Lecture Notes: Respiratory Systems

Question 1

Lungs inside mammals

Answer 1

restricted to one location (thoracic cavity)
Left and right pleural cavities are filled of fluid
inside double walled sac- parietal (adheres to walls of thoracic cavity) and visceral (adheres to lungs) membrane

Question 2

nasal cavity

Answer 2

filtered, humidified, warmed, and sampled

Question 3

pharynx

Answer 3

intersection of esophagus and trachea

glottis is closed when eating

Question 4

larynx

Answer 4

reinforced cartilage

voicebox- houses vocal cords

Question 5

Trachea, Bronchi, and Bronchioles

Answer 5

C- shaped cartilaginous rings
branch to and within lungs
external psuedostratified epithelium is ciliated and produces mucus (goblet cells), which trap and discard particles including pathogens

Question 6

Alveoli

Answer 6

• Air Sac with very thin cells, which reduce distance for diffusion
• large numbers of terminal bronchioles each with many alveoli, increased area
• heavily vascularized with capillaries
• production of surfactants- reduce surface tension of water layer inside alveoli- ability to inflate during inhalation

Question 7

Lung Ventilataion

Answer 7

• Negative Pressure breathing
  1. contracting of external intercostals and diaphragm leads to expansion of thoracic cavity
  2. subatomic pressure and surface tension between parietal and visceral pleura, lungs expand, decrease the pressure in alveolar pressure, leads to inhalation

Question 8

exhalation

Answer 8

• mostly passive
  1. relaxation of intercostals and diaphragm
  2. recoil of lungs and thoracic cavity
• forceful exhalation utilizes the internal intercostals and abdominal muscles

Question 9

plural cavity at rest

Answer 9

retains some negative pressure to prevent collapsing

Question 10

respiratory pigments/hemoglobin

Answer 10

• plasma carries a small percentage of plasma
• erythrocytes carry most oxygen in hemoglobin
• positive cooperativity

Question 11

hemoglobin

Answer 11

• each hemoglobin caries four molecules

- 4 subunits each with a heme group

Question 12

positive cooperativity

Answer 12

• binding of oxygen to one subunit changes the conformation, increases affinity of more oxygen
• results in sigmoidal curve
• Partial pressure of oxygen is 100mm Hg when full saturated, venous blood is 40 mm HG and is 75% saturated

Question 13

hemoglobin/ bohr effect

Answer 13

• oxygen saturation curve of hemoglobin shifts to the right as pH decreases
• release of metabolic acids ( lactic acids) in tissue decrease in pH, leads to unload of oxygen

Question 14

Respiratory Pigments/ myoglobin

Answer 14

• in muscle cells, especially in red fibers
• one polypeptide chain with one iron molecule
• higher affinity for oxygen than hemoglobin, in order to steal oxygen from blood
• reserve of oxygen for muscles when little oxygen is available from blood