Unit 9 Review

Unit 9 Review: ● Identify the structures of the respiratory system and describe their locations, including the pleural cavities and pleural membranes. ○ Nose ■ Air enters through the external nares and enters the nasal cavity ○ Nasal cavity ■ Inside of the inner nose ■ Contains nasal conchae that are ridges in the nasal cavity that create turbulence when you breathe. It increases the likelihood of particles getting trapped in the mucous, as well as time for the air to be warmed, humidified and filtered ○ Paranasal sinuses ■ The sinuses open into the nasal cavity and help with sound resonation, decreasing the weight of the skull, and mucous production ■ Found in the ethmoid, sphenoid, frontal and maxillary bones ○ Pharynx ■ Common passageway connecting the nose, mouth and throat ■ Passage for food and air, sound resonation, and contains tonsils ■ 3 regions (nasopharynx, oropharynx, and laryngopharynx) ○ Larynx ■ Located below the pharynx ■ Production of sound, conduction of air into the lower respiratory tract, and protection of the airway from swallowed food (with epiglottis) ■ Contains lots of cartilages ● Thyroid cartilage: contains adams apple, hyaline cartilage ● Cricoid cartilage: encircles the trachea, hyaline cartilage ● Epiglottis: closes over glottis when swallowing food, elastic cartilage ● Paired arytenoid, corniculate, and cuneiform cartilages helps open the glottis and aids in sound production, all but cuneiform are hyaline, the cuneiform is elastic cartilage ○ Trachea ■ Aka the windpipe ■ Composed of mucosal layer, submucosa, and hyaline cartilage ■ C-shaped rings around the trachea allow the esophagus to expand when swallowing large chunks of food so it doesn’t get stuck ■ Connects the larynx to the bronchi to allow oxygen to enter the lungs ○ Bronchi ■ Primary bronchi: branch from trachea, one to each lung ■ Secondary bronchi: supplies each lobe of each lung (3 on the right lung and 2 on the left) ■ Tertiary bronchi: supply the different bronchopulmonary segments of each lobe of the lungs and divides further into bronchioles and divides even smaller until you get to the alveoli ○ Alveoli ■ Located in the alveoli sacs at the ends of respiratory bronchioles ■ This is where gas exchange occurs (type 1 alveolar cells) ■ Secretes surfactant to prevent collapsing of the alveolar sacs (type 2 alveolar cells) ○ Lungs ■ Parietal pleura covers the body wall ■ Intrapleural space contains intrapleural fluid (serous fluid) to prevent friction when breathing ■ Visceral pleura covers the surface of each lung ● Distinguish between the conducting and respiratory portions of the respiratory tract. ○ Conduction: air to and from the lungs ○ Respiration: gas exchange with alveoli ● Identify the boundaries of the nasal cavity and its relationship with the paranasal sinuses. ○ The roof of the nasal cavity is formed by the ethmoid bone and sphenoid bone, and the floor is formed by the hard palate ○ The sinuses are located in air-filled cavities in the ethmoid, sphenoid, frontal and maxillary bones ○ The paranasal sinuses are lined with mucous membranes and help with sound resonation, mucous secretion, as well as drainage and ventilation, and lightening of the skull ● Differentiate the three anatomical regions of the pharynx. ○ Nasopharynx (air only) ■ At the back of the throat behind the internal nares ■ Contains the eustachian tubes connected to the passages of the ears ○ Oropharynx (food and air) ■ Middle of the pharynx ■ Contains pharyngeal arch and uvula ○ Laryngopharynx (food and air) ■ Bottom of pharynx ● ● ● ● ● ● ■ Opens to the entrance of the trachea and esophagus (where respiratory and digestive systems divide) Describe the structure of the larynx and explain its function in respiration and voice production. ○ During respiration, the larynx serves as a passageway for air to travel between the pharynx and trachea. The vocal cords are within the trachea and remain open to allow air flow ○ During swallowing, the epiglottis covers the glottis so that food does not enter the trachea (windpipe) and if food enters you will probably choke ○ The vocal cords are muscular bands that vibrate when you speak to produce sound, and the larynx adjusts the tension of these vocal folds in order to make different kinds of sounds Describe the location and structure of the bronchial tree and bronchopulmonary segments. ○ Trachea → lungs → primary bronchi → secondary bronchi → tertiary bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar sacs → alveoli Describe the division of the lungs into lobes and compare the structure of the right and left lung. ○ Left lung: 2 lobes separated by oblique fissure. Contains cardiac notch ○ Right lung: 3 lobes separated by oblique and horizontal fissures. It is larger since it doesn't have the cardiac notch taking up so much space Identify and describe the actions of the muscles involved in both quiet and forced respiration. ○ Quiet respiration ■ Diaphragm and intercostal muscles ■ Diaphragm contracts (lowers) for inhalation and relaxes (raises) for exhalation ○ Forced respiration ■ accessory muscles ■ Describe external and internal respiration. ○ External respiration: outside air → fluids ○ Internal respiration: interstitial fluid → cells Define pulmonary ventilation and outline the mechanism of normal quiet inspiration and expiration ○ Pulmonary ventilation refers to the movement of air into and out of the lungs (fancy term for breathing) ● ● ● ● ○ Air moves into and out of the respiratory tract due to pressure gradients present inside the lungs and the outside air when moving the diaphragm and intercostal muscles Describe the role of airway resistance in pulmonary ventilation. ○ Airway resistance makes pulmonary ventilation harder, so the more resistance there is, the less pulmonary ventilation ○ Bronchoconstriction and bronchodilation Explain the principles of partial pressures, gas diffusion, and solubility (and related laws) ○ Boyle’s law: volume vs. pressure ○ Dalton's law: concentration vs. pressure ○ Henry’s law: temperature vs. pressure ○ Bohr effect: high acid concentrations causes more dissociation of O2 from hemoglobin ○ Partial pressures: each gas has a different partial pressure when referring to gases in a mixture and when you have more partial pressures of certain gases in your body, your body does things to compensate such as having high CO2 forces you to breathe out and remove CO2 ○ Gas diffusion: simple diffusion down a partial pressure gradient ○ Solubility: each gas in the atmosphere has different levels of solubility in our body fluids, CO2 is highly soluble, O2 is somewhat less soluble, and nitrogen has very limited solubility Explain how oxygen and carbon dioxide are transported in the blood. ○ 1. Plasma ○ 2. Hemoglobin Discuss the physiology of the control of respiration. ○ Local regulation ■ Smooth muscle in the bronchioles and alveolar capillaries expand or contract to maintain the ventilation-to-perfusion ratio ○ Neural control ■ Voluntary neural control ● Via the cerebral cortex for temporary control like when swimming or singing, but if there's too much CO2 build-up the medulla takes over ■ Involuntary neural control ● Respiratory Rhythmicity Centers (RRC): 3 pairs of nuclei in the reticular formation of medulla oblongata that set the basic rhythm and frequency of breathing ● Dorsal Respiratory Group (DRG) ○ ALL INSPIRATION ○ Controls the external intercostals and diaphragm ● Ventral Respiratory Group (VRG) ○ Primarily controls the respiratory accessory muscles in forced exhalation and inspiration ■ Pontine respiratory group ● Regulates depth and rate of breathing in the pons ● Apneustic Center ○ In quiet breathing: helps increase the intensity of breathing and is inhibited by pneumotaxic center ○ In forced breathing: stimulated by CNS to increase lung inflation (depth control) ● Pneumotaxic Center ○ Inhibits the pneumotaxic center to promote exhalation ● Clinical application (Respiratory distress syndrome, pneumothorax, pleural effusion) ○ Respiratory distress syndrome: respiratory insufficiency due to inadequate production of surfactant in babies, and cause the alveolar sacs to collapse continuously and makes it really difficult to breathe ○ Pneumothorax: when air enters the pleural cavity and can cause the lungs to collapse (often in penetrating chest injuries) ○ Pleural effusion: fluid in the pleural space