1b - The Structure And Function Of The Cardio-respiratory System

Question 1

How is the trachea kept open?

Answer 1

By rings of cartilage

Question 2

When the trachea splits into two branches, what are they called?

Answer 2

Bronchi

Question 3

What are the tiny hairs in your trachea called and what is their job?

Answer 3

• Cilia

- they catch dust particles which are then removed by coughing

Question 4

What is the key feature of the bronchioles?

Answer 4

• they are very narrow; less than 1 mm in diameter

- there is no cartilage between the bronchioles

Question 5

What is found at the end of the bronchioles?

Answer 5

The alveoli

Question 6

What happens when the bronchi enter the lungs?

Answer 6

They split several ways, forming smaller and smaller bronci

Question 7

What is the name of the smaller bronchi?

Answer 7

Bronchioles

Question 8

True or false - there is just one alveolus at the end of a bronchiole?

Answer 8

No, there are several, like a bunch of grapes

Question 9

Describe the function of the alveoli.

Answer 9

• it’s the exchange of gases
• the capillaries carry blood around the alveoli. The exchange of oxygen from the lungs into the blood and the exchange of carbon dioxide in the blood, occurs through the walls of the alveoli

Question 10

How does gaseous exchange take place?

Answer 10

By diffusion

Question 11

What are the two gases involved in gaseous exchange?

Answer 11

Oxygen and carbon dioxide

Question 12

Is there a high or low concentration of carbon dioxide in the capillaries surrounding the alveoli?

Answer 12

There is a high concentration of carbon dioxide, thus the carbon dioxide diffuses into the alveoli from the blood and eventually breathed out

Question 13

What is diffusion?

Answer 13

It is the net movement of particles from a high concentration to low concentration

Question 14

Is there a high or low concentration of oxygen in the alveoli

Answer 14

There is a high concentration. Therefore it is easier for diffusion to occur when the oxygen diffuses into the capillaries and into the blood

Question 15

What order does the respiratory system go in?

Answer 15

Trachea ➡️
bronchi ➡️ 
lungs ➡️ 
bronchioles ➡️ 
And alveoli

Question 16

Describe the 4 key features which the alveoli have to make gaseous exchange more efficient.

Answer 16

1. The alveoli are very small but there is a large number of them hence they have a large surface area
2. They have thin walls (one cell thick) meaning shorts diffusion distance. They are also moist walls
3. That capillaries and the alveoli are touching (short diffusion pathway)
4. There is a rich supply of blood, each alveolus is surrounded by a network of capillaries

Question 17

What is it called when oxygen combines with haemoglobin?

Answer 17

Oxhaemoglobin

Question 18

What is inspiration/inhalation?

Answer 18

• It is the intake of air into the lungs, increasing the chest cavity

Question 19

What is expiration/exhalation?

Answer 19

• it is the release of air out of the lungs, decreasing the chest cavity

Question 20

What happens in inhalation?

Answer 20

• Intercostal muscles contract
• diaphragm contracts and flattens
• chest expands

Question 21

What happens in exhalation?

Answer 21

• Intercostal muscles relax
• diaphragm relaxes and goes to dome shape
• chest relaxes

Question 22

Explain what happens during inhalation?

Answer 22

When the chest cavity expands, its volume increases, this reduces the pressure in the chest cavity. Air passes from the high-pressure outside into lower-pressure inside the lungs.

Thus inhalation happens

Question 23

Explain what happens during exhalation?

Answer 23

When the chest cavity relaxes, its volume decreases, this increases the pressure of the chest cavity. Air passes out of the high-pressure lungs to the lower-pressure of the outside atmosphere.

Thus exhalation happens

Question 24

What muscles help assist inhalation during exercise?

Answer 24

• pectoral muscles

- sternocleidomastoid muscles

Question 25

What muscles assist exhalation during exercise

Answer 25

The abdominal muscles

Question 26

What apparatus is designed to measure the volume of the lungs?

Answer 26

A spirometer

Question 27

What is tidal volume?

Answer 27

Tidal volume is the volume of air that enters the lungs during normal inspiration at rest

Question 28

What is the average tidal volume?

Answer 28

500ml

Question 29

What is residual volume?

Answer 29

It is the volume of left in the lungs following maximal expiration

Question 30

What is inspiratory reserve volume?

Answer 30

The volume of extra air inspired (above tidal volume) during a deep breath in

Question 31

How high can inspiratory reserve volume get?

Answer 31

As high as 3000 mL

Question 32

What is expiratory reserve volume?

Answer 32

It is the volume of extra air expired (above tidal volume) during a forceful breath out

Question 33

What are the 3 blood vessels?

Answer 33

- artery - vein - capillary

Question 34

What is the job of the arteries?

Answer 34

They carry blood away from the heart

Question 35

Is the blood in the arteries at high or low pressure?

Answer 35

High

Question 36

Fully describe arteries.

Answer 36

- Carry blood away from the heart - most (but not all) arteries carry bright red oxygenated blood - they stretch as blood surges through and then return to normal shape / they have a pulse - thick, muscular and elastic walls to withstand pressure - small lumen

Question 37

Fully describe capillaries.

Answer 37

- huge network of tiny vessels linking arteries and veins - very narrow - only one red blood cell at a time - very thin walls (one cell thick) to allow rapid diffusion of substances into and out of the blood

Question 38

Fully describe veins.

Answer 38

- Carry blood towards the heart - most (but not all) veins carry dark red deoxygenated blood - no stretch and no pulse - thin walled - large lumen - contain valves to prevent backflow of blood

Question 39

How does vasoconstriction and vasodilation occur?

Answer 39

The rings of muscle in the arteries can contract. When they make it smaller. This is vasoconstriction. When they make it bigger this is vasodilation. Vasodilation tends to mostly occur during exercise to allow more blood to flow to the working muscles

Question 40

What parts make up the heart?

Answer 40

The heart has 4 chambers: - left and right atrium - left and right ventricle The heart also contains a ventricular septum

Question 41

What side of the heart takes in the deoxygenated blood?

Answer 41

The deoxygenated blood comes through the vena cava into the left atrium and ventricle and gets delivered to the lungs to get oxygenated

Question 42

What is the cardiac cycle?

Answer 42

It is a sequence of events that occur when the heart beats. One cardiac cycle is the heart taking in the blood and then pumping it out.

Question 43

Name the 2 phases of the cardiac cycle?

Answer 43

- diastole | - systole

Question 44

What happens in the diastole phase of the cardiac cycle?

Answer 44

The heart ventricles relax, the valves open and the heart fills with blood

Question 45

What happens in the systole phase of the cardiac cycle?

Answer 45

The heart ventricles contract and this forces the blood to be pumped out into the arteries. The valves also close to prevent backflow of blood into the heart

Question 46

True or false - The systole and diastole phases of the cardiac cycle happen at the same time?

Answer 46

True

Question 47

What are the valves called between the atrium and the ventricles?

Answer 47

The atrioventricular veins

Question 48

What is cardiac output?

Answer 48

It is the volume of blood that the heart is able to pump out

Question 49

What is cardiac output measured in?

Answer 49

Liters per minute

Question 50

What is the equation for cardiac output?

Answer 50

Cardiac output (Q) = Heart rate (HR) x Stroke volume (SV)

Question 51

What is heart rate?

Answer 51

It is the number of times the heart beats each minute

Question 52

What is stroke volume?

Answer 52

It is the volume of blood that leaves the heart during each contraction

Question 53

What happens to the heart rate before exercising?

Answer 53

- it increases, this is called anticipatory rise | - it is the expectation of exercise