways become smaller, the structure of their walls changes. The amount of cartilage decreases and the amount of smooth muscle increases until, at the terminal bronchioles, the walls have a prominent smooth muscle layer but no cartilage.
Roughly describe what happens during an asthma attack.
The smooth muscle in the terminal bronchioles contract, which decreases the volume of airflow.
What happens in the terminal bronchioles during exercise?
During exercise the diameter of the bronchioles can increase due to the relaxation of smooth muscle.
What are the walls of the respiratory bronchioles composed of?
The walls of the respiratory bronchioles are composed of cuboidal epitehlium.
What are the walls of the alveolar ducts and alveoli composed of?
They are composed of simple squamous epithelium.
Where do we find the respiratory membrane?
It is found in the walls of the alveoli and surrounding capillaries.
Describe the six layers of the respiratory membrane:
1. A thin layer of fluid lining the alveolus.
2. The alveolar epithelium, composed of simple squamous epithelium.
3. The basement membrane of the alveolar epithelium.
4. At thin insterstitial space
5. The basement membrane of the capillary endothelium.
6. The capillary endothelium, composed of simple squamous epithelium.
The surfactant can be found in which respiratory membrane?
The fluid lining the alveolus.
What is the name of the body cavity in which the lungs are contained?
The thoracic cavity.
The lungs are contained in the thoracic cavity, but each lung is surrounded by a separate cavity as well called the:
What serous membrane lines the pleural cavity?
Often when speaking of the pleura, we distinguish between its two parts. Which parts? Also: what parts do they cover?
The parietal pleura, which lines the walls of the thorax, diaphraghm and mediastinum; and the visceral pleura, which covers the surface of the lung.
Between the visceral and parietal pleura there is a cavity, the pleural cavity, that contains a fluid called the pleural fluid. What tissue produces this fluid?
The pleural membranes themselves.
Between the visceral and parietal pleura there is a cavity, the pleural cavity, that contains a fluid called the pleural fluid. What are the two functions of this fluid?
1. It acts as a lubricant, allowing the visceral and parietal pleurae to slide past each other as the lungs and thorax change shape during respiration.
2. It helps hold the pleural membranes together. Just like two glass sheets with a thin film of water would be held together by the water.
The lung has two lymphatic supplies. Which two types and where are they situated?
The superficial lymphatic vessels are deep to the visceral pleura, they drain lymph from the superficial lung tissue and the visceral pleura. The deep lymphatic vessels follow the bronchi and drain lymph from the bronchi and associated connective tissues.
Ventilation is the process of moving air into and out of the lungs. There are two phases of ventilation. Which?
Inspiration and expiration.
Which muscles are responsible for the elevation of the ribs during inspiration?
The diaphragm and the external intercostals.
Which muscles are responsible for the depression of the ribs during expiration?
The internal intercostals.
Which two physical principles govern the flow of air into and out of the lungs?
1. Changes in volume result in changes in pressure.
2. Air flows from an area of higher pressure to an area of lower pressure.
"Changes in volume result in changes in pressure". Explain.
As the volume of a container increases, the pressure within the container decreases. The opposite is also true.
"Air flows from an area of higher pressure to an area of lower pressure. " Explain.
If the pressure is higher at one end of a tube than at the other, air or fluid flows from the area of higher pressure toward the area of lower pressure. The greater the pressure difference, the greater the rate of airflow.
Which two factors keep the lungs from collapsing?
1. Surfactant and 2. pressure in the pleural cavity.
What is surfactant?
Surfactant (surface acting agent) is a mixture of lipoprotein molecules produced by secretory cells of the alveolar epithelium. The surfactant molecules form a single layer on the surface of the thin fluid layer lining the alveoli, reducing surface tension.
Why would the lungs collapse without surfactant?
Because of the surface tension in the fluid lining the alveoli. Surface tension exists because the oppositely charged ends of water molecules are attracted to each other. As the water molecules pull together, they also pull on the alveolar walls, causing the alveoli to recoil and become smaller. Surfactant reduces surface tension tenfolds.
Explain how decreases in pleural pressure, the pressure in the pleural cavity, can result in expansion of the alveoli.
The air inside the alveoli has a certain pressure and is relative to the pleural cavity around it. If the pressure surrounding the alveoli, the pleural cavity, is decreased - the pressure in the alveoli is much higher in comparison. This causes the alveoli to expand.
Normally the alveoli are in the expanded state because pleural pressure is lower than alveolar pressure. What causes this pressure difference?
Because of a suction effect caused by fluid removal by the lymphatic system, and by lung recoil.
What is pneumothorax?
Any rupture from the lung to the pleural cavity, or from the outside of the body into the pleural cavity, that causes a pressure equalization that removes the tendence for the alveoli to expand, and allows lung recoil to cause unopposed collapse. A pneumothorax can occur in one lung while the other remains inflated because the two pleural cavities are separated by the mediastinum.
What can cause pneumothorax?
A sharp object like a broken rib or a bullet that penetrates into the thoracic wall, or due to emphysema (KOLS) that causes alveoli at the lung surface to rupture.
What happens to pleural pressure during inspiration?
Why is the pleural pressure decreased during inspiration? Two reasons!
1. Increasing the volume of the thoracic cavity results in a decrease in pleural pressure because a change in volume affects pressure.
2. As the lungs expand, lung recoil increases, increasing the suction effect and lowering the pleural pressure. The increased lung recoil of the stretched lung is similar to the increased force generated in a stretched rubber band.
..... is the process of measuring volumes of air that move into and out of the respiratory system.
Why do we measure the volumes of air that move into and out of the respiratory system?
It can give us information about the health of the lungs.
There are four respiratory volumes. Which?
1. Tidal volume.
2. Inspiratory reserve volume.
3. Expiratory reserve volume.
4. Residual volume.
What is tidal volume?
The volume of air inspired of expired with each breath.
What is Inspiratory reserve volume?
The amount of air that can be inspired forcefully beyond the resting tidal volume.
What is Expiratory reserve volume?
The amount of air that can be forcefully expired beyond the resting tidal volume.
What is Residual volume?
The volume of air still remaining in the respiratory passages and lungs after maximum expiration.
The exchange of gases across the respiratory membrane is influenced by ...
1. The thickness of the membrane.
2. The total surface area of the respiratory membrane.
3. The partial pressure of gases across the membrane.
How does the thickness of the respiratory membrane influence the exchange of gases?
Because the gases must diffuse through a larger, thicker membrane. This happens during certain respiratory diseases.
How does the surface area of the respiratory membrane affect the exchange of gases?
More surface area allows for more gas exchange.
How big is the surface area of the respiratory membrane?
It's about 70 square meters!
How does the partial pressure of gases affect the gas exchange over the respiratory membrane?
The partial pressure of a gas is the pressure exerted by a specific gas in a mixture of gases, such as air. When air is in contact with liquid, the gases dissolve in the liquid until the partial pressure of each gas in the liquid equals that in the air. The higher partial pressure of oxygen in the air, the more oxygen will diffuse into the deoxygenated blood.
Oxygen diffuses into the blood. How much travels in the blood as a dissolved gas, and how much is bound in the hemoglobin?
About 98,5 % of the oxygen transported in the blood combines reversibly with the iron-containing heme groups of hemoglobin.
There are about four factors that influence the release of oxygen from hemoglobin. Which?
1. The Po2 is low.
2. The Pco2 is high.
3. The pH is low
4. The temperature is high.
How is CO2 transported in the blood?
1. About 7% is transported as CO2 dissolved in the plasma.
2. 23% is transported in combination with blood proteins, primarily hemoglobin.
3. 70% is transported in the form of bicarbonate ions.
Write or explain the relationship between CO2 and HCO3 in the blood.
CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-
Explain, by using the chemical equation, why increased CO2 in the blood decreases the pH.
CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-.
The H+ is responsible for the pH decrease.
What area of the brain is responsible for the generation of respiration?
The medullary respiratory center. It consists of two dorsal respiratory groups. each forming a longitudinal column of cells located bilaterally in the dorsal part of the medulla oblongata, and two ventral respiratory groups, each forming a longitudinal column of cells located bilaterally in the ventral part of the medulla oblongata. Also the pontine respiratory group in the pons.
What is bronchitis?
An inflammation of the bronchi caused by irritants, such as cigarette smoke or infections; swelling impairs breathing; bronchitis can progress to emphysema.
What is emhpysema?
Desctruction of alveolar walls; increased coughing increases pressure on the alveoli, causing rupture and destruction; loss of alveoli decreases surface area for gas exchange and decreases the lung's ability to expel air; progression can be slowed, but there is no cure; alone or in combination with bronchitis, the condition is known as chronic obstructive pulmonary disease (COPD) /KOLS.
What is Adult respiratory distress syndrome? (ARDS)
Caused by damage to the respiratory membrane, which promotes inflammation; amount of surfactant is reduced, and fluid fills the alveoli, lessening gas exchange. ARDS usually develops after an injurious event, such as inhaling smoke from a fire or breathing toxic fumes.
What is cystic fibrosis?
A genetic disorder that affects mucus secretions throughout the body due to an abnormal transport protein; mucus is much more viscous and accumulates in ducts and tubes, such as the bronchioles; airflow is restricted, and infections are more likely.
What is pulmonary fibrosis?
Replacement of lung tissue with fibrous connective tissue, making the lungs less elastic; exposure to asbestos or coal dust are common causes.
What is lung cancer?
Occurs in the epithelium of the respiratory tract; can easily spread to other parts of the body because of the rich blood and lymphatic supply to the lungs.
What is a thrombosis of the pulmonary arteries?
Blood clot in the lung blood vessels; inadequate flow through the pulmonary capillaries, affecting respiratory function.
What is anemia?
Reduced hemoglobin lowers oxygen-carrying capacity of blood.
What is carbon monoxide poisoning?
Carbon monoxide binds more strongly to hemoglobin than does O2, and prevents already bound O2 from entering tissues.
Sudden infant death syndrome (SIDS)
Most frequent cause of death of infants between 2 weeks and 1 year of age due to suffocation; cause is still unknown.
Paralysis of the respiratory muscles can be fatal, what can cause it?
Damage to the cervical or thoracic parts of the spinal cord.
What is a strep throat?
An inflammation of the pharynx due to a bacteria called streptococcal.
What is diphteria?
Caused by the bacterium Corynebacterium diphteriae; a grayish membrane forms in the throat and can completely block respiratory passages.
Whooping cough, what is it?
Caused by the bacterium bodetella pertussis, which destroys cilia lining the respiratory epithelium, allowing mucus to accumulate, leads to a very severe cough.
What is tuberculosis?
Caused by the bacterium Clostridium tuberculosis, which forms small, lumplike lesions called tubercles; immune system targets tubercles and causes larges lesions.
Cardiopulmonary resuscitation (CPR) has replaced former methods of sustaining ventilation. The back pressure/arm lift method is one such technique that is no longer used. This procedure must be performed with the victim lying face down. The rescuer presses firmly on the base of the scapulae for several seconds, then grasps the arms and lifts them. The sequence is then repeated. Although this procedure is less efficient than CPR, it does result in ventilation of the lungs. Explain why.
Pressing firmly on the base of the scapulae decreases the volume of the thoracic cavity, pleural pressure increases and alveolar pressure increases to a value greater than atmospheric pressure. Thus, air flows from the lungs. When the arms are lifted, gravity causes the thoracic cavity to sag downward and expand. The volume of the thoracic cavity increases, pleural pressure decreases, and alveolar pressure decreases to less than atmospheric pressure, causing air to flow into the lungs.
Another technique for artificial respiration is mouth-to-mouth resuscitation. The rescuer takes a deep breath, blows air into the victim's mouth, and then lets air flow out of the victim's lungs. The process is repeated.
Why do the victim's lungs expand?
The victim's lungs expand because the rescuer is blowing air into the lungs at a pressure higher than alveolar pressure. When the alveolar pressure exceeds pleural pressure, the lungs tend to expand.
Another technique for artificial respiration is mouth-to-mouth resuscitation. The rescuer takes a deep breath, blows air into the victim's mouth, and then lets air flow out of the victim's lungs. The process is repeated.
Why does air move out of the victim's lungs?
Air flows out of the lungs because of the natural recoil of the lungs. Elastic fibers in the lungs and surface tension of water in the alveoli cause the recoil of the lungs.
A person's vital capacity was measured while she was standing and while she was lying down. What difference, if any, in the measurement would you predict and why?
The best prediction would be that her vital capacity would be greatest when she is standing up. In the upright position, gravity tends to pull the abdominal organs downward. As a result, movement of the diaphragm is not as restricted and thoracic volume is increased. Lying down allows abdominal organs to exert pressure on the diaphragm, decreasing the thoracic volume.
If water vapor forms 10% of the gases in the air at sea level, what is the partial pressure of water?
At sea level, all the gases in the atmosphere exert a pressure of 760 mm Hg. If water vapor is 10% of the gas mixture, then water vapor must have a partial pressure of 760 x 0.10, which is 76 mm Hg.
A patient has pneumonia, and fluid accumulate within the alveoli. Explain why this results in an increased rate of respiration. How can O2 therapy return this rate to normal?
As fluid accumultes in the alveoli, the layer through which O2 and CO2 must diffse in the alveoli becomes thicker. As the layer thickens, the rate at which gases diffuse slows. Consequently, the amount of CO2 that diffuses out of the pulmonary capillaries is reduced and the amount of CO2 that diffuses out of the pulmonary capillaries decreases. The decreased CO2 levels stimulate the respiratory center and cause the rate and depth of respiration to increase. Oxygen therapy increases the PO2 in the alveoli and reduces the PCO2 in the alveoli. Therefore, O2 diffuses more rapidly from the alveoli into the pulmonary capillaries and CO2 diffuses more rapidly from the pulmonary capillaries and into the alveoli. This establishes more normal blood levels of O2 and CO2.