CBT1 Anatomy of respiratory and cardiovascular systems Flashcards
What is the main job of the respiratory system?
Most efficient delivery of air into the lungs
What is the main job of the cardiovascular system?
most efficient delivery of oxygen and all the other blood-borne molecules (proteins, lipids, carbohydrates) to the tissues
Name the layers of the chest wall and lungs from superficial to deep
Skeletal muscle - affixed Skeleton - affixed Parietal pleura - separated by pleural fluid Visceral pleura - affixed Lung
What are the two parts of the lung organ?
The lung tissue and the chest wall
Describe the structure of the chest wall?
rigid support structure comprising mostly the ribcage, sternum and intercostal muscles. It naturally recoils outward.
Describe the structure of the lungs
soft tissue structures, very elastic, and naturally recoil inward. They provide a large surface area for gas exchange.
What are the two layers of connective tissue in between the lungs and chest wall?
- (visceral and parietal) pleura
- pleura fluid (lubricating fluid)
What is the pleura membrane attached to the lungs called?
visceral pleura
Where is the parietal pleura attached?
Inner surface of chest wall
What do the pleura act as?
The lung-chest interface and are integral to normal chest function
What volume of pleural fluid is there in between the pleura?
A few millilitres
What should the interpleural cavity pressure always be in healthy individuals?
negative (-5 cmH20)
atmospheric pressure = 0 cmH20
SA of lungs is roughly equal to?
Tennis court, much of this SA is in the alveolar region
How many litres of air do we inhale on average per day?
12,000 litres
What does patent refer to?
open airways
How are the cartilaginous airways held open?
- C-shape cartilage strips
- The open side of the dorsal strip is the dorsal side
Where is the open side of the cartilaginous airway most important and why?
Trachea, where the open side accommodate the oesophagus, and does not impede swallowing
Describe how the tensile strength of the cartilaginous airways is formed
The C-rings are slightly offset with each other (not stacked) thereby increasing airway wall support properties
How do the bronchioles remain open?
Not by cartilage but by surfactant to reduce surface tension and limit airway collapse
What are acini?
Discrete anatomical alveolar regions
What does bifurcate mean?
Branching off into two new branches called dichotomous branching
What do the two main bronchi split into?
four smaller extrapulmonary bronvhi
As the number of airways progressively increases, what happens to their diameter and length? and the cross-sectional area?
proportionally decreases
cross-sectional area increases markedly
In chronic obstructive pulmonary disease and other respiratory diseases which increase difficulty breathing, what is the diameter of the bronchioles?
<2mm