UNIT 7 - RESPIRATORY SYSTEM Flashcards
what does the respiratory system ensure?
-oxygen enters the body
-carbon dioxide leaves the body
where does air move during inspiration/inhalation?
-from the atmosphere to the lungs through cavities and tubes
where does air move during expiration/exhalation?
-from the lungs to the atmosphere through cavities and tubes
what are the 2 aspects of ventilation (breathing)?
-inspiration
-expiration
what does ventilation (breathing) depend on?
-the cardiovascular system to transport oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs
where is carbon dioxide produced and where is oxygen used?
-in cellular respiration
what is contained within the upper respiratory tract? DIFFERENT FROM ANATOMY
-nasal cavity
-pharynx
-larynx
what is the structure of the nose?
-nose opens at the nares (nostrils) which leads to the nasal cavity
what separates the left and right nasal cavities?
-by a septum composed of bone and cartilage
how does the nasal cavity trap particles from the air?
-hair filters and traps small particles so they don’t enter air passages
-mucous membrane lining produces mucus which traps particles and moves them to the pharynx
what is the layer under the mucous membrane? what is the purpose of this layer?
-submucosa
-contains lots of capillaries that help warm and moisten incoming air
what does the abundance of capillaries within the submucosa make humans susceptible to?
-nosebleeds
what is contained within the nasal cavities?
-odor receptors
why does crying cause a runny nose?
-tear glands in the eye drain into the nasal cavity by tear ducts
what do the nasal cavities connect with of the skull? what can happen here?
-sinuses
-fluid may accumulate, causing an increase in pressure
-results in a sinus headache
where will air in the nasal cavities pass?
-into the nasopharynx
what connects the nasopharynx to the middle ear? what does this cause?
-auditory tubes (eustachian tubes)
-when air pressure in the middle ear equalizes with air pressure in the nasopharynx, auditory tube openings may create a popping sensation
what is the pharynx?
-the throat
-funnel shaped cavity that connects the nasal and oral cavities to the larynx
-has 3 portions
what are the 3 portions of the pharynx?
-nasopharynx
-oropharynx
-laryngopharynx
what are tonsils? what is their purpose?
-lymphoid tissue at the junction of the oral cavity and pharynx
-provide defense against inhaled pathogens
what is the larynx?
-cartilaginous structure between the pharynx and trachea
-has 3 regions
-houses the vocal cords
what is a laryngeal prominence?
-adam’s apple
-at the front of the neck
what are the 3 regions of the larynx?
-supraglottic (top)
-glottic (middle)
-subglottic (bottom)
what are the vocal cords?
-mucosal folds supported by elastic ligaments
what is the glottis?
-slit between the vocal cords
how is sound produced by the vocal cords?
-air passing through the glottis causes the vocal cords to vibrate
what does the loudness of sound depend on?
-loudness depends on the degree of vibration
what does pitch depend on?
-pitch depends on tension
-greater tension = higher pitch
-wider glottis = lower pitch
how is food kept out of the larynx?
-larynx will move upwards against the epiglottis
what is the epiglottis?
-a flap of tissue that prevents food from passing into the larynx
what is included within the lower respiratory tract? DIFFERENT FROM ANATOMY
-trachea
-bronchial tree
-lungs
what is the trachea?
-the windpipe
-connects the larynx to the primary bronchi
what are the walls of the trachea reinforced by? what is their purpose? why is the C-shape significant?
-C-shaped cartilaginous rings
-prevent the trachea from collapsing
-C shape allows the esophagus to expand into the trachea when swallowing
what is the lining of the trachea?
-pseudostratified ciliated columnar epithelium with goblet cells
what is the purpose of the goblet cells within the trachea lining?
-produce mucus to trap debris
what is the purpose of the trachea lining being ciliated?
-sweeps the mucus away from the lungs and towards the pharynx
what is an example of something that damages the cilia?
-smoking
-causes a smokers cough
what is a tracheostomy?
-a breathing tube inserted into the trachea
what makes up the bronchial tree?
-two primary bronchi
-secondary bronchi
-bronchioles
where do the primary bronchi lead?
-from the trachea to the lungs
how small do the bronchioles become in diameter?
-about 1mm
what is similar between the bronchi and the trachea? how does this similarity deplete?
-bronchi contain cartilage
-cartilage disappears as bronchi get smaller
what occurs to the bronchi during an asthma attack?
-smooth muscle of the bronchi will contract
-constricts and causes wheezing
what does each bronchiole lead to?
-an elongated space enclosed by many air sacs called alveoli
what makes each lung?
-secondary bronchi
-bronchioles
-alveoli
how many lobes does each lung have? what is the reason for this?
-right has 3 lobes
-left has 2 lobes
-to make room for the heart
what is each lobe of the lungs divided into?
-lobules
what encloses each lung?
-membranes called pleurae (visceral and parietal)
what is secreted by the pleura?
-secretes pleural fluid
what effect does the pleural fluid have on the lungs?
-increases the size of the lungs
-pleural fluid has surface tension (hydrogen bonds between H20)
-when the thoracic cavity enlarges, the parietal pleura pulls the visceral pleura (pulls the lungs outwards)
what is pleurisy?
-inflammation of the pleurae
-very painful
how many alveoli are within the lungs?
-300 million
what is each alveolar sac surrounded by? what tissue creates both the sac and these?
-blood capillaries
-simple squamous epithelium
where does gas exchange occur?
-between air in the alveoli and blood in the capillaries
-performed by type I pneumocytes
what covers the internal surface of each alveolus?
-type I pneumocytes (majority)
-type II pneumocytes
-macrophages
what are type II pneumocytes responsible for?
-the production and secretion of the pulmonary surfactant
how does gas exchange occur within the alveoli?
-oxygen diffuses across the alveolar wall to enter the bloodstream
-carbon dioxide diffuses from the bloodstream into the alveoli
what prevents the alveoli from closing? how does it achieve this?
-lined with surfactant
-lowers the surface tension of water
-when the lungs recoil during expiration, pressure between pleurae decreases (keeps them open)
what is the surfactant that lines the alveoli?
-a film of lipoprotein
what is infant respiratory distress syndrome?
-when premature infants don’t make enough surfactant
-alveoli will collapse
where do the lungs lie?
-within the sealed thoracic cavity
what are 3 aspects of the thoracic cavity?
-rib cage (tops and sides of the cavity)
-intercostal muscles (between the ribs)
-diaphragm (floor of the cavity) (skeletal muscle)
how are the lungs adhered to the thoracic wall?
-by the parietal and visceral pleura
what is between the 2 pleurae?
-space called the pleural cavity
-filled with pleural fluid
what governs ventilation?
-Boyle’s law
-PV= k
-at a constant temp, the pressure of a gas is inversely proportional to its volume
-when volume increases, pressure decreases
what is inspiration?
-active phase of ventilation
-diaphragm and external intercostal muscles contract (size of thoracic cage increases)
-both actions increase the size of the thoracic cage
how does the diaphragm change shape?
-in a relaxed state, diaphragm is dome shaped
-during inspiration, it contracts and flattens
how does the contraction of external intercostal muscles change the shape of the rib cage during inspiration?
-rib cage moves upwards and outwards
what happens to pressure and volume in various aspects of the respiratory system during inspiration?
-as thoracic volume increases, lungs also increase in volume (lung is adhered)
-as lung volume increases, air pressure in the alveoli decreases
-since alveolar pressure is now less than atmospheric pressure
-causes air to flow from outside the body into the lungs
what is expiration?
-passive phase of breathing
-diaphragm and external intercostal muscles relax
-lungs will recoil
-air pressure increases and air flows out
how does the relaxation of external intercostal muscles change the shape of the rib cage during expiration?
-rib cage returns to its resting position
-moves down and inward
what keeps the alveoli from collapsing during expiration?
-surfactant
what happens during a punctured lung accident?
-air or blood may enter the space between the two pleurae
-increases intrapleural pressure
-causes the lung to collapse (pneumothorax)
what happens when you use maximum inspiratory effort?
-muscles of the back, chest, and neck are used (breathing hard)
-increases the size of the thoracic cavity more than usual
-maximum lung expansion
what are examples of forced expiration? how is this achieved?
-singing and blowing air
-contraction of the internal intercostal muscles forced the ribcage downward and inward
-abdominal muscles contract and push on the organs, pushing them upward against the diaphragm
what is tidal volume?
-the amount of air that moves in and out with each normal breath
what is vital capacity?
-the max volume that can be moved in plus the max amount that can be moved out during one breath
what is inspiratory and expiratory reserve volume?
-the increased volume of air moving in (inspiratory) or out (expiratory) of the body with forced inspiration and expiration
what is a spirometer?
-apparatus for measuring the volume of air inspired and expired by the lungs
what is vital capacity the sum of?
-tidal, inspiratory reserve, and expiratory reserve volumes
what does the air that never reaches the alveoli fill? are these used for gas exchange? what are they said to contain?
-the nasal cavities, trachea, bronchi, and bronchioles
-not used for gas exchange
-contain dead air space
what is residual volume?
-the air remaining in the lungs after exhalation
what controls our breathing?
-the nervous system
-certain chemicals
what is the nervous systems control of breathing?
-respiratory control center in the brain stem
-sends nerve signals to the diaphragm and the external intercostal muscles for inspiration
-stops sending nerve signals for expiration to occur
what does the respiratory control center connect?
-connects the cerebrum to the spinal cord and cerebellum
what is involved in forced ventilation?
-accessory respiratory muscles
-internal intercostal muscles
what is SIDS?
-sudden infant death syndrome
-crib death
-while sleeping the infant stops breathing
-cause is not known (vaccinations, vomiting, and infections have been ruled out)
-may be a miscommunication between the respiratory center of the brain and the lungs
what else influences the respiratory control center? what is this for?
-other parts of the nervous system
-voluntary change breathing patterns for speaking, singing, eating, swimming
what follows forced inspiration?
-stretch receptors in the airway initiate inhibitory nerve impulses
-stops the respiratory center from sending out nerve signals
-stops overstretching of the lungs
what are chemoreceptors?
-sensory receptors that are sensitive to the chemical composition of body fluids
what occurs when cells produce CO2 during cellular respiration? (chemical control of breathing)
-CO2 enters the blood and combines with water to form carbonic acid
-carbonic acid breaks down and gives off hydrogen ions
-additional H+ decreases blood pH
what is the response to a decrease in blood pH?
-two sets of chemoreceptors sensitive to pH will cause breathing to speed up
-respond to carbon dioxide levels in blood
-respiratory center increases the rate and depth of breathing to remove CO2 from blood (increases pH)
-breathing rate returns to normal
what are the 2 sets of chemoreceptors for the chemical control of breathing?
-set in the medulla oblongata of the brain stem (detects pH of spinal fluid)
-set is the carotid bodies of the carotid arteries and aortic bodies of the aorta
what happens to your blood pH when you hold your breath? how does it respond to this?
-CO2 begins to accumulate in your blood (decreases pH)
-respiratory center is stimulated by chemoreceptors and overrides the voluntary inhibition of respiration
-forces breathing
why is oxygen important within the body?
-needed to make ATP
what is included within respiration?
-exchange of gases within the lungs (external)
-exchange of gases within tissues (internal)
how does gas exchange work in terms of diffusion?
-gases exert pressure
-if the partial pressure of a gas differs across a membrane it will diffuse from higher to lower partial pressure
what is partial pressure?
-the amount of pressure each gas exerts
what is external respiration?
-exchange of gases between the lung alveoli and blood capillaries
-partial pressure of CO2 is higher in lung capillaries than in the air
-CO2 will diffuse out of the blood into the lungs
-O2 diffuses from the alveolar air into the red blood cells in the pulmonary capillaries
where is most CO2 carried?
-in the plasma as bicarbonate ions
what is carbonic anhydrase?
-enzyme that speeds the breakdown of carbonic acid into water and carbon dioxide in RBCs
what is hyperventilation?
-breathing at a high rate
-alkalosis occurs (high blood pH)
-more CO2 is created and H+ ions are depleted
what is hypoventilation?
-breathing at a low rate
-acidosis occurs (low blood pH)
-less CO2 is created and H+ ions are in excess
how is oxygen taken up in the pulmonary capillaries?
-pulmonary capillaries are low in oxygen
-alveolar air is high in oxygen
-oxygen diffuses from the lungs into the blood
-hemoglobin takes up oxygen and becomes oxyhemoglobin
what is internal respiration?
-exchange of gases between the blood in systemic capillaries and the tissue cells
-oxyhemoglobin enters systemic capillaries and gives up oxygen
-deoxyhemoglobin will diffuse out of blood and into the tissues to take up CO2
where does CO2 collect?
-in the interstitial fluid
why is there a lower partial pressure of oxyegn?
-cells continuously use up oxygen during cellular respiration
what are examples of upper respiratory tract infections?
-strep throat
-sinusitis
-otitis media
-tonsillitis
-laryngitis
what can strep throat lead to?
-a generalized URI
-systemic infection
what are symptoms of strep throat? how is it treated?
-severe sore throat
-high fever
-white patches on a dark red throat
-treated with antibiotics
what is sinusitis?
-blockage of sinuses
what is otitis media?
-infection of the middle ear
what is tonsilitis?
-inflammation of the tonsils
-if repeatedly occurs, tonsils are surgically removed (tonsillectomy)
what is laryngitis?
-infection of the larynx
-leads to voice loss
what kind of lower respiratory tract disorders are there?
-infections
-restrictive pulmonary disorders
-obstructive pulmonary disorders
-lung cancer
what are examples of infections of the lower respiratory tract?
-acute bronchitis
-pneumonia
-tuberculosis
what is acute bronchitis?
-infection of the primary and secondary bronchi
what is pneumonia?
-bacterial or viral infection
-bronchi and alveoli fill with a thick fluid
what is tuberculosis?
-bacterial infection that leads to tubercles (encapsulated bacteria)
what occurs with restrictive pulmonary disorders of the lower respiratory tract?
-vital capacity is reduced (lungs have lost elasticity)
-lungs cannot inflate properly
-can lead to cancer
what is an example of a restrictive pulmonary disorder of the lower respiratory tract?
-pulmonary fibrosis
-fibrous CT builds up in the lungs
-typically because of inhaled particles like sand, coal dust, asbestos, or fiberglass
what occurs with obstructive pulmonary disorders of the lower respiratory tract?
-air does not flow freely in the airways
what are examples of obstructive pulmonary disorders of the lower respiratory tract?
-chronic bronchitis
-emphysema
-asthma
-collectively referred to as chronic obstructive pulmonary disease (COPD) (tend to recur)
what is chronic bronchitis?
-airways are inflamed and filled with mucus
-bronchi undergo degenerative changes (loss of cilia)
-smoking is the frequent cause or exposure to pollutants
what is emphysema?
-chronic and incurable
-alveoli are swollen and walls are damaged (reduce in SA for gas exchange)
-less oxygen reaches the heart and brain (feel fatigued)
-smoking the frequent cause
-elastic recoil of the lungs is reduced
-airways narrowed and driving force of expiration is reduced
how is severe emphysema treated?
-lung transplantation
-lung volume reduction surgery (LVRS)
how does lung volume reduction surgery work?
-a third of the most diseased lung tissue is removed
-enables the remaining tissue to function better
what is asthma?
-treatable but not curable (inhaler)
-when exposed to an irritant like pollen or tobacco smoke, smooth muscle in the bronchioles spasms
what are symptoms of asthma?
-wheezing
-breathlessness
-coughing
-expectoration of mucus
what kinds of inhalers are there?
-controllers
-relivers
what are controller inhalers?
-corticosteroids
-orange puffer (anti-inflammatory)
what are reliever inhalers?
-bronchodilators
-blue puffer (salbutamol)
is lung cancer more prevalent in men or woman?
-men
what are the major events of lung cancer?
-thickening of the lining of the bronchi
-cilia are lost
-cells with atypical nuclei appear in the lining (form a tumor)
-atypical nuclei cells break loose and penetrate other tissues (metastasis)
-original tumor may grow until a bronchus is blocked (cutting air supply to that lung)
what does the loss of cilia from lung cancer cause?
-impossible to prevent dust and dirt from settling in the lungs
what must be done before metastasis occurs?
-pneumonectomy
-removal of a lobe or the whole lung
