Physiology Of Respiratory System

Front 1

define respiration:

Back 1

-the exchange of gases between a living organism and it environment.

Front 2

define ventilation:

Back 2

-the mechanical process of moving air into and out of the lungs

Front 3

when does the respiratory cycle begin:

Back 3

-when the lungs have achieved a normal expiratioin and the pressure inside the thoracic cavity equals the atmospheric pressure.

Front 4

what comes next:

Back 4

-the phrenic nerve communicates to the diaphram signaling it to contract.

Front 5

what happens next:

Back 5

-as thorax increases in size, the pressure within the thorax decreases. this negative pressure invite air into the thorax via airway.

Front 6

because these 2 pleura remain in contact this happens:

Back 6

-the perietal and the visceral pleura surround the the lungs giving it the elasticity.
-the lungs immediately assume the thoracic cavities internal contour.

Front 7

as the lungs assume the internal contour this also happens:

Back 7

-the alveoli inflate with the lungs. as they expand they become thinner allowing oxygen and CO2 to diffuse accross membranes.

Front 8

When thoracic pressure reaches that of the atmosphere this happens:

Back 8

-pulmonary expansion stimulates receptors in the bronchi via vagus nerve to inhibit inspiration.

Front 9

what happens next:

Back 9

-respiratory muscles relax which decreases size of chest and increases the intrathoracic pressure.

Front 10

itrathoracic pressure is achieved by:

Back 10

elastic lungs recoiling which forces air out through the airway until pressure is once again equal.

Front 11

Pulmonary circulation:
step 1

Back 11

-deoxygenated blood delivered via venous system to RIGHT side of heart