Chapter 1: Cardio-Respiratory System

Question 1

During inspiration, which one of these must air first pass through before entering the bronchi?

A: Alveoli

B: Bronchioles

C: Lungs

D: Trachea

Answer 1

D

Trachea

Question 2

Adam plays badminton every week at a local leisure centre.

How would the mechanics of Adam’s breathing change during inhalation as a result of exercise?

Answer 2

• (During inhalation) his lungs can expand more during exercise (1)
• Due to the use of other muscles (sternocleidomastoid / pectorals) (1)

Accept any other relevant point about how an aspect of the mechanics of breathing changes as a result of exercise. Answers must refer to inhalation.

Question 3

Identify the blood vessel that carries oxygenated blood away from the heart.

Answer 3

Artery (1) Accept aorta

Question 4

State two characteristics of the artery

Answer 4

• Thick elastic walls (1)
• Small lumen (1)
• Smooth muscle layer (1)
• Carries blood at high pressure (1)

Accept any other suitable characteristic of arteries

Question 5

Evaluate the importance of vasodilation when taking part in physical exercise

Answer 5

AO1

• Vasodilation is part of the vascular shunt / opening of vessels to allow more blood through (1)

AO2

• Exercise requires more blood to the working muscles / more oxygenated blood (1)

AO3

• Vasodilation allows more blood to travel through the arteries to the muscles which need a greater supply of oxygen during exercise (1)
• Vasodilation must work with vasoconstriction, i.e. limit the blood to the areas which do not need large supply during exercise (1)
• To maintain exercise intensity / sustained performance (1)
• The higher the intensity, the greater the importance that oxygen is supplied to the desired areas (1)
• A lack of oxygen during exercise would result in waste products / lactic acid, etc (1)

Accept any other suitable evaluative point about the importance of vasodilation when taking part in physical exercise.

Question 6

Breathing enables gaseous exchange to occur at the alveoli.

Outline how two features of the alveoli assist in gaseous exchange.

Answer 6

• Large surface area of alveoli to allow larger volumes of gases / oxygen and carbon dioxide to move between the lungs and the bloodstream (1)
• Moist thin walls / one cell thick creating a short distance for diffusion / short diffusion pathway (1)
• Lots of capillaries around the alveoli so large area for gas exchange (1)
• Large blood supply to carry gases / oxygen and carbon dioxide (1)
• Movement of gas from high concentration to low concentration means there is a pressure gradient which allows diffusion to occur (1)

Accept any other suitable outline of how features of the alveoli assist in gaseous exchange. Answers must link the feature to how it assists in gaseous exchange.

Question 7

Define cardiac output.

Answer 7

• The amount of blood ejected / pumped from the heart in one minute (1)
• Stroke volume × heart rate (1)

Question 8

Define the terms tidal volume and residual volume.

Answer 8

• Tidal volume – volume of air inspired or expired / exchanged per breath (1)
• Residual volume – volume of air left in the lungs after maximal expiration (1)

Accept any other suitable definitions of tidal volume and residual volume.

Question 9

Outline what will happen to Zack’s tidal volume and residual volume once exercise starts.

Answer 9

• Tidal volume increases (once exercise starts) (1)

* Residual volume stays the same (once exercise starts) (1)

Question 10

How is maximum heart rate calculated?

Answer 10

220 - age

Question 11

Name two of the air passages which allow air to enter the body.

Answer 11

• mouth
• nose
• pharynx
• epiglottis
• larynx
• trachea
• bronchi
• bronchioles

Question 12

Describe what gaseous exchange is and clearly state where it takes place.

Answer 12

Oxygen being taken in / being exchanged for the carbon dioxide which is to be breathed out.

Gaseous exchange occurs
in the lungs / alveoli

Question 13

Explain how the heart acts as a pump in a double circulatory system.

Answer 13

• blood enters the right atrium / dark red in colour with little oxygen
• right atrium pumps blood / into the right ventricle
• the right ventricle pumps through the pulmonary artery / to the lungs
• from the lungs the blood returns / to the left atrium
• the left atrium pumps the blood / into the left ventricle
• the left ventricle pumps the blood / into the aorta/ to the body

Accept the above plus other suitable examples.

In order to obtain the maximum marks you must clearly identify at least three of the stages identified above.

Question 14

The air passages are one part of the breathing system. Name three other parts.

Answer 14

• trachea
• alveoli
• bronchioles lungs
• diaphragm
• mouth
• nasal cavity or nose
• larynx
• pharynx
• intercostal muscles
• bronchus, bronchi.

Question 15

Describe how respiration takes place.

Answer 15

• the process by which the body / takes in oxygen / and gives out carbon dioxide
• the process of the lungs / inspiring / and expiring

• reference to aerobic and anaerobic respiration is also
acceptable.

Accept the above plus any other suitable examples.

Question 16

What is the pulse?

Answer 16

The beat/pump (a single contraction) of the heart.

      accept.... heart beat

Question 17

What is blood pressure?

Answer 17

Resistance in the cardio-vascular system (one mark) to the flow of blood
round the body (one mark).

force of the blood (one mark) passing through an artery (one mark)

accept a measure of blood flow/ease at which blood flows around the body.

a measure of the blood flow through an artery = 2 marks.

do not accept the speed at which blood travels/how fast blood travels.

Question 18

What does the Cardio-Respiratory System consist of?

Answer 18

The Cardiovascular system and Respiratory System.

It includes: Heart, Blood Vessels & Blood as well as Lungs & Airways

Question 19

Describe the pathway of air into the lungs

Answer 19

Nose/Mouth
Trachea
Bronchi
Bronchioles
Alveoli
(Capillaries)

Question 20

Explain the process of Gaseous Exchange

Answer 20

1. Oxygen that is breathed in passes to the alveoli where it has a high concentration
2. Oxygen passes through the alveoli into the red blood cells in the capillaries, which have a low concentration
3. In the red blood cells, oxygen combines with haemoglobin to form oxyhaemoglobin before being carried around the body to be used
4. At the same time, haemoglobin carries carbon dioxide (high concentration) from the body
5. Carbon dioxide in the capillaries passes through into the alveoli and is breathed out.

Question 21

What is the diffusion pathway?

Answer 21

Gases (inc. oxygen and carbon dioxide) move from an area of higher concentration to an area of lower concentration in an attempt to reach equilibrium.
The distance that the molecules travel = diffusion pathway and is short in gaseous exchange.

Question 22

What is haemoglobin?

Answer 22

The protein found in red blood cells that transports oxygen (as oxyhaemoglobin) and carbon dioxide around the body

Question 23

What is oxyhaemoglobin?

Answer 23

A chemical formed when haemoglobin bonds to oxygen

Question 24

Describe the mechanics of breathing

Answer 24

Inspiration:

• Diaphragm contracts & flattens
• Intercostal muscles contract, pulling the ribs up and pushing the sternum out
• Chest cavity increases in size, reducing air pressure inside the lungs

Expiration:

• Diaphragm relaxes & becomes dome shaped
• Intercostal muscles relax, lowering the ribs and dropping the sternum
• Chest cavity becomes smaller, increasing air pressure inside the lungs