Exchange surfaces

Question 1

Mammalian gas exchange system

Answer 1

-Trachea
-Bronchi
-Bronchioles
-alveoli

Question 2

Adaptations of the trachea

Answer 2

• C shaped rings of cartilage for support
  -Ciliated epithelium with goblet cells
  -Smooth muscle within the walls of the trachea, muscle contracts if there are harmful substances detected in the air, this results in lumen of the trachea constricting and reducing airflow into the lungs.
  -When the smooth muscle relaxes, the lumen dilates
  This is due to elastic fibres

Question 3

Adaptations of the bronchus and bronchioles

Answer 3

The trachea, spilt in two bronchi (one for each lung)
These split into smaller tubes to create a network of bronchioles
Both the B have cartilage withing their walls for structural support and to keep the tubes open

Question 4

Adaptations of the Alveoli

Answer 4

Located at the end of the bronchioles and are the site of gas exchange
Oxygen diffuses from the alveoli into the blood in the capillaries and CO2 diffuses from the blood in the capillaries to the alveoli

LSA- large number of alveoli’s
Short diffusion distance - the alveoli walls are very thin
Maintains a concentration gradient - Each alveolus is surrounded by a network of capillaries to remove exchanged gases

Question 5

What is ventilation and what does it do?

Answer 5

Ventilation is the mechanism of breathing which involves te diaphragm and agnostic interaction between the external and internal intercoastal muscles bringing pressure changes in the thoracic cavity

Ventilation maintains the concentration gradient for gas exchange at the alveoli.

Question 6

What is inspiration in ventilation and what does it do ?

Answer 6

The process of inspiration is results an increased volume inside the thorax. This increased volume therefore means that there will be a drop in air pressure in the thorax. This will cause air to flow into the lungs

Question 7

What is expiration in ventilation and what does it do ?

Answer 7

In expiration, there is a decrease in volume of the thorax and hence there is an increased air pressure within the thorax. This will force air out of the lungs

Question 8

What is a spirometer?

Answer 8

A spirometer is something that measures the volume of air inhaled and exhaled

Question 9

What can be measured using a spirometer?

Answer 9

-vital capacity
-Tidal volume
-Residual volume
-Breathing rate

Question 10

What is vital capacity?

Answer 10

The maximum volume of air an individual can inhale and exhale during a deep breathe

Question 11

What is tidal volume ?

Answer 11

The air inhaled (peaks) and exhaled (troughs) when at rest

Question 12

What is residual volume?

Answer 12

The volume of air that always stays in the lungs so that they dont collapse

Question 13

What is breathing rate ?

Answer 13

The number of breathes taken per minute

Question 14

What is oxygen uptake?

Answer 14

Oxygen uptake is something that will increases when the ventilation rate increases, This will occur during exercise.

Question 15

What are interleukins ?

Answer 15

A chemical through which cells can talk to each other, immune cells talk to each other

Question 16

Features of an effective exchange surface

Answer 16

1- Increased surface area
2- Thin layers
3- Good bloody supply
4- Ventilation to maintain diffusion gradient

Question 17

Key structures of a nasal cavity

Answer 17

1- Large surface area will a good blood supply which warms the air to body temperature
2- A hairy lining, which secretes mucus to trap dust and bacteria protecting delicate lung tissue from irritation and infection
3- moist surfaces , which increase the humidity of the incoming air, reducing evaporation from exchange surfaces

Question 18

What is the trachea and branches lined with?

Answer 18

ciliated epithelium with goblet cells between and bellow the epithelial cells

Question 19

Is the trachea in front or behind the esophagus?

Answer 19

the esophagus is behind the trachea

Question 20

What do goblet cells do?

Answer 20

secrete mucus onto the lining of the trachea to trap dust and microorganisms that have escaped the nose lining. Cilia beat and move mucus away from the lung , mostly goes to the throat , is swallowed and digested

Question 21

The main adaptations of alveoli for effective gaseous exchange

Answer 21

1- large surface area
2- Thin layers
3-Good blood supply
4- Good ventilation

Question 22

What d insects have which is tough through which little or no gas exchange can happen?

Answer 22

Exoskeleton

Question 23

What are spiracles in insects?

Answer 23

Along the thorax and abdomen of most insects , are small openings known as spiracles

Question 24

What do spiracles do?

Answer 24

Air enters and leaves the system through spiracles but water is also lost

Question 25

What do insects need to minimize and how does it do so?

Answer 25

1- Loss of water
2- In many insects spiracles can be opened and closed by sphincters , the spiracle sphincters are kept closed as much as possible to minimize water loss

Question 26

What happens when an insect is inactive and oxygen demands are low?

Answer 26

The spiracles will all be closed most of the time

When the oxygen demand is raised or the carbon dioxide levels build up, more of the spiracles open

Question 27

What lead away from the spiracles

Answer 27

Tracheae

Question 28

What are tracheae?

Answer 28

These are the largest tubes of the insect respiratory system

Carry air into the body