ch 6 - the respiratory system Flashcards Preview

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Flashcards in ch 6 - the respiratory system Deck (25)
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1

pathway of respiration

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

2

surfactant

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

3

visceral pleura

surface adjacent to lungs

4

parietal pleura

surface outside of visceral pleura

5

intrapleural space

space between visceral pleura and parietal pleura which is lubricated

6

spirometer

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

7

total lung capacity (TLC)

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

8

residual volume (RV)

minimum air in lungs on exhaling completely

9

vital capacity (VC)

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

10

Tidal volume (TV)

volume of air inhaled or exhaled in a normal breath

11

expiratory reserve volume (ERV)

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

12

inspiratory reserve volume (IRV)

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

13

ventilation center

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

14

chemoreceptors

in ventilation center; primarily sensitive to CO2 conc

15

hypercarbia (hypercapnia)

high CO2 in blood; causes increases in respiratory rate

16

Gas exchange pathway

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)

17

thermoregulation

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

18

lysozyme

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

19

mucociliary escalator

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

20

macrophages

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

21

IgA antibodies

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

22

mast cells

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

23

bicarbonate buffer system

CO2 (g) + H2O (l) ->

24

acidemia

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

25

alkalemia

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)