Ch1 Flashcards
(34 cards)
What are the main functions of the respiratory system?
The main functions are:
* Obtain oxygen from the external environment
* Supply oxygen to the cells
* Remove carbon dioxide produced by cellular metabolism
What components make up the respiratory system?
The respiratory system is composed of:
* Lungs
* Conducting airways
* Parts of the central nervous system controlling respiration
* Chest wall
What muscles are included in the chest wall for respiration?
The chest wall includes:
* Diaphragm
* Intercostal muscles
* Abdominal muscles
* Rib cage
What is the role of the respiratory system in acid-base balance?
The respiratory system participates in acid-base balance by removing CO2 from the body, affecting hydrogen ion concentration.
What is gas exchange in the respiratory system?
Gas exchange involves:
* Oxygen from ambient air exchanged for carbon dioxide in alveoli
* Fresh air inspired into lungs
* Venous blood with high CO2 content pumped into lungs
What happens to blood after gas exchange in the lungs?
Blood leaving the lungs has a high oxygen content and a relatively low carbon dioxide content, distributed to tissues by the left side of the heart.
True or False: The conducting zone of the airways contains alveoli.
False
At which airway generations do alveoli start to appear?
Alveoli start to appear at the 17th through the 19th generations.
What is the anatomic dead space in the respiratory system?
The anatomic dead space consists of the first 16 generations of airways, which contain no alveoli and are incapable of gas exchange.
What is the alveolar-capillary unit?
The alveolar-capillary unit is the site of gas exchange in the lung, comprising alveoli enveloped in pulmonary capillaries.
How many alveoli are estimated to be in an adult human lung?
Approximately 300 million, with some estimates suggesting up to 480 million.
What type of cells line the airways of the respiratory system?
The airways are lined with:
* Ciliated cells
* Mucus-secreting goblet cells
* Club cells
What is the function of Club cells in the bronchioles?
Club cells secrete proteins, lipids, glycoproteins, and modulators of inflammation; they also act as progenitor cells.
What are the primary characteristics of the trachea?
The trachea is a fibromuscular tube supported by C-shaped cartilage and completed by smooth muscle.
What happens to the cartilage structure as bronchi enter the lungs?
The cartilage rings disappear and are replaced by irregularly shaped cartilage plates.
What is the role of mast cells in the airways?
Mast cells contain inflammatory mediators that can induce bronchoconstriction, stimulate mucus secretion, and increase permeability of bronchial vessels.
Fill in the blank: The alveolar surface is mainly composed of _______ cells.
squamous epithelial
What are the two types of alveolar cells?
The two types of alveolar cells are:
* Type I alveolar cells
* Type II alveolar cells
What is the main composition of the alveolar surface?
A thin layer of squamous epithelial cells (type I alveolar cells) and cuboidal type II alveolar cells
Type II cells produce the fluid layer that lines the alveoli.
What is the primary function of type I alveolar cells?
Allow gas exchange between the alveolar air and the pulmonary capillary blood
They also help remove liquid from the alveolar surface.
How do type II alveolar cells compare in number to type I cells?
There are about twice as many type II cells as type I cells in the human lung
Type I cells cover 90% to 95% of the alveolar surface due to their larger surface area.
What role do alveolar macrophages play?
They patrol the alveolar surface and phagocytize inspired particles such as bacteria.
What forms the pulmonary capillaries?
A single layer of squamous epithelial cells aligned to form tubes.
What is the thickness of the barrier to gas exchange in the lungs?
0.2 to 0.5 mm thick.
