ANSCI LECT 4.4 RESPIRATORY

• Functions of paranasal sinuses

  • Lightening the skull
  • Resonance and vocalization
  • Thermal regulation
  • Protection
• Carbon dioxide


  Waste product that needs to be removed from the body
• Upper Respiratory Tract structures

  • Nose
  • Paranasal sinuses
  • Pharynx
  • Larynx
  • Trachea
  • Bronchi
• Oxygen


  Essential for cellular respiration, which produces energy
• Paranasal sinuses

  Air-filled cavities within the bones of the skull connected to the nasal cavity
• Nose

  Anatomical structure of the snout or muzzle, including nostrils and surrounding tissues used for breathing and smelling
• Alveoli


  Terminal zones of gas exchange with simple squamous epithelium enveloped by blood capillaries for efficient gas exchange
• Respiratory system


  Crucial for sustaining life by facilitating the exchange of gases (oxygen and carbon dioxide) between the atmosphere and the body's cells
• Larynx


  Cartilaginous segment in the anterior aspect of the neck, protects the lower respiratory tract from aspirating food into the trachea while breathing
• Pharynx


  Supports the respiratory and digestive system, routes air and food from nose and mouth to larynx
• Trachea

  Tubular structure originating from the larynx, lined with pseudostratified ciliated epithelium and goblet cells for air filtration and humidification
• Bronchi


  Primary extensions from the trachea with irregular cartilage plates and increasing smooth muscle layers for airflow control
• Bronchioles


  Branching from bronchi, lack cartilage, and transition from pseudostratified to simple epithelium, leading to terminal bronchioles for refined adjustments in air passage
• Thorax


  Part of an animal's body between the head and midsection, in vertebrates, it is the chest
• Pleura


  Surrounds the outer surface of the pulmonary parenchyma, separating it from the pleural space
• Lungs


  Organs used for breathing in reptiles, mammals, and birds; birds also have air sacs and air spaces within bones for efficient breathing; insects breathe through tracheae, while arachnids use 'book lungs'
• Thorax


  Part of an animal’s body between its head and its midsection; in vertebrates, the chest is between the neck and the abdomen
• Physiology of respiration

  Series of intricate processes involved in the exchange of gases, primarily oxygen (O2) and carbon dioxide (CO2), between the body and the environment
• Pleura


  Surrounds the outer (visceral) surface of the pulmonary parenchyma, separating it from the pleural space; consists of connective tissue interspersed with lymphatics and vessels
• Pulmonary ventilation

  Air enters and exits the lungs through muscle action; inhalation involves diaphragm contraction, lowering and expanding the thoracic cavity, while exhalation involves muscle relaxation, allowing chest wall and diaphragm to recoil for air expulsion
• Control of Ventilation

  Breathing is an unconscious, involuntary, automatic process controlled by the respiratory centre in the brainstem, regulating the rate and depth of respiration
• Gas transport in Blood

  Gas exchange occurs in the alveoli and capillaries; oxygen moves from alveoli to blood, and carbon dioxide moves from blood to alveoli
• Gas Exchange


  External respiration in the lungs' alveoli involves oxygen diffusing into the bloodstream from alveolar air, while carbon dioxide moves from the blood into the alveoli for exhalation, driven by partial pressure gradients
• Avian respiratory system


  • Specialized system in birds for breathing, highly efficient and adapted for flight
• Avian respiratory system features

  • Air sacs
  • One way air flow
  • Crosscurrent exchange
  • High metabolic rate
  • No diaphragm