Chapter 1.2 The Respiatory System

Question 1

Name the passage of air

Answer 1

Nose 
Pharynx
Larynx
Trachea
Bronchi 
Bronchioles 
Alveoli

Question 2

What muscles are used in inspiration at rest (mention the pressure gradient)

Answer 2

Diaphragm contracts and flattens
External intercostals contract lifting the rib cage up and out
This decreases the pressure in the lungs and air is drawn into the lungs from the high pressure in the atmosphere.

Question 3

What muscles are used at expiration at rest (mention the pressure gradient)

Answer 3

Diaphragm relaxes into a dome
Intercostal muscles relax
This increases the pressure on lungs, pushing the air out of the lungs

Question 4

What muscles are used in inspiration DURING EXERCISE (mention the pressure gradient)

Answer 4

Diaphragm contracts and moves down
External intercostals contract 
Sternocleidomastoid 
Scalene’s 
Pectoral is minor 
These muscles help to expand the rib cage lowering the pressure in the lungs, drawing air into the lungs

Question 5

What muscles are used in expiration DURING EXERCISE (mention the pressure gradient)

Answer 5

Internal intercostals
Abdominals
They assist this passive process by increasing the pressure inside the lungs and expelling air out of the lungs

Question 6

In gaseous exchange, __________ moves from the high concentration in the lungs into the capillaries which have a _____ concentration of oxygen.

Carbon dioxide diffuses from the _____ concentration in the capillaries to the ____ concentration in the ________ .

Answer 6

Oxygen, low

High, low, alveoli

Question 7

Name the features that assist gaseous exchange/ diffusion

Answer 7

1. Large surface area
2. Thin walls
3. Short diffusion pathway
4. Lots of capillaries
5. Large blood supply

Question 8

What is the function of haemoglobin

Answer 8

Haemoglobin binds with oxygen in red blood cells to transport it to the working muscles.
It can also bind with CO2 to transport it out of the body.

Question 9

Define tidal volume

Answer 9

Volume of air breathed in or out in a single breath

Question 10

Define inspiratory volume

Answer 10

Volume of air that you can forcibly inspire after a normal breath

Question 11

Define expiration volume

Answer 11

The amount of air that can be forcibly exhaled after a normal breath

Question 12

Define Residual volume

Answer 12

Volume of air that stays in the lungs after maximal expiration

Question 13

Define minute ventilation

GIVE EQUATION

Answer 13

Volume of air breathed in and out per minute

Number of breaths (per min) x tidal volume = minute ventilation

Question 14

Why does minute ventilation increase during physical activity ?

Answer 14

The more demanding the physical activity, the higher demand for oxygen.
With a higher demand for oxygen, breathing increases to meet the extra demand

Question 15

what is a spirometer

Answer 15

a device used to measure the volume of air inspired and expired by the lungs

Question 16

define partial pressure

Answer 16

the pressure exerted by an individual gas when it exists in a mixture of gases

Question 17

explain the diffusion gradient

Answer 17

explains how gases flow form an area of high pressure or concentration to an area of low pressure or concentration.

Question 18

what 3 factors are involved in pulmonary ventilation during exercise

Answer 18

• neural control (parasympathetic and sympathetic nervous systems)
• chemical control (chemoreceptors)
• hormonal control (adrenaline)

Question 19

explain how neural and chemical control regulates the rate of breathing

Answer 19

When the blood acidity is high (sensed by the chemoreceptors) nerve impulses are sent to the respiratory centre in the medulla oblongata. which then regulates the inspiration and expiration.

Question 20

what is the order of neural/chemical control for inspiration

Answer 20

receptors (baro, chemo, proprioceptors> medulla > phrenic nerve >diaphragm and external intercostals

Question 21

what is the order of neural/chemical control for expiration

Answer 21

receptors > medulla > intercostal nerve > abdominals and internal intercostals

Question 22

what 2 areas does the respiration centre have and what are their roles

Answer 22

1- inspiratory centre is responsible for inspiration and expiration (via the phrenic nerve)
2- the expiratory centre stimulates the expiratory muscles during exercise (via the intercostal nerve)

Question 23

the inspiratory centre sends out nerve impulses via the ______ nerve to the inspiratory muscles (the ______ and ______ __________) to cause them to contract. This stimulation acts for approximately _ seconds until the impulses stop and then passive _______ occurs due to the elastic recoil of the lungs.

Answer 23

phrenic, diaphragm, external intercostals, 2, expiration

Question 24

what is the role of the chemoreceptors in neural and chemical control of pulmonary regulation

Answer 24

detect a change in the blood chemistry. For example when there is an excess of CO2 or lactic acid in the bloodstream chemoreceptors (located in the carotid artery and the aortic arch) will send nerve impulses to to the inspiratory centre to increase ventilation until blood acidity has been returned to normal.

Question 25

identify and explain the other factors that affect neural control of breathing apart from chemoreceptors.

Answer 25

mechanical factors- proprioceptors are located in the muscles and joints and they detect increased muscle movement and send feedback to the respiratory centre to increase breathing during exercise
baroreceptors- detect a decrease in blood pressure resulting in increased breathing
stretch receptors- during exercise the lungs are stretched more. stretch receptors prevent over inflation by sending impulses to the expiratory centre which sends signal down the intercostal nerve to contract the expiratory muscles.

Question 26

how does hormonal control regulate ventilation during exercise

Answer 26

adrenaline is a natural stimulant made in the adrenal gland in the kidneys. before we start exercise the brain sends impulses to the adrenal glands which then pump adrenaline into the bloodstream in anticipation for the increased need for oxygen and CO2 exchange. breathing rate increases.