Chapter 6- The Respiratory System Flashcards
hypoxia
deficiency in amount of oxygen reaching the tissues due to low oxygen concentration in blood.
location of lungs
thorasic cavity, structure specially designed to perform breathing.
vibrissae
nasal hairs
nasal hairs
vibrissae
pharynx
behind nasal cavity at back of mouth. common pathway for both air and food
larynx
below pharynx. only pathway for air. contains two vocal cords
epiglottis
opening of larynx (glottis) is covered by this to keep food away from this pathway.
where does air go after larynx?
passes into cartilaginous trachea and into one of two mainstream bronchi (both contain ciliated epithelial cells to catch material that has made it past the mucous membranes in the nose and mouth)
anatomy of lungs
bronchi divide into smaller bronchioles which divide into small balloon-like structures at the end where gas exchange occurs called alveoli. each alveolus is coated with surfactant (detergent that lowers surface tension and prevents the alveolus to carry O and CO2)
why is left lung smaller than right?
heart is near the left lung
pleurae, visceral pleura, and parietal pleura
surround each lung and form a closed sac against which the lung expands. visceral (directly touches lung during expansion), parietal (outer layer touching chest wall). space in between the two is called intrapleural space which has a thin layer of fluid
Diaphragm
Skeletal muscle that generates negative pressure to allow lung expansion. divides thoracic cavity from abdominal cavity. under somatic control, even tho breathing is under autonomic control. contracts during inhalation and relaxes during exhalation.
what drives air into the lungs?
pressure differentials between lungs and intrapleural space
inhalation
active process using both diaphragm and external intercostal muscles (one layer of muscles between the ribs) to expand thoracic cavity. deep breath in = more volume so less intrapleural pressure
negative-pressure breathing
pressure inside lungs decreases due to increased volume so its pressure is less than the environment which means that the air will be sucked into the lower pressure lungs.
exhalation
not an active process. relaxation of external intercostal muscles. chest cavity decreases in volume so pressure is increased and air goes out to lower pressure air.
spirometer
assess lung capacities and volumes
total lung capacity (TLC)
maximum volume of air in the lungs when one inhales completely. 6-7 liters
residual volume (RV)
minimum volume of air in lungs when one exhales completely.
vital capacity (VC)
difference between minimum and maximum volume of air in the lungs (TLC-RV)
tidal volume (TV)
volume of air inhaled or exhaled in a normal breath
expiratory reserve volume (ERV)
volume of additional air that can be forcibly exhaled after a normal exhalation
inspiratory reserve volume (IRV)
volume of additional air that can be forcibly inhaled after a normal inhalation
ventilation center
located in the medulla oblongata. regulates breathing. neurons here contain chemoreceptors that are CO2 sensitive. as CO2 in blood increases then repiratory rate will increase so CO2 levels will fall with increased exhalation.
hypercarbia/ hypercapnia
CO2 level in blood rising
what surround the alveolus?
a network of capillaries which bring deoxygenated blood from the pulmonary arteries
pulmonary arteries
originate from the right ventricle of the heart then oxygenated blood returns to the left atrium of the heart via pulmonary veins.
pulmonary capillaries
O2 in alveoli flows down its partial pressure gradient from alveoli into these. O2 will bind to hemoglobin for transport here.
vascularization
developing more blood vessels
thermoregulation and the respiratory system
vasodilation and vasoconstriction. due to large surface area over which alveoli and capillaries interact.
lines of defense for lungs
- nasal cavity with small hairs to trap particulate matter
- nasal cavity contains enzyme: lysozyme- attacks peptidoglycan walls of gram-positive bacteria
- internal airways lined up with mucus/ mucociliary escalator (mucous catches germs then it will either be spit out or swallowed)
- alveoli contain immune cells (macrophages)
- mast cells in lungs- performed antibodies release imflammatory chemicals to promote an immune response. (can be cause of some allergies)
bicarbonate buffer system
in blood. body wants to maintain pH between 7.35 and 7.45. lower pH= acidemia (result is to increase respiratory rate), higher ph= alkalemia (result is to decrease respiratory rate)
bicarbonate buffer system equation
(more basic) CO2 +H2O H2CO3 H+ + HCO3- (more acidic)
