The Respiratory System

1
The Respiratory System
2
Respiration

• Exchange of gases between living cells and the
  environment
• Involves three steps
• pulmonary ventilation
• gas exchange (diffusion)
• gas transport

3
Structures of the RS

• Nose
• Nasal cavity
• Sinuses
• Pharynx
• Larynx
• Trachea
• Bronchi/Bronchioles
• Alveoli

4
Nose

• Nose hairs guard nasal cavity from large airborne
  particles like dust, sand and insects

5
Nasal Cavity

• Divided by nasal septum
• Lots of surface area
• Functions to warm and humidify air

6
Pharynx

• Part of digestive system and respiratory system
• passageway for food and air

7
Glottis and Larynx

• Glottis is passageway for air
• larynx surrounds glottis
• epiglottis covers opening to glottis
• false vocal cords protect glottis from large
  foreign objects
• Vocal cords modulate air to produce sound

8
Trachea, Bronchi and Bronchioles

• Trachea and bronchi are surrounded by
  cartilaginous rings
• Trachea branches into Lt. and Rt. Bronchi
• Bronchi divide into smaller bronchi and then into
  bronchioles
• bronchioles do not have cartilage

9
Alveoli

• Where gas exchange takes place
• Very thin epithelium
• sacs surrounded by capillaries
• Grapes

10
Respiratory Membrane

• Thin
• Moist
• gases must be dissolved for diffusion to take
  place

11
Gas Exchange

• Concentration gradients
• Diffusion down the gradient
• Lungs
• high O2, low CO2
• Tissues
• low O2, high CO2
• Blood
• changes as it circulates between lungs and tissues

12
Pulmonary Ventilation

• Inhalation
• Contraction of muscles causes pleural cavity to
  increase volume
• Negative pressure cause air to be sucked in
• Exhalation
• release of muscle and elastic recoil

13
(No Transcript)
14
Control of breathing (rate)

• Various sensors
• blood pressure
• stretch
• chemical
• O2 and pH (CO2)

15
(No Transcript)