Chapter 17 & 18 respiratory system

Question 1

What are the four functions of the respiratory system? Describe each.

Answer 1

1. Gas exhcange:
   a. To take in oxygen and eliminate carbon dioxide.
   b. takes oxygen from atmosphere to lungs to blood to tissues then goes back the opposite direction during carbon dioxide pathway.
2. Regulation of blood pH
   a. CO2 can serve as a buffer and H+
3. Vocalization:
   a. air moves across vocal cords and causes vibrations
4. Protection
   a. epithelium-cells lining the respiratory tract are for protection agaisnt dust, pathogens and chemicals

Question 2

What is a conducting zone? What is a respiratory zone? Give* an example of each*.

Answer 2

1. Conducting zone: brings air into lungs
   a. nasal cavity brings air into terminal branchioles
2. Respiratory zone: are sites of gas exchange
   a. respiratory bronchioles to alveolar sacs

Question 3

What do the conduction zones do to air as it passes? What happens as air passes outward over vocal focals?

Answer 3

1. It conditions air by:
   a. Warming air to 37 degrees C
   b. Humidifies
   c. Filteres and cleans the air
2. Voice or speech is produced

Question 4

What is a characteristic of the respiratory zone? What are the two types of alveolar cells? What is their purpose?

Answer 4

1. They are typoically moist filled sacs
2. There are:
   a. Type I alveolar cells which are the site of gas exchange due to their thin simple squamous epithelieum
   b. Type II alveolar cells reabsorb excess fluid and secrete a surfactant which helps reduce surface tension

Question 5

What is surfactant composed of? When is it produced? What risk do premature babies face?

Answer 5

1. It is a mixture of protein and phosopholipids
2. Production begins in late fetal life
3. Premature risk respiratory distress sydndrome as inadequate surfactant may lead to collapsed alveoli

Question 6

What is ventilation? What is perfusion? What relationship do they have?

Answer 6

1. Ventilation: is the movement of air betwen atmosphere and lungs
2. Perfusion: is the blood flow through vessels
3. They are both equally matched to maximize gas exchange

Question 7

What happens when the ventilation/perfusion relationship is mismatched? What mechanisms take place to keep the ventilation perfusion relationship matched?

Answer 7

1. If ventilation decreases in an alveoli group, Co2 will increase where o2 will decrease. Blood flowing past these alveoli will not get oxygenated
2. If tissue has low O2 and the surrounding alveoli in an alveoli group is underdeveloped, the arteriole or tissue will constrict and divert blood to the better ventillated alveoli

Question 8

What does normal alveolar ventilation look like? What about asthma? What about pulmonary edema? Fibrotic lung disease? Or emphysema?

Answer 8

1. Normal alveolar ventilation: there is an adequate supply of O2 in the alveoli. Deoxygenated blood in arteriole becomes oxygenated by alveoli.
2. Asthma: Airway resistance increases which constricts bronchioles. Alveoli have a low supply of oxygen and are unable to supply deoxygenated blood with oxygen.
3. Pulmonary edema: Fluid in the interstitial space increases which also increases the distance for diffusion of oxygen between the alveoli and arteriole. Oxygen levels in the alveoli are adequate but the increased distance lowers the amount of oxygen available to the arterioles.
4. Fibrotic lung diease: The wall of the alveolar membrane thickens which decreases ventilation.
5. Emphysema occurs when air sacs are destroyed by rupturing or meging into one air sac which decreases surface area for gas exchange. This decreases ventilation

Question 9

What is respiation? What is the respiratory cycle? What is respiration rate? What is ventilation? what are the two types of ventilation?

Answer 9

1. Respiration: exchange of O2 and CO2 between atmosphere and body cells
2. Respiratory cycle: breathing in and out
3. Respiration rate: the amount of breaths per minute
4. Ventilation: breathing
   a. Inspiration: breathing in
   b. Experation: breathing out

Question 10

What is the pathway of respiration?

Answer 10

1. Exhcange 1: O2 is exchanged between the atmosphere and lungs from the airways and the lungs.
2. Exchange 2: O2 is exchanged in alveoli between the lungs and the blood in the pulmonary circuit.
3. Transport: gases in the blood are circulated through the pulmonary circuit into the systemic circuit
4. Exchange 3: oxygen is exchanged between the blood and the cells for CO2. CO2 is then returns via the systemic and pulmonary circuits where it is then expeled intot the atmopshere.

Question 11

What is external respiration? What is the equation for internal cellular respiration?

Answer 11

1. External respiration begins with:
   a. exhcange of air between atmorphere and lungs
   b. exchange of O2 and CO2 between lungs and blood
   c. transport of O2 and CO2 gases by blood
   d. exchange of O2 and CO2 between blood and cellls
2. Equation: C6H16)6 + 6O2 =^CO2 + 6H2O

Question 12

What are the four gas laws? Explain them.

Answer 12

1. Grahams law: gases diffuse from areas of higher pressure to areas of lower pressure
2. Daltons law: the total pressure of a mixture of gases is the sum of individual gas pressures
3. Boyles law: the pressure of a gas is inversely proportional to the volume of the container
4. Henrys law: the solubility of a gas in a liquid is proportional to partial pressure at equilibrium

Question 13

How is **atmospheric pressure **measured? What is average atmospheric pressure at sea level?

Answer 13

1. Pressure can be measured using a barometer
2. At sea level pressure is at 760mmHg

Question 14

How can Daltons law be calculated? What is the partial pressure of oxygen in the atmosphere?

Answer 14

1. Partial pressure of a gas can be calculated by multiplying the % of gas by total pressure
2. Oxygen makes up about 21% of the atmosphere so partial pressure of O2 =760 X .21 = 159mmHg.
   To calculate O2 from partial pressure use: 159/760 X 100

Question 15

What is Boyles law? What happens when lung volume increases or decreases?

Answer 15

1. Pressure is inversely proportional to volume
2. a. an increase in lung volume during inspiration decreases lung pressure and air goes in
   b. a decrease in lung volume during exhalation increases lung pressure and air goes out

Question 16

What happenes to air as the volumes of the thoracic cavity and lung volume change? What are the three pleuras?

Answer 16

1. As the volumes of the thoracic cavity and lung change, air moves from higher to lower pressure.
2. a. parietal pleura line thoracic wall
   b. visceral pleura cover the lungs
   c. pleural cavity with potential intrapleural space between

Question 17

What are the three types of pressure in relation to the body?

Answer 17

1. Atmospheric pressure: pressure of air outside the body
2. Intrapulmonary pressure: pressure in the lungs
3. Intrapleural pressure: pressure within intrapleural space(between parietal and visceral pleura)

Question 18

At rest, what keeps the lungs adhered to the chest wall? What is pneumothorax and what causes it?

Answer 18

1. At rest the pleural fluid keeps the lung adhered to the chest wall.
   a. elastic recoil of the chest wall tries to pull the chest wall outward while elastic recoil of lung creates an inward pull.
2. Pneumothorax: when the bond holding the lung to the chest is broken and the lung collapses as the pleural cavity is opened to the atmosphere; air flows in.

Question 19

What are the muscles used in inspiration? What are the muscles used for expiration?

Answer 19

1. Inspiration: sternocleido-mastoids, scalenes, external intercostals, diaphragm
2. Expiration: internal intercostals, abdominal muscles

Question 20

How is the the movement of the rib cage during inspiration?

Answer 20

1. It has a bucket handle motion which increases lateral dimension of rib cage vertebrae

Question 21

What are the movements of the diaphragm at rest and during contraction.

Answer 21

1. When diaphragm contracts the thoracic volume increases
2. When diaphragm relaxes the thoracic volume decreases

Question 22

What are the factors that depend on the amount of gas that can dissolve in liquid?

Answer 22

1. The amount of gas that can dissolve in liquid depends on:
   a. solubilityof the gas in the liquid
   b. temperature of the fluid
   c. partial pressure of the gases

Question 23

How is gas exchanged when Oxygen is higher in the lungs? How is gas exchanged when CO2 is higher in the blood?

Answer 23

1. When O2 is higher in lungs than blood O2 diffuses from the lungs to blood
2. When CO2 is higher in blood than lungs CO2 diffuses from blood to lungs

Question 24

What is decompression sickness? What is the cause? Who can it happen to?

Answer 24

1. When a person experiences a sudden change in pressure
2. Dissolved N2 gas comes out of solutions as pressure decreases/increases with ascent/descent which causes bubbles to form in the blood and travel to tissues and organs.
3. This can happen to scuba divers who surface to quickly or airplane attendants when a spacecraft looses pressure

Question 25

Why is Hemoglobin neccesary?

Answer 25

1. Oxygen is not a very soluble liquid so most O2 in blood is transported while bound to a hemoglobin

Question 26

What percentage of blood in the body is bound to a hemoglobin? What percentage is dissolved in plasma? What is the hemoglobin/plasma relationship?

Answer 26

1. 98% of the blood is bound to a hemoglobin
   a. also called HbO2 or Oxygen–haemoglobin
2. 2% of blood is found dissolved in plasma
3. Oxygen is dissolved in the plasma of the alveoli where the hemoglobin in red blood cells binds to it and transports it to other cells/tissue where it is dissolved in the plasma of said cell/tissue for cellular respiration

Question 27

In the carbon dioxide transport, how much CO2 is dissolved in plasma? How much is converted to a bicarbonate ion? How much is bound to hemoglobin?

Answer 27

1. 7% is dissolved in the plasma
2. 70% is converted to bicarbonate ion
3. 23% is bound to hemoglobin
   a. also called carbamino hemoglobin

Question 28

What regulates breathing? Where are the these chemoreceptors located?

Answer 28

1. Breathing is regulated by chemoreceptors that monitor the pH, PCO2 and PO2

Chemoreceptors are located in:

a. in the Medulla of the CNS
b. and carotid and aortic arteries of PNS

Question 29

How does the medulla contribute to the regulation of ventilation? What is the pons responsible for? How?

Answer 29

1. The medualla sets respiratory rate and depth. Does this with both:
   a. dorsal respiratory group (inspiratory center) : increases depth of breath by fireing frequently to diaphragm or slows rate by taking a longer duration to fire. Thus it sets basic respiratory rate
   b. ventral respiratory center (expiratory center): inactive during normal breathing but stimulates both inspiratory and expiratory muscles to create forced expiration
2. Pons modifies breathing such as gasping and sneezing. Does this with both:
   a. pneumotaxic center: sends inhibiting impulses to inspiratory center in medulla to which shortens the duration of inspiration and expiration which increases breathing rate.
   b. apneustic center: causes apneusis or gasping

Question 30

What is tidal volume(TV), inspiratory reserve volume(IRV), expiratory reserve volume(ERV), residual volume(RV), vital capacity(VC), and total lung capacity(TLC)?

Answer 30

1. Tidal volume(TV): volume of air moved in and out of lungs during queit breathing.
2. Inspiratrory reserve volume(IRV): the maximal volume that can be inhaled from the end inspiratory level
3. Expiratory reserve volume(ERV): the maximal volume of air that can be exhaled from the end inspiratory level
4. Residual volume(RV): the volume of air remaining in the lungs after a maximal exhalation
5. Vital capacity(VT): the volume of air breathed out after the deepest inhalation
6. Total lung capacity(TLC): the volume in the lungs at maximal inflation which includes the sum of VC and RV

Question 31

What is eupnea, hypernea, hyperventilation, hypoventilation, tachypnea, dyspnea, and **apnea? **

Answer 31

1. Eupnea: normal quiet breathing
2. Hyperpnea: increased respiratory rate and/or volume in response to increased metabolism
   a. example: exercise
3. Hyperventilation: increased respiratory rate and/or volume without increased metabolism
   a. Example: emotional hyperventilation or blowing up a balloon
4. Hypoventilation: decreased alveolar ventilation
   a. Example: shallow breathing, asthma
5. Tachypnea: rapid breathing. Usually with increased respiratory rate with decreased depth.
   a. Example: panting
6. Dyspnea: difficulty breathing(air hunger)
   a. Example: various pathologies or hard exercise
7. Apnea: cessation of breathing
   a. Example: deliberate breath holding, or depression of CNS control centers