Respiratory Physiology

4 Parts of Respiration• Pulmonary ventilation- air moving

into and out of lungs• External respiration- gas exchange;

blood - alveoli• Respiratory gas transport- transport

of gases via bloodstream• Internal respiration- gas exchange;

blood - cells

3D view of moving diaphragmhttps://www.youtube.com/watch?v=hp-gCvW8PRY

Respiratory Capacities• tidal volume- normal quiet breathing, ~500 ml of air (1

pint) into and out of lungs/breath• inspiratory reserve volume - more air can be forcibly

inhaled than during normal breathing ~2100 — 3200 ml (a 2-3 Liter bottle of soda)

• expiratory reserve volume- more air can be forcibly exhaled than during normal breathing ~1700 ml

• residual volume -after forcible exhalation about 1200 ml of air remains in lungs and cannot be voluntarily exhaled = (1 liter bottle of soda)

• vital capacity total amount of exchangeable air

Spirometers…slightly better than ours

Gas Exchange• Occurs across the alveolar capillary membrane• Alveoli– Thin flaps of tissue that are inflated by air– Have holes so air can fill sac if bronchioles are clogged– Produce surfactant– Lined with “dust cells” white blood cells to prevent illness

Oxygen Transport in Blood

• Accomplished via blood– RBC carry O2 on hemoglobin– Plasma (liquid part of blood) has O2 dissolved in it

• Works because the likes O2 high affinity

• But CO has a higher affinity

https://www.youtube.com/watch?v=5LjLFrmKTSA

https://www.youtube.com/watch?v=XTMYSGXhJ4E

If…• Oxygen level are low in the blood hypoxic• Low O2 can lead to a person becoming

cyanotic which causes necrosis

CO2 in blood…• When CO2 enters blood RBC

join…

• Carbonic acid is unstable and breaks into H+ & HCO3-

HCO3- is a GREAT buffer… but if too much H+ accumulates…

CO2 in blood…

Oxygen transport in bloodhttps://www.youtube.com/watch?v=5LjLFrmKTSA

http://www.youtube.com/watch?v=d-f3RL0KiUg

Page 454 in text book

Neural Regulation of Breathing

• Rhythm is set by the pons and medulla (parts of the brainstem)– Pons- assists medulla by

sending sensory input to the medulla– Medulla- sets basic rhythm 12-18

breaths/min; sends message to diaphragm & intercostals to contract via the phrenic nerve (hiccups)

• Eupnea- normal breathing (phrenic nerve)

• Hyperpnea- deeper, more vigorous breathing (exercise)

Your Medulla + Alcohol = • Alcohol is a depressant• Alcohol inhibits the medulla’s function • Too much inhibits your reflexes…

no gag or cough reflex… don’t drink when passed out!!!

https://www.youtube.com/watch?v=7Wbq2tWomSk

Other factors that influence Respiratory Rate

1. Physical factors Temp, talking, coughing, sneezing, hiccupping,

exercising2. Conscious Control

Singing, swimming underwater, swallowing3. Emotional Factors

Sad crying, fear, anxiousness4. Chemical Factors

Many but most important is CO2 concentration

Regulation of Breathing in Controlled Chemoreceptors

• Chemoreceptors sense a chemical change in blood composition– Inc. or dec. of H+ in blood

• When an inc. of H+ is detected medulla to breathes more

• When a dec. of H+ is detected medulla breathes less

Spirometer Lab Data

Class Averages

Class Males Females Athletes Non Horn

Players Non

Tidal 910 1180 820 970 835 1150 890

ERV 2080 2670 2010 2370 1950 3050 2120

IRV 1570 1860 1420 1700 1380 1200 1700

Respiratory Capacities• tidal volume- normal quiet breathing, ~500 ml of air

(1 pint) into and out of lungs/breath• inspiratory reserve volume - more air can be

forcibly inhaled than during normal breathing ~2100 — 3200 ml (a 2-3 Liter bottle of soda)

• expiratory reserve volume- more air can be forcibly exhaled than during normal breathing ~1700 ml

• residual volume -after forcible exhalation about 1200 ml of air remains in lungs and cannot be voluntarily exhaled = (1 liter bottle of soda)