Breathing And Exchange of Gases Flashcards
What is the primary function of oxygen (O2) in organisms?
To indirectly break down simple molecules like glucose, amino acids, and fatty acids to derive energy
Oxygen is essential for cellular respiration, which produces energy for various activities.
What harmful substance is released during catabolic reactions?
Carbon dioxide (CO2)
CO2 is a byproduct of metabolism and must be expelled from the body.
What is the process of exchanging oxygen from the atmosphere with carbon dioxide produced by cells called?
Breathing, commonly known as respiration
This process is crucial for maintaining the balance of gases in the body.
How do lower invertebrates like sponges and flatworms exchange gases?
By simple diffusion over their entire body surface
This method relies on the direct exchange of gases with the surrounding environment.
What structures do earthworms use for gas exchange?
Moist cuticle
The moisture in their skin facilitates the diffusion of gases.
What is the function of tracheal tubes in insects?
To transport atmospheric air within the body
This system allows for efficient oxygen delivery directly to tissues.
What are gills used for in aquatic arthropods and mollusks?
Branchial respiration (gas exchange)
Gills are specialized structures that extract oxygen from water.
What type of respiration do terrestrial forms of animals primarily use?
Pulmonary respiration (lungs)
Lungs are adapted for gas exchange in air.
Which respiratory structures do fishes use?
Gills
Gills allow fishes to extract oxygen from water.
What unique method of respiration can amphibians like frogs use?
Cutaneous respiration (through their moist skin)
This allows amphibians to absorb oxygen directly from their environment.
What opens into the nasal chamber?
External nostrils
What is the common passage for food and air?
Pharynx
What is the function of the larynx?
Sound production
What prevents the entry of food into the larynx during swallowing?
Epiglottis
What does the trachea divide into?
Right and left primary bronchi
Where does the trachea divide?
At the level of the 5th thoracic vertebra
What supports the trachea and bronchi?
Incomplete cartilaginous rings
What are the very thin, irregular-walled structures called that arise from terminal bronchioles?
Alveoli
What comprises the lungs?
Branching network of bronchi, bronchioles, and alveoli
How many lungs do we have?
Two
What covers the lungs?
Double layered pleura
What is located between the layers of the pleura?
Pleural fluid
What does pleural fluid reduce?
Friction on the lung-surface
The outer pleural membrane is in close contact with the _______.
Thoracic cavity
What is the inner pleural membrane in contact with?
The lung surface
What constitutes the conducting part of the respiratory system?
The part starting with the external nostrils up to the terminal bronchioles
What is the function of the conducting part of the respiratory system?
Transports atmospheric air to the alveoli, clears it from foreign particles, humidifies, and brings the air to body temperature
What is the exchange part of the respiratory system made up of?
The alveoli and their ducts
What occurs at the exchange part of the respiratory system?
Diffusion of O2 and CO2 between blood and atmospheric air
Where are the lungs situated?
In the thoracic chamber
What forms the thoracic chamber?
Dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs, and lower side by the diaphragm
What happens to the lung cavity when there is a change in the volume of the thoracic cavity?
It is reflected in the lung (pulmonary) cavity
What is the first step of respiration?
Breathing or pulmonary ventilation
What is the second step of respiration?
Diffusion of gases (O2 and CO2) across alveolar membrane
What is the third step of respiration?
Transport of gases by the blood
What is the fourth step of respiration?
Diffusion of O2 and CO2 between blood and tissues
What is the fifth step of respiration?
Utilisation of O2 by the cells for catabolic reactions and resultant release of CO2
What are the two stages of breathing?
Inspiration and expiration
What creates the pressure gradient for air movement during breathing?
Difference between intra-pulmonary pressure and atmospheric pressure
What initiates inspiration?
Contraction of the diaphragm
What happens to the thoracic chamber during inspiration?
The volume increases in the antero-posterior axis
What muscles assist in the movement of air during breathing?
Diaphragm and external and internal intercostals
Fill in the blank: Expiration takes place when the intra-pulmonary pressure is _______ than the atmospheric pressure.
higher
True or False: The diaphragm helps in decreasing the volume of the thoracic chamber during inspiration.
False
