Cardio-respiratory AI ILO Answers

• Components of the Respiratory System and Their Functions

  • Nose/Nasal Cavity
  • Pharynx
  • Larynx
  • Trachea
  • Bronchi and Bronchioles
  • Lungs
  • Alveoli
  • Diaphragm
• Nose/Nasal Cavity


  • Filters, warms, and humidifies inhaled air; houses olfactory receptors
• Pharynx


  • Passageway for air and food; aids in sound production
• Larynx


  • Contains vocal cords; guards entrance to the trachea; involved in sound production
• Trachea


  • Windpipe; conducts air to the bronchi
• Bronchi and Bronchioles


  • Distribute air to the lungs; bronchi branch into smaller bronchioles
• Lungs


  • Principal organs of respiration; facilitate gas exchange
• Alveoli


  • Tiny air sacs where gas exchange occurs
• Diaphragm


  • Muscle that aids in ventilation by contracting and relaxing
• Key Features of the Lungs and Arrangement of the Bronchial Tree

  • Right Lung: Typically has three lobes (cranial, middle, caudal)
  • Left Lung: Typically has two lobes (cranial, caudal)
  • Primary Bronchi: One for each lung
  • Secondary Bronchi: Branch into each lobe
  • Tertiary Bronchi: Further branch within lobes
  • Bronchioles: Smallest branches leading to alveoli
  • Alveoli: Surrounded by capillaries for gas exchange
• Histology of the Respiratory System

  • Nasal Cavity: Lined with pseudostratified ciliated columnar epithelium and goblet cells
  • Trachea and Bronchi: Lined with pseudostratified ciliated columnar epithelium; contain cartilage and smooth muscle
  • Bronchioles: Lined with simple ciliated columnar or cuboidal epithelium; lack cartilage
  • Alveoli: Lined with simple squamous epithelium; type I and type II pneumocytes (produce surfactant)
• Structure and Location of Serous Membranes

  • Pleura: Parietal pleura lines the thoracic cavity; visceral pleura covers the lungs
  • Pericardium: Parietal pericardium lines the pericardial sac; visceral pericardium (epicardium) covers the heart
  • Peritoneum: Lines the abdominal cavity and covers abdominal organs
• Role of Pleural Membranes in Inspiration and Expiration

  1. Inspiration: Pleural membranes create a negative pressure that expands the lungs

  2. Expiration: Elastic recoil of the lungs reduces the thoracic volume, expelling air
• Components and Key Functions of the Cardiovascular System

  • Heart: Pumps blood through the body
  • Blood Vessels: Arteries, veins, and capillaries that transport blood
  • Blood: Carries oxygen, nutrients, waste products, and immune cells
• Histology of the Cardiovascular System

  • Heart: Cardiac muscle, connective tissue, endocardium, myocardium, and epicardium
  • Arteries: Thick muscular and elastic walls
  • Veins: Thinner walls, valves to prevent backflow
  • Capillaries: Thin walls for gas and nutrient exchange
• Structure of Blood Vessels

  • Arteries and Arterioles: Thick tunica media, elastic fibers
  • Veins and Venules: Thin tunica media, larger lumen, valves
  • Capillaries: Single endothelial cell layer
• Structure of the Pericardium

  • Fibrous Pericardium: Tough outer layer
  • Serous Pericardium: Inner layer with parietal and visceral layers
• Key Features of the Heart Structure


  • Four Chambers: Right atrium, right ventricle, left atrium, left ventricle
  • Valves: Tricuspid, pulmonary, mitral, and aortic valves
  • Conductive System: SA node, AV node, bundle of His, Purkinje fibers
• Structure and Importance of the Lymphatic System

  • Lymph Nodes: Filter lymph, house lymphocytes
  • Lymphatic Vessels: Transport lymph fluid
  • Spleen: Filters blood, immune response
  • Thymus: T cell maturation
• Nasal Cartilages and Form of the Nostril

  • Types of Nasal Cartilages: Septal, lateral, and alar cartilages
  • Brachycephalic Breeds: Shortened nasal passage, often leads to respiratory issues
• Significance of the Alar Cartilage in Horses

  • False Nostril: Alar cartilage supports the structure, aids in airflow regulation
• Structure and Names of Conchae

  • Conchae: Scroll-like bones in the nasal cavity (dorsal, middle, and ventral conchae)
  • Function: Increase surface area for warming and humidifying air
• Structure and Names of Meatuses

  • Dorsal Meatus: Leads to olfactory region
  • Middle Meatus: Leads to sinuses
  • Ventral Meatus: Main airway, leads to pharynx
  • Common Meatus: Vertical passage along the septum
• Nasogastric Tube Passage in Equine Patients

  • Pass through the ventral meatus to avoid damaging delicate structures
• Paranasal Sinuses in Horses and Ruminants

  • Horses: Extensive, include maxillary, frontal, and conchal sinuses
  • Ruminants: Frontal sinus extends into the horn core
• Guttural Pouches in Horses

  • Location: Dorsal part of the pharynx
  • Function: Cooling of blood
  • Clinical Significance: Prone to infections (mycosis)
• Hyoid Apparatus Bones and Function

  • Bones: Stylohyoid, epihyoid, ceratohyoid, basihyoid, and thyrohyoid
  • Function: Supports the tongue and larynx
• Location and Functions of the Larynx

  • Location: Between the pharynx and trachea
  • Functions: Sound production, airway protection
• Laryngeal Cartilages


  • Thyroid, Cricoid, Arytenoid, and Epiglottis
  • Articulations: Provide structure and support for the larynx
• Intrinsic Muscles of the Larynx

  • Location: Within the larynx
  • Action: Adjust tension of the vocal cords
  • Innervation: Recurrent laryngeal nerve
• Laryngeal Folds, Ventricles, and Regions

  • Folds: Vocal folds (true cords) and vestibular folds (false cords)
  • Ventricles: Lateral recesses between folds
  • Regions: Vestibule, glottis, infraglottic space
• Recurrent Laryngeal Nerves Path

  1. Origin: Vagus nerve

  2. Path: Loop around aorta (left) or subclavian artery (right); innervates intrinsic muscles of the larynx
• Anatomical Differences in the Larynx Among Species

  • Horses: Larger and more complex due to their need for high oxygen intake during exercise
  • Dogs/Cats: Simpler structure
• Clinical Significance of the Larynx in Horses

  • Conditions: Laryngeal hemiplegia (roaring) affects airflow during exercise
• Haemostasis and Clotting


  • Vasoconstriction: Immediate response to vessel injury
  • Platelet Plug Formation: Platelets adhere to damaged site
  • Coagulation Cascade: Series of reactions leading to fibrin clot formation
  • Fibrinolysis: Breakdown of clot after healing
• Proteases


  Play a crucial role in the clotting process through zymogen activation and amplification cascades
• Zymogen Activation


  1. Inactive precursors (zymogens) are converted to active enzymes (proteases) in response to injury

  2. Example: Factor X is converted to active Factor Xa by the action of Factor VIIa and tissue factor
• Amplification Cascades


  1. Once activated, proteases activate additional clotting factors, creating a cascade that amplifies the initial signal

  2. Example: Thrombin (Factor IIa) activates Factors V, VIII, and XI, further amplifying the clotting process
• Clot Dissolution (Fibrinolysis)


  1. Plasminogen Activation: Plasminogen, an inactive zymogen, is incorporated into the clot and activated to plasmin by tissue plasminogen activator (tPA) or urokinase

  2. Plasmin Action: Plasmin degrades fibrin into fibrin degradation products (FDPs), dissolving the clot
• Immune-Mediated Thrombocytopenia (IMT)


  Autoimmune destruction of platelets