Mechanics of Breathing

Ganong 26 : 645-646

The medium-sized bronchi actually constitute the site of highest resistance along the bronchial tree. Although the small radii of the alveoli might predict that they would have the highest resistance, they do not because of their parallel arrangement. In fact, early changes in resistance in the small airways may be “silent” and go undetected because of their small overall contribution to resistance.

Reference: Guyton 14th; P- 492

Volume, which cannot be measured by spirometry, is the residual volume. Capacities, which include residual volume also cannot be measured. Capacities that include residual volume are functional residual capacity and total lung capacity.

[Ganong 24th p-638]

Ganong 26 th p 619-620

Reference: Guyton 14th; P- 496

কোন ব্যাখ্যা যোগ হয় নি।

কোন ব্যাখ্যা যোগ হয় নি।

Elastic work 65%

Ganong 26,Page 620

Reference: Guyton 14th; P- 491

Energy Required for Respiration.
During normal quiet respiration, only 3% to 5% of the total energy expended by the body is required for pulmonary ventilation. However, during heavy exercise, the amount of energy required can increase as much as 50-fold, especially if the person has any degree of increased airway resistance or decreased pulmo- nary compliance. Therefore, one of the major limitations on the intensity of exercise that can be performed is the person's ability to provide enough muscle energy for the respiratory process alone.

Volume, which cannot be measured by spirometry, is the residual volume. Capacities, which include residual volume also cannot be measured. Capacities that include residual volume are functional residual capacity and total lung capacity.

Guyton  13th-501-502

Reference: Guyton 14th; P- 495

Volume, which cannot be measured by spirometry, is the residual volume. Capacities, which include residual volume also cannot be measured. Capacities that include residual volume are functional residual capacity and total lung capacity.

During normal breathing, the volume inspired and then expired is a tidal volume (TV). The volume remaining in the lungs after expiration of a TV is the functional residual capacity (FRC).

Reference: Guyton 14th; P- 498

Contraction of the smooth muscle that lines the bronchial airways will increase airway resistance and make breathing more difficult.

Explanation:

Reference: Guyton 14th; P- 492

Ganong 26th Page 624
 

কোন ব্যাখ্যা যোগ হয় নি।

Explanation:
Internal intercostal muscle is primary expiratory muscle

Uncal Herniation
Space-occupying lesions from large tumors, hemorrhages, strokes, or abscesses in the cerebral hemisphere can drive the uncus of the temporal lobe over the edge of the cerebellar tentorium, compressing the ipsilateral cranial nerve III (uncal herniation).
Before the herniation these patients experience a decreased level of consciousness, lethargy, poorly reactive pupils, deviation of the eye to a "down and out" position, hyperactive reflexes, and a bilateral Babinski sign (due to compression of the ipsilateral corticospinal tract).
After the brain herniates, the patients are decerebrate and comatose, have fixed and dilated pupils, and eye movements are absent. Once damage extends to the midbrain, a Cheyne-Stokes respiratory pattern develops.

Reference: Guyton 14th; P- 496

Volitional tests of respiratory include
a- Mouth Pressures (Maximal Static Inspiratory and Expirato Pressure).
b- Sniff Test
c- SNIP Test (Sniff pressure at nose measured )
d- Cough Tests

Movement of the diaphragm accounts for 75% of the change in intrathoracic volume during quiet inspiration. Attached around the bottom of the thoracic cage, this muscle arches over the liver and moves downward like a piston when it contracts. The distance it moves ranges from 1.5 cm to as much as 7 cm with deep inspiration.