Respiration

• The respiratory system has two parts: the upper and lower airways.
• The upper airway includes the nasal cavity, oral cavity, pharynx, and larynx.
• The pharynx/throat contains the nasopharynx, oropharynx, and laryngopharynx also known as hypopharynx
• The lower airway includes the trachea, bronchi, and lungs
• Nasal Cavity: the nasal passage filters and warms the air, and makes it moist before it goes into the lung
• Oral cavity: bring air into lungs
• Larynx: protects the lower respiratory tracts from aspiring food into the trachea while breathing. It also contains the vocal cords and functions as a voice box for producing sounds.
• Respiration: Exchange of gas between an organism and its environment
• Inspiration: Process by which we bring oxygen to the cells of the body to sustain life.
• Expiration: process of elimination of waste products such as carbon dioxide by breathing out
• Trachea: allow passage of inspired and expired air into and out of the lung
• Bronchi: two large tubes that carry air from the windpipe (trachea) into the lungs and back out again
• Bronchi contains primary, secondary, and tertiary bronchi
• Lungs: there are ~300 million alveoli in our lungs
• Lower airway supporting structures are the pectoral and pelvic girdle
• Pectoral girdle: clavicles and scapulae
• Pelvic girdle: Hip bones and some of the vertebrae
• Supporting muscle structures include the diaphragm, accessory muscles of inspiration and expiration, and muscles of postural control.
• Diaphragm: inspiration (muscle that helps you breathe)
• Two types of breathing Quite (tidal) breathing and speech (forced) breathing
• Quite (tidal) breathing is automatic and usually happens when writing, reading, etc. Quiet expiration is a passive process, as it requires no muscular contractions. When inspiration happens diaphragm is used. When expiration happens the torque, gravity, and elasticity take place
• Speech(forced) breathing happens when running, walking, signing, etc. Need more air; voluntary manipulation; and different degrees of automaticity. Inspiration and expiration accessory muscles are used. Accessory muscles help control the airflow to support speech (effective communication.)
• Quiet versus speech breathing

  Inspiration: three major differences

  1. Volume of air
  2. Degree of automaticity
  3. Respiratory cycle
• Volume of air

  The amount of air inspired for speech sounds is greater than that inspired during quiet breathing. The diaphragm and other muscles capable of elevating the rib cage and sternum inspire greater air volume.
• Degree of automaticity

  Quiet breathing is under reflexive control. However, we assume voluntary control over our breathing during speaking, reading, or singing
• Respiration Cycle

  During speech, the inspiration phase comprises less of the total respiratory cycle than during quiet breathing. Quiet breathing ratio is 40%- 60%. The forced speech ration is 10% -90%.
• Quiet versus speech breathing

  Inspiration: 3 major differences

  • Volume of air
  • Degree of automaticity
  • Respiration cycle
• Boyles law

  • Given a gas of constant temperature, if you increase the volume of the chamber in which the gas is contained, pressure will decrease.
  • Gas pressure and volume are inversely proportional. During inspiration, the volume of the lungs increases, which results in lower pressure. This allows air at atmospheric pressure to rush and fill the lungs.
• Inspiration:

  • Expansion of the thorax
  • By contracting and pushing the diaphragm down, elevating and torquing ribs outwards.
• Expiration:

  • Reduction in the volume of the thorax
  • (a) by passive recoil of diaphragm, (b) ribs resume original position due to gravity
  • use of expiration muscles to further push the ribs down and inwards and diaphragm upwards in order to reduce dimensions of the thoracic cavity
• Capacities and volumes-spirogram

  Lung volume: refers to the amount of air each compartment can hold.

  Capacities: refer to the combination of lung volumes

  • Total lung capacity: ~7 liters
  • Vital Capacity: ~5 liters
  • Tidal Volume: ~0.5 liters
  • Inspiratory reserved volume
  • Expiratory reserved volume
  • Residual volume: 2 liters
• Tidal Volume (TV): Volume of air we breath in during a respiratory cycle.
• Inspiratory Reserved Volume (IRV): Volume of air that can be inspired after a tidal inspiration.
• • Expiratory Reserve Volume (ERV): Volume of air that can be expired following a quiet tidal expiration.
• • Residual Volume (RV): Volume of air remaining in the lungs after a maximum exhalation.
• • Vital Capacity (VC): Is the total volume of air that can be maximally inspired after a maximum expiration. It is the capacity available for speech. VC = IRV+ERV+TV.
• Total Lung Capacity (TLC): Is the sum of all volumes.

  TLC = TV+IRV+ERV+RV
• Instruments used to measure respiratory capabilities

  • Respiration Spirometer
  • U-tube Manometer
• • Respiration Spirometer: the most common type of pulmonary function or breathing test. This test measures how much air you can breathe in and out of your lungs, as well as how easily and fast you can blow the air out of your lungs.
• • U-Tube Manometer:  oxygen uptake is detected by manometry. Typically, a U-tube manometer is used, which directly shows the pressure difference between the container and the atmosphere.