Human Breathing Flashcards
Respiratory system location
Thoracic cavity
Nose
2 nostrils separated by septum. Leads to nasal passage. Filters air by cilia + makes it warm and moist
Buccal cavity
Mouth - allows for movment of air
Pharynx
Throat, contains epiglottis
Larynx
Voice box - produces sound when air moves over vocal cords
Trachea
Allows air to pass into lungs
Held open by c shaped rings of cartilage
Bronchus
Transports air to lungs
Bronchioles
Transports air to alveoli
Alveoli
Site of gas exchange. large surface area
Lungs
Location of bronchi, bronchioles + alveoli
Takes in oxygen gets rid of carbon dioxide
Pleural membrane
Allows friction free movement of the lungs
Intercostal muscles
Allow ribs to move during inhalation + exhalation
Gas exchange - oxygen
Air has more oxygen than deoxygenated blood in the lungs. Oxygen diffuses from alveoli into capillaries
Gas exchange - Carbon dioxide
Blood has more carbon dioxide than air - carbon dioxide diffuses from blood in capillaries into alveoli
Alveoli adaption
Lots of alveoli + capillaries - increased surface area for diffusion
Walls 1 cell thick - short diffusion pathway
Moist surface of alveoli - allows gases to diffuse quickly
How is breathing controlled
Medulla oblongata in the brain monitors CO2 levels - Sends signals to diaphragm to increase respiration when they get high
Inhalation steps
Medulla oblongata tells intercostal muscles + diaphragm to contract. Ribs move up + out, diaphragm moves down. Chest cavity volume increases - lung volume increases. Air pressure is lower inside lungs than out - air moves in
Exhalation
Intercostal muscles + diaphragm relax. Ribs move down + in, diaphragm moves up. Chest volume + lung volume decreases. air pressure is higher in lungs than out. Air moves out
Is inhalation active or passive and why
Active - requires energy for intercostal muscles to contract
Is exhalation active or passive
Passive - muscles relax - no energy needed
