physiology of the respiratory system

Question 1

What is Physiology?

Answer 1

A science that deals with the ways that living things function.

Question 2

What is pressure?

Answer 2

Force exerted over an area

Question 3

Elements of pressure

Answer 3

Air is springy. It has inherent elasticity, very suitable for compression and expansion. In a container, air molecules tend to bounce around at random, colliding into the walls of the container The force of these collisions is a function of the number of molecules inside the container. This force is Pressure. Pressure is Force exerted on an Area → P=F/A Example: the air pressure in your car’s tires is about 32 pounds/in2 (PSI)

Question 4

Different Types of Pressure

Answer 4

Atmospheric air pressure Negative air pressure Positive air pressure Intrapleural pressure Intrapulmonary pressure -

Question 5

Atmospheric air pressure

Answer 5

760 mm Hg (at sea level)

Question 6

Negative air pressure

Answer 6

LESS than 760 mm Hg

Question 7

Positive air pressure

Answer 7

MORE than 760 mm Hg

Question 8

Intrapleural pressure

Answer 8

pressure within the pleural “balloon” which surrounds the lung

Question 9

Intrapulmonary pressure

Answer 9

pressure within the alveoli (tiny sacs) of the lung itself

Question 10

Boyle’s Law equation

Answer 10

An equation to explain the relationship between pressure and volume P * V = K, where: P = pressure V = volume K is a constant (a fixed value), at a given temperature. Pressure and volume are inversely related

Question 11

Boyle’s Law Breathing Out

Answer 11

If the volume of the lung is decreased…. The pressure increases…. The pressure in the lung is higher than atmosphere….

Question 12

Boyle’s Law Breathing In

Answer 12

If the volume of the lung is increased…. The pressure decreases… The pressure in the lung is lower than atmosphere….

Question 13

Lung-Thorax Interface

Answer 13

Lungs have natural tendency to collapse and shrink What would this do to lung volume? At resting state, thorax has natural tendency to expand At resting state, the lung and thorax tissue exert a recoil force So, what keeps them together?

Question 14

What keeps the thorax tissue and lungs together?

Answer 14

Pleural Linkage

Question 15

Three essential components of Pleural Linkage

Answer 15

Pleural Linings Intra-Pleural Space Intra-Pleural Fluid

Question 16

Pleural membrane “sandwich” consists of…

Answer 16

composed of the visceral pleura and parietal pleura. Intrapleural fluid helps establish linkage between these two membranes. Pressure within the intra-pleural space is negative

Question 17

Why is the pressure within the intra-pleural space negative?

Answer 17

Remember, in the separate state: Lung tissue shrinks Rib cage will expand So…. when lungs and ribs are joined… one tissue is trying to pull away from the other, producing suction within the intra-pleural space.

Question 18

What is the importance of pleural linkage?

Answer 18

Ribs are acted upon by muscles of respiration Due to pleural linkage, wherever the ribs (and diaphragm) go, the lungs will go too With “bucket and pump” handle maneuvers and movement of the diaphragm, lung volume is altered

Question 19

sequence of events (expiration)

Answer 19

Question 20

changes in anterior-posteroir and superior-inferior dimensions (expiration)

Answer 20

Question 21

changes in lateral dimensions (expiration)

Answer 21

Question 22

sequence of events (inspiration)

Answer 22

Question 23

changes in anterior and superior dimensions (inspiration)

Answer 23

Question 24

changes in lateral dimensios (inspiration)

Answer 24