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Flashcards in Gas Exchange Deck (126)
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What is the total oxygen requirement of an organism proportional to?

Its total volume


What is proportional to the organisms surface area?

The rate of absorption of oxygen


What has an organism done if it has increased in size?

Developed different adaptations to overcome these problems


What are the 5 common features of surface areas?

1. Large surface area relative to volume
2. Permeable
3. Thin
4. Moist - potential region of water loss
5. Mechanism to maintain diffusion gradients


How can large surface area be obtained in small organisms?

The large surface area can be formed by the folding of the exchange surface


Why is being permeable important to an exchange surface?

This allows easy diffusion of gases


Why is being thin important to an exchange surface?

It creates a short diffusion pathway, as diffusion is only effective across less than 1mm.


How far is diffusion effective?

Less than 1mm


Why is being moist important to an exchange surface?

O2, CO2 and nutrients diffuse in solution


Why is having a mechanism to maintain diffusion gradients important to an exchange surface?

Transport system, ventilation mechanism or creation of currents across surface allows for exchange.


What are the 3 mechanisms to maintain diffusion gradients?

1. Transport System
2. Ventilation Mechanism
3. Creation of currents across a surface


What adaptation have terrestrial vertebrates made for gas exchange with air?

Internal Lungs


What is the epiglottis?

a flap of cartilage behind the root of the tongue, which is depressed during swallowing to cover the opening of the windpipe.


What are the similarities and differences between the trachea and bronchi?

Similar in structure
Different in size


What is the inner surface of the trachea and bronchi covered in?

Ciliated Epithelium


What is the function of ciliated cells?

Rhythmic wave like movement moves mucus to top of trachea where it is swallowed


What are the 3 functions of goblet cells?

1. Secrete sticky mucus containing glycoprotein
2. Protects from dehydration, traps microbes and dust
3. Lysozyme also present which causes bacterial lysis


What is the function of cartilage ?

Holds the airway open during inhalation and exhalation throughout the pressure changes to prevent collapse.


Where is cartilage found?

In the trachea and bronchi


What shape is the cartilage found in the trachea?

C- shaped rings


What shape is the cartilage found in the bronchi?

In irregular blocks


What is found on the inside of the cartilage?

Smooth muscle


What is the function of the smooth muscle in cartilage during exercise?

Relax during exercise to allow more air into the lungs


What causes asthma attacks?

Contracts during asthma which causes constriction and breathlessness


What recoils during exhalation?

Elastic Fibres


What are the three features of the alveoli that make them good for gaseous exchange?

1. They provide an enormous surface area
2. Their surface is moist so gases can dissolve in the moisture and diffuses through the epithelial lining
3. The walls are thin providing a short diffusion pathway


Why is it important that alveoli are well ventilated?

Because ventilation movement ensure air is inhaled and exhaled from the lungs


Why do alveoli have a good blood supply?

Because they are covered with an extensive network of capillaries


Why do the alveoli have a maintained diffusion gradient?

Because blood is always moving taking oxygen away and bringing carbon dioxide


What three structural features of alveoli walls are important?

1. They are a single layer of squamous epithelium cells
2. Thin flattened cells
3. Adjacent blood capillaries are also lined with squamous endothelium