Respiratory System Flashcards
Which of the following best describes the pleural cavity?
an air-filled cavity that is slightly lower than atmospheric pressure
an air-filled cavity that is slightly higher than atmospheric pressure
a fluid filled cavity between the parietal pleura and the thoracic wall
a fluid-filled cavity that makes sure the visceral and parietal pleurae remain attached
an air-filled cavity between the visceral pleura and the lung
a fluid-filled cavity that makes sure the visceral and parietal pleurae remain attached
Which of the following explain why the partial pressure of O2 in alveolar air is lower than in atmospheric air?
alveoli contain a mixture of inspired and expired air
the lungs are not completely emptied during each expiratory/inspiratory cycle.
O2 diffuses out of the alveoli into the blood
all
Which of the following is the most important chemical regulator of breathing?
carbon dioxide
sodium ions
potassium ions
oxygen
haemoglobin
carbon dioxide
What is the name of the respiratory variable that is measured using a spirometer when a subject takes a maximal inspiration and then exhales as completely as possible?
tidal volume
total lung capacity
vital capacity
residual volume
expiratory reserve volume
vital capacity
When it is really cold why is it better to breathe through your nose rather than your mouth?
the vibrissae humidify the inspired air
your tongue might get stuck to the roof of your mouth
turbulence in the air flow through the nose helps humidify the air
the air is denser and the resistance of the nasal cavity is lower than the oral cavity
the nasal cavity contains blood vessels that warms the inspired air
the nasal cavity contains blood vessels that warms the inspired air
Which of the following is/are voluntary muscle(s)?
external intercostals
diaphragm
internal intercostals
abdominal muscle
all
Which of the following statements is TRUE?
the bronchial arteries carry blood from the right ventricle of the heart
blood in the pulmonary artery is deoxygenated
blood in the bronchial arteries is deoxygenated
as the bronchial tree generation number increases the amount of cartilage increases
the trachea is lined with D-shaped rings of cartilage
blood in the pulmonary artery is deoxygenated
The respiratory membrane consists primarily of which type of epithelium?
silly ate de cuboidal epithelium
squamous epithelial cells
pseudostratified ciliated columnar epithelium
moist cuboidal epithelium
moist columnar epithelium
squamous epithelial cells
Which of the following statements is/are TRUE?
Lung compliance determines how easy it is to inflate the lungs
Healthy young adults have low lung compliance
People with cystic fibrosis have high lung compliance?
Lung compliance determines how easy it is to inflate the lungs
Which of the following would you NOT find in the lungs?
sympathetic neurones
stretch receptors that detect the degree of stretching of the lungs
irritant receptors that initiate the cough reflex
parasympathetic neurones
chemoreceptors that detect levels of CO2 in inspired air
chemoreceptors that detect levels of CO2 in inspired air
Which of the following is NOT likely to occur in response to hypercapnia?
elevated bicarbonate concentrations in the brain
an increase in the frequency of pulmonary ventilation
increased activity in central chemoreceptors in the medulla oblongata
an increase in the amount of CO2 moving across the blood brain barrier
a decrease in the depth of pulmonary ventilation
a decrease in the depth of pulmonary ventilation
How many cells does a gas have to pass through when it crosses the respiratory membrane?
0
1
2
3
4
2
Why is airway resistance so low in the later generations of the bronchial tree?
Terminal bronchioles are so numerous that collectively they contribute little to the overall airway resistance.
They are able to expand as the lungs expand during inspiration
Their resistance reduces during inspiration
all
Which of the following statements about O2 transport in the blood is TRUE?
each polypeptide in haemoglobin has hydrogen-containing core called a heme group
each heme group has a has a ferrous iron (Fe2+) atom at its core.
around 1.5% of O2 in the blood is bound to haemoglobin
each Fe2+ atom can binds irreversibly to one molecule of O2
haemoglobin consists of three polypeptide chains
each heme group has a has a ferrous iron (Fe2+) atom at its core.
Which of the following functions is part of external respiration?
the movement of CO2 from blood draining from peripheral tissues into air to be expired
the transport of O2 in the blood
the transport of O2 in the blood supplying peripheral tissues
the movement of CO2 from peripheral tissues into the blood
the expulsion of air carrying CO2 during expiration
the movement of CO2 from blood draining from peripheral tissues into air to be expired
How much O2 does a 70 Kg normal man use at rest?
280 ml/min
40 ml/min
4 ml/min
94 ml/min
90 ml/min
280 ml/min
Pulmonary Ventilation
Pulmonary Ventilation involves the cyclical movement of air with a relatively high concentration of O2 into the lungs during inspiration and the expulsion of air carrying elevated levels of CO2 during expiration.
External Respiration
External Respiration is the transfer of the O2 in inspired air to blood supplying peripheral tissues and the removal of CO2 from blood draining from peripheral tissues into air destined to be expired.
Gas Transport
Gas transport is the transport of O2 in the blood supplying peripheral tissues and CO2 draining from peripheral tissues
Internal respiration
Internal respiration is the delivery of O2 to cells of peripheral tissues and the removal of CO2 from these cells by gas exchange.
oxygen utilisation at different levels of physical activity
Humans at rest use O2 at approximately 4ml/min/Kg of body weight. During strenuous exercise this can increase to 40ml/min/kg in untrained subjects and up to 90ml/min/Kg in elite athletes.
Major parts of the nasal cavity and their function
- pseudostratified epithelium - secretes viscous mucus - prevents hazardous particles reaching lower airways
- ciliated epithelial cells - pushes mucus and embedded particulate matter back into pharynx
- hairs (vibrissae) protruding down into airflow - trap larger particles
- specialised sensory epithelium (olfactory mucosa) located on the superior surface that contains specialised chemoreceptors - detect odours in inspired air and responsible for sense of smell
- extensive network of blood vessels - warms the inspired air and thereby prevents harmful cold air reaching the body core
Understand the relationship between the nasal and oral cavities and understand the functional significance of the latter in breathing.
During strenuous activity, the mouth and oral cavity become an additional conduit for inspired air. Due to their larger diameter, represents a lower resistance pathway than the nose and nasal cavity and therefore are used when larger volumes of gas exchange are required. However the inspired air reaching the pharynx through the oral cavity is not filtered, humidified or warmed to the same level.
Pharynx and its 3 major compartments and their function
Nasopharynx: The region located immediately behind the nasal cavity, which normally acts as conduit for air.
Oropharynx: The region located behind the oral cavity and continuous with the nasopharynx, which acts as a conduit for both air and foodstuffs.
Laryngopharynx: This is the most inferior compartment of the pharynx, which connects the oropharynx with the larynx.