Respiratory System

Question 1

What does the respiratory system consist of?

Answer 1

Nasal Cavity
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Alveoli

Question 2

What are the two main functions of the respiratory system?

Answer 2

Pulmonary Ventilation - the inspiration (breathing in) and expiration of air
Gaseous Exchange:
a. external respiration - the movement of oxygen into blood stream and CO2 into lungs
b. internal respiration - the release of oxygen to respiring cells for energy production and collection of waste products

Question 3

In what order does air travel through the respiratory system?

Answer 3

1. Air is drawn into the nasal cavity through the nose and travels down the pharynx, larynx and trachea
2. The trachea, then divides into left and right bronchi as they enter the lung cavity.
3. The bronchi subdivide into smaller bronchioles and end in alveolar ducts, this is the entrance for air to move into the alveoli

Question 4

What are the alveoli?

Answer 4

clusters of tiny air sacs covered in a dense network of capillaries, which together serve as the external site for gaseous exchange

Question 5

in what two ways is oxygen transported?

Answer 5

1. carried with haemoglobin in red blood cells. (97%) Hb + O2 = HbO2
2. Carried within blood plasma (3%)

Question 6

in what 3 ways is carbon dioxide transported?

Answer 6

1. Dissolved in water and carried as carbonic acid (70%)
2. Carried with haemoglobin (23%). Hb + CO2 = HbCO2
3. Dissolved in blood plasma (7%)

Question 7

What is the definition of breathing rate?

Answer 7

The number of breaths taken per minute

Question 8

What is the definition of tidal volume?

Answer 8

The amount of air inspired or expired per breath (ml)

Question 9

what is the definition of minute ventilation?

Answer 9

The volume of air inspired or expired per minute

Question 10

what is vital capacity?

Answer 10

The maximum amount of air exhaled following a maximum inhalation

Question 11

How do you calculate minute ventilation?

Answer 11

VE = TV x F

Question 12

what are the average resting values of tidal volume, breathing rate and minute ventilation?

Answer 12

f- 12-15 breaths per minute
TV- 500ml
VE- 6-7.5 l/min

Question 13

what would be the difference between the resting values of a trained and an untrained athlete?

Answer 13

A trained athlete would have less breaths per minute as I don’t have to work as hard to meet the demands of oxygen. This would mean overall they have a lower resting minute ventilation.

Question 14

what is breathing rates response to exercise?

Answer 14

-The breathing rate increases in proportion to exercise intensity
-increases to around 50 to 60 breaths per minute
-Breathing rate can plateau once demand is met in submaximal exercise

Question 15

what is tidal volumes response to exercise?

Answer 15

-tidal volume increases in line with exercise intensity at submaximal intensities, until approximately 3L
-Tidal volume, reaches a plateau during submaximal intensity, because increased breathing rate towards maximal intensity is does not allow enough time and requires too much muscular effort.

Question 16

what is minute ventilation’s response to exercise?

Answer 16

-VE increases in line with exercise intensity
-VE can plateau during sustained submaximal intensity exercise, as you reach a comfortable state
-During maximum intensity, VE does not plateau as exercise intensity continues to increase as there is a growing demand for oxygen and waste removal, which would be a must continually strive to meet. TV will plateau and f will continue to increase
-during recovery, there is a rapid decrease, followed by a slower decrease to resting levels 

Question 17

What will the graph look like for VE during light intensity exercise?

Answer 17

1. an initial anticipatory rise in VE prior to exercise due to release of adrenaline
2. A rapid increase in VE at the start of exercise due to increased breathing rate and tidal volume to increase oxygen delivery and waste removal in line with exercise intensity.
3. A steady state VE throughout the sustained intensity exercise, as oxygen supply meets demand
4. An initial rapid Ben, more gradual decrease to resting levels as recovery is entered and the demand for oxygen dramatically reduces

Question 18

what are the average f, TV and VE values for an untrained performer at rest and maximal intensity

Answer 18

F:
rest- 12-15
maximal intensity- 40-50

TV:
rest- 500ml
maximal intensity- 2.5-3L

VE:
rest- 6-7.5L/min
maximal intensity- 100-150L/min

Question 19

what are the average f, TV and VE values for a trained performer at rest and maximal intensity?

Answer 19

F:
rest- 11-12
maximal intensity- 50-60

TV:
rest- 500ml
maximal intensity- 3-3.5L

VE:
rest- 5.5-6L/min
maximal intensity- 160-210 l/min

Question 20

What are the mechanics of inspiration at rest?

Answer 20

-active process
-external intercostals contract = lift ribs + sternum up and out
-diaphragm contracts and flattens
-increase size of thoracic cavity
-decrease in pressure

Question 21

What are the mechanics of inspiration during exercise?

Answer 21

-active process
-increase demand for oxygen and production of CO2 increases
-diaphragm contracts with more force
-external intercostals muscles contract with more force - ribs move up and out more
-sternocleidomastoid is recruited - contracts to lift sternum more
-pectorialis minor recruited - lifts ribs more
-increased volume of thoracic cavity
-decreased pressure
-increased concentration gradient, air enters lungs quicker

Question 22

What are the mechanics of expiration at rest?

Answer 22

-passive process
-external intercostals relax - rib cage moves down and in
-diaphragm relaxes - returns to dome shape
- decrease size of thoracic cavity
-increase in pressure = air forced out lungs

Question 23

What are the mechanics of expiration during exercise?

Answer 23

-active process
-internal intercostals contract = pull ribs down and in
-external intercostals relax
-diaphragm relaxes
-recuts abdominis contracts = pulled diaphragm up
-muscles recruited to reduce size of thoracic cavity more
-increase in pressure is greater = higher concentration gradient = air forced out lungs quicker

Question 24

Where is the respiratory control centre located?

Answer 24

Medulla Oblongata

Question 25

What are the two areases of the RCC? What do they do?

Answer 25

Inspiratory Centre (IC) -active at rest, stimulates inspiratory muscles to contract at rest and during exercise Expiratory Centre (EC) - active during exercise, stimulates, additional expiratory muscles to contract during exercise. Helps meet, increasing O2 demand and increases, depth and frequency of breathing

Question 26

how is respiratory regulation controlled at rest?

Answer 26

INSPIRATORY CENTRE- -external intercostal muscles stimulated to contract by the intercostal nerve -diaphragm is stimulated by the phrenic nerve EXPIRATORY CENTRE- inactive due to natural relaxation of the diaphragm and external intercostals

Question 27

How is respiratory regulation controlled during exercise?

Answer 27

-Sensory nerves, relay information to the RCC, where response is initiated by both the IC and the EC -Chemoreceptors (in aorta and carotid arteries) pick up an increase in blood acidity and CO2 concentration + a decrease in oxygen concentration -Thermoreceptors- inform of an increase blood temperature -Proprioreceptors (in muscles and tendons) inform of motor activity -Baroreceptors (lung tissue and bronchioles) inform of the state of a lung inflation -Chemoreceptors, thermoreceptors, and proprioreceptors inform the IC which increases stimulation of diaphragm and external intercostals. Recruits, sternocleidomastoid, and pictorial is minor to contract. -Baroreceptors inform the EC on the extent of lung inflation. If lung tissue becomes excessively stretched the EC stimulates additional exploratory muscles, internal intercostal is rectus abdominis to contract -Combination of the IC and EC lead to increased breathing rate and decrease breathing depth to maximise efficient respiration

Question 28

what is partial pressure?

Answer 28

The pressure exerted by individual gas held in a mixture of gases

Question 29

Where are two sites in the body which are primary concerned with pO2 and pCO2?

Answer 29

-External site for gaseous exchange between the alveoli and blood capillary membrane -Internal site for gaseous exchange between the blood capillary and muscle cell membrane

Question 30

What is gas exchange?

Answer 30

-The movement of gases across the membrane -Achieved by the fusion -The gases diffuse from an area of high partial pressure to an area of low partial pressure -The difference between high to low, partial pressure is known as a diffusion gradient -The steeper, the diffusion gradient, the greater the rate of gas exchange 

Question 31

In terms of gaseous exchange what happens during external respiration at rest?

Answer 31

-Exchange of gases at the lungs -Oxygen moves from high partial pressure in alveoli to low partial pressure in capillary blood down a diffusion gradient. Haemoglobin molecules combine with oxygen molecules to form oxyhaemoglobin as blood passes to the alveoli. -CO2 moves from a high partial pressure in capillary blood to low. Partial pressure in alveoli down a diffusion gradient. Diffusion gradient is small, but CO2 can cross membrane rapidly.

Question 32

in terms of gaseous exchange what happens during internal respiration at rest?

Answer 32

-Exchange of gases at the muscle cells and capillary -Oxygen moves from a high partial pressure in capillary blood to low partial pressure. Muscle cell down the diffusion gradient. The haemoglobin molecules dissociate from oxygen as they pass the muscle cells -Carbon dioxide move from a high partial pressure in the muscle cells into a low partial pressure in the capillary blood download diffusion gradient. This insures blood that leaves the muscle cells have been saturated with waste products ready for removal

Question 33

In terms of gases exchange, what happens during external respiration during exercise?

Answer 33

-The muscle tissues use a greater volume of oxygen for aerobic respiration, and consequently produce a greater volume of CO2 -The O2, diffusion gradient is steeper and O2 diffuses from high pO2 in the alveoli to a lower pO2 in the capillary blood at a greater rate -The CO2, diffusion gradient, steepens, and CO2 diffuses from the higher pCO2 in the capillary blood to the low pCO2 in the alveoli at a greater rate

Question 34

in terms of gaseous exchange what happens during internal respiration during exercise?

Answer 34

-The muscle tissues demand for oxygen increases in line with exercise intensity to produce energy through aerobic respiration. -The O2, diffusion gradient steepens O2 diffuses from a high pO2 in the capillary blood to a lower pO2 in the muscle cell -The CO2 diffusion gradient steepens and CO2 diffuses from a higher pCO2 in the muscle cell to a low pCO2 in the capillary blood

Question 35

What is the definition of association?

Answer 35

The combining of oxygen with haemoglobin to form oxyhaemoglobin

Question 36

what is dissociation?

Answer 36

The release of oxygen from haemoglobin for gaseous exchange

Question 37

what is the oxyhaemoglobin disassociation curve?

Answer 37

A graph showing the relationship between pO2 and percentage saturation of haemoglobin

Question 38

What does the oxyhaemoglobin dissociation curve show at rest and during exercise?

Answer 38

-pO2 at rest is approximately 40mmHg and approximately 25% of oxygen has disassociate from haemoglobin -75% of oxygen remains associated with haemoglobin in the bloodstream -As exercise intensity increases, pO2 lowers in the muscle cell, more oxygen dissociates from haemoglobin for diffusion

Question 39

what is the Bohr shift?

Answer 39

A move in the oxyhaemoglobin dissociation curve to the right cause by: Increase in temperature - due to exercise generating heat Increase in production of CO2 - due to increased diffusion gradient as CO2 being created as a byproduct respiration Increase in production of lactic acid and carbonic acid - lowers pH

Question 40

What happens to the oxyhaemoglobin disassociation curve during recovery?

Answer 40

-shift back to the left -Returning haemoglobin saturation with oxygen to its original relationship -Allows a greater Association of oxygen to haemoglobin at the alveoli, which is essential to oxygenate the bloodstream, flushing out waste products, and returning the body to pre-exercise state