B5 The Respiratory System Review

Question 1

What are the stages in respiration?

Answer 1

1. Breathing: involves inhalation and exhalation
2. External respiration
3. Internal respiration
4. Cellular respiration

Question 2

What is external respiration?

Answer 2

-Exchange of oxygen and carbon dioxide between the air and the blood

Question 3

What is internal respiration?

Answer 3

-Exchange of oxygen and carbon dioxide between the body tissues and blood

Question 4

What is cellular respiration?

Answer 4

-Series of energy releasing chemical reactions in the cells
-produces energy (ATP) for all cellular activities

Question 5

Describe nasal passages

Answer 5

-Warms, moistens, and cleans incoming air
-cilia moves foreign particles into the nose and throat to be coughed or sneezed out
-mucous cleans air by trapping foreign particles

Question 6

What is the pharynx?

Answer 6

-Air filled channel in the mouth
-2 openings branch into the esophagus (stomach) and the trachea (lungs)

Question 7

Describe the larynx

Answer 7

-Voice box
-composed of 2 thin sheets of elastic ligaments called vocal cords
-vocal cords vibrate as air is forced from the lungs towards the pharynx
-different sounds are caused by a change in vocal cord tension

Question 8

Describe the trachea

Answer 8

-Windpipe
-contain ciliated cells which produce mucous
-the mucous traps debris
-cilia sweep the debris from the windpipe
-the wall is supported by cartilage rings which keep the trachea open

Question 9

Bronchi (bronchus singular)

Answer 9

-Contain cartilage rings
-bronchioles are smaller airway branches that don’t contain cartilaginous rings ~60 000

Question 10

Describe Alveoli (alveolus singular)

Answer 10

-Tiny blind ended sacs ~300 million
-each alveolus is surrounded by capillaries
-gases diffuse between air and blood according to the concentration gradient (passive transport)
-single layer of cells permit rapid fade exchange
-during inhalation the alveoli are bulb shaped but during exhalation the sacs collapse
-to avoid sticking together there is a film of lipoprotein (non stick)
-allows alveoli to pop during inhalation

Question 11

What is respiratory distress syndrome?

Answer 11

-Some new born babies do not produce enough lipoprotein

Question 12

What is the pleural membrane?

Answer 12

-Lines the inner wall of the thoracic (chest) cavity
-filled with fluids that reduce friction between the lungs and the thoracic cavity

Question 13

What is the diaphragm?

Answer 13

-A sheet of muscle that separates the organs of the thoracic cavity from those of the abdominal cavity

Question 14

Where are intercostal muscles located?

Answer 14

-Found between the ribs and along the inside surface of the ribs

Question 15

Describe inhalation

Answer 15

-Inspiration: breathing in
-begins when the external rib muscles and the diaphragm contract
-rib cage expands up and outward
-diaphragm flattens (down)
-increase in volume therefore the air pressure in the thoracic cavity decreases
-air moves with its pressure gradient (high to low pressure) from the environment to the lungs

Question 16

Describe exhalation

Answer 16

-Expiration: breathing out
-begins when the diaphragm and the rib muscles relax
-reduces the volume of thoracic cavity
-lung volume decreases and air pressure increases
-air moves from lungs to environment

Question 17

What is a Spirograph?

Answer 17

-Represents the amount of air that moves into and out of the lungs with each breath

Question 18

What is tidal volume?

Answer 18

-Volume of air that is inhaled and exhaled in a normal breath
-average is 500 mL

Question 19

What is inspiratory reserve volume?

Answer 19

-Additional volume of air that can be taken into the lungs beyond tidal inhalation
-average is 3000 mL

Question 20

What is expiratory reserve volume?

Answer 20

-Additional volume of air that can be forced out the lungs beyond tidal volume
-average is 1200 mL

Question 21

What is vital capacity?

Answer 21

-Total volume of gas that can be taken into and forced out the lungs
-average is 3000-5000 mL
-vital capacity = tidal volume + inspiratory reserve volume + expiratory reserve volume

Question 22

What is residual volume?

Answer 22

-Amount of gas that remains in the lungs and respiratory system passageways even after full exhalation
-necessary so the lungs don’t collapse

Question 23

What is Dalton’s law of partial pressure?

Answer 23

-Each gas in a mixture exerts it’s own pressure, which is proportional to the total value
-gases diffuse from an area of high partial pressure to areas of low partial pressure

Question 24

What are external respirations?

Answer 24

-Gases exchanged between the alveoli and the blood in capillaries

Question 25

What is inspiratory respiration?

Answer 25

-Occurs when oxygen and carbon dioxide are exchanged in the tissues

Question 26

How is oxygen transported in the blood?

Answer 26

1. By hemoglobin (99%)
2. Dissolved in the blood

Question 27

How is carbon dioxide transported in the blood?

Answer 27

1. By hemoglobin (23%)
2. Carried in plasma (7%)
3. Dissolved in the blood as a bicarbonate ion (70%)

Question 28

How does carbon dioxide get dissolved in the blood as a bicarbonate ion?

Answer 28

-Carbon dioxide combines with water to from carbonic acid
-carbonic acid breaks down and dissociates into a hydrogen ion and a bicarbonate ion (occurs in RBC)
-the hydrogen combines with hemoglobin
-the bicarbonate ion diffuses into the plasma

Question 29

What are chemoreceptors?

Answer 29

-Specialized nerve receptors that are sensitive to specific chemicals
-2 are involved: oxygen chemoreceptors and carbon dioxide or acid chemoreceptors
-carbon dioxide are the most sensitive and the main regulators

Question 30

Describe carbon dioxide chemoreceptors

Answer 30

-CO2 dissolves in the blood and forms an acid (carbonic acid)
-once CO2 accumulates the chemoreceptors are activated
-the medulla oblongata is then activated and relays messages to the diaphragm and ribs to begin breathing movements
-CO2 levels decrease and chemoreceptors are deactivated

Question 31

Describe oxygen chemoreceptors

Answer 31

-Found in the carotid and aortic arteries
-detect low levels of O2
-work the same as CO2 receptors
-O2 levels increase with increases ventilation (breathing)

Question 32

What is the medulla oblongata?

Answer 32

-Part of the brain stem, located at the base of the brain
-plays a crucial role in controlling vital functions such as heart rate, blood pressure, breathing and swallowing