5. Respiratory System Flashcards
(30 cards)
What are the main functions of the respiratory system
The respiratory system is responsible for gas exchange (o2 and co2), regulating blood ph and protection against pathogens
What are the main structures of the upper respiratory tract
The upper respiratory tract includes the external nares, nasal cavity, nasal conchae, internal nares, pharynx, and larynx
What is the function of the nasal conchae?
The nasal conchae act as ‘shelves’ to filter, warm, and humidify the air as it enters the nasal cavity.
What is the larynx and what are its key components?
The larynx connects the pharynx to the trachea and contains the vocal cords, glottis (opening between vocal folds), and epiglottis (flap that prevents food from entering the larynx).
How is the trachea structured and why?
The trachea is formed by 16-20 C-shaped rings of hyaline cartilage, which provide structural support and prevent collapse.
What are the pleura and their functions?
The pleura are membranes surrounding the lungs. The visceral pleura adheres to the lung surface, and the parietal pleura lines the thoracic cavity. The pleural cavity between them contains lubricating fluid.
What happens if one lung’s pleural membrane is punctured?
Each lung is contained separately, so if one lung is punctured, the other remains unaffected.
Describe the structure of the lower respiratory tract.
It consists of primary bronchi, secondary and tertiary bronchi, bronchioles, and terminal bronchioles, leading to alveoli where gas exchange occurs.
What are alveoli and why are they cup-shaped?
Alveoli are small sacs where gas exchange occurs. Their shape increases surface area, maximizing diffusion efficiency.
What are the three types of alveolar cells and their functions?
Type I cells facilitate gas exchange, Type II cells produce surfactant (prevents alveolar collapse), and macrophages remove debris.
How does gas exchange occur at the alveolus?
O2 and CO2 diffuse across the alveolar epithelium, capillary endothelium, and red blood cell membrane, following concentration gradients.
State Boyle’s Law and its significance in breathing.
Boyle’s Law states that volume and pressure are inversely related. During inhalation, lung volume increases, lowering pressure and allowing air to enter.
What muscles are involved in normal quiet inhalation?
The diaphragm and external intercostal muscles contract, increasing thoracic volume and decreasing pressure to draw air in.
What muscles are involved in forceful inhalation?
In addition to the diaphragm and external intercostals, the sternocleidomastoid, scalenes, and pectoralis minor contract.
What muscles are involved in quiet exhalation?
The diaphragm and external intercostals relax, decreasing thoracic volume and increasing pressure to push air out.
What muscles are involved in forceful exhalation?
Abdominal and internal intercostal muscles contract, expelling air more forcefully.
Which brain structures control breathing?
The medulla oblongata (Dorsal Respiratory Group and Ventral Respiratory Group) and the pons (Pontine Respiratory Group).
DRG and VRG
What are the functions of the DRG and VRG?
The DRG controls quiet inhalation, while the VRG is activated during forceful exhalation.
What do the pneumotaxic and apneustic centers in the pons do?
The pneumotaxic center shortens inspiration (e.g., during exercise), while the apneustic center prolongs it (e.g., at high altitudes).
How do chemoreceptors regulate breathing?
They detect CO2, O2, and H+ levels, adjusting respiratory rate accordingly.
What is the role of a spirometer?
A spirometer measures lung volumes and respiratory rates, recording a spirogram.
What is tidal volume?
The volume of air inspired or expired during normal quiet breathing.
What is vital capacity?
The maximum amount of air exhaled after a deep inhalation (sum of inspiratory reserve, tidal volume, and expiratory reserve)
How is oxygen transported in the blood?
98.5% of O2 is bound to hemoglobin as oxyhemoglobin, while 1.5% is dissolved in plasma.
