Respiratory System Respiratory System Chapter 16

Terminology  Respiration: exchange of oxygen and carbon dioxide between atmospheric air, blood, tissue, & cells Respiration  Pulmonologist: specialist of lung disorders  Otorhinolaryngologist: ear, nose & throat specialist  Heimlich maneuver: procedure performed when trachea becomes blocked  Tracheostomy: surgical procedure that opens up trachea if Heimlich maneuver is unsuccessful  Oxyhemoglobin: hemoglobin with oxygen bonded  Carbaminohemoglobin: hemoglobin with carbon dioxide bonded

Functions  Provides for oxygen intake  Provides for carbon dioxide elimination  Regulates blood pH  Filters inhaled air  Chemoreceptor (olfaction)  Produces sound  Rids body of some heat and water

Respiration  4 processes: –Ventilation (breathing) = inhalation + exhalation –External respiration = gas exchange between lungs & blood (pulmonary circulation –Transportation = of oxygen and carbon dioxide to and from lungs –Internal respiration = gas exchange between blood & tissues (systemic circulation)

Divisions of Respiratory System  Upper Respiratory System –Nose –Pharynx (throat)  Lower Respiratory System –Larynx (voice box) –Trachea (windpipe) –Bronchii –lungs

Nose  air passageway only  external = nares (nostrils)  Internal = paranasal sinuses  Both lined with mucous membrane  Function: to warm & moisten air, olfaction, resonating chamber for sound  Nostril hair & cilia trap foreign particles and sweep toward pharynx

Pharynx (throat)  Air and food passageway  3 divisions –Nasopharynx: behind nose  No food here  Adenoid tonsils here –Oropharynx: behind mouth  Air & food here  Palatine & lingual tonsils here –Laryngopharynx: above larynx  Air & food here  Divides anteriorly into trachea and posteriorly into esophagus **Smoking causes overproduction of mucus = smoker’s cough**

Larynx (voice box)  9 pieces of cartilage –Largest piece = thyroid cartilage (Adam’s apple)  Epiglottis: closes off trachea when swallowing  Vocal cords: elastic ligaments –Men have thicker & longer cords = deeper voice –Women have thinner & shorter cords = higher voice  Laryngitis: inflammation of larynx = hoarseness/voice less **Smoking causes larynx to swell = smoker’s voice**

Trachea (windpipe)  Air passage only  Connects larynx to primary bronchii  Made of C-shaped cartilage rings that open posteriorly (esophogeal expansion)

Bronchii  Branches extensively after entering lungs (bronchial tree)  Right and left primary bronchus: one goes into each lung; divide into secondary bronchi  Secondary bronchi: one goes into each lobe of lungs (3 in right lung & 2 in left lung); divide into tertiary bronchi  Tertiary bronchi branch into bronchioles  Bronchioles branch into terminal bronchioles  Cartilage gets less and less as you move down this bronchial tree Bronchitis = excessive mucus production from bronchiole lining

Bronchial Tree

Lungs  In thoracic cavity  Serous membranes = pleura –Visceral pleura: covers lungs –Parietal pleura: lines cavity  Pleurisy = inflammation of pleural membranes

Lungs (continued)  Apex at clavicle to base on diaphragm  Hilus: notch on medial side where all vessels enter and exit  Left lung: 10% smaller due to heart  Right lung: thicker, broader, shorter due to liver  Alveoli: sites of gas exchange in lungs; found on the end of terminal bronchioles; resemble clusters of grapes  Surfactant: substance lining alveoli that reduces collapse Emphysema: permanently stretched alveoli; gas exchange not efficient = labored exhalation

The entire Respiratory Tract

Breathing Rates  Eupnea: normal breathing –Approx. 12 breaths per minute  Dyspnea: labored breathing –Often seen with asthma, bronchitis, & other respiratory ailments  Apnea: absence of breathing –Usually will resume after a few seconds

Lung Volumes  Tidal volume (TV): volume of 1 breath; measured with a spirometer  Inspiratory reserve volume (IRV): what can be forcefully inhaled after a normal inhalation  Expiratory reserve volume (ERV): what can be forcefully exhaled after a normal exhalation  Residual volume (RV): air remaning in lungs (prevents collapse)  Total lung capacity (TLC): the sum of all of the above –TLC = TV + IRV + ERV + RV

Ventilation  Inhalation = inspiration –Breathing IN –Active process as diaphragm & rib muscles contract –Air moves into lower pressure(lungs) from higher pressure (atmosphere)  Exhalation = expiration –Breathing OUT –Passive process as diaphragm & rib muscles relax –Air moves out from higher pressure (lungs) to lower pressure (atmosphere)

Connection with Brain  Respiratory center = brain stem –Medullary rhythmicity area + pons = rhythmic breathing –Pneumotaxic area = rapid breathing –Apneustic area = slow breathing

Other Disorders Other Disorders  Asthma: closing off of air passageway due to spasms from allergens  Pneumothorax: collapsed lung due to low surfactant, chest wound, or obstructed airway (anything that may change pressure)  Cystic fibrosis: genetic disease that causes overproduction of mucus in lungs that may cause blockage and difficulty in breathing