16. Anatomy of Breathing Flashcards
How many surfaces do the lungs have
3
Name the three surfaces of the lungs and draw and label them
1) Costal (outermost towards thorax)
2) Mediastinal
3) Diagrphragmatic (sits on the diaphragm)
Draw labelled diagram of lungs showing where the apex and costal surfaces are located
Costal is on the outside. Apex is the topmost part of the lungs.
Which lung is wider and shorter
The right lung
Which lung is narrower and longer
The left lung
Describe the structure of the right lung, and draw a diagram showing these structures.
3 Lobes (Superior, middle,inferior) 2 fissures - oblique and horizontal
Describe the structure of the left lung
2 Lobes (Superior and inferior) 1 fissue - the oblique fissure.
What is meant by a serous membrane
A membrane that produces watery liquid.
Describe the structure of the pleura
Double serous membrane consisting of visceral pleura and parietal (external) pleura that are separated by a hypothetical (potential) space, filled with watery fluid.
State the 3 functions of the pleura
1) compartmentalisation therefore reduce the spread of infection
2) help create a pressure gradient therefore help in ventilation
3) Help reduce friction of the lungs during breathing
How many Ribs form the bony thorax?
12
How many True ribs are part of the bony thorax?
7 pairs of true ribs
How many pairs of false ribs form the bony thorax?
3 false ribs
How many pairs of floating ribs form the bony thorax?
2 pairs
What is meant by distensibility?
The ability of the lungs to expand
State the three factors that affect lung compliance
- Connective tissue structure
- Level of surfactant
- Mobility of the Thoracic Cage
Describe the structure of the Sternum.
- Manubrium
- Body
- Xiphisternum/ xiphoid process
> The inferior portion of the breast bone or sternum
Describe the structure of the ribs.
- Attached by the head and tubercle to the thoracic vertebrae
- Slope downwards and forwards
- Ribs 1-10 attached by costal cartilage to the sternum
How are the ribs attached to the tubercule
- Head of rib articulates with the body of the thoracic vertebra
- Tubercle (Head) of rib articulates with the transverse process of the thoracic vertebra
How are the intercostsal muscles structured?
Span the spaces between the ribs (intercostal spaces)
- External intercostal muscles -superficial layer
- Internal intercostal muscles - middle layer
- Innermost intercostal muscles - deep layer
External and internal intercostal muscle fibres run in opposite directions = more strength.
Which nerve innervates the diaphragm?
The phrenic nerve
Describe the structure of the Diaphragm.
- Separates the thorax from the abdomen
- Separates lungs from the abdominal cavity
- Dome-shaped skeletal muscle with a central tendon
- Openings for the inferior vena cava, oesophagus & aorta
- Fibrous pericardium fused to central tendon
- Innervated by the phrenic nerve
- Has 3 openings in it for the inferior vena cava, the abdominal aorta and the oesophagus
Describe Inspiration.
- Movement of air into the lungs
- Occurs when intrapulmonary pressure is lower than atmospheric pressure
Describe Exhalation.
- Movement of air out of the lungs
- Occurs when intrapulmonary pressure is greater than atmospheric pressure
What is the Pectoralis?
The major and minor muscles that sit across the chest and aid ventilation
How is Thoracic Volume altered?
altered by changing the;
- vertical diameter
- anterior posterior (AP) diameter
- transverse diameter
How is the vertical diameter of the Thoracic cage altered?
- Contraction of diaphragm increases vertical diameter
- Relaxation of the diaphragm decreases vertical diameter
- Contraction responsible for 75% increase in thoracic capacity during inspiration
