The respiratory system

Question 1

State and define the 2 types of respiration

Answer 1

1. External respiration - exchange of O2 and CO2 between the lungs and blood
2. Internal respiration - exchange of O2 and CO2 between the blood and the muscle tissues

Question 2

Define the term breathing rate (f)

Answer 2

The number of inspirations or expirations per minute

Question 3

Define the term tidal volume (TV)

Answer 3

The volume of air inspired or expired per breath

Question 4

Define the term minute ventilation (VE)

Answer 4

The volume of air inspired of expired per minute TV X f = VE

Question 5

Describe inspiration at rest

Answer 5

• active process
• external intercostal muscles between the ribs contract pulling the chest walls up and out
• the diaphragm muscles below the lungs contracts and flatten, increasing the size of the chest

Question 6

Describe inspiration during exercise and state the effect

Answer 6

• the sternocleidomastiods lifts the sternum
• the scalene and pectoral minor contract and lifts the ribs more

Effect - the volume of the thoracic cavity increases, creating a larger concentration gradient between inside the lungs and outside the body. Air enters the lungs more quickly

Question 7

Describe expiration at rest

Answer 7

• passive process
• external intercostal muscles between the ribs relax so that the chest walls move in and down
• the diaphragm muscle relaxes moving upwards reducing the volume within the lungs

Question 8

Describe expiration during exercise and state the effect

Answer 8

• active process
• internal interc
  ostal muscles contract and pull the ribs down and in
• the recuts abdominus contracts and pushes the diaphragm up

Effect - a decrease in volume in the thoracic cavity increases pressure within the lungs, therefore creating a larger concentration gradient

Question 9

What system is responsible for adjusting breathing rate and depth

Answer 9

The respiratory control centre (RCC) located in the medulla oblongata

Question 10

What 2 centres can be found within the RCC and what are they responsible for

Answer 10

1. The inspiratory centre (IC) - stimulates inspiratory muscles to contract at rest and during exercise
2. The expiratory centre (EC) - inactive at rest due to it being a passive process but stimulate additional expiratory muscles to contract during exercise

Question 11

Explain some key info about respiratory regulation at rest

Answer 11

• The IC (inspiratory centre) is responsible for the rhythmic cycle of breathing
• nerve impulses are generated and stimulate the inspiratory muscles causing them to contract
• this is via the intercostal nerve to the external intercostal and phrenic nerve to the diaphragm

Question 12

Explain key info about respiratory regulation during exercise

Answer 12

• sensory nerves relay info to the RCC where a response is initiated by the IC and the EC
• the RCC receives info from chemoreceptors, thermoreceptors, proprioceptors and baroreceptors

Question 13

Define the term gaseous change

Answer 13

Gaseous change is the exchange of oxygen and carbon dioxide by the process of diffusion

Question 14

Define the term diffusion

Answer 14

The movement of gas from an area of high pressure to an area of low pressure

Question 15

Define the term diffusion gradient

Answer 15

The difference between the high and low pressure (found between the lungs and alveoli + the capillaries and muscles)

Question 16

Explain key info about partial pressure

Answer 16

Partial pressure is the pressure a gas exerts within a mixture of gases

Gas always move from an area of high partial pressure to an area of low partial pressure

Question 17

Summarise gaseous exchange at rest - external respiration

Answer 17

• external respiration = the exchange of gases at the lungs
• oxygen moves from high pp in the alveoli to low pp in capillary blood down the diffusion gradient
• carbon dioxide moves from high pp in capillary blood to low pp in the alveoli down the diffusion gradient

Question 18

Summarise gaseous exchange at rest - internal respiration

Answer 18

• internal respiration = the exchange of gases at the muscle cells
• oxygen moves from high pp in capillary blood to low pp of the muscle cells down the diffusion gradient
• carbon dioxide moves from high pp in the muscle cell to low pp in capillary blood down the diffusion gradient

Question 19

Summarise gaseous exchange during exercise

Answer 19

• muscle tissues use a greater volume of O2 and produce a greater volume of CO2
• diffusion gradient steepens
• gaseous exchange occurs at a faster rate

Question 20

Define the oxyhemoglobin dissociation curve

Answer 20

A graph showing the relationship between the p02 and percentage saturation of haemoglobin

Question 21

Define the term dissociation and saturation

Answer 21

1. The process of oxygen unloading from haemoglobin
2. Haemoglobin fully loaded with oxygen

Question 22

Summarise the Bohr shift (key info)

Answer 22

• the movement of the oxyhaemoglobin dissociation curve to the right

The effects are -

-increase in blood and muscle temperature

• increase in pp of carbon dioxide

-increase in production of lactic acids and carbonic acid

Question 23

Describe the impact of the Bohr shift on performance

Answer 23

• the dissociation of 02 to respiring tissues is greater
• this enhances the volume of 02 available for diffusion and therefore aerobic energy production for exercise