Lungs, Pulmonary Ventilation & Circulation Flashcards
The Pleura
Serous membrane that lines body cavities & secretes serous fluid Visceral Pleura (covers lungs) Parietal Pleura (lines throat, mediastinum)
Pleural Cavity
Space between the membranes, contains serous fluid
Apex
Superior region of the lung, near the clavicle
Rounded tip of structure - such as heart/lung
Base
Inferior region of the lung, sits on the diaphragm
Costal Surface
Outer surface of the lungs, against the ribs
Hilum
Medial region of the lungs, where structures enter/exit
Pulmonary Arteries & Veins Purpose
Connection between the cardiovascular and respiratory systems
Right Lung
3 lobes, 2 fissures
Left Lung
2 lobes, 1 fissure
Veins..
always bring blood to the heart
Arteries…
always take blood away from the heart
Alveolar Epithelium
Type 1 pneumocytes - squamous, thin, epithelial cells
Type 2 pneumocytes - cuboidal, surfactant-secreting cells
Surfactant
Secreted by Type II Pneumocytes - Glycolipid/phospholipid that reduces the surface tension for the alveolar fluid
Blood Gas Barrier
Type 1 pneomocytes
Fused base membrane - alveolar and capillary epithelium
Capillary endothelium
Boyles Law
*Air will move from a region of high pressure to a region of low pressure
Relationship between pressure & volume
Pulmonary ventilation uses the law to provide respiratory cycles
- Inspiration (moves air into the lungs)
- Expiration (moves air out of the lungs)
Inspiration
*Air flows in - inspiration
Lung (alveolar) pressure is lower than atmospheric pressure
Contracted diaphragm and external intercostals
Thorax volume increases
Expiration
*Air flows out - expiration Lung (alveolar) pressure is higher than atmospheric pressure Passive process (like elastic recoil) Relaxation of respiratory muscles Thorax volume decreases
Respiratory Accessory Muscles Function
Used during forced breathing
During increase in activity (exercise)
When airway resistance is high (narrow airways with asthma)
Pulmonary Circulation
Heart is a pump
Right side pumps blood to pulmonary circuit (lungs)
Left side pumps blood to the systemic circuit (organs)
Delivers deoxygenated blood from the right ventricle to the lungs
Return oxygenated blood from the lungs to the left atrium
Pulmonary Circuit Structure
Pulmonary Trunk Pulmonary Arteries (L & R) Pulmonary capillaries Pulmonary Venules Pulmonary Veins
