Respiratory system

Question 1

what does the respiratory system consist of?

Answer 1

ventilation, external respiration, internal respiration + cellular respiration

Question 2

what is ventilation?

Answer 2

breathing air in and out of the lungs

Question 3

what is external respiration?

Answer 3

gaseous exchange between the lungs and blood

Question 4

what is internal respiration?

Answer 4

gaseous exchange between the capillaries and body cells

Question 5

what is cellular respiration?

Answer 5

metabolic reactions that take place in a cell to obtain energy from fuels (glucose)

Question 6

what is diffusion?

Answer 6

the movement of gas molecules from an area of high partial pressure to an area of low partial pressure

Question 7

what are the structures of the alveoli and their functions?

Answer 7

-walls are one cell thick= short diffusion pathway
-extensive capillary network= good blood supply to transport gases away
-huge surface area= allows greater uptake of O2

Question 8

explain the mechanics of breathing, during inspiration at rest and during exercise.

Answer 8

-diaphragm= contracts and is pulled down/flat
-ribcage= moves up and out
-muscles at rest= diaphragm + external intercostals
-muscles during exercise= diaphragm, external intercostals, sternocleidomastoid, scalenes and pectoralis major
-volume= increases
-pressure- decreases
-air= rushes in

Question 9

explain the mechanics of breathing during expiration at rest and during exercise.

Answer 9

-diaphragm= relaxes and rises to dome-shape
-ribcage- moves down and in
-muscles at rest= diaphragm and external intercostals passively
-muscles during exercise= internal intercostals + abdominals
-volume= decreases
-pressure= increases
-air=rushes out

Question 10

what is tidal volume?

Answer 10

the volume of air inspired and expired per breath

Question 11

what is minute ventilation?

Answer 11

the volume of air inspired or expired per minute
== number of breaths per minute X tidal volume

Question 12

what is inspiratory reserve volume?

Answer 12

the volume of air that can be forcibly inspired after a normal breath

Question 13

what is expiratory reserve volume?

Answer 13

the volume of air that can be forcibly expired after a normal breath

Question 14

how does exercise affect lung volumes?

Answer 14

TV= increases as more O2 required so depth of breathing increases

IRV+ERV= decreases as more used up by TV

minute ventilation= increases as more air is inspired/expired per minute to meet O2 demand

residual volume= stays the same

Question 15

what is a spirometer?

Answer 15

the measurement of volume of air breathing in + out

Question 16

what is gaseous exchange?

Answer 16

the diffusion of O2 from the lungs/alveoli into the capillaries to be transported around the body + the removal of CO2 from the capillaries into the lungs

Question 17

what occurs at the alveoli during gaseous exchange?

Answer 17

the partial pressure of O2 is higher in the alveoli than the capillaries so O2 diffuses into the capillaries down the concentration gradient until the pressure is equal in both

the partial pressure of CO2 is higher in the capillaries than the alveoli so it diffuses into the alveoli, down the concentration gradient

Question 18

what is the diffusion pathway of O2?

Answer 18

alveoli->blood->muscles

Question 19

what is the diffusion pathway of CO2?

Answer 19

muscles->blood->alveoli

Question 20

explain gaseous exchange at the muscles.

Answer 20

the partial pressure of O2 is higher in the capillaries/blood than in the muscles so it diffuses into the muscles
-PO2 of capillaries/blood= 100mmHg
-PO2 of muscles capillaries=40mmHg

the partial pressure of CO2 is higher in the muscles than the capillaries/blood so it diffuses down the concentration gradient into the blood
PCO2 of muscles capillaries= 46mmHg
PCO2 of capillaries/blood= 40mmHg

Question 21

what factors affect pulmonary ventilation during exercise?

Answer 21

-neutral control mechanism
-chemical control
-hormonal control

Question 22

what increases and decreases breathing rate?

Answer 22

increases= sympathetic nervous system
decreases= parasympathetic nervous system

Question 23

what is the neural and chemical regualtion of pulmonary ventilation controlled by?

Answer 23

the respiratory centre - in the medulla oblongata

Question 24

how does PCO2 affect breathing rate?

Answer 24

increased CO2= respiratory centred stimulated-> triggers sympathetic nervous system-> increases breathing rate

decreases CO2= respiratory centre stimulated-> triggers parasympathetic nervous system -> decreases breathing rate

Question 25

what is the inspiratory centre responsible for?

Answer 25

inspiration+ expiration

Question 26

what is the expiratory centre responsible for?

Answer 26

stimulating expiratory muscles during exercise

Question 27

how does the expiratory centre work?

Answer 27

receptors-> nerve impulses sent via the phrenic nerve-> to expiratory muscles -> so muscles contract

Question 28

how do chemoreceptors aid pulmonary ventilation during exercise?

Answer 28

they detect increases in blood acidity due to increases in CO2+ lactic acid -send impulses to respiratory control centre-> send impulses down phrenic nerve to stimulate more inspiratory muscles to contract--> so rate, depth and rhythm of breathing increases/ increases ventilation

Question 29

how do proprioceptors aid pulmonary ventilation during exercise?

Answer 29

they detect increases in movement in joints muscles --> stimulates respiratory centre--> send impulse down phrenic nerve to increase breathing rate

Question 30

how do baroreceptors aid pulmonary ventilation during exercise?

Answer 30

they detect decreases in blood pressure -> stimulates respiratory centre--> send impulse down phrenic nerve and causes breathing rate to increase

Question 31

how do stretch receptors aid pulmonary ventilation during exercise?

Answer 31

they prevent over inflation of the lungs -- --> by sending impulses to the expiratory centre + down the intercostal nerve--> to the expiratory muscles to cause expiration to occur

Question 32

how does the hormonal control mechanism aid pulmonary ventilation during exercise?

Answer 32

before exercise it send impulses to the renal glands--> so they pump adrenaline into the blood --> so breathing rate increases to prepare for exercise

Question 33

what are some poor lifestyle choices?

Answer 33

lack of exercise/poor diet + smoking

Question 34

how does a lack of exercise/poor diet impact a person?

Answer 34

- it reduces cardiovascular endurance -causes inefficient gas exchange

Question 35

how does smoking impact a person?

Answer 35

--increases breathlessness --nicotine constricts bronchioles --damages cilia causing excess mucus to build up in the lung passages ==smokers cough --damages alveoli by breaking down their walls==larger air sacs + reduces efficiency of gaseous exchange --reduces number of alveoli --CO bind to Hb more easily than O2- so reduces O2 carrying capacity of the blood --decreases athletes ability to utilise O2 in energy production == less energy for activity + quicker fatigue due to working anaerobically --increased risk of COPD(chronic obstructive pulmonary disease)