Download Pre-Lab Questions: What type of epithelium lines the lumen of the

Pre-Lab Questions:
1. What type of epithelium lines the lumen of the trachea? Pseudostratified epithelium
2. The two modifications of the epithelium are cilia and goblet cells. What is the function of:
Cilia
move dust and mucus away from lungs
Goblet cells produce mucus
3. What is the effect of cigarette smoking on the cilia?
Cigarette smoking inhibits and destroys the ciliary action.
4. Where is there a deficiency in the hyaline cartilage of the tracheal rings? Yes
5. What is the functional reason for this deficiency?
allow easy passage of food in the esophagus
6.
What characteristics make alveoli ideal for gas exchange?
Single layer of epithelial cells on the wall of the alveoli, and large surface area for
diffusion of gases
7. Describe the respiratory membrane.
Made of simple squamous epithelium of the alveoli on one side (alveolar wall) and
simple squamous epithelium (endothelium) of the capillary on the other side
(capillary wall) and a fused basement membrane of the two in the middle.
8. What is the driving force that moves oxygen from the alveoli into the pulmonary capillary
blood?
Oxygen diffuses down its pressure gradient, from a higher partial pressure region
in the alveoli to lower partial pressure region in the pulmonary capillary.
9. Activation of the diaphragm and the external intercostal muscles begins the inspiratory
process. What results from the contraction of these muscles and how is this
accomplished?
There is a resultant increase in the thoracic volume from the contractions of the
muscles. When the diaphragm contracts, it flattens out and increases the
superior- inferior dimension and when the external intercostals contract, it raises
the rib cage and increases the anterior-posterior and lateral dimensions.
10. At the end of a normal inspiration the diaphragm relaxes and the ribs return to their preinspiratory position. What is the result of these muscular changes in terms of thoracic
volume and pressure?
The thoracic volume decreases and the pressure increases.
11. The presence of a partial vacuum between the plural membranes is integral to normal
breathing movements. What happens if an opening is made into the chest cavity,
as with a puncture wound? How is this condition treated medically?
The partial vaccum created in the pleural space is destroyed and the lung on the
damaged side collapses.
This is treated by inserting a chest tube and removing the air and closing off the
wound.
12. Write the respiratory volume or capacity described by the statements below. Indicate
the usual value for an adult next to the definition
a. Maximum volume of air that can be expired after a tidal expiration.
Expiratory reserve volume
1200 ml
b. Volume of air corresponding to TV + IRV + ERV
Vital capacity 4800 ml
c. Volume of air inspired and expired during normal breathing
Tidal volume 500 ml
d. Volume of air remaining in the lungs at the end of maximal expiration
Residual volume 1200 ml
e. Maximal volume of air that can be inspired at the end of a tidal inspiration
Inspiratory reserve volume 3100 ml
13. How might vital capacity be different in a smoker compared to a non-smoker?
Vital capacity in a smoker would be lower than the non smoker
14. Vital capacities of individuals with the following disorders would change over normal
values. Define the following and predict the change in vital capacity that may result from
the disease:
a. Emphysema
is a chronic obstructive pulmonary disorder characterized by destruction of
alveolar walls, enlarged air spaces, loss of elasticity of lung tissues and
hyperinflation of the alveoli.
Vital capacity will be lower than normal values
b. Asthma
Is a inflammatory lung disease characterized by constriction of the airway
passages, swelling of the mucosa and excessive mucus secretion
Vital capacity is lower
c.
Chronic bronchitis
is a chronic obstructive lung disorder characterized by inflammation of the
airways in lungs and excessive mucus production.
Vital capacity will be lower.
15. Explain the difference between obstructive and restrictive pulmonary disease:
obstructive pulmonary disease – impaired air flow into and out of lungs due to
narrowing or blockage of the airways
restrictive pulmonary disease – reduction in the volume of air that the lungs can
hold. It may be due to decrease in the elasticity of the lung tissues ,skeletal
abnormalities of the thoracic region etc.
16 How is the FEV1/FVC ratio used to differentiate between obstructive and
restrictive lung disease?
The FEV1 / FVC ratio will be lower than normal values in obstructive lung disease
and normal or greater than normal values in restrictive lung disease.