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Flashcards in Gas Exchange Deck (126)
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1

What is the total oxygen requirement of an organism proportional to?

Its total volume

2

What is proportional to the organisms surface area?

The rate of absorption of oxygen

3

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

Developed different adaptations to overcome these problems

4

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

5

How can large surface area be obtained in small organisms?

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

6

Why is being permeable important to an exchange surface?

This allows easy diffusion of gases

7

Why is being thin important to an exchange surface?

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

8

How far is diffusion effective?

Less than 1mm

9

Why is being moist important to an exchange surface?

O2, CO2 and nutrients diffuse in solution

10

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.

11

What are the 3 mechanisms to maintain diffusion gradients?

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

12

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

Internal Lungs

13

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.

14

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

Similar in structure
Different in size

15

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

Ciliated Epithelium

16

What is the function of ciliated cells?

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

17

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

18

What is the function of cartilage ?

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

19

Where is cartilage found?

In the trachea and bronchi

20

What shape is the cartilage found in the trachea?

C- shaped rings

21

What shape is the cartilage found in the bronchi?

In irregular blocks

22

What is found on the inside of the cartilage?

Smooth muscle

23

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

Relax during exercise to allow more air into the lungs

24

What causes asthma attacks?

Contracts during asthma which causes constriction and breathlessness

25

What recoils during exhalation?

Elastic Fibres

26

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

27

Why is it important that alveoli are well ventilated?

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

28

Why do alveoli have a good blood supply?

Because they are covered with an extensive network of capillaries

29

Why do the alveoli have a maintained diffusion gradient?

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

30

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