Respiratory system

Respiratory system physiology  

1. Adams Apple – Voice Box
2. Trachea – muscles that control the voice
3. Right Lung
4. Left Lung
5. Cardiac Notch

Right Lung

Has 3 Lobes

1. Upper Lobe
2. Middle Lobe

Lower Lobe

Left Lung

Has 2 Lobes

1. Upper Lobe
2. Lower Lobe

1. Has cardiac notch

Cardiac Notch

Located in between Left and Right LungRibs make up the wall

Diaphram make up the floor for Heart and Lung

We call thi entire room Thorax

Lung Looks similar to a tree(upside down)

We call this entire structure Bronchial Tree

Lung is 3 dimensional

Air pathways end in Alveoli

Alveoli transfers oxygen into the blood and takes carbon di oxide(come from cell wastes) from the blood

Inhaling

1. Lung Volume Increases
2. Pressure Decreases (757 mmHg) – Negative Pressure Comparing to the atmosphere and the initial pressure inside Lung 760 —> 757
3. Air Molecules Starts to move in
4. Pressure Increases (760 mmHg)
5. Chemical Energy – ATP
6. Muscles Contract
7. Alveoli Stretched Open

Exhaling

1. Lung Volume Decreases
2. Pressure Increases 763 mmHg – Positive Pressure Comparing to the atmosphere
3. Air Molecules Move out
4. Pressure Decreases (760 mmHg)
5. Elastic Potential Energy
6. Muscles Relax
7. Alveoli recoil

Central Bone is called Breast Bone or Sternum

All the ribs on both sides attached to the sternum

Seven Pairs of Ribs

Inter costal Muscle – Muscle available between ribs and lungs

Ribs – Costal

Diaphragm moves up downUp – Curve

Down – Flat

Alveoli expands and contracts

500 million alveoliAlveoli has proteins. This protein is called elastin

Concentration C of Oxygen in Surface Water = 0.27 milli moles/ litre

Henry’s Law = P/C = Kh

P = Pressure

C = Concentration

Kh = constant

Kh = 769 Litre * atmospheres/ moles

Concentration C of CO2 in Surface Water = 7.24 milli moles/litre

Henry’s Law = P/C = Kh

Kh = 29 Litre times the atmospheres/ moles

P is same for both O2 and CO2

Henry’s law states that 21% oxygen, carbon di oxide goes to the water but whats leaving from the water is different for oxygen and carbon di oxide

Carbon Di Oxide is very comfortable with the water than the oxygen

769/29

Carbon Di Oxide is 26 times more soluble than Oxygen in Room Temperature (25 Degree Celsius)

in Lungs we have 37 Degree Celcius

Kh value is temperature dependentin 37 Degree Celcius CO2 is 22 times more soluble than oxygen

William Henry’s Law

P(in)/Kh(out) = Concentration of molecules in the surface layer

P = Kh * Concentration

P = Partial Pressure

in = molecules going  into

out = molecules going outKh depends on Solute, Solvent, Temperature

Total Pressure = 1 Atmosphere = 760 millimeters of Hg

When partial pressure increases for a type of a molecule(ex. oxygen) it is suppose move to liquid from gas

Kh tells you the likelihood of going out of the liquid

Partial Pressure tells you the likelihood of going into the liquid

Adolf Fick’s Law of Diffusion

Rate of Particles Moving(V.) = Amount(Moles), Volume = ((P1 Pressure on the first side – P2 Pressure on the second side) * A(Surface Area) * D (Diffusion Constant))/(T) Thickness of the Wall

Delta P = P1 – P2

Rate of Particles Moving (V.)/ Surface Area(A) = ((P1 – P2)/T) *  D

Flux = Gradient * Diffusion Constant

Flux = Rate Of Particles Moving (V.)/ Surface Area(A)

Gradient = (P1 -P2)/T

Flux = Net Rate of Particles Moving Through an Area

Gradient = Change in Pressure over a distancePressure = Particles in a volume

Graham’s Law

Kinetic Energy

(1/2) Mass for oxygen  * Velocity of oxygen Square = (1/2) Mass for CO2 * Velocity of C02 Square

Mass = Molecular Wight

V = Diffusion Rate

(MW1) * (Rate1) Square = (MW2) * (Rate2) Square

(Rate1/Rate2) = Square Root of (MW2/MW1)

Rate is proportional to the Square Root of Molecular Weight

Carbon Molecular Weight = 12.0107 u

Oxygen Molecular Weight = 15.999 u

CO2 = 44.01

Oxygen movement from alveoli to capillaries  

Journey of Oxygen Molecule

Alveolus contains

1. Layer of Fluid
2. Epithelial Cells
3. Basement Membrane

Capillary Consists of

1. Basement Membrane
2. Endothelial Cell
3. Plasma
4. Hemoglobin
5. Red Blood Cell (RBC)

Connective Tissue

Blood Red CellsHemoglobin

pO2 = IN – OUT

pO2 = FiO2(Patm – Ph20) – pCO2/RQ

V = ((P1 – P2) * Area * D)/Thickness,

Where

V = Amount of O2 diffusing overtime

P1 = pO2 = Pressure in Alvelous (in Gas State)P2 – Pressure in Red Blood Cell

Alveolar Gas Equation

Atmospheric Pressure at Sea Level is

P atm = 760 mmHg

FiO2 = Fraction of Inspired Oxygen = 21%

Partial Pressure of Oxygen = 0.21 * 760 millimeters of Mercury = 160 mmHg

Body Temperature = 37 Degree Celcius

Vapor Pressure is going to change depending on the temperature

For 37 Degree Celcius Vapor Pressure is = 47 mmHg

When you boil water Vapor Pressure will be 760 mmHg

Initially Lung Pressure will be same as that of atmospheric pressure i.e 760 mmHg

Now water(H20) is going to take 47 mmHg so the rest of the gas will be 713 mmHg

O2 = 21% of 713mmHg

N2 = 78% of 713mmHG

Nitrogen =

What will be the partial pressure of air entering alveolar sac?

PO2 = FiO2(P atm – P H20) = 21%*(760 – 47) = 150 mmHg

Partial Pressure of Oxygen PO2 = 150 mmHg

PH20 is due to the water vapor that we get in lungs

PO2 = IN – OUT

PaO2 = Alveolar

PaCO2 = 40Respiratory Quotient => RQ=> RelationShip between Oxygen and Carbon Di Oxide

PaCO2/0.8 = 40/0.8 = 50 mmHg of O2

Pa02 = IN – OUT

PO2 = FiO2(P atm – P H20) = 21%*(760 – 47) = 150 mmHgPaO2 = 100 mmHg  = 150 – 50

Cooperativity – O2 in Blood Vessel

1. HBO2  – Hemoglobin Oxygen – OxyHemoGlobin – Majority of Oxygen

2. Dissolved into Plasma – Minority of OxygenCellular Respiration always happens

CO2 Diffuses in blood vessel too

Respiratory Center is located below the brain

– Makes Decisions and executed based on the information it receives

Cells – Central Chemo Receptors

– Gathers information about Co2 levels, Ph levels

– Dont gather information about O2 levels

Cells – Peripheral Chemo Receptors

Detects O2, CO2, PH Levels

Sends information through neurons

– Aortic Body – CN10 – Cranial Nerve 10

Connects to brain through vagus nerve

– Carotid Body – CN9 – Cranial Nerve 9Connects to brain through glossopharyngeal nerve

Mechanoreceptors

Available at

Nose – Cranial Nerve 5 – CN5 – Trigeminal Nerve – inhaling a pollen would trigger

Lungs – CN10 – Smoke could trigger

GI – CN10 – Distention could trigger

Baroreceptors are one type of mechanoreceptors – found inside blood vesselsDetects information about pressure

Hypothalamus

Anxiety, Pain, Fear

Voluntary Control of breathingCerebrum – is responsible for all the voluntary stuff that we do (Ex. singing, yelling,

screaming)

Spinal Column4 Muscle groups are going to control the resipiratory center

Thermoregulation in the lungs

Inhale – 70 F

Exhale – 98 F

Not to overheat the lungs

Ex. Dogs Panting – expels heat during every breath