1 / 14

Respiratory System Overview

Respiratory System Overview. F ‘08 P. Andrews, Instructor. Respiration and Ventilation - It’s just breathing, isn’t it?. Respiration Exchange of gases between an organism and it’s environment Pulmonary (external) respiration Occurs in lungs Cellular (internal) respiration

tamyra
Download Presentation

Respiratory System Overview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Respiratory System Overview F ‘08 P. Andrews, Instructor

  2. Respiration and Ventilation -It’s just breathing, isn’t it? • Respiration • Exchange of gases between an organism and it’s environment • Pulmonary (external) respiration • Occurs in lungs • Cellular (internal) respiration • Occurs in peripheral capillaries • Is the exchange of respiratory gases between RBCs and tissue • Produces CO2 • Ventilation • The mechanical process that moves air into and out of lungs

  3. The structure • The thorax • Moves air in and out • Oxygen and CO2 are exchanged • Also contains heart, major vessels, trachea, bronchi, lungs, mediastinum

  4. Ventilations are controlled by a series of centers in the brain and blood vessels • Main control center – medulla oblongata • Connected to respiratory muscles via VAGUS NERVE • Additional control center – pons • Apneustic center • Pneumotoxic center

  5. Hering – Breuer reflex – learn it! • Stretch receptors • Decrease inspiratory stimulus

  6. Chemorecepors • In the medulla and carotid bodies and arch of the aorta • Stimulated by changes in O2 and CO2 as well as pH

  7. Hypoxic drive • Hyoxemia is a profound stimulus of respiration in a normal person • People with COPD retain CO2 – have chronically elevated PaCO2 • Peripheral chemoreceptors become used to this; CNS stops using PaCO2 to regulate. • A default mechanism – HYPOXIC DRIVE – is activated • Increased respiratory stimulation when PaO2 falls; inhibited respiratory stimulation when PaO2 climbs

  8. Major muscles of respiration • Intercostal muscles • Diaphragm • Sternocleidomastoid muscles • Accessory muscles are also used • Scalene muscles • Anterior abdominal muscles • Rhomboid muscles • Cough reflex relies on latissimusdorsi muscles

  9. Whew – take a breath! • Sternocleidomastoid muscles • raise upper rib and sternum • Intercostal muscles contract • elevate ribs and increase anterior-posterior dimension • Diaphragm is the primary muscle of respiration – it contracts and flattens • increases volume of cavity. • Pressure in cavity becomes less than atmospheric • air rushes in to alveoli to equalize pressure

  10. Ok…. Breathe out! • Muscles relax… • Diaphragm moves upward • Ribs and sternum move inferiorly • Ribs move closer together in inferior and posterior position • Thoracic volume decreases • Intrathoracic pressure increases

  11. T's all connected! • Changing volume and pressure of thoracic cage also helps with • Pumping blood to and return from systemic circulation • Affects BP and pulse strength • Normally, systolic BP and pulse strength fall during inspiration, rise during exhalation

  12. What's normal? • Adults – 12 – 24 breaths per min. • Children – 18 – 24 breaths per min. • Infants – 40 – 60 breaths per min.

  13. You must also know • Total lung capacity – TLC • ~ 6 L • Tidal Volume – VT • ~ 500 ml (5 – 7 ml/kg) • Dead space volume – VD • ~ 150 ml • Alveolar Volume – VA • ~ 350 ml • Minute volume - Vmin

More Related