Anatomy & Physiology of Respiratory system
dr. moshtak wtwt FIBMS
Anatomical & physiological considrations:
*gas exchange
*inspired air travels through the nose & pharynx, where heated & humidified , filtiring particales > 10 Mm.
* enterance to the trachea through larynx which open during ventilation & closed by epiglottis during swallowing.
*trachea divided into RT &LF bronchi *foreign body dislodge in RT bronchus. *bronchi ---- respiratory bronchioles ---- alveolar ducts--- alveoli .
*respiratory zone: *type I pneumocytes: *type II pneumocytes: (surfactant)
Gas exchange
* ventilation perfusion diffusion
*ventilation:
----outward elastic force of thoracic cage
----inward elastic recoil of lung
---- inhalation & exhalation
---- muscles of respiration
----ventilation depend on:
1- resp control centers 2- respi effectors 3- resp sensors
* RT to LF shunt not corrected by O2 ????
* low conc of O2 in copd ?????
*Lung defense mechanisms
1- physical
2- mucocilliary clearance
3- surfactant & other defensive proteins
Like IgA, G, M, complement, protinase inhibitors, MQ
CXR:
*name&date *view *pateint’s position *trachea *over or under pentration * sc *bone *lung tissue *costophrenic angle *cardiac chambers *cervical rib *under diaphragm
() CT scan: ()MRI ()PET ()Pul angiography ()U/S ()Fluoroscopy ()V/P scanning ()oximetry ()bronchoscopy ()pleural biopsy , aspiration
Ultrasound : is sensitive at detecting pleural fluid and may also be employed to direct and improve the diagnostic yield from pleural biopsy. It is also used to investigate the anatomy of an empyema cavity to facilitate directed drainage, and to guide needle biopsy of superficial lymph node or chest wall masses. Endobronchial ultrasound is now possible using specialised bronchoscopes, and is used for imaging and sampling peribronchial lymph nodes.
| Ventilation-perfusion imaging |
| In this technique, the lungs are imaged using a gamma camera that is able to distinguish two isotopes, inhaled 133Xe (yielding ventilation images) and injected macroaggregates of 99mTc-albumin (yielding perfusion images). Pulmonary emboli appear as perfusion defects with preserved ventilation. However, the utility of this technique is limited in patients with underlying lung disease, in whom up to 70% of scans may be indeterminate. It is increasingly being replaced by CTPA. |