ch 6 - the respiratory system

Question 1

pathway of respiration

Answer 1

air enters nares, down nasal cavity, filtered by mucous membranes and nasal hairs (called vibrissae); into pharynx (behind the nasal cavity at back of mouth) and then larynx (under pharynx and is only for air), into the glottis (the opening of the larynx) which is covered by epiglottis (to keep food from entering lungs), past the vocal chords, into trachea, then into one of the two mainstem bronchi (bronchi and larynx have ciliated epithelial cells to further filter), then down into the lungs where bronchi are further divided into bronchioles, then into alveoli which are covered with surfactant

Question 2

surfactant

Answer 2

covers alveoli - a detergent that lowers surface tension and prevents alveolus from collapsing on itself; branching allows for surface area of about 100 m^2

Question 3

visceral pleura

Answer 3

surface adjacent to lungs

Question 4

parietal pleura

Answer 4

surface outside of visceral pleura

Question 5

intrapleural space

Answer 5

space between visceral pleura and parietal pleura which is lubricated

Question 6

spirometer

Answer 6

instrument used to measure lung capacities and volumes; cannot measure residual volume

Question 7

total lung capacity (TLC)

Answer 7

max volume which is usually around 6 to 7 Ls, residual

Question 8

residual volume (RV)

Answer 8

minimum air in lungs on exhaling completely

Question 9

vital capacity (VC)

Answer 9

difference bt the minimum and max volume of air in lungs (TLC-RV)

Question 10

Tidal volume (TV)

Answer 10

volume of air inhaled or exhaled in a normal breath

Question 11

expiratory reserve volume (ERV)

Answer 11

volume of additional air that can be forcibly exhaled after a normal exhalation

Question 12

inspiratory reserve volume (IRV)

Answer 12

volume of additional air that can be forcibly inhaled after a normal inhalation

Question 13

ventilation center

Answer 13

collection of neurons in medulla oblongata which is primary regulation of ventilation

Question 14

chemoreceptors

Answer 14

in ventilation center; primarily sensitive to CO2 conc

Question 15

hypercarbia (hypercapnia)

Answer 15

high CO2 in blood; causes increases in respiratory rate

Question 16

Gas exchange pathway

Answer 16

alveoli are surrounded by capillaries which bring deoxygenated blood from the pulmonary arteries (from the R ventricle of the heart). oxygenated blood returns to L ventricle through pulmonary veins; low partial pressure of O2 and high partial pressure of CO2 facilitate movement down pressure gradients (no energy is required for gas transfer)

Question 17

thermoregulation

Answer 17

vasodilation causes cooling, vasoconstriction causes heat preservation primarily in capillaries in respiratory system. Also capillaries in the skin and sweat glands, shivering, evaporation of water in mucous secretions

Question 18

lysozyme

Answer 18

enzyme in nasal cavity and tears and saliva. able to attack the peptidoglycan walls of gram-positive bacteria

Question 19

mucociliary escalator

Answer 19

cilia in mucus which lines respiratory pathway move particulate up the pathway that can be expelled or swallowed

Question 20

macrophages

Answer 20

immune cell in lungs and alveoli which engulf and digest pathogens and signal that there is an invader

Question 21

IgA antibodies

Answer 21

contained in mucosal surfaces of respiratory pathway to help protect against pathogens that contact mucus membranes

Question 22

mast cells

Answer 22

in lungs, have preformed antibodies which, when bound to correct substance, mast cell releases inflammatory chemicals into surrounding to promote an immune response (also involved in allergic reaction

Question 23

bicarbonate buffer system

Answer 23

CO2 (g) + H2O (l) ->

Question 24

acidemia

Answer 24

physiological pH is about 7.4 (range is 7.35-7.45). if H+ conc is increased, CO2 is increased (movement to left) and then acid-sensing chemoreceptors send signals to brain to increase respir rate which produces more CO2 (which is the shifting of the equilibrium to left). Then more CO2 is blown off with increased respir rate which still moves the equation to the left which allows the H+ conc to drop back to normal

Question 25

alkalemia

Answer 25

blood pH is too basic; slowing of respir rate will retain CO2 moving the equilibrium to the r which will produce more H+ (note (HCO-)3 is weak base; H+ is strong acid)