cardiorespiratory

• list common cardiorespiratory problems

  • respiratory difficulty / dyspnoea ( +/-) a cough (+/-) cyanosis
  • sneezing / nasal discharge
  • respiratory noise
  • collapse, weakness and exercise intolerance
  • heart murmur
  • dysrhythmia
• which breathing phase is longer in the normal animal, inspiratory or expiratory?


  inspiratory
• in LRT disease the expiratory phase of breathing may be longer and breathing will be fast and shallow
• in URT disease there is likely to be a slow respiration rate accompanied with an increased inspiratory effort
• with pleural disease, the loss of pleural adhesion increases the effort to inspire and expire
• Tachypnoea = increased respiratory rate
• Hyperpnoea = Increased respiratory effort
• Orthopnoea = Dyspnoea in any position other than standing or erect sitting –usually due to bilateral pulmonary oedema
• Trepopnoea = Dyspnoea in one lateral recumbency but not the other –unilateral lung or pleural disease, or unilateral airway obstruction e.g unilateral pleural effusion

  • Often seen in patients when hospitalised and in lateral recumbency

  • Can be dramatic deterioration so always be vigilant for this
• wheezing is high pitched while rhonchi is low pitched noises heard on a thoracic auscultation andis commonly an expiratory noise
• wheezing and rhonchi indicate what?

  narrowing of the airways
• crackles / rales can be dry or moist. moist crackles indicate CHF and are more prominent on inspiration. dry crackles can be acute or chronic
• percuss the chest and listen for areas with an increased or decreased tympanic sound to help localise the area of concern. a dull tympanic sound means there is fluid in that location.
• cardiorespiratory cases often occur in older dogs so concurrent diseases are common so haematology and biochemistry can help identify these as well as aid with the cardiorespiratory concern
• label the diagram

  A) larynx

  B) pharynx

  C) bronchi

  D) trachea

  
• which parts of the respiratory tract are part of the air-conducting portion and which are part of the respiratory portion?

  A) air conducting

  B) respiratory

  
• simple squamous epithelia and scant with loos connective tissue best describes which portion of the respiratory tract?

  respiratory
• epithelial lining and support tissues describe which portion of the respiratory tract?

  air conducting
• proximal respiratory epithelium = ciliates, pseudostratified columnar epithelium
• what extra layer does the bronchi have in comparison to the trachea?

  muscularis (smooth muscle)
• what are the layers of the trachea?

  cartilage and epithelium
• bronchioles lack cartilage, they have two layers which include epithelium and smooth muscle
• distal respiratory epithelium (bronchioles) = simple columnar or simple cuboidal but are still ciliated
• what part of the respiratory tract is this cross section from?

  bronchiole

  
• what part of the respiratory tract is this cross-section from?

  bronchi

  
• what type of epithelium is found in the alveoli?

  simple squamous
• alveolar ducts = elongated airways that are lined by alveoli only
• alveolar sacs: spaces surrounded by clusters of alveoli
• alveolar septum (septal wall) = tissue between adjacent alveolar air spaces
• label the image of the respiratory tract

  A) bronchiole

  B) alveoli

  C) pleura

  
• which is more common a type 1 or 2 alveolar cell?

  type two
• type one alveolar cell = very thin squamous cell, line 95% of the alveolar surface
• type two alveolar cell = cuboidal cell that secretes surfactant
• the tissue containing the capillaries surrounding the alveoli = interstitial tissue
• respiratory difficulty is associated with disease of 1 of 4 areas

  • URT
  • pleural space
  • lung (alveolar interstitial)
  • non CRD (metabolic / physiologic)
• URT disease is characterised by inspiratory difficulty and audible noise. treatment is often surgical.
• pleural space disease may have characteristic respiratory patterns, and muffled heart and lung sounds. treatment often includes the removal of fluid
• Physiologic and metabolic causes of often open-mouthed / panting / shallow breathing are

  • Hyperthermia / heat stroke / fever
  • Obesity
  • Excitement / fear / stress / pain / shock
  • Parturition / false pregnancy / eclampsia
  • Anaemia/abnormal haemoglobin
  • Acidosis
  • CNS disease
  • Endocrine disease
  • Neuromuscular disease