Week 27 - the respiratory system 1

Question 1

Functions of the respiratory system : respiration

Answer 1

Ventilation
1. The movement of air into and out of the lungs
2. External Respiration: exchange of oxygen (O2) and carbon dioxide (CO2) between the air in the lungs and the blood
3. Transport of O2 and CO2 in the blood
4. Internal Respiration: exchange of O2 and CO2 between the
blood and the tissues
Also refers to cellular metabolism/ respiration
Respiration:
-Respiratory processes are directly related
-Breathing provides O2 needed for cellular respiration - make
ATP from glucose
-Breathing rids the body of potentially toxic CO2

Question 2

Functions of the respiratory system: Other

Answer 2

-Regulation of blood pH
->Altering blood CO2 levels
->PaCO2 35-45mmHg
-Voice production
->Air movement past the vocal cords
-Olfaction
->Airborne molecules are drawn into the nasal cavity
-Innate immunity
->Protects against certain microorganisms and other pathogens - preventing them
from entering the body and by removing them from respiratory surfaces

Question 3

Structures and function of the respiratory system

Answer 3

UPPER respiratory tract:
-Nose and nasal cavity
-Mouth -> air enters (also through mouth)
-Pharynx (throat)
-Larynx -> maintains an open airway, protects the airway during swallowing (epiglottis), produces the voice
LOWER respiratory tract:
-Trachea
-Bronchi
-Lungs

Question 4

The lungs

Answer 4

-Within the thoracic cavity
-2 lungs -> separated by the mediastinum in which the
heart is situated
-Each lung is divided into lobes:
->Left lung – 2 lobes (upper and lower)
->Right lung – 3 lobes (upper, middle and lower)
Heart sits within the ‘cardiac notch’ -> so the left lung slightly narrower

Question 5

Lungs

Answer 5

Each lung: Surrounded by a pleural cavity -> formed by 2 pleural membranes
-> Visceral and parietal
pleurae
-Passages branch
->Decrease in size
->Increase in number

Question 6

Conducting airways / zone

Answer 6

Conducting passages:
UPPER respiratory tract ->
-Nasal cavity
-Pharynx
-Larynx
LOWER respiratory tract ->
-Trachea
-Primary bronchi
-Lungs
Strictly for ventilation:
-The trachea (wind pipe)
made from cartilage that eventually splits into: the left and right bronchi
->When an airway divides it always divides into 2 (bifurcation)

Question 7

Bronchial tree

Answer 7

->Left and right bronchi (one bronchus) or primary bronchi divide into;
-Secondary bronchi (in lobes of lung) - divide further into;
-Tertiary bronchi - which divide into;
-Bronchioles – divide (several times) forming terminal bronchioles
Top of tree:
-Lots of cartilage some smooth muscle
-Keep airways open
Bottom of tree:
-Lots of smooth muscle less cartilage
-Change diameter of airways