Lab 4/15 Podcast

These flashcards cover key concepts related to the anatomy and mechanics of respiration, including lung structure, breathing muscles, lung capacities, and disorders affecting breathing.

What are the two main zones of the lung anatomy?

Conducting zone and Respiratory zone.

What is the main role of Type I alveolar cells?

They are the main site of gas exchange.

What do Type II alveolar cells secrete?

Surfactant.

Name the muscles involved in inspiration.

Sternocleidomastoid, scalenes, external intercostals, and diaphragm.

What decrease occurs in intrapulmonary pressure during normal inspiration?

It decreases to about -3 mmHg.

During normal expiration, what contributes to an increase in intrapulmonary pressure?

Relaxation of diaphragm and external intercostals, plus elastic recoil of lungs.

What is the intrapulmonary pressure during forced expiration?

It can increase to +30 mmHg or higher.

Describe emphysema in terms of lung anatomy.

A progressive condition where alveolar tissue is destroyed, resulting in fewer but larger alveoli, decreasing surface area for gas exchange.

What characterizes asthma episodes?

Obstruction of airflow through bronchioles due to inflammation of airway mucosa and bronchoconstriction.

What is the typical residual volume in the lungs?

It is the volume of air remaining in the lungs after maximum expiration.

2 zones of the lungs

Conducting zone & respiratory zone

What happens in the conducting zone of the lungs?

Responsible for the passage of air into the lungs, where it filters, warms, and humidifies the air before it reaches the alveoli.

Structures of the conducting zone

• Trachea

• Primary bronchus

• Terminal bronchioles

What is the purpose of the respiratory zone of the lungs

The respiratory zone is the region of the lungs where gas exchange occurs, primarily in the alveoli, allowing oxygen to enter the blood and carbon dioxide to be removed.

Important structures of the respiratory zone

Respiratory bronchioles, aveolar sacs and alveolus

What are the 2 types of cells in the respiratory zone

Type I alveolar and Type II aveolar cells

Purpose of type I alveolar cells

Main site of gas exchange

Purpose of type II alveolar cells

Secrete surfactant

What muscles are involved in breathing

Muscles of inspiration and muscles of expiration

Mechanics of normal quiet breathing for inspiration

Contraction of diaphragm and external intercostal muscles increases thoracic and lung volume, decreasing intrapulmonary pressure -3mmHg.

Mechanics of normal breathing for expiration

Relaxation of diaphragm and external intercostals, plus elastic recoil of lungs,

decreases lung volume and increases intrapulmonary pressure to about +3mmHg.

Mechanics of forced breathing - inspiration

Inspiration aided by contraction of accessory muscles such as the scalenes, pectoralis minor and sternocleidomastoid, decreases intrapulmonary pressure to -20mmHg or lower

Mechanics of forced breathing - expiration

Expiration, aided by contraction of abdominal muscles and internal intercostal muscles, increases intrapulmonary pressure to +30mmHg or higher.

What is a spirometer

A device used to measure the volume of air inhaled and exhaled by the lungs. It helps assess lung function and capacity.

Total lung capacity

is the maximum amount of air the lungs can hold, including tidal volume, inspiratory reserve volume, and expiratory reserve volume.

Vital capacity

is the maximum amount of air that can be exhaled after a maximum inhalation, comprising tidal volume, inspiratory reserve volume, and expiratory reserve volume.

Tidal volume

is the amount of air inhaled or exhaled during normal breathing at rest, typically around 500 mL in adults.

Inspiratory capacity

is the maximum amount of air that can be inhaled after a normal expiration, consisting of tidal volume and inspiratory reserve volume.

Inspiratory reserve volume

is the additional air that can be inhaled after a normal inhalation, contributing to the inspiratory capacity.

functional residual capacity

is the volume of air remaining in the lungs after a normal exhalation, composed of both expiratory reserve volume and residual volume.

Expiratory reserve volume

is the amount of air that can be forcibly exhaled after a normal tidal expiration, contributing to functional residual capacity.

residual volume

is the volume of air remaining in the lungs after a maximal exhalation, preventing lung collapse and maintaining gas exchange.

Emphysema

is a chronic respiratory disease characterized by the destruction of the alveoli, leading to decreased elasticity of the lungs and difficulty in exhaling air. This causes a decrease in surface area for gas exchange

Asthma

is an obstruction of air flow through the bronchioles occurring in episodes. The obstruction is due to inflammation of airway mucosa and bronchoconstriction.