Introduction and anatomy of lungs, airways and blood supply

Question 1

What is the breathing rate of an adult?

Answer 1

10-20/min at rest

40-45/min during exercise

Question 2

Function of the nose

Answer 2

Air enters, cilia and mucus trap particles and warm/moisten the air

Question 3

Function of the Pharnyx

Answer 3

Air moves down into pharynx or throat, which is shared with digestive system

Question 4

Function of Epiglottis

Answer 4

Small flap of tissue folds over the trachea and prevents food from entering when you swallow

Question 5

Function of Larynx

Answer 5

Larynx or voice box, contains vocal chords which vibrate to produce sound

Question 6

Function of Trachea

Answer 6

From the pharynx, air moves down towards lungs through the trachea. Made up of stiff rings of cartilage that support and protect it

Question 7

Describe the structure of the Lungs?

Answer 7

Soft, spongy texture is due to thousands of tiny hollow sacs that compose them

Question 8

Function of Bronchus

Answer 8

Air moves from trachea to right and left bronchi

Question 9

What composes the URT?

Answer 9

Nasal cavity, tongue, pharynx, vocal cords, larynx & oesophagus

Question 10

What composes the LRT?

Answer 10

Trachea, lungs, diaphram & bronchi

Question 11

Describe differences between the right & left bronchi

Answer 11

Right bronchi: wider, shorter, more vertical, more commonly associated with foreign bodies, enters lungs at T5.

Question 12

Describe the branching of the trachea

Answer 12

Branches into 2 bronchi, one to each lung. Then branches 22 more times, finally terminating in a cluster of alveoli

Question 13

What is patency?

Answer 13

The condition of being open

Question 14

How is patency maintained in the airways?

Answer 14

Larynx, trachea & bronchi = rings of cartilage

Bronchiole = physical forces in the thorax

Question 15

Describe the resistance to air flow

Answer 15

It is proportional to diameter of the airways. Most resistance to air flow occurs in the trachea and bronchi. It is increased by contraction of bronchial smooth muscle.

Question 16

Describe the structure of the lung lobule

Answer 16

Each cluster of alveolis is surrounded by elastic fibres and a network of capillaries

Question 17

Describe the structure of the alveoli

Answer 17

Thin walls, site of gas exchange, contain elastic fibres
Composed of :
type I cells = gas exchange type II cells = synthesise surfactant
alveolar macrophages = ingest foreign material that reaches the alveoli (escape to pharynx/lymph nodes

Question 18

Describe gas exchange in the lungs

Answer 18

Only possible in alveoli because of the very thin walls - huge surfaces area enhances function. The air in upper airways is known as anatomical dead space.

Question 19

Describe the lining of the respiratory tract & progression from nose to alveoli

Answer 19

• epithelium (pseudo-stratified, ciliated, columnar)
• glands
• lymph nodes
• blood vessles
• ciliated
• mucous

Epithelium becomes more squamous, mucous cells lost first then cilia

Question 20

What is the function of mucous?

Answer 20

Moistens air, traps particles, provides large surface area, goblet cells, subepithelial glands

Question 21

Describe type I Pneumocytes

Answer 21

97% of alveolar surface
Simple squamous epithelium
Gas exchange

Question 22

Describe type II Pneumocytes

Answer 22

Surfactant
Phospholipids and protein
Reduces surface tension at alveolar surface
Reduces work of breathing

Question 23

What are the functions of respiratory system?

Answer 23

1) Gas exchange
2) Acid base balance - (ECF) around 7.4 (renal system)
3) Protection from infection
4) Communication via speech