anatomy and physiology midterm 2

resp system and homeostasis

supply O2 and eliminate CO2 are the cardiovascular (transports gases) and respiratory system (gas exchange), failure of these systems results in disruption of homeostasis, rapid death of cells from oxygen starvation and buildup of waste products

resp system functions

gas exchange, regulated blood pH, receptors for sense of smell, filters inspired air, produces sound, rids body of some water and heat in exhaled air

steps of respiration

pulmonary ventilation, external (pulmonary) respiration and internal (tissue) respiration

pulmonary ventilation

air flow btwn the atmosphere and alveoli of lungs

external (pulmonary) respiration

exchange of gases btwn alveoli and blood in pulmonary capolaries, pulmonary capilary blood gains O2 and loses CO2

internal (tissue) respiration

exchange of gas btwn blood in capilaries and tissue cells, consume O2 and give off CO2 (cellular respiration)

repiration image

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components of resp system

upper resp system and lower resp system + conducting zone and respiratory zone

upper resp system

nose, pharynx, and associated structures

lower resp system

larynx, trachea, bronchi and lungs

conducting zone

interconnecting cavities and tubes both outside and within the lungs, includes nose, pharynx, larynx, trachea, bronchi and bronchioles

respiratory zone

tubes and tissues within the lungs where gas exchange occurs, includes: respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli

nose functions INSERT IMAGE

warming, moistening and filtering incoming air, detecting olfactory stimuli, modifying speech vibrations as they pass through nasal sinuses

nose- insert image of bones

sinuses put together are called paranasal sunuses which are located within cavity within the bones- contain mucous membranes with drain through the nasal cavity- divded by nasal septum, anterior portion of cavity is called vestibule

internal nose

mucous membranes line nasal cavity, mucus secreted by goblet cells moistens the air and traps dust particles, structural design increases surface area but prevents dehydration by trapping water droplets during exhalation, drainage from nasolacrimal ducts into the nasal cavity moistens air

Pharynx - image on parts of pharynx

muscular tube lined by mucous membranes, passageway fro food and air, also provides resonating chamber for speech sounds and houses tonsils (immune)

nasopharynx- respiration

oropharynx and laryngopharynx- digestion and respiration

larynx

aka voice box, walls made from cartilage connects pharynx and trachea, thyroid cartilage- adams apple), epiglottis- prevents food from entering larynx, cricoid cartilage- connects larynx and trachea by a ring of hyaline cartilage, paired artenoid- corniculate and cuneiform cartilages

epiglottis image

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voice production

sounds come from vibration of vocal folds, vocal folds called vocal cords which produces sounds (taut folds is high and loose folds are low),

laryngitis

inflammation of larynx, can be acute or chronic

trachea

aka windpipe, anterior to esophagus, extends from larynx to bronchi, composed of smooth muscles and c shaped cartilage rings (keep airway open), lined with pseudostratified ciliated columnar epithelium (cilia to sweep debris away from lungs)

bypassing respiratory passageway obstructions

tracheostomy and endotracheal intubation

bronchi insert image of bronchial tree components)

trachea divides into righ and left main bronchi

bronchi tissue changing chart

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particle removal

epithelium of resp membrane removes particles in 2 ways: mucus produced by goblet cells traps particles, cilia moves mucus and trapped particles towards pharynx for removal, sometimes removed by macrophages

lung membranes

enclosed and protected by double layered serous membrane called pleural membrane, parietal pleura is outer layer which attatches to thoracic cavity while the visceral pleura is the inner layer attatched to the lungs, the space btwn the lungs is called the pleural cavity which has a serous lubricating fluid secreted by membranes to reduce friction but allows membranes to adhere

pneumothorax

caused by injuries that allow air to enter intrapleural space

pleural effusion

accumulation of excess fluid in pleural space

thoracentesis

removal of excessive fluid in the pleural cavity, domne by inserting a needle into pleural space

parts of lungs and location

lungs extend from diaphragm to just slightly superior to clavicles, lie against the ribs, broad inferior portion is the base which is concave and the narrow superior portion is the apex, the surface against ribs is called costal surface

lobes and fissures of lungs insert image

right lung- 3 lobes by 2 fissures

left- 2 lobes by 1 fissure and a depression called the cardiac notch

bronchopulmonary segment

supplied by lobar branch → segmentak bronchi →, each segment consists of many small compartments called lobules which contain lymphatics, arterioles, vunules, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli

where does the respiratory zone start and ends

when the conducting zone ends at the termminal bronchioles, the respiratory zone begins and the resp zone ends at the alveoli

alveoli

air sacs within the lungs

alveolus insert image

walls consist of pneumocyte type 1 (gas exchange), pneumocyte type 2 (surfactant) and alveolar macrophages

respiratory membrane insert as chart

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pneumocytes type 1 insert image

simple squamous epithelial cells that form continous lining of alveolar wall, main site of gas exchange, occurs across the alveolar-capilary membrane

pneumocyte type 2

secrete alveolar fluid which keeps alveolar cells moist and contains component called surfactant- lowers surface tension of alveolar fluid, preventing collapse of alveoli with each expiration

blood supply to the lungs insert image

blood enters lungs via pulmonary arteries (pulmonary circulation) and the bronchail arteries (systemic circulation), most of the blood leaves by pulmonary veins, but some drain into bronchial veins

ventilation-perfusion coupling

unique feature of pulmonary blood vessels is the response to localised hypoxia, in all tissues hypoxia causes vasodilation to increase blood flow, in case of lungs, vasoconstriction in response to hypoxia diverts pulmonary blood from poorly ventilated areas of the lungs to well ventilated areas

review and insert images of summary

pulmonary ventilation

inhalation and exhalation and involves exchange of air btwn atmosphere and alveoli, air flows btwn atmosphere and alveoli bc of alternating pressure differences created by contraction and relaxation of resp muscles, rate of airflow and effort needed for breathing influenced by alveolar surface tension, compliace of lungs and airway resistance

inhalation or inspiration

bringing air into lungs, depends on pressure changes governed by Boyle’s law, first step in expanding lungs involves contraction of diaphragm and then also the intercostal muscles, inhalation only occurs when alveolar or intrapulmonic pressure falls below atmospheric pressure

Boyle’s law

volume of a gas varies inversely with its pressure

increase in size of cavity → decreased pressure

decrease in size of cavity → increased pressure

exhalation or expiration

occurs when alveolar pressure is higher than atmospheric pressure, relaxation of diaphragm and external intercostal muscles results in decreased lung volume which leads to increase of intrapleural pressure and alveolar pressure so that air moves out of lungs, also an inward pull of surface tension due to film of alveolar fluid