MECHANICS OF RESPIRATION Flashcards
______ - the exchange of gases between the lungs and bloodstream.
External respiration
Four phases of external respiration:
- pulmonary ventilation (breathing)
- diffusion of gases at the alveoli
- transport of gases in the blood
- diffusion of gases at the tissues
______ moves air into and out of the lungs, creating pressure gradients that drive the diffusion of oxygen from the ______ into the ______ and carbon dioxide from the ______ into the ______. Oxygen is transported throughout the ______ bound to ______ in ______, while carbon dioxide is transported as ______, bound to ______, or as ______. Finally, oxygen diffuses from the ______ into the ______, where it is used for cellular respiration, while carbon dioxide diffuses from the ______ into the ______ to be transported back to the ______.
Pulmonary ventilation, alveoli, blood, blood, alveoli, body, hemoglobin, red blood cells, dissolved gas, hemoglobin, bicarbonate ions, blood, tissues, tissues, blood, lungs
The ______, which are measurements of the chest cavity in different directions, are crucial for assessing lung function and diagnosing chest conditions.
diameters of the chest
The three main diameters are the ______ (front to back), ______ (side to side), and ______ (top to bottom).
anteroposterior, transverse, vertical
Normal chest diameters have a specific ratio, with the anteroposterior diameter typically about ______ the size of the transverse diameter. Changes in these diameters, like increased ______ in barrel chest or a sunken ______ in pectus excavatum, can indicate various conditions.
half, anteroposterior diameter, sternum
During respiration, the chest diameters undergo dynamic changes to facilitate air movement. Inspiration involves an increase in the ______ as the diaphragm contracts, and an increase in the ______ as the rib expands. The ______ may also slightly increase. Conversely, during expiration, the ______ decreases as the diaphragm relaxes, and the ______ decreases as the rib cage contracts. The ______ also reduces.
vertical diameter, transverse diameter, anteroposterior diameter, vertical diameter, transverse diameter, anteroposterior diameter
The ______ and the ______ act as a duo in changing chest diameters during respiration.
ribs, diaphragm
The ______, a dome-shaped muscle, contracts to flatten and move downwards, increasing ______. This downward movement also expands the thoracic cavity by pushing ______ downwards.
diaphragm, vertical diameter, abdominal organs
The ______, aided by intercostal muscles, lift upwards and outwards during ______, increasing the ______ and ______ diameters.
ribs, inspiration, transverse, anteroposterior
During expiration, the diaphragm ______, reducing ______, and the rib cage moves ______ and ______, decreasing the ______ and ______ diameters.
relaxes, vertical diameter, downwards, inwards, transverse, anteroposterior
Quiet respiration primarily relies on the ______ and ______ for inspiration, while expiration is ______.
diaphragm, external intercostal muscles, passive
Forced respiration engages additional ______ muscles like the ______, ______, and ______ muscles during inspiration to increase the force and volume of air intake. Expiration during forced breathing becomes an ______ process, employing ______ muscles and ______ muscles to forcefully reduce thoracic cavity volume.
accessory, scalene, sternocleidomastoid, pectoralis minor, active, internal intercostal, abdominal
The mechanics of respiration involve the coordinated processes of air movement driven by pressure changes. During inspiration, the ______ and ______ contract, increasing ______ and decreasing ______, drawing air in. In expiration, these muscles ______, and the ______ of the lungs expels air as ______ decreases.
diaphragm, external intercostal muscles, thoracic volume, intrapulmonary pressure, relax, elastic recoil, thoracic volume
Efficient respiration depends on factors like ______, ______, and the ______ to reduce ______ and prevent ______. Proper elasticity ensures ______, while disturbances in any of these elements can impair ______.
lung compliance, airway resistance, presence of surfactant, alveolar surface tension, collapse, smooth breathing, gas exchange
______ refers to the pressure inside the alveoli, which fluctuates with breathing, becoming ______ during inspiration and ______ during expiration.
Intrapulmonary pressure, negative, positive
______ describes the slightly negative pressure within the thoracic cavity, essential for maintaining lung inflation. This negative pressure is created by the ______ of the lungs and chest wall, as well as the ______ of the pleural fluid.
Intrathoracic negativity, elastic recoil, suction effect
These pressure differences drive air movement during respiration, as the negative ______ pulls air into the lungs during inspiration, and the positive ______ pushes air out during expiration.
intrathoracic pressure, intrapulmonary pressure
If intrathoracic negativity becomes atmospheric, the lungs will ______.
collapse
The slightly negative pressure within the thoracic cavity is essential for keeping the lungs ______ and attached to the ______. When this pressure becomes equal to atmospheric pressure, the ______ that maintains lung expansion ______. The lungs, naturally wanting to collapse due to their elasticity, will then collapse ______, making it impossible to breathe effectively. This situation can occur in cases of ______ or ______, where air leaks into the ______, disrupting the negative pressure.
inflated, chest wall, pressure gradient, disappears, inward, pneumothorax, open chest wounds, pleural space
Primary respiratory muscles, the ______ and ______, are responsible for normal, quiet breathing, rhythmically expanding and contracting the chest cavity.
diaphragm, external intercostal muscles
Accessory muscles, including the ______, ______, and ______, become active during increased respiratory demands , such as ______ or ______, to assist the primary muscles in expanding and contracting the chest cavity, ensuring adequate ______ intake and ______ removal.
sternocleidomastoid, scalene, abdominal muscles, exercise, illness, oxygen, carbon dioxide
______ involves muscle contraction to move air, requiring conscious effort and energy expenditure, typically used during exercise, labored breathing, or forced exhalation.
Active respiration
______ is effortless and relies on the natural elasticity of the lungs and chest wall, occurring during rest or normal breathing.
Passive respiration
While ______ is used when the body needs more oxygen or when breathing is difficult, ______ is the primary mode of breathing during rest and normal activity.
active respiration, passive respiration
