1. IVS and AST Chapter 5 Respiratory System
Unit 5
IVS and AST
Chapter 5
Respiratory System

2. The Respiratory System
Function
Respiratory system + circulatory system =supply body with oxygen and rid body of carbon dioxide.
Structures
Nostrils (used to take in air) open into the nasal cavity which divides into many scroll-like sheets of bone.

3. The Respiratory Tract Covered in mucous, filters incoming air
Nostrils and upper airways:
Covered in mucous, filters incoming air
Example: dust/dirt become trapped in the mucus, mucus accumulates and is eventually swallowed
Trapped particles cause irritation, causes sneezing (reflex action)
Warms cold air and adds moisture before it enters lungs
Protection for the airways
Olefactory receptors: detect smell

4. Pharynx Where the respiratory and digestive systems meet
Food and air travel thru the pharynx
Swallowing and breathing take place

5. Epiglottis
Flap of tissue that covers larynx so food does not enter the trachea (windpipe).

6. Larynx Firm cartilage structure at the opening to the major airways
Contains vocal folds- structures that allow vocalization

7. Trachea Larynx leads to the trachea
Series of cartilage rings joined by connective tissues
Rings are C shaped
Lined with smooth epithelium that has surface cilia

8. Bronchi
The trachea enters the chest about the region of the heart then branches into two bronchi
Two bronchi - each leads to a lung
Major bronchi divide into smaller bronchi to form bronchioles

9. Alveoli Air exchange happens here
O2 exchanged with CO2 in the capillaries

10. The Respiratory Tract Lungs appear spongy with entrapped air
Pleura- covers the lungs, small amount of fluid is present in the space to provide lubrication as lungs come close to chest wall

11. The Respiratory Tract
Surfactant- produced in the lungs to keep the alveoli from collapsing, makes it easier for them to inflate
Premature animals may lack surfactant

12. Respiration The act of inhalation & exhalation creating a breath
Two Step process:
1. Inspiration (inhalation)- air is taken into lungs
2. Expiration (exhalation)- air is forced out

13. Mechanisms of Breathing
Exhalation
Intercostal muscles relax, ribs lower
Diaphragm relaxes- arches towards the chest
Drives the air out

14. Mechanisms of Breathing
Involuntary process
Occurs without thought
But can be consciously controlled
We think of this more as humans

15. Clinical Practice
Cyanosis- tissues appear bluish, indication of inadequate oxygen being delivered to the tissues

16. Clinical Practice
Pneumonia- inflammation or infection of the lungs usually caused by infection which leads to fluid (pus, mucous or other fluid) build up in the air sacs, oxygen cannot get to the blood. Can be bacterial or viral

17. Kennel Cough (Bordetella)
Occurs in the respiratory tract of animals
Severe/Chronic cough mostly in dogs
Vaccines
typically used with a nasal vaccine
important to frequently vaccinate dogs that are kenneled and active with other dogs

18. Shipping Fever
Occurs in livestock (horses, cattle) which are transported
Causes a respiratory infection, affecting lungs and chest cavity
Symptoms: fever, nasal discharge, coughing
Treatment: antibiotics and proper sanitation, vaccines available prior to transportation

19. Diaphragmatic Hernia Diaphragm condition
Muscle in chest tears and organs can pass through
Lungs can’t expand fully and labored and difficult breathing occurs
Common in trauma, HBC
Surgical correction needed

20. Heaves Allergic respiratory condition in horses; lifelong condition
Common term for COPD (chronic obstructive pulmonary disease)
Symptoms: coughing, nasal discharge, labored breathing, tire easily

21. Roaring
Condition in horses when larynx opens only a small amount due to trauma of the nerves
Causes a sound like roaring
Surgical correction

22. Heartworms Spread by mosquitoes Affect the heart and lungs
Can be fatal

23. Review: The Flow of Air Nostrils= Pharynx= Larynx= Trachea= Bronchi=
Bronchioles=
Alveoli=