Respiratory System Flashcards
What does the upper respiratory tract consist of?
- Nasal cavity
- Paranasal sinuses
- Pharynx
- Larynx (ABOVE vocal cords)
What does the lower respiratory tract consist of?
- Larynx (BELOW vocal cords)
- Trachea
- Bronchi
- Bronchioles
- Lungs
What components do the lungs contain?
- Respiratory bronchioles
- Alveolar ducts
- Alveolar sacs
- Alveoli
How does gaseous exchange occur across the alveoli?
- O2 diffuses out of alveoli, across alveolar epithelium and the capillary endothelium into Hb into the blood.
What 2 factors affect the rate of diffusion?
- THIN EXCHANGE SURFACE - alveolar epithelium is only 1 cell thick. (short diffusion pathway)
- LARGE SA for gaseous exchange (millions of alveoli)
What are the differences between breathing and respiration? INVOLVEMENT, PROCCESS, WHERE?
BREATHING
- Involves intake of O2 and CO2
- Physical process
- Involves organs
RESPIRATION
- More complex (involves breakdown of food to release energy)
- Biochemical process
- Occurs at cellular level
What is the definition of ventilation?
- Mechanical activity that moves gases in and out the lungs.
Which two components allow filling and emptying of the lungs? (x2)
- Diaphragm and intercostal muscles
How much oxygen will an individual inspire each day?
250ml
How much CO2 will an individual expire each day?
200ml
What are the main points of inspiration?
- Intercostal muscles and diaphragm CONTRACT
- Ribcage moves UP and OUT
- Diaphragm FLATTENS
(INCREASES vol of thoracic cavity)
(DECREASES lung pressure)
What are the main points of expiration?
- Intercostal muscles and diaphragm RELAX
- Ribcage moves DOWN and IN
- Diaphragm returns to normal DOME shape
(DECREASES vol of thoracic cavity)
(INCREASES lung pressure)
How does air flow travel during inspiration?
- Air flows from an area of high pressure to an area od low pressure
- DOWN trachea and into lungs
How does air flow travel during expiration?
- Air is forced DOWN the pressure gradient and OUT the lungs
Why does the respiratory tract need to defend itself?
- Large SA
- Needs to stop pathogens from entering the body
Where is the respiratory control centre located?
- In the medulla (in the brain stem)
What does the respiratory control centre affect?
- Affects the activity of the inspiratory and expiratory neurones that control the respiratory muscles
Where does the respiratory centre receive information from?
- STRETCH receptors in the lungs
- PERIPHERAL and CENTRAL CHEMORECEPTORS that monitor PH and O2 content in the blood
Where are stretch receptors located?
- In the lungs
What do the peripheral and central chemoreceptors monitor?
- PH and O2 content in the blood
What value does the homeostatic regulation of acid-based balance to maintain PH is needed to keep narrow parameters?
7.3
