Respiratory anatomy and physiology Flashcards
What are the two divisions of the respiratory system and what are they?
- Air-conducting: delivers air (nose, mouth, trachea, bronchi, and bronchioles)
- Gas-exchanging: swaps gases between air and blood (alveoli and capillaries)
What does gas exchange require?
Adequate ventilation and perfusion
What is VQ ratio?
Ideally 4L air/min to 5L blood/min
What is the normal VQ ratio?
0.8
Right bronchus
shorter and wider (more air to right)
How many alveoli are there?
150 million
How is O2 delivered?
The cardiovascular system
Since O2 is in the blood, it binds with hemoglobin
Oxyhemoglobin travels to cells and releases
What is surfactant?
Lipoprotein produced by alveoli that produces surface tension, enhancing pulmonary compliance and preventing alveoli collapse (negative pressure)
promotes alveolar function
What does surfactant promote?
Reinflation of alveoli during inspiration
What is alveoli collapse called?
Atelectasis
Describe pulmonary circulation
LOW PRESSURE, HIGH-FLOW SYSTEM
neural central control system
involuntary
medulla oblongata (rate and volume of breathing regulated)
Sensory input system
Nerve cells generate impulses
Muscular effect system
respiratory muscles receive nerve impulses
Inspiration
nerve impulses travel from brain to diaphragm and cause it to contract, lower, flatten (how air is pulled into lung)
Expiration
passive (muscles relax) or active (contracting chest/abdominal muscles)
Air moved in and out with a normal breath?
Tidal volume
Air moved in and out in one minute?
Minute respiratory volume (-6L)
