C1 - Structure of the respiratory system

Question 1

What does the respiratory system do?

Answer 1

• Provides oxygen to all living cells/ tissues in the body
• Removes waste products such as carbon dioxide, heat and water vapor

Question 2

Where does gaseous exchange occur?

Answer 2

• Lungs
• Removal of waste products also takes place

Question 3

Basic description of the structure of the respiratory system …

Answer 3

• Air is drawn into the body via the mouth and nose, passes through a series of airways is referred to as the ‘respiratory tract’

Question 4

What are the two main sections of the respiratory tract called?

Answer 4

Upper respiratory tract - nose, nasal cavity, mouth, pharynx and larynx
Lower respiratory tract - trachea, bronchi and lungs

Question 5

Nasal cavity is …

Answer 5

• breath in, air enters the nasal cavity by passing through the nostrils
• hairs within the cavity filter out dust, pollen and other foreign objects
• sticky mucous layer traps the small particles and tiny hairs (cilia) transport them to the pharynx to be swallowed
• air is warmed/ moistened in the internal nasal cavity before it enters the pharynx

Question 6

Pharynx is …

Answer 6

• throat
• small tube (10-13 cmfrom base of skull to C6 vertebrae)
• pharynx wall is made of strong skeletal muscle
• shaped like a funnel it connects the nasal cavity and the larynx
• passageway for food as well as air, special adaptations are required to prevent food entering the bronchus

Question 7

Epiglottis is …

Answer 7

• small flap of cartilage at the back of the tongue which closes the top of the trachea when surrounding food
• ensures that food and drink does not enter the trachea and down into the bronchus
• this is essential as the pharynx allows both food/ drink and air to travel in this direction

Question 8

Larynx is …

Answer 8

• voice box
• has rigid walls of strong muscles and cartilage
• contains the vocal cords and connects the pharynx to the trachea
• inline with C6 vertebrae

Question 9

Trachea is …

Answer 9

• windpipe
• denotes the start of the lower respiratory tract
• 12 cm long and 2cm diameter
• contains strong/rigid rings of cartilage to prevent it from collapsing but it is flexible
• it travels down and branches into the left and right bronchi

Question 10

Lungs are …

Answer 10

• key organs and allows oxygen to be drawn into the body
• right lung is larger than the left and has 3 sections
• left only has 2 sections (heart takes up room)
  -both suspended in the right and left pleural cavities

Question 11

Bronchi is …

Answer 11

• branch off the trachea and carry air into the lungs
• when air enters the bronchi’s, it has been filtered, moistened, warmed and saturated with water vapor
• when inside the lungs, each bronchus divides further into lobar bronchi
• lobar bronchi branch into segmental bronchi, which divide again into smaller bronchi (bronchioles)
• 23 different sized bronchi in the lungs
• branching pattern means that the bronchial network is often referred to as the ‘bronchial tree’

Question 12

Bronchioles are …

Answer 12

• small airways that extend from the bronchi and connect the bronchi to small clusters of thin walled sacs (alveoli)
• 1mm in diameter and are the first airway branches of the respiratory system that DO NOT contain cartilage

Question 13

Alveoli is …

Answer 13

• end of each bronchioles is a mass of air sacs called alveoli
• there is 300 million alveoli
• responsible for the transfer of oxygen into the circulatory system and remove waste products like carbon dioxide out of the blood (process called gaseous exchange)
• have a huge surface are of maximal gaseous exchange to take place
• surrounding each alveoli is a dense network o capillaries (this aids gaseous exchange)

Question 14

Diaphragm is ..

Answer 14

• flat muscle that is located beneath the lungs within the thoracic cavity, it separates the chest and the abdomen
• essential during the breathing process as its contraction downwards draws air into the lungs
• this contraction increases the volume of the chest cavity (drawing air in) and the relaxation of the diaphragm reduces the volume (pushing air out)

Question 15

Intercostal muscles are …

Answer 15

Internal
- lie inside the ribcage
- draw ribs downwards and inwards, decreasing the volume of the chest cavity (forcing air out of the lungs when breathing air)
External
- lie outside the ribcage
- pull the ribs upwards outwards, increasing the volume of the chest cavity (drawing air into the lungs)