Respiratory system

Question 1

What is the function of the respiratory system?

Answer 1

allows for the intake and exchange of oxygen and carbon dioxide between the human body and the atmosphere

Question 2

How does air enter the body to allow gaseous exchange?

Answer 2

Air moves in through the nasal or oral cavities, through the pharynx and larynx, into the trachea and then the bronchi where it is distributed through the lungs via the bronchial tree

Question 3

Label the thoracic cage

Answer 3

Question 4

What is the trachea?

Where does the trachea begin?

How is the trachea kept patent?

Where does the trachea end?

Answer 4

Mobile and cartilaginous tube

at the neck as a continuation of the larynx

by the presence of U-shaped bars of hyaline cartilage embedded in its wall

Trachea ends by dividing into right and left principal bronchi in the thorax

Question 5

Describe how the bronchi of the lungs divides

Answer 5

Bronchi divide dichotomously, giving rise to several million terminal bronchioles that terminate in one or more respiratory bronchioles in the lungs

Question 6

Label the tracheobronchial tree

Answer 6

Question 7

Label the lungs in situ

Answer 7

Question 8

Where are the lungs suspended?

How are the lungs attached to the mediastinum?

Which lung is larger?

How many lobes does each lung have?

Why are the lungs not the same size?

Answer 8

Each lung is suspended free in its pleural cavity

Attached to the mediastinum by its root, where the main blood vessels and bronchi enter the lung

Right slightly larger than the left

Right has three lobes, left has two

Due to space taken on the left hand side of the thoracic cavity by the heart

Question 9

Label the lungs and the bronchial tree

Answer 9

Question 10

What type of image is this?

Answer 10

Bronchogram

Question 11

Describe the following structures of the lungs:

Apex

Base

Costal surface

Mediastinal surface

Answer 11

 Apex
 Projects upwards into the neck above the clavicle

 Base
 Concave surface, sits on the diaphragm

 Costalsurface
 Corresponds to the concave chest wall

 Mediastinal surface

 Molded to mediastinal structures

 Location of hilum, where bronchi, vessels and nerves enter and leave the lung (lung root)

Question 12

Which vessel supplies the bronchi and connective tissue of the lungs?

Where do the alveoli receive deoxygenated blood from?

Where does the oxygenated blood leaving the alveolar capillaries drain into?

Answer 12

bronchial arteries, which are branches of the descending aorta

Alveoli receive deoxygenated blood from the terminal branches of the pulmonaryStudy arteries

Oxygenated blood leaving alveolar capillaries drains into the tributaries of the pulmonary veins

Question 13

Label the blood supply of the lungs

Answer 13

Question 14

What is a pleura?

Answer 14

A pleura is a serous membrane which folds back onto itself to form a two-layered membrane

Question 15

What are the 2 parts of the pleura of the lungs?

Answer 15

Parietal pleura - Lines the thoracic wall, thoracic surface of the diaphragm, lateral aspect of the mediastinum

Visceral Pleura - Completely covers the outer surfaces of the lungs and extends into the depths of the interlobar fissures

Question 16

How does the 2 parts of the pleura become continuous?

Answer 16

The two layers become continuous by means of a cuff that surrounds the structures entering and leaving the lung at the hilum

Question 17

Label the development of the pleural membrane

Answer 17

Question 18

label the following diagram

Answer 18

Question 19

What seperates the 2 layers of the pleura

What does it contain and what is its function?

Answer 19

pleural cavity

Contains tissue fluid, covers the surface of the pleura

 Reduces friction

 Surface tension of the fluid allows close apposition of the lung surfaces with the chest wall

 Aids in expanding volume of the lungs during breathing

Question 20

What is the most important muscle of respiration?

What does it seperate?

Describe its shape

What does it consist of?

How does this muscle affect the thorax?

Answer 20

Diaphragm - thin muscular and tendinous septum

 Separates the thoracic cavity above and the abdominal cavity below

 Domeshaped

 Consists of;

 Peripheral muscular part

 Centrally placed tendon

 On contraction the diaphragm pulls down its central tendon and increases the vertical diameter of the thorax

Question 21

How are the fibres of the intercostal muscles arranged?

Answer 21

External

Fibres directed downward and forward from the inferior border of the rib above to the superior border of the rib below

Internal
Fibres directed downward and backward

Innermost = Deepest layer

Incomplete muscle layer that crosses more than one intercostal space

Question 22

Label the intercostal muscles

Answer 22

Question 23

Describe the mechanism of respiration

Answer 23

Consists of two phases: inspiration, expiration

Alternate increase and decrease of capacity of the thoracic cavity

As there is only a single entrance (trachea) an increase in capacity of the thoracic cavity results in air moving into the lungs under atmospheric pressure

Question 24

How is the capacity of the thorax increased?

Answer 24

Vertical diameter = Diaphragm

Anteroposterior diameter:
 Downward sloping ribs raised at sternal end

 First rib is fixed, intercostals contract bringing ribs closer together

Transverse diameter:

 Ribs articulate in front with the sternum and behind with vertebral column

 Curve downward and resemble bucket handles

Question 25

How is the transverse diameter increased?

Answer 25

Ribs raised upwards

Question 26

How does expiration occur?

Answer 26

Largely a passive process

Brought about by;
 Elastic recoil of lungs

 Relaxation of intercostals and diaphragm

 Increase in tone of the muscles of the anterior abdominal wall