Chapter 7 ~ Exhange Surfaces And Breathing

Question 1

Why are specialise exchange surfaces needed?

Answer 1

Because they provide a surface area to volume ratio, which is needed for diffusion
For metabolic activity
Single celled and multicellular organisms

Question 2

What are the features of an efficient exchange surface?

Answer 2

Increase surface area which is provided by the root hair cells
Thin layer provided by the alveoli
Good blood supply/ventilation to maintain gradient provided by the girls and alveolus

Question 3

Mammalian gas exchange system:
Explain the features of nasal cavity

Answer 3

Large surface area with good blood supply this warms the air to body temperature. It has a hairy lining which secretes mucus to trap dust and bacteria. It has a moist surface which increases the humidity of incoming air which reduces evaporation from exchange services.

Question 4

Mamalian gas exchange system:
What is the function and structure of a trachea?

Answer 4

It is a wide tube, supported by incomplete ring of strong fixable cartilage which provides support. The rings are incomplete so that food can move easily. It is lined with ciliated epithelium with goblet cells between and below the epithelial cells. The goblet cells to create mucus and the cilia beat and move the mucus

Question 5

Mammalian gas exchange system:
Explain the function and structure of bronchus and bronchioles

Answer 5

The trachea to form two bronchi, which form bronchioles. the bronchioles contain cartilage for structural support. The smaller bronchioles have no cartilage rings, and the walls of the bronchi contains smooth muscles. When the small smooth muscles contract, the bronchi constrict when it relaxes the bronchi dilate.

Question 6

** mammalian gas exchange system:**
Describe the structure and function of alveoli

Answer 6

Alveoli are the main gas exchange surfaces of the body.
Each alveolus consist of a layer of thin flattened, epithelial cells, along with some collagen and elastin fibre. These elastic tissues allow the alveoli to stretch as it is drawn in. When they return to their resting size, they help squeeze the air out. This is known as the elastic recoil of lungs.
The inner surface of the alveoli is covered in thin layer of solution of salt, water and lung surfactant which makes it possible for alveoli to remain inflated.

Question 7

What are the two ways of ventilate from the lungs?

Answer 7

Inspiration and expiration

Question 8

Explain the process of inspiration

Answer 8

The external intercostal muscles contract and the internal intercostal muscles relax.
The rib cage moves in and out and the diaphragm muscles contract flatten and move down.
The volume of the thorax increases .
The pressure in the thorax decreases and becomes lower than atmospheric pressure .
Air flows into the lungs and down the pressure.

Question 9

Explain the process of expiration

Answer 9

The external intercostal muscles relax and the internal intercostal muscles contract.
The rib cage moves down and inwards.
The diaphragm muscles relaxes and moves up.
The volume of the thorax decreases.
pressure in the thorax increases and becomes higher than atmospheric pressure.
Air flows out of the lungs down a pressure gradient

Question 10

What are ways to measure the capacity of the lungs with explanation?

Answer 10

A peak flow meter measures, the rate at which air can be expelled from the lungs
A vitalograph is a sophisticated version of the peak flow meter
A spirometer measures the volume of air in held and exhaled

Question 11

Explain the definition of tidal volume

Answer 11

It is the volume of air that moves into an out of the lungs with each resting breath

Question 12

Explain the definition of vital capacity

Answer 12

It is the volume of air that can be breathed in when the strongest possible exhalation is followed by the deepest possible intake of breath

Question 13

Explain residual volume

Answer 13

Volume of air that is left in your lungs when you have exhaled as hard as possible

Question 14

What is inspiratory reserve volume?

Answer 14

Maximum volume of air, you can breathe in over and above a normal inhalation

Question 15

What is expiratory reserve volume?

Answer 15

Extra amount of air, you can force out of your lungs over and above the normal title volume of the air breathe out

Question 16

What is total lung capacity?

Answer 16

Some of residual volume and vital capacity

Question 17

What is the breathing rate?

Answer 17

Number of breath taken per minute

Question 18

What is ventilation rate?

Answer 18

Tidal volume x breathing rate

Question 19

Process of ventilation in fish

Answer 19

1.the fish opens its mouth, lowering the floor of the Bakal cavity. This increases the volume of cavity which lowers the pressure in the cavity
2. As pressure in the buccal cavity is lower than outside pressure, water flows up.
3. The fish closes its mouth raising the floor of the buccal cavity. This increased pressure pushes water into the cavity which is lower pressure.
4. The pressure now builds up in the cavity which forces that are opperculum to open and water out.

Question 20

Explain, inspiration in fish

Answer 20

The mouth opens. The floor of the mouth is lowered, increasing volume and reducing water pressure in the vocal cavity so water enters the mouth. As a result the pressure in cavity drops and water moves into the buccal cavity. At the same time the oppercular valve is shut and the oppercular cavity containing gills expand. This lowers the pressure in the oppercular cavity containing gills. The floor of the buccal cavity starts to move up, increasing the pressure there so water moves from buccal cavity over the gills.

Question 21

Explain, expiration in fish

Answer 21

The mouth closes. The floor of the buccal cavity is raised, pushing any remaining water from the mouth to the gills. Muscles squeeze that particular walls in with raising the water pressure in the gill chamber. Higher water pressure opens the flexible edge of the opperculum so water flows between the girls and out of the chamber. The gills extract oxygen from the water and pass carbon dioxide into it.

Question 22

How does gas exchange take place in insects?

Answer 22

On the thorax and abdomen of insects, there are small openings known as spiracles air enters and leaves the system through the spiracles, but water is also lost. The spiracles sphinicors are kept closed as much as possible to minimise water loss.

Question 23

Explain gas exchange of insects

Answer 23

Insect contracts and relax their muscles to move gases on mass into an out of the spiracles to the trachea

Question 24

Explain how tracheal fluid buildup in insects

Answer 24

The end of the trachioles are filled with water, the muscle cells which are around the tracheal respire and carry out an aerobic respiration. This produces lactate. This lowers the water potential and water moves from the tracheal into the cell via osmosis. This decreases the volume of liquid in the tragal, causing more air from the atmosphere to move in.

Question 25

What are ways, insects control water loss?

Answer 25

The closest very close using muscles/sphinicters
They have waterproof, waxy cuticles, which were reduces evaporation
They have thin hairs which also reduce evaporation