Class two

Question 1

Henrys Law

Answer 1

Gases diffuse (move) from high pressure areas to low pressure areas.

Often called a pressure gradient

Pressure gradient is a force (p) that acts in a direction from higher toward lower pressure.

Question 2

How does oxygen get into the blood stream?

Answer 2

Inhale

Pressure of oxygen in alveoli is greater than pressure, the pressure of the oxygen in the blood entering pulmonary capillaries

Oxygen leaves the alveoli and enters the blood stream to be circulated and supply tissues with oxygen

Question 3

How carbon dioxide leaves the blood stream?

Answer 3

Pressure of carbon dioxide in blood stream is greater than the pressure of carbon dioxide in the alveoli

So, carbon dioxide enters the alveoli, and we exhale

Question 4

Effect of smoking on lungs:

Answer 4

Smoking introduces particulate carbon (from pollution and tobacco) into the lungs
● Macrophages in the lungs engulf these particles but they cannot be broken down leading to black spots in the lung tissue.
● Loss of elasticity and lung volume which usually enables them to inflate efficiently

Question 5

Gases exchange:

Answer 5

refers to the movement of oxygen into the blood and carbon dioxide out of the blood.

Question 6

Components of the Pleural linkage

Answer 6

Pleura
Visceral pleura
Parietal pleura
Interpleural space

Question 7

Pleura

Answer 7

single celled membrane

small amount of fluid produced by pleura Creates smooth surface for lungs to expand and get smaller within the ribcage

Question 8

Visceral pleura

Answer 8

encloses lungs

Question 9

Parietal pleura

Answer 9

lines inside of chest wall (rib cage)

Question 10

Interpleural space

Answer 10

• Between the parietal and visceral pleura ,contains a small amount of fluid which helps lungs move smoothly within the chest during breathing

Question 11

Negative pressure

Answer 11

Pleural membranes constantly absorb the fluid and gases that exist in the space between them.

This constant absorption causes negative pressure

Because of the negative pressure, visceral and parietal pleura are sucked together

Maybe referred to as “pleural cavity pressure” – always negative

Question 12

Pleural linkage

Answer 12

Forces both lungs and ribcage away from their normal rest positions .. Definition: The connection between the lungs and the chest wall, maintained by negative pressure in the pleural space.
● Function: This linkage forces the lungs to expand and the ribcage to contract, allowing for breathing.

Question 13

Lungs-Thorax Unit

Answer 13

Lungs are naturally in a collapsed state – will recoil to 1/3 of their size when thorax is opened

Thorax is naturally expanded

Question 14

Resting Expiratory level

Answer 14

The point in the respiratory system where the opposing forces of the lungs and thorax are in balance

Balance point to which we always return after a quiet exhalation

moving above or below this determines how much and what type of muscle effort is required

This is because of the Pleural linkage.

Muscle activity is needed to breathe in but not out.

Question 15

Pleurisy

Answer 15

Inflammation of visceral and parietal pleura
inflammation of the pleura

The condition can make breathing extremely painful.

Sometimes it is associated with another condition called pleural effusion, where excess fluid fills the area between the membrane’s layers.

Question 16

Pneumothorax -

Answer 16

Collapsed lung

Loss of negative pressure due to surgical or accidental punctures (negative pressure keeps this structure together, anything that disrupts the pleural linkage will do this)

Lung can move away from inside of ribcage

The air enters to the pleural space and cannot escape, then the intra-pleural pressure increases, and the lung becomes collapsed.

Question 17

Diaphragm Peak inspiration -

Answer 17

Diaphragm contracts and flattens

Question 18

Diaphragm Peak expiration

Answer 18

Diaphragm relaxes

Question 19

Diaphragmatic movement

Answer 19

Descent of the diaphragm accounts for half or more of the resting inspired volume

diaphragm can move as much as 10 cm.

Designed for mechanical efficiency

Question 20

Action of External Intercostals

Answer 20

Raise the ribs for inspiration in quiet breathing or maximal respiration

Summary: contract for inspirtation

Question 21

Internal Intercostal Muscles

Answer 21

Between ribs

Move diagonally inward

Diagonal muscles are longer – can become shorter on contraction and do more work

Summary: contract for forced expiration

Question 22

Muscular Action in quiet expiration

Answer 22

None – all muscles relax

Question 23

Passive and Active Forces in Respiratory Function

Answer 23

Passive forces – no muscle activity – determined by physiological structure

Active forces – muscles are active