Oxygenation and Perfusion Flashcards
Exam 4/Final
Factors essential to normal functioning of the respiratory system
- Integrity of the airway system to transport air to and from lungs
- Properly functioning alveolar system in lungs
- Properly functioning cardiovascular and blood supply
Properly functioning alveolar system in lungs means:
- Oxygenates venous blood
- Removes carbon dioxide from blood
Properly functioning cardiovascular and blood supply means
Carry nutrients and wastes to and from body cells
Function of the upper airways
Function: warm, filter, humidify inspired air
Components of the upper airways
Nose
Pharynx
Larynx
Epiglottis
Functions of the lower airways/tracheobronchial tree:
Functions: conduction of air, mucociliary clearance, production of pulmonary surfactant
Components of the lower airways/tracheobronchial tree
Trachea
Right and left mainstem bronchi
Segmental bronchi
Terminal bronchioles
What are the main organs of respiration?
Lungs
How does the lungs exist in the body?
Extend from the base of the diaphragm to the apex above the first rib
How many lobes does the lungs have:
Right lung: 3 lobes
Left lung: 2 lobes
What are the lungs composed of?
The lungs are composed of elastic tissue
Alveoli
small air sacs where gas exchange occurs
Surfactant
reduces the surface tension between alveoli, preventing their collapse
Pleura
serous membrane lining the lungs (visceral) and thoracic cavity (parietal)
Respiratory function includes:
- Pulmonary ventilation
- Respiration
- Perfusion
PULMONARY VENTILATION
is the movement of air into and out of the lungs (inspiration and expiration)
RESPIRATION
involves gas exchange between the atmospheric air in alveoli and the blood in the capillaries
PERFUSION
is the process by which oxygenated capillary blood passes through body tissues Inspiration: the active phase of ventilation
Pulmonary ventilation is mostly controlled by what?
Diaphragm
What influences breathing
Parasympathetic and sympathetic nervous systems
Process of Ventilation
The diaphragm contracts and descends, lengthening the thoracic cavity.
The external intercostal muscles contract, lifting the ribs upward and outward.
The sternum is pushed forward, enlarging the chest from front to back
Increased lung volume and decreased intrapulmonic pressure allow air to move from an area of greater pressure (outside lungs) to lesser pressure (inside lungs).
The relaxation of these structures results in expiration.
During inspiration, what does the diaphragm do?
The diaphragm contracts and descends, lengthening the thoracic cavity.
During inspiration, what does the external intercostal muscles do?
The external intercostal muscles contract, lifting the ribs upward and outward.
During inspiration, what does the sternum do?
The sternum is pushed forward, enlarging the chest from front to back
What allows air into lungs?
Increased lung volume and decreased intrapulmonic pressure allow air to move from an area of greater pressure (outside lungs) to lesser pressure (inside lungs).
What results in expiration?
Relaxation of sternum, external intercostal muscles and diaphragm
Gas exchange (respiration) refers to what?
Refers to the intake of oxygen and release of carbon dioxide
What is gas exchange made possible by:
Made possible by respiration and perfusion
How does gas exchange occur?
Occurs via diffusion (movement of oxygen and carbon dioxide between the air and blood)
Factors Influencing Diffusion of Gases in the Lungs
Change in surface area available
Thickening of alveolar–capillary membrane
Partial pressure
Solubility and molecular weight of the gas
How is oxygen carried in the body?
Oxygen is carried in the body via plasma and red blood cells.
How is most oxygen carried? What percent?
Most oxygen (97%) is carried by red blood cells in the form of oxyhemoglobin.
Carboxyhemoglobin
Hemoglobin also carries carbon dioxide in the form of carboxyhemoglobin.
What must occur between circulating blood and tissue cells?
Internal respiration between the circulating blood and tissue cells must occur.
Alterations in Respiratory Function
Hypoxia
Dyspnea
Hypoventilation
Hypoxia
inadequate amount of oxygen available to the cells
Dyspnea
Difficulty breathing
Hypoventilation
decreased rate or depth of air movement into the lungs
What is the main organ of circulation?
heart
What structures make up the heart
The heart is the main organ of circulation, composed of two upper atria and two lower ventricles