The Mechanics of Breathing

Two muscles involved.

Intercostal Muscles

Diaphragm

Two muscles involved.

Intercostal Muscles- moves the rib cage

Diaphragm- Muscle layer that separates the cavity of the (lungs) from the abdomen (stomach)

InhalationExternal intercostals contract- ribs

move up and out

Diaphragm contracts- to pull downward

(this increase the amount of space in the chest which lowers thoracic air pressure)

Air rushes in

Exhalation

Internal intercostals relax- ribs move down and in

Diaphragm relaxes- pulls upward

(this decrease the amount of space in the chest which increases thoracic air pressure)

Air rushes out

Part of BreathingVo

lum

e A

ir

6000 ml

1000 ml

Time--->

Tidal Volume - regular rate of relaxed breathing

Part of BreathingVo

lum

e A

ir

6000 ml

1000 ml

Time--->

Inspiratory reserve volume - the extra volume one can inhale beyond normal breath

Part of BreathingVo

lum

e A

ir

6000 ml

1000 ml

Time--->

Expiratory reserve volume - the extra volume that one can exhale beyond normal breath

Part of BreathingVo

lum

e A

ir

6000 ml

1000 ml

Time--->

Residual volume - the volume one can’t exhale and remains in the lungs (1 L)

Part of BreathingVo

lum

e A

ir

6000 ml

1000 ml

Time--->

Vital Capacity - Maximum working lung volume. (5 L- ave. adult male)

Male FemaleVital capacity (FVC) 4.8 L 3.7 LTidal volume (Vt) 500mL 390mLTotal lung capacity (TLC) 6.0 L 4.7 L

Who is….

Smoking male

Fit male

Female

What parts of breathing is represented by the following? a. A student sneezes b. Normal sleeping rhythm. c. A student exhales and then gets punched in the stomach and gets the wind knocked out of them. d. Nick reaches the end of a marathon with a sprint e. A student takes a breath before swimming to the bottom of a pool’s deep end. f. A patience’s lungs collapse

Required table

Tidal Volume

Inspiratory Capacity

Inspiratory Reserve Volume (B-A)

Calculated Vital Capacity

Expiratory Reserve volume D-(A+C)

A Make a breathing curve for your results and then for another student of the opposite sex around the same size as you (TO BE HANDED IN ALONG WITH DATA). B When you have completed this, answer question on page 449, # 10,11,12

A B C D E F

trial

1

2

3

Ave

Oxygen Transport

• hemoglobin (hb) • contains heme- an iron

molecule that makes blood red

• picks up to 4 molecules of oxygen at lungs

• releases oxygen in presence of high carbonic acid (CO2 at tissues)

• some carbon dioxide will bind to hb.

Carbon Dioxide Transport

20% CO2

20% CO2

20% CO2

80% CO2 + H2O H2CO3

H+ HCO3-

H+

H+

H+

• some dissolves in blood • some binds to hb • most reacts with water to form

carbonic acid -the H+ will accumulate on

hb to prevent low blood pH

Breathing Lab 1