ch 23 respiratory system video 2

contract external intercostals

lift ribs

thorax enhances anteriorly and laterally

muscles involved in normal inhalation

diaphragm

external intercostals

inhalation is an active process because it involves

muscle contraction

normal exhalation

is passive

diaphragm and external intercostals relax

diaphragm goes up, ribs go down

in exhalation

pressure in lungs decreases until it is equal with atmosphere

quiet inspiration

1. intrapulmonary pressure = atmosphereic pressure -760 mmHg- no air flow

2. diaphragm goes down, ribs go up, intrapulmonary pressure gets less than atmospheric pressure- air flows in - alveolar volume increases

at beginning of exhalation

atmospheric pressure and intrapulmonary pressure are the same

exhalation step 3

diaphragm and external intercostals relax

pressure in lungs will increase as alveolar volume decreases

exhalation step 4

intrapulmonary pressure becomes greater than atmospheric pressure

air flows out

pleural cavity volume decreases- pressure goes up to 756 mmHg

muscles in forced inhalation

sternocleidomastoid

scalenes

pectorales

serratus anterior

muscles in forced exhalation

rectus abdominis

external abdominal oblique

internal abdominal oblique

internal intercostals

less elastic lungs are

the more difficult it will be to expand

cystic fibrosis

lungs will lose elasticity

arthritis of thoracic cage, ribs or sternum

difficult to expand lungs

damage to cervical spinal cord above c2

cannot breathe on their own

nerves that signal muscles to contract for breathing are damaged

spirometry

measurement of lung volumes and capacities

tidal volume

amount of air moved in and out of lungs in a normal cycle

500 mL air in quiet inhalation and exhalation

inspiratory reserve volume

1900-3100 mL

amount of air that you can force into lungs beyond tidal volume

expiratory reserve volume

amount of air that you can forcible exhale beyond tidal volume

700-1200 mL

residual volume

volume of air remaining in lungs after forced exhalation

1100-1200 mL

capacities

combination of volumes

inspiratory capacity

max amount of air that can be put into lungs

inspiratory reserve volume + tidal volume

2400-3600 mL

functional residual capacity

expiratory reserve volume + residual volume

1800-2400 mL

vital capacity

max amount of air you can put in and out of lungs

insp reserve volume + tidal vol + exp reserve vol

3100-4800 mL

total lung capacity

insp reserve volume + tidal vol + exp reserve vol + residual vol

4200-6000 mL

partial pressure of oxygen in atmos directly related to

concentration of oxygen in atmos

atmospheric air partial pressure of oxygen

159 mmHg

atmospheric air partial pressure of carbon dioxide

0.3 mmHg

alveolar air partial pressure of oxygen

105 mmHg

alveolar air partial pressure of carbon dioxide

40 mmHg

deoxygenated blood partial pressure of oxygen

40 mmHg

deoxygenated blood partial pressure of carbon dioxide

45 mmHg

oxygenated blood partial pressure of oxygen

100 mmHg

oxygenated blood partial pressure carbon dioxide

40 mmHg

systemic tissue cells partial pressure oxygen

40 mmHg

systemic tissue cells partial pressure of carbon dioxide

45 mmHg

when blood travels to tissues the first oxygen that leaves blood to the tissues

the 1.5% in plasma

oxygen leaves hemoglobin

to plasma then to tissue cells

co2 binds to amino acid part of

hemoglobin molecule

becomes carbaminohemoglobin

hemoglobin molecules

4 polypeptide chains each with a heme group where oxygen binds to iron atoms

respiration is controlled by

nervous system

locations of areas of the respiratory center

medulla oblongata

pons

in medulla oblongata and pons there are

clusters of neurons responsible for cycle of respiration

medullary respiratory center

pre-Botzinger complex

dorsal respiratory group

ventral respiratory group

in upper portion of pons

pontine respiratory group

inhalation is faster because

it is active and muscles make process go faster

in forceful breathing

dorsal respiratory group and ventral respiratory group work

normal rate of breathing at rest

12 times per minute