respiratory system

Question 1

Nasal Cavity:

Answer 1

 Hairs filter dust, pollen and other particles
 Air is warmed and moistened

Question 2

Pharynx:

Answer 2

 Commonly known as the throat
 Connects the nasal cavity to the larynx

Question 3

Larynx

Answer 3

 Commonly known as the voice box
 Has rigid walls of cartilage
 Connects the pharynx to the trachea

Question 4

Trachea

Answer 4

 Commonly known as the wind pipe
 Is surrounded by rings of cartilage
 Branches into the left and right bronchi

Question 5

Epiglottis

Answer 5

 Small flap of cartilage that allows food to pass into the stomach and not into the lungs

Question 6

Lungs

Answer 6

 The lungs are an organ that allow oxygen to be drawn
into the body
 You have a left and right lung

Question 7

Bronchi

Answer 7

 Bronchi branch off from the trachea and carry air into the lungs. They branch off 25 times.

Question 8

Bronchioles

Answer 8

 Bronchioles are small airways that extend from the bronchi
 they are about 1mm in diameter
 They connect the bronchi to the alveoli

Question 9

alveoli

Answer 9

 Alveoli are a mass of tiny air sacs
 There are about 300,000,000 alveoli in each lung
 Gaseous exchange happens at the alveoli and capillaries

Question 10

Diaphragm

Answer 10

 Is a flat muscle that is located beneath the lungs
 The muscle is involved in inspiration and expiration

Question 11

Thoracic Cavity

Answer 11

 This is the chamber in the chest that is protected by the ribs and sternum (thoracic wall)

Question 12

Internal Intercostal Muscles

Answer 12

 Muscles lie inside the ribcage
 They draw the ribs downwards and inwards

Question 13

External Intercostal Muscles

Answer 13

 Muscles lie outside the rib cage
 They draw the ribs upwards and outwards

Question 14

Inspiration

Answer 14

. internal intercostals relax, external contract
. diaphragm contracts, flattens, and external intercostal muscles raise the ribs upwards and outwards
. increases volume of thoracic cavity= decreases pressure in lungs compared to outside= air forced into lungs
. when exercising: scalenes muscle, sternocleidomastoid muscle and pectoralis major/minor all contract to help expiration

Question 15

Expiration

Answer 15

. external intercostals relax, internal contract
. diaphragm relaxes, raises up, and the internal muscles contacts they lower the ribs downwards and inward
. decreases volume of thoracic cavity= increased pressure in lungs to outside= air forced out
. exercise: abdominals and internal intercostals contract to help with expiration

Question 16

gas exchange

Answer 16

 O2 passed down respiratory system to alveoli. O2 diffuses out of alveolar epithelium into the dense capillary network surrounding it (blood- attaches to haemoglobin). It is now in bloodstream, so O2 can travel where needed in body.
 at muscles, oxygen in capillaries exchanges with CO2, so myoglobin will pick it up and transfer to mitochondria.
 At the same time, CO2 (deoxygenated blood) passes from capillary into alveolus, ready to be breathed out.

 Inspiration= O2 breathed in, diffuses from alveoli to bloodstream
 Expiration= CO2 from bloodstream (byproduct of respiration) diffuses into alveoli and breathed out

 Has plentiful blood supply= more efficient exchange
 Large SA for diffusion of gases = due to many alveoli/ capillaries and very small
 Moist lining of alveoli = assists diffusion of O2 into blood as some blood dissolves here and so passes into plasma as a dissolved substance = efficient
 Thin alveolar/capillary walls (1ct) = short diffusion pathway= efficient

 simple diffusion across the respiratory membrane as blood entering the capillaries from the pulmonary arteries has a lower oxygen concentration and a higher carbon dioxide concentration than the air in the alveoli. So O2 diffuses from higher O2 conc in alveoli to low O2 conc in capillary, and CO2 diffuses from high CO2 conc in capillary to lower CO2 conc in alveoli.

Question 17

Tidal Volume

Answer 17

 Is the amount of air inspired or expired in a normal breath when the person is at rest
 On average it is 0.5 litres

Question 18

Vital Capacity

Answer 18

 Is the volume of air that can be forced out the lungs after maximal inspiration
 Vital capacity can be as much as 4.8 litres

Question 19

Residual Volume

Answer 19

 Is the amount of air left in the lungs even after forced breathing out
 This volume of air cannot be breathed out
 It prevents the lungs from collapsing
 Average volume is 1.2 litres

Question 20

Total Lung Capacity

Answer 20

 Is the vital capacity + residual volume
 Average volume is 6.0 litres

Question 21

Pulmonary Ventilation

Answer 21

 The process of moving air in and out of the lungs is called pulmonary ventilation

Question 22

Minute Volume

Answer 22

 The passing of air through the lungs in one minute is known as minute volume

Question 23

Breathing and exercise

Answer 23

. exercise= more 02 needed for ATP= breathing rate needs to increase
. The medulla oblongata is responsible for involuntary functions such as breathing

Question 24

Responses of the respiratory system to exercise: Increased Breathing Rate

Answer 24

. exercise= more O2 demand= CO2 levels increase= breathing rate increases
. more intense exercise = increased breathing rate
. stop exercise = breathing rate slows
. Prior to exercise = anticipatory rise in breathing rate

Question 25

Responses of the respiratory system to exercise: Increased Tidal Volume

Answer 25

. tidal volume increased due to O2 demand
. = more air to pass through the lungs (pulmonary ventilation)
. = O2 goes to working muscles
. = tidal volume increases for both aerobic and anaerobic exercise

Question 26

Adaptations of the respiratory system to training: Increased Vital Capacity

Answer 26

 Training will increase vital capacity
 An increase in vital capacity will mean there will be a more efficient supply of oxygen to the working muscles

Question 27

Adaptations of the respiratory system to training: Increased Strength of Respiratory Muscles

Answer 27

 Training will increase the strength of the diaphragm and intercostal muscles
 A stronger diaphragm and intercostal muscle will increase the chest cavity allowing more oxygen to be taken into the lungs

Question 28

Adaptations of the respiratory system to training: Increased Oxygen and Carbon Dioxide Diffusion Rate

Answer 28

 Due to the increase in capillaries there is an increase in efficiency of the diffusion of gasses
 More oxygen can be delivered to the working muscles
 More carbon dioxide can be removed and exhaled

Question 29

Additional factors affecting the respiratory system: Asthma

Answer 29

 Asthma = condition whereby the airways of the respiratory system become restricted
 Asthma = the bands around the airways contract and tighten = air cannot move
freely in or out of the body, phlegm can also narrow the airway further
 Exercise can induce an asthma attack
 Asthma reduces performance = restricts oxygen getting to the working muscles
 Exercise can benefit someone with asthma = can reduce the effects by increasing
respiratory muscles, vital capacity and the oxygen and carbon dioxide diffusion rate

Question 30

Additional factors affecting the respiratory system: Partial Pressure/Altitude

Answer 30

. Oxygen moves from high pressure (alveoli) to low pressure (capillaries) until the pressure are equal
. The greater the difference in gasses, the faster the rate of diffusion
. At altitude there is less oxygen reducing the partial pressure = you have to work harder this can cause: shortness of breath, dizziness and difficulties in concentration
. lack of oxygen altitude = hypoxia which causes an increase in breathing rate and depth
. Performance levels at altitude will reduce, however over a period of time your respiratory system will adapt
. Elite athletes will train at altitude so their body adapts = include an increase in red blood cells & capillaries which will allow more oxygen to be carried and diffused to the working muscles

Question 31

neural control

Answer 31

• involuntary (controlled by respiratory centre = medulla oblongata and Pons)
• voluntary (cerebral cortex = holding breath/deliberately hyperventilating)
• two areas: (DRG) Dorsal respiratory group and (VRG) Ventral respiratory group. They are responsible for the ‘rhythm generation’ that allows rhythmic and continuous breathing.

Question 32

chemical control- when active

Answer 32

• chemoreceptors receive info about chemicals in blood. Located in Medulla Oblongata, Carotid arteries or aortic arch
• change in CO2 conc (increases when exercising, so breathing rate increases so can remove CO2 faster)
• change in pH activity (exercise means lactic acid builds up, pH decreases, breathing rate increases, lactate breakdown faster)
• During inhalation, signals increase frequency, diaphragm and external intercostals contract more forcefully.
• during exhalation, internal intercostals are recruited to actively pull the rib cage down.
• these responses allow for greater minute ventilation (vol of air breathed in per min)

Question 33

Explain why gaseous exchange of oxygen is faster at the alveoli during exercise than at rest. (4)

Answer 33

Muscles are using more O2 (1) therefore a lower partial pressure/ppO2 in the capillaries near the alveoli (1). There is an increased breathing rate (1), which means more O2 /higher partial pressure/ppO2 is in the alveoli (1) which creates a steeper diffusion gradient (1) and O2 moves quicker (from the alveoli) into the blood/capillaries (1)

Question 34

Name the structures, A–C, described in Table 1.

Answer 34

A flap of cartilage at the base of the tongue, which
prevents food from entering the windpipe.= Epiglottis
Large single tube strengthened by rings of
cartilage = Trachea
Tiny airways that carry oxygen to the alveoli. = Bronchioles

Question 35

Explain the role of the diaphragm during inspiration and expiration.

Answer 35

When inspiring/breathing in the
diaphragm contracts/flattens/is
forced downwards (1) to increase the
size/decrease the pressure of the
thoracic cavity (1)

When expiring/breathing out the
diaphragm
relaxes/rises/domes/moves up (1)
to decrease the size/increase the
pressure of the thoracic cavity (1)

Question 36

(a) State the meaning of the term ‘tidal volume’.

Answer 36

The volume of air breathed in and out
with each breath (1)