Respiratory System PDF

Dr Govender  Upper respiratory tract  Paranasal sinuses  Lower respiratory tract  ALVE-  The Latin word alveus means a hollow or a cavity. In the respiratory system the basic form ALVE- is applied in the diminutive form alveolus (pl. alveoli) referring to the small air sacs of the l...

Dr Govender  Upper respiratory tract  Paranasal sinuses  Lower respiratory tract  ALVE-  The Latin word alveus means a hollow or a cavity. In the respiratory system the basic form ALVE- is applied in the diminutive form alveolus (pl. alveoli) referring to the small air sacs of the lungs.  AMYGDAL- and TONSILL-  Both the original Greek and Latin words (amygdala and tonsilla) mean almond. The almond- like appearance of these small, rounded masses of lymphoid tissue delivered the combining forms TONSILL- and AMYGDAL-, which form the basic elements of medical terms such as  tonsillitis: inflammation of a tonsil  amygdalotome: an instrument for excision of a tonsil  BRONCH- and BRONCHI-  The Latin bronchus (Greek bronchos) refers to a windpipe. In the respiratory system the basic form BRONCHI- is applied in the diminutive form bronchiolus/bronchiole (pl. bronchioli/bronchioles), referring to one of the smaller subdivisions of the bronchial tubes.  GLOTT-  The glottis is a slit between the true vocal cords, helping to produce sound. The epiglottis is the lid-like uppermost cartilage that covers the entrance to the larynx.  LOB-  Lobe literally means the part hanging down. In the respiratory system it refers to the major divisions of the lungs. There are three lobes on the right and two on the left. Lobe is also applied to other parts of the body, such as the lobe of the ear, liver, brain, pancreas, prostate gland, thyroid gland, etc.  The combining form is often combined with the diminutive suffix to indicate a small lobe or subdivision of a lobe, e.g. lobules of the lung: units of the lung consisting of a respiratory bronchiole and its branches.  PLEUR-  The pleura is a serous membrane encasing the lungs, lining the thoracic cavity and enclosing the pleural cavity. The original Greek word refers to the side of the body.  THORAC- and THORAX  The thorax is the body cavity between the base of the neck and the diaphragm. The lungs and most of the respiratory tract are situated in the thorax. To investigate the thorax visually (thoracoscopy), an endoscope (an instrument to observe the inside of a hollow organ) called a thoracoscope is used. Endoscopic thoracotomy is the term used to describe the use of an endoscope to perform a thoracotomy. Today, endoscopic surgery is a common term that describes modern surgery conducted by means of endoscopes.  TRACH-, TRACHE- and TRACHY-  The trachea is the passage reinforced by cartilage rings through which air reaches the bronchial tubes. Ancient Greek anatomists were under the impression that the arteries carried air, and they called the trachea a rough (artery) as a result of the rings of cartilage surrounding it.  As cells use oxygen, they give off carbon dioxide, a waste product the body must get rid of. They also generate dangerous free radicals, the inescapable by-products of living in a world full of oxygen.  The major function of the respiratory system is to supply the body with oxygen and dispose of carbon dioxide.  To accomplish this function, at least four processes, collectively called respiration, must happen.  Includes:  Nose and paranasal sinuses  Pharynx larynx  Trachea  Bronchi  Lungs  Alveoli  Upper respiratory system – structures from nose to larynx  Lower respiratory system – structures from larynx onwards  Nose is the only external visible part  Nose provides:  An airway for respiration  Moisten and warm entering air  Filters and cleans inspired air  Serves as a resonating chamber for speech  Houses olfactory receptors  Divided into external nose and internal nasal cavity  Surface features include:  Root  Bridge  Dorsum nasi  Apex  External openings of the nose = nostrils/nares bounded laterally by flared alae  Skeletal framework:  Nasal and frontal bone superiorly  Maxillary bone laterally  Hyaline cartilage inferiorly  Lie in and posterior to the external nose  Air enters the cavity through the nostrils  Cavity is divided by a midline septum  Anteriorly: septal cartilage  Posteriorly: vomer and perpendicular plate of the ethmoid bone  Continues posteriorly with the pharynx  Roof formed by the ethmoid and sphenoid bones  Floor is formed by the palate  Anteriorly – palatine bone and processes of the maxillary bones (hard palate)  Posteriorly – muscular soft palate  The rest of the nasal cavity is lined with two types of mucous membrane.  The small patch of olfactory mucosa lines the slitlike superior region of the nasal cavity and contains smell receptors in its olfactory epithelium  The respiratory mucosa lines most of the nasal cavity. The respiratory mucosa is a pseudostratified ciliated columnar epithelium, containing scattered goblet cells, that rests on a lamina propria richly supplied with serornucous nasal glands.  Nasal conchae – protruding medially from each lateral wall of the nasal cavity  Superior  Middle  Inferior  The nasal cavity is surrounded by a ring of paranasal sinuses  They are located in the frontal, sphenoid, ethmoid, and maxillary bones  The sinuses lighten the skull, and they may help warm and moisten the air.  The mucus they produce ultimately flows into the nasal cavity, and the suctioning effect created by nose blowing helps drain the sinuses.  Funnel shaped  Connects the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly  From superior to inferior it is divided into three regions:  Nasopharynx - serve as an airway passage  Oropharynx  Laryngopharynx  From superior to inferior it is divided into three regions:  Nasopharynx  Oropharynx – allow food and air to pass through it  Laryngopharynx  From superior to inferior it is divided into three regions:  Nasopharynx  Oropharynx  Laryngopharynx – passage for food and air  Consists of the:  Conducting zone  Respiratory passageways from nose to bronchioles  Transports air for gas exchange  Respiratory zone  Site for gas exchange  Composed of respiratory bronchioles – alveoli  Extends from level of the 3rd – 6th cervical vertebra  Superiorly – attached to hyoid bone  Inferiorly – continue with trachea  Three functions  Provide a patent airway  Act as a switching mechanism to route air and food into proper channels  Voice production  Trachea/windpipe descends from the larynx through the neck into the neck and mediastinum  Ends by dividing into two main bronchi at the midthorax  Flexible and mobile  Several layers  Air passage ways in the lunch branch multiple times = bronchial tree  Tips of the tree – conducting zones  Cones shaped structure, surrounded by pleura  Various surfaces  Area in contact with the ribs (anterior, lateral and posterior) = costal surface  Area in contact with the diaphragm = diaphragm surface  Area in contact with lungs = mediastinal surface  Left and right lung differs