Chapter 17- Mechanisms of breathing Flashcards
What does cellular respiration refer to?
Cellular metabolism that uses oxygen and produces ATP and CO2
What is external respiration?
The exchange of gas between the external environment and the cells and tissues of the body
Which parts are included in the upper respiratory tract?
The mouth, nasal cavity, pharynx and larynx
Which parts are incluced in the lower respiratory tract?
The trachea, bronchi, bronchioles, and the alveoli
There are two types of cells in the alveoli. Name them and their function
type 1 alveolar cells aid in gas exchange. type 2 alveolar cells produce surfactant and helps with fluid balance by moving solutes (and thus water) to and from the airways
Blood flow through the lungs equals ————————-
cardiac output
What are the four primary functions of the respiratory system?
pH regulation, gas exchange, vocalization, protection of the internal environment from foreign substances
What are the four processes of external respiration?
- Air moves in and out of the lungs by pulmonary ventilation
- Diffusion between air and blood allows for exchange of gases
- The gases are transported through the blood
- Diffusion between blood and tissues allows for exchange of gases
What are the three major components of the respiratory system?
The airways, the alveoli in the lungs, and the bones and muscles that assist in ventilation
What are the steps involved in inspiration? What happens with the intrapleural, intra-alveolar and transpulmonary pressure?
The thoracic cavity expands, so the intrapleural pressure drops. Because of this, the transpulmonary pressure goes up, and the lungs expand. The alveolar volume goes up. The intra-alveolar pressure drops, and the pressure gradient created by this causes air to flow into the lungs. Air flow stops when Patm= Palv
What are the steps involved in expiration? What happens with the pressures?
The muscles of inspiration relax, causing the lung volume to decrease. This increases intra-alveolar pressure, creating a pressure gradient causing outflow of air.
What is the relationship between the lungs, the pleura, and the pleural fluid?
Each lung is surrounded by a pleural sac, which imitates an air-filled balloon( the lung) surrounded by a water-filled balloon.
Which structures does an oxygen molecule pass starting in the air and ending at the exchange epithelium of the lungs
The mouth and nasal cavity, pharnyx, larynx, trachea, primary bronchi, bronchioles, alveoli
As the molecule moves into the airways, the diameter of the airways gets progressively smaller and the total cross-sectional surface area of the airways ————————- (increase or decrease)?
It increases
The velocity of air flow is highest in the —————————– and lowest in the ——————-
upper respiratory tract (mouth/ nasal cavity)
lower respiratory tract (bronchioles / alveoli)
How is the air conditioned before it reaches the alveoli? Name all three and explain how it is done
Warming air to body temperature, which is done by the body’s heat and moistened water evaporating from the mucosal lining of the airways
Adding water vapor until the air reaches 100% humidity.
Filtering out foreign materials, which is aided by ciliated epithelium and mucus that keep the foreign invaders from going into the lungs but rather to the pharnyx and then the stomach.
Describe the structure of the alveoli and the alveolar walls
The alveoli are air-filled sections composed of a single layer of epithelium. The walls are thin, allowing for rapid gas exchange. They cannot contract due to a lack of muscles
What is the surrounding tissue of the alveoli like? What type of tissue is it?
Connective tissue between the alveoli cells contains elastin and collagen fibers that create elastic recoil when lung tissue gets stretched.
What is the assocation between alveoli and the circulatory system?
Blood vessels fill 80-90% of the space between alveoli, forming a continuous sheet of blood in close contact with the alveoli. This short distance allows for rapid transfer.
Name the three aspects that affect the bulk flow of air
Air flows from high pressure to low pressure areas
The pressure gradient is created by a muscular pump
Resistance to air flow is influenced by the diameter of the airway
What are the two functions of pleural fluid?
Creating a slippery surface to decrease friction when the lungs move in the thorax. It also helps stick the pleural membranes to the thoracic cage.
How is air cleaned before it enters the alveoli?
The air passes ciliated epithelium bathed in a watery saline layer. Particles are trapped in this solution. The mucus is then rhythmically beaten upwards to the pharynx, this process is known as the mucocillary escillator.
What cells secrete mucus containing immunoglobins?
Goblin cells
How is the saline fluid in the airways produced?
As Cl- moves into the lumen, it draws Na+ with it. Movement of these solutes creates osmotic gradient, which makes water follow after the solutes.