Respiratory System Flashcards
Respiratory system
Organ system responsible for gas exchange in the body
3 main gases being exchanged
Oxygen
Carbon dioxide
Water vapour
3 levels of respiration
Cellular
Internal
External
Cellular respiration
Chemical reaction occurring at the cellular level
Oxygen and sugar react to produce water, carbon dioxide and ATP
Occurs in the mitochondria
Internal respiration
Exchange of gas molecules across walls of capillaries
Transports oxygen from red blood cells to tissue and transports carbon dioxide in opposite direction
External respiration
Exchange of gases between blood and air
2 sites of entry/exit of gases to/from body
Nasal cavities
Mouth
Pharynx
The central cavity where nasal cavities and mouth lead to
At the end of pharynx, what 2 directions can air go?
Trachea
Esophagus
Trachea
Large channel surrounded in cartilage rings which keeps it open
What part of the airway has no role in respiration?
Esophagus
Where does the trachea lead to?
Bronchi
Bronchi
The 2 main channels which lead to left and right lungs
Also uses rings of cartilage to keeps airway open
What do bronchi branch out into?
Bronchioles
What do bronchioles lack? What do they have in replacement?
Cartilage rings
Muscles that are capable of changing diameter
What is at the end of bronchioles?
Alveoli
Alveoli
Very tiny bulbs wrapped in capillaries where external respiration occurs
How does exchange proceeed?
According to difference in oxygen concentration between alveoli and red blood cells
High oxy concentration in alveoli + low oxy concentration in blood = diffusion of oxygen from higher to lower concentration (to the blood)
What does hemoglobin produce when it binds to oxygen? Where does this molecule go?
Produces carbon dioxide
Travels out of blood and into alveoli
What happens to carbon dioxide that doesn’t leave your bloodstream?
Dissolves into plasma and reacts with water to produce carbonic acid
What does your body use to limit effects of carbonic acid or blood pH?
A buffer called bicarbonate
Why is bicarbonate so important for the blood?
Bad pH can denature blood
Bicarbonate prevents this
What happens when solid particles enter bronchioles?
Can cause scarring = prevents gas exchange or can block air flow
Epiglottis
Important structure in keeping bronchioles free of solid debris
Nasal hairs
Block solid particles from reaching pharynx through nasal cavities
Cilia
Tiny, hair-like structures which line inside of nasal cavities, pharynx, and trachea
Which direction do cilia sweep?
Towards the stomach
Where do cilia in trachea sweep towards?
Pharynx
What are cilia covered in?
Mucus
Mucus
Traps solid particles, removing them from airways
Breathing
Process of transporting air into and out of lungs
What is breathing the result of?
Pressure differences between environment and thoracic cavity
Pleural pressure
Air pressure in thoracic cavity
Inspiration/inhalation
The inflation of lungs with air from the environment
Pleural pressure decreases, volume of thoracic cavity increases
Expiration/exhalation
Pleural pressure increases, volume of thoracic cavity decreases, causing lungs to deflate and push air into environment
What is pleural pressure controlled by?
Diaphragm
Diaphragm
Muscle separating thoracic and abdominal cavities
What happens when diaphragm is relaxed?
Forms an upwards arc that increases pleural pressure
What happens when diaphragm contracts?
Flattens, decreasing pleural pressure and drawing air into lungs
Hiccup
The rapid contraction and relaxation of diaphragm causing air to rapidly enter/re-exit the body
Larynx
Contains 2 sheets of ligament which vibrate as air passes by them causing sound to be produced
Where is the larynx located?
Trachea
Vocal chords
The special sheets of ligaments in the larynx
What decides the different sounds produced in vocal cords?
The tension of vocal cords
