Pulmonary System Flashcards
Define ventilation, perfusion, and diffusion. What is external and internal respiration?
Ventilation= Exchange of gases between atmosphere and lungs
Perfusion= Movement of blood into a capillary bed
Diffusion= Movement of particles down a concentration gradient
External respiration= Oxygen diffusing from the lungs into the blood and CO2 from blood to lungs
Internal respiration= Oxygen diffusing from blood into cells and CO2 diffusing out into the blood
Which protective mechanisms are responsible for filtering, warming, and humidifying inspired air?
- Mucous secreting Goblet cell lining in the nasal canal and trachea trap large particles via the mucous
- Microvilli (cilia) = Hair like epithelial cells which move mucous towards the throat and humidify the air
- Blood vessels warm up the inspire air in the nasal canal
- Conchae cause air turbulence which forces large inspired particles into the walls of the nasal canal and into the mucous
- Airflow also facilitates movement of mucous
What is the respiratory zone? the conducting zone?
The respiratory zone= Respiratory bronchioles, alveolar ducts, and alveoli, all microscopic structures.
Conducting zone= All other respiratory passageways that conduct the air to the resp. bronchioles but also warm, humidify, and cleanse it
True or false: “The nose is also a resonance chamber for speech”
_____ is the passageway connecting the nasal cavity to the larynx and the mouth to the esophagus. It houses the ______.
The larynx connects the pharynx to the ______. Has an ______ which prevents food from entering the trachea. It also houses the ______ which are important for voice production
True Pharynx tonsils trachea epiglottis vocal cords
What are the layers that makeup the walls of the trachea?
From innermost: mucosa (cilia), submucosa (mucous production), Hyaline cartilage (rings), and Adventitia (encases the cartilage)
describe the passageways from the primary bronchi to the alveolar pulmonary capillaries
2 primary bronchi–> Lobar, secondary bronchi (2 on the left 3 on the right)—> Segemental, tertiary bronchioles—> terminal bronchioles—> respiratory bronchioles—> alveolar duct—> alveoli —> Respiratory membrane —> capillaries
Type 2 alveolar cells secrete ___ which reduces _____ tension. What do alveolar pores do?
How are microbes terminated in the alveoli?
surfactant
give passageways for air to enter surrounding alveoli
Via alveolar macrophages
The respiratory membrane is a fusion of alveolar ____ and capillary _____. Is it a double or single membrane?
epithelium
endothelium
Double
What does the mediastinum contain?
What is the hilum?
Where is the base of the lung, where is the apex
The heart, part of the trachea and esophagus
the hilum is an indentation of the mediastinum surface of each lung through which pulmonary blood vessels, bronchi, lymphatic vessels, and nerves enter and leave each lung.
base is the distal concave ending of the lung, apex is deep to the clavicle
Describe the blood supply and innervation of the lungs
the lungs are perfused by the pulmonary circuit and the bronchial circuit. The pulmonary circuit involves deoxygenated blood from the heart in the pulmonary arteries and oxygenated blood leaving the lungs in pulmonary veins, it is a low-pressure high volume circuit.
The bronchial circuit brings oxygenated blood to the lungs from arteries arising in the aorta which enter the lungs at the hilum and coarse along the branching bronchi.
Most of the venous blood from the lungs returns via the pulmonary circuit.
The lungs are innervated by parasympathetic and sympathetic motor fibers and visceral sensory fibers entering the lungs via pulmonary plexus in the lung root (vascular and bronchial attachments to the lung)
What is the clinical importance of bronchopulmonary segments?
Each segment is served by an individual artery, vein, and tertiary bronchus. This is important because in pulmonary disease one or more segments is affected but can be surgically removed without causing much disruption to the others
What are the smallest subdivisions of the lungs called?
The sympathetic fibers innervating the lungs ______ the air tubes and the parasympathetic _______ the air tubes
lobules
Dilate
Constrict
describe the pleura surrounding the lungs.
The parietal pleura covers the inner thoracic wall and the superior face of the diaphragm, it forms the lateral walls of the mediastinal enclosure and encloses the lung root. The visceral pleura covers the external surface of the lungs. They also secrete pleural fluid which keeps the pleura sticking together.
Which opposing forces contribute to the negative intrapleural pressure?
The _____ pressure rises and falls with breathing but always equalizes with the atmospheric pressure
What is the transpulmonary pressure?
The greater the transpulmonary pressure the _____ the lungs
How do these pressures change on inspiration and expiration?
The natural tendency f the lungs to recoil and the surface tension of the alveolar fluid that pulls the alveoli closer together (collapsing forces of lungs) are opposed by the elasticity of the chest wall which pushes the thorax outward (Expanding the lungs)
It is the difference between the intrapulmonary and intrapleural pressure. This difference prevents the lungs from collapsing
larger
Inhale: Due to increase in volume from muscular contractions intrapulmonary pressure starts lower than the atmospheric pressure by around 1mmHg (759mmHg) as the inhale continuous the intrapulmonary pressure increases back to 760mmHg. The intrapleural pressure follows but with a drop to 754mmHg, from (756mmHg). Transpulmonary pressure is -6 once the intrapulmonary pressure equalizes
Exhale: muscles relax and lungs recoil decreasing the volume and intrapulmonary pressure rises to 761mmHg, intrapleural pressure also rises to 756mmHg and transpulmonary pressure is -5
What is pneumothorax? Atelectasis?
Pneumothorax= Air entering the pleural cavity Atelectasis= lung collapse due to pneumothorax or from bronchiolar blockage
During quiet inspiration which inspiratory muscles are active
During deep or forced inspirations which accessory muscles are activated?
What is the difference between quiet expiration and forced expiration? Which muscles are active during forced expiration?
External intercostal muscles and diaphragm
scalenes and sternocleidomastoid muscles of the
neck and the pectoralis minor of the chest. Also the erector spinae straighten the spine.
Quiet expiration is more about lung elasticity (recoil) where the inspiratory muscles relax and it is passive while forced expiration is an active contraction of the abdominal wall muscles.
Obliques and transversus muscles
Which 3 physical factors affect pulmonary ventilation?
- Airway resistance (but is negligible)
- Alveolar surface tension
- Lung AND thoracic wall compliance
What are the 2 reasons that airway resistance is an insignificant influence on ventilation?
Where is airway resistance highest?
Where does the driving force become diffusion and not pressure?
- Large airway diameters in the first part of the conducting zone relative to the low air viscosity
- As the bronchiole diameters become smaller distally the number of branches increases allowing for a large total cross-section and therefore less resistance
At the medium sized bronchi (lobar bronchi)
At the terminal bronchioles
Surface tension draws ____ molecules closer together and reduces their contact with _____ molecules. It also reduces any force that has a tendency to increase ______ of the liquid.
Surfactant is produced by _____ cells, it decreases the _____ of water molecules and increases lung ______
water gas surface area type 2 alveolar cells cohesiveness compliance
What is lung compliance?
The higher the lung compliance the easier it is for the lungs to _____ at a given _______
Which 2 factors affect lung compliance?
total respiratory compliance depends on lung compliance and ______ compliance
It is a measure of the change in lung volume that occurs with a given change in transpulmonary pressure.
= change in vol / (intrapulmonary pressure- intrapleural pressure)
expand
transpulmonary pressure
- the distensibility of the lungs (elasticity)
- Alveolar surface tension
Thoracic wall
The amount of air inhaled or exhaled with each resting breath is called _____ volume it is _____ml
The amount of air that can be forcefully inhaled after a normal tidal volume inhale is called ______ volume and it is ____ml
The amount of air forcefully exhaled after a normal tidal volume exhale is called ______ volume and it is ____ml
The amount of air that remains in the lungs after a forced exhale is called _____ volume and it is _____ml
Tidal, 500
inspiratory reserve, 3100
expiratory reserve, 1200
residual, 1200
