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Flashcards in Respiration and Breathing 1 Deck (37):

What are the key events of respiration and breathing.
5 things
(Bob Eats Ten Enormous Icecreams)

Breathing/ ventilation (moving air in and out of lungs). Gas exchange between air in lungs and blood (external respiration: oxygen uptake and carbon dioxide removal). Gas transport around the body. Gas exchange between blood and body cells. Internal respiration (cellular metabolism: oxygen consumption and production of carbon dioxide)


What happens in healthly lungs

They expand to fill the chest cavity


What is the space between the lung and plural membrane called

Intraplural space


What are the components of the upper respiratory tract

Nasal cavity, pharynx, larynx


What are the components of the lower respiratory tract

Trachea, primary bronchus, lungs, diaphragm


What is the purpose of the ribs

To protect the soft mass of the lungs


What are alveoli

The mass of lungs and sight of gas exchange


What is are the functions of the respiratory system

To provide a sight for gas exchange and to maintain normal levels of oxygen and carbon dioxide in systemic arterial blood


Why does the respiratory system provide a sight for gas exchange

Intake of oxygen and for delivery to respiring cells and elimination of Co2 produced by respiring cells


What is normal arterial partial pressure of oxygen



What is normal arterial pressure of carbon dioxide



What is respiration matched to



What are the other functions of the respiratory system

Contributes to regulation of blood pH. Filters, warms and humidifies inspired air. Contains smell receptors. Produces sounds. Metabolism of biologically active chemicals


How does the respiratory system contribute to the regulation of blood pH

Increased CO2 results in acidification of the body. pH must be maintained as enzymes are optimised at specific pHs


Why does the respiratory system filter, warm and humidify air

Filtering air helps protect from harmful products, warming and humidifying air means diffusion takes place faster so helps oxygen uptake


Describe the conducting zone/ dead zone

No gas exchange takes place. Air moves by bulk flow and is conditioned, filtered and warmed. As airways branch the space becomes narrower


Describe the transitional and respiratory zones

Location of respiration, at Z17 alveoli start to appear enabling respiration to take place. Whenever alveoli occur they are encased by a capillary network which enables the delivery of oxygen to blood and removal of CO2


When does ventilation occur

When active muscle force is applied to a relaxed respiratory system


What type of process is inspiration

An active process and so requires ATP


What happens during inspiration

The volume of the thorax is increased, as the diaphragm contracts and flatterns the external intercostal muscles contract.


What is the most important muscle in inspiration

The diaphragm. If there are issues with the diaphragm assistance is needed to breathe


What happens as the volume of the thorax increases

Intrapleural pressure falls. Lungs expand. Alveolar pressure is less than atmospheric pressure (pressure gradient is established). Air flows into lungs until alveolar pressure is equal to atmospheric pressure. Air moves passively due to change in volume


What type of process is expiration

A passive process (so no ATP required)


What happens during expiration

The diphragm and external intercostal muscles relax. The elastic recoil of the lungs and chest walls reduces the volume of the thorax (passive mechanism).


What happens as the volume of the thorax decreases.

Intrapleural pressure rises. Lungs recoil. The pressure of the alveoli is greater than atmospheric pressure. Air is expelled from the lungs


What is used to measure lung function

A spirometer


What is a spirometer

A drum that moves to measure movement, movement data is sent to a computer


What are spirometers useful in

Health diagnostics, measuring the effectiveness of treatment, monitoring disease


What is normal tidal volume

1/2-1/4 of a litre


What is maximum tidal inspiration and expiration

5 litres (10x bigger than normal tidal volume)


During inspiration what resistive forces oppose airflow

Airway resistance. Pulmonary tissue resistance.
Inertia of air and tissues


What is airway resistance

Resistance to movement of air through airways (intrinsic resistance which requires 90% of work done to overcome)


What is pulmonary tissue resistance

Friction between lungs and chest wall


What is inertia of the air and tissues

Coughing or sneezing results in a sudden change from static to dynamic and therefore energy is required to overcome the inertia


During inspiration what resistive forces assist airflow

Elastic recoil of lungs and chest wall. Surface tension in alveoli


What is elastic recoil of lungs and chest wall

The fibres are made from elastin and collagen and therefore are stretchy and recoil after expansion


What is surface tension in the alveoli

The fluid lining of the alveoli dissolves oxygen from gas to aqueous, however oxygen in solution generates more surface tension due to attractive forces of the molecules in the fluid lining and the alveoli, this contributes to ejecting air