Anatomy Of Breathing Flashcards
(38 cards)
Where are the lungs located?
In the thorax, separated by mediastinum (space between the lungs) and heart
Extend from the neck to the diaphragm
What separates the thoracic and abdominal cavities?
The diaphragm
Describe the shape and texture of the lungs.
Conical shaped with a soft, spongy texture
What is the apex of the lung?
The top part of the lung that lies above the clavicle
What are the three surfaces of the lungs?
- Diaphragmatic surface (base) - sits on the diaphragm
- Costal surface (large surface) - lies adjacent to the ribs
- Mediastinal surface - faces the mediastinum
How many lobes does the right lung have?
Three lobes: Superior, Middle, Inferior
What fissures (slits) are present in the right lung?
- Oblique fissure - separates superior and middle lobe from the inferior lobe
- Horizontal fissure - separates superior and middle lobe
How many lobes does the left lung have?
Two lobes: Superior, Inferior
What fissure is present in the left lung?
Oblique fissure
What is the hilum of the lung?
Located on the mediastinal surface
The area where the pulmonary vessels, bronchi, bronchial vessels, lymphatics, and nerves enter/leave the lung
What factors affect the lungs?
Compliance (distensibility)
Ability of the lungs to expand and allow air to enter
Affected by
- connective tissue structure of the lungs
- level of surfactant (hard for alveoli to reexpand)
- mobility of the thoracic cage (lungs are connected)
Elasticity
- elastic tissue allow lung expansion during inspiration and recoil during expiration
What is the function of the pleura?
- Reduces friction during breathing (friction causes pain)
- Creates a pressure gradient which assists in ventilation
- Compartmentalises (separates) each lung to reduce spread of infection
What are the two layers of the pleura?
- Visceral pleura - adheres to the lung
- Parietal pleura - attaches to the thoracic wall and diaphragm
What does the bony thorax consist of?
Forms the skeleton of the chest wall
- Sternum
- Ribs (12 pairs)
- Thoracic vertebrae (12)
What are the parts of the sternum?
- Manubrium
- Body
- Xiphisternum (cartilaginous)
How are the ribs attached to the thoracic vertebrae?
By the head and tubercle
Slope downwards and forwards
How are the ribs arranged?
Ribs 1-10 attached by costal cartilage (at the front) to the sternum
- 7 pairs true
- 3 pairs false
- 2 floating
Head of rib articulates with the body of the thoracic vertebra
Tubercle of rib articulates with the transverse process of the thoracic vertebra
What are the three types of intercostal muscles?
Span the spaces between the ribs (intercostal spaces)
- External intercostal muscles = superficial layer
- Internal intercostal muscles = middle layer
- Innermost intercostal muscles = deep layer
What is the main function of the diaphragm?
Separates the thorax from the abdomen
What is the role of the diaphragm in breathing?
Increases vertical diameter of the thorax during inspiration
What is the difference between inspiration and expiration?
Inspiration:
- Movement of air into the lungs
- Occurs when intrapulmonary pressure is lower than atmospheric pressure
Expiration:
- Movement of air out of the lungs
- Occurs when intrapulmonary pressure is greater than atmospheric pressure
What alters intrapulmonary pressure?
Changes in thoracic volume
Fill in the blank: The contraction of the diaphragm is responsible for _______ increase in thoracic capacity during inspiration.
75%
What muscles assist in forced inspiration?
- Pectoralis minor - pulls towards the scapula = pulls ribs up
- Sternocleidomastoid - brings sternum down
- Scalenes - holds 1st and 2nd ribs = pulls lower ribs
- Serratus anterior - pulls scapula forward
- Pectoralis major - normally acts on arms but acts on ribs when humorous is fixed
