Respiratory System Flashcards
What is the function of the nasal cavity?
Warms air
Moistens air with secretions of the epithelial tissue
Cleans air by trapping debris in mucus and fine hairs
What are bronchi and bronchioles?
Left and right bronchi also have cartilage rings
Bronchi branch out in the lungs to become bronchioles which have no cartilage
Smooth muscle in bronchioles can decrease in diameter
What are alveoli?
Small in size and the number of alveoli increase surface area
Each alveolus is surrounded by capillaries
O2 diffuses into blood and CO2 diffuses out of blood
During inhalation they inflate, during exhalation they collapse
Membranes are prevented from sticking by a film of lipoprotein
Describe the process of Inhalation
Air enters the lungs when pressure of air outside is greater then pressure inside
Increase size of chest cavity
Diaphragm moves down
External intercostals contract
Describe the process of exhalation
Air leaves lungs when plural pressure inside is greater than air pressure outside
Diaphragm relaxes and pushes up
Volume of chest cavity decreases
External intercostals relax
What are the two bands of muscles on the ribs called?
External intercostals - found between ribs
Internal intercostals - are not used during normal breathing but during exercise
What is Tidal Volume?
Amount of air exchanged at rest
What is Vital Capacity?
Amount of air exchanged at maximum conditions
What is a disorder in which the walls of the alveoli break down causing less surface area for gas exchange called?
Emphysema
What sections of a respiratory volume graph represent vital capacity?
All the sections except the last one
How do you calculate vital capacity?
Inspiration reserve + expiratory reserve + tidal volume
What are carbon dioxide chemoreceptors?
Located in the medulla oblongata of the brain
Detects increased amount of carbon dioxide in blood
Nerve cells in medulla oblongata send nerve impulses to diaphragm and intercostals
Breathing rate increases and exchange of CO2 and O2 is sped up
Once level of CO2 decreases, chemoreceptors become inactive
What are oxygen chemoreceptors?
Sensitive to low oxygen levels in blood
Messages are sent to intercostals muscles and diaphragm to increase breathing rate
Act as a backup system
Only called into action when O2 levels are low and CO2 levels are high
What is the process of oxygen transport?
O2 moves from atmosphere to alveoli then move into blood and dissolves in plasma
When oxygen dissolves into plasma, hemoglobin forms a weak bond with oxygen molecule
How does partial pressure affect the oxygen transport?
Drop in partial pressure causes split of oxygen from hemoglobin
Oxygen diffuses into tissues
