MECHANICS OF RESPIRATION

Question 1

______ - the exchange of gases between the lungs and bloodstream.

Answer 1

External respiration

Question 2

Four phases of external respiration:

Answer 2

1. pulmonary ventilation (breathing)
2. diffusion of gases at the alveoli
3. transport of gases in the blood
4. diffusion of gases at the tissues

Question 3

______ 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 ______.

Answer 3

Pulmonary ventilation, alveoli, blood, blood, alveoli, body, hemoglobin, red blood cells, dissolved gas, hemoglobin, bicarbonate ions, blood, tissues, tissues, blood, lungs

Question 4

The ______, which are measurements of the chest cavity in different directions, are crucial for assessing lung function and diagnosing chest conditions.

Answer 4

diameters of the chest

Question 5

The three main diameters are the ______ (front to back), ______ (side to side), and ______ (top to bottom).

Answer 5

anteroposterior, transverse, vertical

Question 6

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.

Answer 6

half, anteroposterior diameter, sternum

Question 7

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.

Answer 7

vertical diameter, transverse diameter, anteroposterior diameter, vertical diameter, transverse diameter, anteroposterior diameter

Question 8

The ______ and the ______ act as a duo in changing chest diameters during respiration.

Answer 8

ribs, diaphragm

Question 9

The ______, a dome-shaped muscle, contracts to flatten and move downwards, increasing ______. This downward movement also expands the thoracic cavity by pushing ______ downwards.

Answer 9

diaphragm, vertical diameter, abdominal organs

Question 10

The ______, aided by intercostal muscles, lift upwards and outwards during ______, increasing the ______ and ______ diameters.

Answer 10

ribs, inspiration, transverse, anteroposterior

Question 11

During expiration, the diaphragm ______, reducing ______, and the rib cage moves ______ and ______, decreasing the ______ and ______ diameters.

Answer 11

relaxes, vertical diameter, downwards, inwards, transverse, anteroposterior

Question 12

Quiet respiration primarily relies on the ______ and ______ for inspiration, while expiration is ______.

Answer 12

diaphragm, external intercostal muscles, passive

Question 13

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.

Answer 13

accessory, scalene, sternocleidomastoid, pectoralis minor, active, internal intercostal, abdominal

Question 14

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.

Answer 14

diaphragm, external intercostal muscles, thoracic volume, intrapulmonary pressure, relax, elastic recoil, thoracic volume

Question 15

Efficient respiration depends on factors like ______, ______, and the ______ to reduce ______ and prevent ______. Proper elasticity ensures ______, while disturbances in any of these elements can impair ______.

Answer 15

lung compliance, airway resistance, presence of surfactant, alveolar surface tension, collapse, smooth breathing, gas exchange

Question 16

______ refers to the pressure inside the alveoli, which fluctuates with breathing, becoming ______ during inspiration and ______ during expiration.

Answer 16

Intrapulmonary pressure, negative, positive

Question 17

______ 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.

Answer 17

Intrathoracic negativity, elastic recoil, suction effect

Question 18

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.

Answer 18

intrathoracic pressure, intrapulmonary pressure

Question 19

If intrathoracic negativity becomes atmospheric, the lungs will ______.

Answer 19

collapse

Question 20

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.

Answer 20

inflated, chest wall, pressure gradient, disappears, inward, pneumothorax, open chest wounds, pleural space

Question 21

Primary respiratory muscles, the ______ and ______, are responsible for normal, quiet breathing, rhythmically expanding and contracting the chest cavity.

Answer 21

diaphragm, external intercostal muscles

Question 22

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.

Answer 22

sternocleidomastoid, scalene, abdominal muscles, exercise, illness, oxygen, carbon dioxide

Question 23

______ involves muscle contraction to move air, requiring conscious effort and energy expenditure, typically used during exercise, labored breathing, or forced exhalation.

Answer 23

Active respiration

Question 24

______ is effortless and relies on the natural elasticity of the lungs and chest wall, occurring during rest or normal breathing.

Answer 24

Passive respiration

Question 25

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.

Answer 25

active respiration, passive respiration