3A exchange transport system

Question 1

What is each gyll made of in fish

Answer 1

Fin plates called Gill filaments which give big surface area for gas exchange

Question 2

What are the tiny structures which cover Gill filaments

Answer 2

Lamellae which increases surface area even more

Question 3

Why do the lamella have lots of blood capillaries

Answer 3

speed up the difusion

Question 4

Explain counter current system for gas exchange and fish

Answer 4

Blood flows throughlamella in One Direction and water flows over in opposite direction
maintaining large concentration gradient between water and blood
concentration of oxygen in water is always higher than in blood so top diffusion efficiency

Question 5

What do you insects use for gas exchange

Answer 5

Trachea

Question 6

In insects what are the paws on the surface of the trachea called

Answer 6

Spiracles

Question 7

How does gas exchange work in trachea of insects

Answer 7

air moves into trachea through spiracles
O2 travels down conc grad towards cells
trachea branch to tracheols which have thin permeable walls to individual cells
02 diffusers directly into respiring cells
CO2 from cells move down conc grad to spiracles to be released

Question 8

What do you insects to use to move air in and out of spiracles

Answer 8

Rhythmic abdominal movements

Question 9

Where do Dicotyledonous plants exchange gases

Answer 9

Surface of mesophyll cells

Question 10

Brief explanation of how gas exchange works on the surface of mesophyll cells

Answer 10

Mesophyll cells inside the leaf- gases move in and out through stomata in the epidermis
stomata open via guard cells

Question 11

How do you insects stop losing too much water

Answer 11

They close their spiracles using muscles

have a waterproof waxy cuticle and tiny hairs around spiracles which reduce evaporation

Question 12

How does stomata prevent water loss

Answer 12

Water enters guard cells making them turgid which opens stomato pore
if plant gets dehydrated Guard cells lose water and become flaccid which closes pores

Question 13

What are plants which are specially adapted for life in warm dry or windy habitats called

Answer 13

xerophytes

Question 14

Examples of xerophytic adaptations

Answer 14

Stomata in sunken pits trapping moist air reducing conc grad of water between leaf and air reduces diffusion of water out of leaf
Hairs on epidermis trapped moist air
Curled leaves with stomata inside protect from wind
Reduced number of stomata fewer places for water to escape
Waxy waterproof cuticles on leaves reduce evaporation

Question 15

Why do humans need to breathe

Answer 15

To get oxygen into blood for respiration to remove carbon dioxide made by respiring cells

Question 16

Explain process of breathing

Answer 16

Air enters into trachea
trachea split into two bronchi
each bronchus then branches into bronchioles bronchials end in alveoli where gas is exchange
rib cage intercostal muscles and diaphragm all work together to move in and out

Question 17

What are the two layers of intercostal muscles

Answer 17

Internal and external

Question 18

Explain inspiration

Answer 18

External intercostals and diaphragm muscles contract
Causes rib cage to move upwards and outwards and diaphragm to flatten this increases volume of thoracic cavity
As volume of thoracic cavity increases lung pressure decreases
Air flows from area of higher pressure to lower pressure so airflows down trachea into lungs
Inspiration is an active process requiring energy

Question 19

Explain expiration

Answer 19

External intercostals and diaphragm muscles relax
Rib cage moves down and inwards and diaphragm becomes curved again
Volume of thoracic cavity decreases causing air pressure to increase
Air force down pressure gradient out of lungs
Exploration is passive process

Question 20

How can expiration be forced

Answer 20

External intercostal muscles relax and internal intercostal muscles contract pulling with cage further down
during this movement the two sets of intercostal muscles is said to be antagonistic

Question 21

What is the single layer of thin flat cells which alveolus is made from

Answer 21

Alveolar epithelium

Question 22

Describe the Alveolus

Answer 22

Huge number of alveoli in the lungs meaning large surface area for exchange in O2 and CO2
alveoli surrounded by network of capillaries

Question 23

How does gas exchange happen in alveoli

Answer 23

O2 defuses out of alveoli across Alveolar epithelium and capillary endothelium and into haemoglobin in the blood
CO2 defuses into alveoli from blood and breathe out

Question 24

Summarise gas exchange in humans

Answer 24

02 moves down trachea bronchi bronchioles into alveoli
Movement happens down a pressure gradient
alveoli -O2 defuses across Alviolar epithelium then the capillary endothelium ending up in the capillaries this movement happens down a diffusion gradient

Question 25

How are alveoli adapted for gas exchange

Answer 25

Thin exchange surface- alveolar epithelium only one cell thick -short diffusion pathway
Large surface area -large number of alveoli
Steep concentration gradient of O2 and CO2 between the alveoli and capillaries

Question 26

what is tidal volume

Answer 26

volume of air in each breath normal between 0.4dm3 and 0.5dm3

Question 27

what is ventilation rate

Answer 27

number of breaths per minute normally 15

Question 28

what Is forced expiratory volume

Answer 28

Maximum volume of air which can be breathed out in one second

Question 29

What is forced vital capacity

Answer 29

Maximum volume of air its possible to breathe forcefully out of lungs after deep breath in

Question 30

What can be used to find tidal vol ventilation rate and more

Answer 30

spirometer

Question 31

Describe pulmonary tuberculosis

Answer 31

Immune system cells build wall around bacteria and lungs forming small hard lumps called tubercles
Tissue infected with tubercles dies gas exchange surface damage so tidal volume decreased
Tuberculosis causes fibrosis further reducing tidal volume

Question 32

What does reduced tidal volume mean

Answer 32

Less Air can be inhaled with each breath and therefore patients have to breathe faster ventilation rate increases

Question 33

Symptoms of tuberculosis

Answer 33

Persistent cough coughing up blood mucus chest pains shortness of breath and fatigue

Question 34

Describe fibrosis

Answer 34

Formation of Scare tissue in lungs result of infection or exposure to asbestos or dust
Scar tissue thicker and less plastic than normal tissue
Meaning lungs less able to expand can’t hold as much air tidal volume reduced and so is FVC
Reduction in rate of gasseous exchange diffusion is slower across the scars

Question 35

Symptoms of fibrosis

Answer 35

Shortness of breath dry cough chest pain fatigue weakness

Question 36

What is it mean that fibrosis patients have faster ventilation rate

Answer 36

Can’t get enough air to lungs to oxigenate blood

Question 37

Describe asthma

Answer 37

Respiratory condition airways become inflamed irritated usually from allergic reaction to pollen and dust
During attack smooth-muscle lining the bronchioles contracts large amount of mucus produced
Causes constriction of airways, airflow is severely reduced this oxygen enters alveoli causing FEV to reduce

Question 38

Symptoms of asthma

Answer 38

Wheezing tight chest shortness of breath in

Question 39

How do inhalers work

Answer 39

Drugs cause muscle in bronchioles to relax opening up the airways

Question 40

describe emphysema

Answer 40

Caused by smoking or long-term exposure to pollution from foreign particles become trapped in alveoli
Causes inflammation attracting phagocytes these produce enzyme that breaks down elastin
Loss of elastin means alveoli can’t recoil to expel air as well
Also leads to destruction of alveoli walls -reduces surface area of alveoli -rate of gas exchange decrease

Question 41

what is elastin

Answer 41

Protein found in the walls of the alveoli

Question 42

What does elastin help with in alveoli

Answer 42

Causes alveoli to return to normal shape after inhaling and exhaling air

Question 43

symptoms of emphysema

Answer 43

Shortness of breath wheezing increased ventilation rate

Question 44

How can tuberculosis fibrosis asthma and emphysema cause tiredness and weakness

Answer 44

They reduced rate of gas exchange in alveoli less O2 able to diffuse into bloodstream body receives less o2 rate of aerobic respiration reduced therefore less energy is released