Cardio-respiratory System

Question 1

Respiratory system pathway

Answer 1

We breathe air moves through mouth and nose and travels into trachea
The trachea carries air from throat to lungs
Near lungs, trachea divides into two tubes called bronchi, one entering left lung, other entering right
Once inside lung, the bronchi split in several ways, forming smaller and smaller bronchi
These bronchi further divide into bronchioles
At the end of the bronchioles, there are openings to the alveoli
Usually several alveoli coming from one bronchioles, forming a little clump that resembles a cluster of grapes
Function of alveoli is the exchange of gases
Capillaries carry blood surrounding the alveoli, exchange of oxygen from lungs into the blood and exchange carbon dioxide in the blood from these capillaries occur through the walls of the alveoli

Question 2

Trachea

Answer 2

Windpipe
Carries air from the mouth and nose to the lungs
Inner surface of trachea covered in tiny hairs called cilia, which catch particles of dust, which are removed when coughing
Trachea kept open but rings of stiff cartilage

Question 3

Lungs

Answer 3

Pair of large spongy organs optimised for gaseous exchanges between our blood and the air

Question 4

Bronchi

Answer 4

Carry air from trachea into lungs

Question 5

Bronchioles

Answer 5

Carry air from the bronchi to the alveoli

Question 6

Alveoli

Answer 6

Many tiny air sacs in the lungs which allow for rapid gaseous exchange

Question 7

Gaseous exchange

Answer 7

In lungs, takes place by diffusion
Gases CO2 and oxygen move down a conc gradient from high concentration to low concentration
Means oxygen in alveoli (high concentration) diffuses into blood where conc of oxygen is lower
Oxygen diffuses out of alveoli and is replaced by the air that we continue to breathe
Same thing happens to CO2
Blood has high concentration of CO2, low in alveoli
CO2 diffuses into alveoli and breathed out

Question 8

What type of process is diffusion

Answer 8

Passive

Question 9

Factors that help diffusion

Answer 9

Alveoli are very small, provide large surface area for the exchange of gases
Surface of alveoli and walls of blood capillaries are very thin (one cell thick) , and moist which helps
Alveoli and capillaries are touching each other, very short distance for diffusion to occur, short diffusion pathway
Each alveolus is surrounded by network of blood capillaries, rich supply of blood for the gases to diffuse from / into

Question 10

Oxygen diffusion

Answer 10

Oxygen combines with haemoglobin forming oxyhemoglobin.

Question 11

Haemoglobin

Answer 11

Red pigment that is found in red blood cells that carries oxygen and carbon dioxide

Question 12

Breathing

Answer 12

Two stage process
Inspiration = inhalation
Expiration = exhalation

Question 13

Inspiration

Answer 13

Intake of air into lungs
Brought by increasing the volume of the chest cavity
Breathing muscles contract, contraction of dome shape diaphragm causes it to flatten, thus enlarging chest cavity
Intercostal muscles causes the ribs to also rise, also increasing chest cavity

Question 14

Expiration

Answer 14

Expulsion of air from lungs through reducing the volume of the chest cavity
Breathing muscles relax
Diaphragm curves and returns to its dome shape, weight of ribs causes them to descend and chest volume decreases
Reduction in size of the chest cavity increases the pressure of air in the lungs and causes it to expelled
Air passes from high pressure in lungs to the low pressure in the bronchi and trachea

Question 15

Process of inspiration

Answer 15

Chest expands
Diaphragm contracts

Question 16

Expiration process

Answer 16

Chest contracts
Diaphragm relaxes

Question 17

How is inspiration and expiration assisted during exercise

Answer 17

By additional contraction of pectoral and sternocleidomastoid muscles
Further increase size of chest cavity so allow more air to enter lungs

Abdominal muscles contracting help and speed up expiration

Question 18

What type of process is inspiration

Answer 18

Active

Question 19

What type of process is expiration

Answer 19

Passive

Question 20

Spirometer

Answer 20

Piece of apparatus to measure lung volume
Consist of chamber filled with oxygen that floats on tank of water
Person breathes from mouthpiece attached to a tube which is connected to the chamber

Breathing in chamber takes away oxygen, which then sinks down. Breathing out pushing air into chamber, causing it to float. During these movements, lung volume can be measured and seen

Question 21

Lung volume

Answer 21

Amount of air breathed in, breathed out and found in lungs at any given time

Question 22

Tidal volume

Answer 22

The volume of air breathed in or out during a normal breath at rest

Question 23

Inspiratory reserve volume

Answer 23

Additional air that can be forcibly inhaled after inspiration of a normal tidal volume

Question 24

Expiratory reserve volume

Answer 24

The additional air that can be forcibly exhaled after the expiration of normal tidal volume

Question 25

Residual volume

Answer 25

The volume of air that remains in the lungs after a maximal expiration

Question 26

Three blood vessels

Answer 26

Artery
Vein
Capillaries

Question 27

Arteries

Answer 27

Blood vessels carrying blood away from heart
Under highest pressure
Elastic, they maintain blood pressure by recoiling and narrowing when the heart is relaxing
Have muscular walls that can adjust their diameter to increase or decrease blood flow to a particular part of body
Muscles contract = diameter reduces = vasoconstriction
Muscle relaxes = diameter increases = vasodilation
Have a pulse
Small lumen

Question 28

Vasoconstriction

Answer 28

Reducing diameter of small arteries to reduce blood flow to tissues

Question 29

Vasodilation

Answer 29

Increasing the diameter of small arteries to increase blood flow to tissues

Question 30

Capillaries

Answer 30

Very thin blood vessels that allow gas exchange to happen
Thin walled blood vessels that join arteries and veins
Thin walls allow gas exchange
Nutrients also diffuse into surrounding tissue and waste products diffuse from the tissue

Question 31

Veins

Answer 31

Blood vessels carrying blood towards heart
Smaller walls than arteries because blood pressure is much lower
Have large internal diameter (lumen)
Have valves to prevent backflow of blood

Question 32

Cardiac cycle

Answer 32

Sequence of events that occur when the heart beats

Question 33

The phases of cardiac cycle

Answer 33

Diastole and systole

Question 34

Diastole

Answer 34

Term used to describe the relaxation phase of cardiac cycle
The heart ventricles are relaxed and the heart fills with blood

Question 35

Systole

Answer 35

Term used to describe the contraction phase of cardiac cycle
The ventricles contract and pump blood to the arteries

Question 36

Cardiac output

Answer 36

Volume of blood that the heart is able to pump out
Represents the volume of oxygenated blood that is delivered to body

Question 37

Stroke volume

Answer 37

Volume of blood that leaves the heart during each contraction

Question 38

Cardiac output formula

Answer 38

Cardiac output = heart rate x stroke rate