Lecture 12

Question 2

1. what is the primary controller of ventilation?
2. what will happen generally when it is activated

Answer 2

1. PaCO2
2. Will increase tidal volume and increase respiratory rate

Question 3

What are 2 other controllers of ventilation

Answer 3

1. Increase in [H+] in arterial blood or CSF causes increase in alveolar ventilation
2. Decrease in PaO2 causes increase in alveolar ventilation

Question 4

1. what will you see in animals on examination during dyspnea or respiratory distress
2. what can lead to it

Answer 4

1. breathing appears difficult, uncomfortable, or labored
2. Results from alterations in any part of the respiratory system
   
   • May be due to abnormal mechanics of the lung or chest wall

Question 5

1. what is cyanosis?
2. what leads to it?

Answer 5

1. Bluish or red-purple color in the mucous membranes
2. Increased amount of deoxygenated Hemoglobin 3 to 5 g/dl of reduced Hemoglobin

Question 6

1. What will your SpO2 will show during cyanosis
   * PaO2?

Answer 6

1. SaO2 or SpO2 of 73 to 78% (normal [Hb])
2. PaO2 of 39 to 44 mmHg

Question 7

will you see cyanosis in severe anemia?

Answer 7

may not show cyanosis

Question 8

What is CRT

Answer 8

capillary refill time

Question 9

Define

1. Eupnea-
2. Tachypnea-
3. Hyperpnea -
4. Bradypnea-

Answer 9

1. Eupnea- normal breathing
2. Tachypnea- Increase in respiratory rate
3. Hyperpnea - Increase in respiratory rate
4. Bradypnea- Decrease in respiratory rate

Question 10

define

1. Hypocapnea-
2. Hypercapnea-
3. Hypercarbia-

Answer 10

1. Hypocapnea- Decrease in PCO2 concentration
2. Hypercarbia-Increase in PCO2 concentration
3. Hypercapnea- Increase in PCO2 concentration

Question 11

what is being shown at 1?

Answer 11

• Periodic Deep Breath = Sigh
• Complimentary Breath

Question 12

1. What type of breathing pattern is this
2. when will this commonly happen in

Answer 12

1. Biot Breathing
   
   • Group Breathing
2. common in anesthetized animals

Question 13

1. What is this called?
2. what can cause this

Answer 13

1. Kussmaul’s Breathing
   
   • Tidal volume will increase
2. Metabolic Acidosis

Question 14

1. what is this breathing pattern called
2. when will this generally happen

Answer 14

1. Cheyne - Stokes Breathing
   
   • You will see a waxing and waning
   • Increase in tidal volume and then go back down
2. Heart Failure
   
   • Poor feedback group of chemoreceptors back to brainstem

Question 15

1. What is the second breathing pattern called
2. when can this happen

Answer 15

1. Apneustic breathing
   
   • Will exhale first and then inhale
2. Brain Stem Injury
   
   • Ketamine Anesthesia

Question 16

what are 3 nonrespiratory functions of the respiratory system

Answer 16

1 Filter
2 Thermoregulation
3 Defense Mechanisms

Question 17

Describe the 3 particle sizes, where they will be deposited in

Answer 17

1. >5 µm, large airways
2. 1-5 µm, small airways
   3.

Question 18

What is an aerosol?

Answer 18

small particles or liquid droplets suspended in air

Question 19

List 2 or 3 toxic gases

Answer 19

1. carbon monoxide
2. nitrogen oxides
3. sulfur oxides

Question 20

Which animals can do thermoregulation through nasal or mouth

Answer 20

• Dogs
• cats
• sheep
• birds

Question 21

What happens during panting to allow animals to thermoregulate

Answer 21

1. Rapid frequency (200-400 breaths/min)
2. Small tidal volume
   
   • –Constant dead space ventilation (D)
   • –Small alveolar ventilation () avoids hyperventilation and alkalosis
3. Vascular engorgement of respiratory and oral mucosa
4. Increased salivation

Question 22

What is the VD/VT ratio? 2. Why is the VD/VT ratio important for thermoregulation in the dog?

(this maybe on exam)

Answer 22

• The VD/VT ratio is the fraction of each breath ventilating the dead-space area.
• Thermoregulation in the dog: when it is too hot the dog starts to pant and this has a smaller VT which increases water evaportaion and promotes heat loss to cool them off,
• if they are too cold they slow down their respiration to preserve their heat and have a higher VT.

Question 23

what is special about thermoregulation in even-towed ungulates (e.g thomson’s gazell)

Answer 23

• Nasal Evaporation
• Will be in circle of willis where it will cool blood going to brain.

Question 24

What are 5 nonspecific defenses of the respiratory system

Answer 24

1. Surfactant proteins A & D, defensin peptides
2. Mucociliary system
3. Cough
4. Alveolar macrophages
5. Toll-like receptors - recognize bacteria/fungi

Question 25

What is a specific defense of the respiratory tract

Answer 25

Immune system: IgA in lining fluid

Question 26

Explain the mucociliary system of the lung and include: its function, where the mucus comes from, its distribution, how it’s moved cranially, and the value of the sol layer

Answer 26

• Escalator to the pharynx (4 mm – 2 cm/min)
• Cilia beat 1000x minute
• Beat in coordinated manner
• Sol layer – inner, liquid, low viscosity
• Viscous gel layer – outer, catches particles
• Blanket propelled by cilia and gravity
• Mucus – nonciliate Clara cells, goblet cells, submucosal bronchial glands
• Transepithelial movement of water and ions affects the thickness of the sol layer

Question 27

1. What does a cough accomplish?
2. what stimulates it?
3. How high of a pressure can it generate?

Answer 27

1. Clears mucoid secretions from intrathoracic trachea and large bronchi
2. Subepithelial irritant or stretch receptors
   
   • Mechanical deformation
   • Hyperresponsive when passages are inflamed
3. 100 mmHg

Question 28

Describe the function of the alveolar macrophage

Answer 28

• Resident phagocyte in the normal lung
  
  • Mucociliary blanket
  • Traverse the alveolar wall and enters the lymphatic tissues
• First line of defense
  
  • Produce bactericidal agents (lysozymes)
  • Phagocytosis- Engulf sediment