exchange surfaces

Question 1

what is tidal volume?

Answer 1

the volume of air in each breath at rest

Question 2

what is vital capacity

Answer 2

maximum volume of air that can be breathed in or out

Question 3

breathing rate?

Answer 3

how many breaths per minute

Question 4

inspiration process?

Answer 4

1. external intercostal + diaphragm muscles contract.
2. ribcage moved upwards + outwards and diaphragm flattens
3. Volume of thorax increases
4. Pressure of lungs decreased
5. Air flows into lungs
   (active process)

Question 5

Expiration Process:

Answer 5

1. External intercostal + diaphragm muscles relax
2. Ribcage moves downwards + inwards and diaphragm becomes curved again.
3. Volume of thorax decreases
4. Pressure of lungs increases
5. Air forced out of lungs
   (passive process)

Question 6

goblet cells (function and placement)

Answer 6

•line the airways
•secrets music which traps microorganisms and dust particle and prevents them from reaching the alveoli

Question 7

ciliated cells (function and placement)

Answer 7

•on the surface of epithelial cells lining the airway.
•beats mucus secreted by goblet cells upwards towards the throat to be swallows
(prevents lung infections)

Question 8

elastic fibres (function and placement)

Answer 8

•on the walls of the trachea, bronchi, bronchioles and alveoli
•helps with breathing as when u inhale, lungs inflate and fibres are stretched. then they recoil to help push the air out when exhaling.

Question 9

smooth muscles (function and placement)

Answer 9

•on the walls on the trachea, bronchi + bronchioles
•allows their diameter to be controlled as during exercise, the smooth muscles relax and widen the tube with allows air to move in and out easier

Question 10

cartilage (function and placement)

Answer 10

•walls of trachea and bronchi
•provides support, stops trachea and bronchi collapsing when u breathe in + air pressure drops

Question 11

explain the counter current system in fish

Answer 11

•water with a high oxygen concentration flows next to blood with a lower concentration of oxygen.
•this maintains a steep concentration gradient which allows as much oxygen to diffuse from the water into the blood as possible.

Question 12

two main features of gas exchange in fish

Answer 12

Gills = located within the body, supported by arches, along
which are multiple projections of gill filaments, which are stacked up in piles.
Lamellae = at right angles to the gill filaments, give an
increased surface area. Blood and water flow across them in opposite directions (countercurrent exchange system).

Question 13

ventilation in fish?

Question 14

gas exchange in insects?

Answer 14

• insects have an open circulatory system (no blood)
• trachea branch out as spiracles and co2 from cells moves down it’s own concentration gradient towards the spiracles to be released into the atmosphere
• air circulates within the body in tiny vessels
  -trachea branch inwards in tracheoles.

Question 15

ventilation in insects?

Question 16

spirometer method?

Answer 16

Used to measure lung volume. A person breathes into an airtight chamber which leaves a trace on a graph which shows the volume of the breaths.

Question 17

what is soda lime used for?

Answer 17

to absorb the CO2

Question 18

How do you improve validity of the experiment?

Answer 18

-person must wear a nose clip
-machine must be airtight

Question 19

how do single celled organisms exchange and what do they have that improves this?

Answer 19

substances diffuse directly in and out of the cell.
they have a large surface area to volume ration so diffusion rate is quick because of the shorter distances substances have to travel

Question 20

how are root hair cells adapted for exchange?

Answer 20

1. millions of microscopic hairs which stick up into the soil.
2. this increases surface area which increases rate of absorption of water (osmosis) and minerals (active transport) from the soil.

Question 21

how are alveoli adapted for exchange? (gas exchange)

Answer 21

•alveolus is made up from thin flat cells called alveolar epithelium
•reduces diffusion distance for Co2 and O2 which increases the rate of diffusion.

Question 22

how are alveoli well ventilated?

Answer 22

1. each alveolus has its own capillary network which gives it a good blood supply as blood constantly takes away oxygen and brings in Co2
2. lungs are ventilated as they have a constant supply of air from breathing in and out
   - maintains concentration gradient of Co2 and O2

Question 23

what is residual volume

Answer 23

air always left in ur lungs