PSIO 202 EXAM 2

what are the main functions of the respiratory system

what are the main functions of the respiratory system

ventilation and gas exchange

filtering, warming, and humidifying inhaled air

sound production

sense of smell

metabolism of hormones

acid base balance

what is external respiration

the exchange of gases between the atmosphere and blood

what is internal respiration

gas exchange between capillary blood and the cells in tissues

what is cellular respiration

the use of oxygen by cells to produce ATP by oxidizing glucose

what are the major divisions of the respiratory system

upper airway

lower airways

what is the function of the upper airway

connect the nasal and oral openings with the esophagus and trachea

what are the 3 upper airways

nasopharynx

oropharynx

laryngopharynx

what is the function of the larynx

separate the upper and lower parts of the respiratory system

what is the largest conducting airway

trachea

do you always want the trachea open

yes

what is the purpose of c shaped rings in the trachea

to prevent collapse of main airway

what are the 2 lungs separated by

mediastinum

how many lobes are in the right lung

3

superior

middle

inferior

how many lobes are in the left lung

2

superior

inferior

what is a bronchopulmonary segment

portion of the lung supplied by a tertiary bronchus

how many bronchopulmonary segments does the right lung have

10

how many bronchopulmonary segments does the left lung have

8

why does the right lung have more bronchopulmonary segments than the left lung

bigger lung

more lobes

more segments

what is a lobule

a small segment of lung tissue wrapped in connective tissue

each terminal bronchiole supplies ____

a single lung lobule

what does a lobule contain

lymph vessel

pulmonary arteriole (deoxy)

pulmonary venule (oxy)

respiratory bronchioles

alveolar ducts

alveoli

where does the site of gas exchange occur

alveoli

alveolar sac

what type of alveolar cells do 97% of the alveolar walls consist of

type 1

what are type 1 alveolar cells made of

simple squamous epithelial cells

what is the function of simple squamous epithelium

prevent fluid leakage into alveolar air spaces

what type of alveolar cells do 3% of the alveolar walls consist of

type 2 alveolar cells

what do type 2 alveolar cells secrete

surfactant

what is the function of surfactant

prevent alveoli from collapsing during exhalation

reduces surface tension

what are the two different types of pulmonary blood supply

nutritional flow

pulmonary flow

what is nutritional flow

lung tissue receives oxygenated blood from the bronchial arteries, which branch off the aorta

part of systemic circulation

what is pulmonary flow

pulmonary arteries supply the lung capillaries with deoxygenated blood

what is the function of pulmonary flow

gas exchange to provide the body with oxygen

what is the function of nutritional flow

feed/oxygenate the hard working lung tissue

what is pulmonary ventilation

alternating flow of air into and out of the lungs

what is the function of inspiratory muscles

expand the rib cage

drive airflow into the lungs

what is the function of the expiratory muscles

depress or compress the rib cage

force air out of the lungs

what does boyle’s law state

pressure and volume are inversely related

what is the thoracic cage

the skeletal portion of the thorax

what is included in the thoracic cavity

ribs

costal cartilages

thoracic vertebrae

sternum

what is respiratory mechanics

the study of how the respiratory muscles move the rib cage

what is the respiratory pump

the respiratory muscles

rib cage

pleural membranes

lung elastic tissues

what is the role of the diaphragm in quiet and labored inspiration

enlarge the thoracic cavity longitudinally

what is the role of the external intercostal muscles during quiet and labored inspiration

move ribs upward and outward

what is the function of the sternocleidomastoid during labored inspiration

elevate the sternum

what is the function of scalenes during labored inspiration

elevate the top two ribs

what is the function of the internal intercostal during expiration

pull ribs downward and inward reducing the diameter of the rib cage

what is the function of the abdominal muscles during expiration

depress the lower ribs and elevate the diaphragm by increasing abdominal pressure

when does inspiration occur

when pressure in the lungs is less than the atmospheric pressure

when does exhalation occur

when pressure in the lungs is greater than the pressure in the atmosphere

what is transpulmonary pressure (Ptp)

difference between the pressure in the pleural cavity and the pressure inside the alveoli

Palv-Pip

what is intra pleural pressure (Pip)

the pressure in the pleural cavity

what is intra alveolar pressure (Palv)

the pressure inside the alveoli

what does transpulmonary pressure show

a measure of the force being exerted on the lungs to keep them inflated

what is minute ventilation

a measure of the rate of air movement into the lungs

what is alveolar ventilation

a measure of the rate of air movement into alveoli

where gas exchange occurs

what is anatomic dead space

the region in the respiratory tract where no gas exchange occurs

what is true in any period between breaths

alveolar pressure equals atmospheric pressure

intrapleural pressure is less than atmospheric pressure

what is tidal volume

normal breathing volume

what is the average tidal volume

500 ml

what is vital capacity

volume that you cant control

what is residual volume

volume you can’t expel/control

what is expiratory reserve volume

expiration beyond comfort zone

what is inspiratory reserve volume

extra volume you can breathe in beyond normal

what is inspiratory capacity

tidal volume plus inspiratory reserve volume

maximum volume you can inhale above functional residual capaicty

what is functional residual capacity

lung volume at the end of comfortable expiration

what is total lung capacity

everything added together

what does functional residual capacity define

the volume that fresh air must mix with to increase lung oxygen stores and decrease carbon dioxide stores

what does a large frc indicate

labored breathing

what does a small frc indicate

large fluctuations in oxygen and carbon dioxide

what is lung compliance

the ease at which the lungs can be inflated (stretched)

how are pressure and compliance related

increase in one leads to a increase in the other

is transpulmonary pressure always positive or negative

positive

what does dalton’s law state

in a mixture of gases each gas will exert a pressure that is proportional to its concentration

what is the partial pressure of gas

pressure exerted by each gas will be a function of the total gas pressure and its concentration

what is the average arterial PO2

95 mmHg

what is the average arterial PCO2

40 mmHg

what is the average mixed venous PO2

40 mmHg

what is the average mixed venous PCO2

45 mmHg

why don’t the average alveolar values change much between breaths

the volume of fresh air is relatively small compared to the volume already present in the lungs

expired air has a lower or high O2 concentration than inspired air

lower

expired air has a low or higher CO2 concentration than inspired air

higher

how is O2 removed from the lungs during inspiration

by capillary blood flow

how is CO2 exhaled

moving from the blood to the lungs

venous blood has a relatively _____ [O2] and a relatively _____ [Co2]

low

high

what is the respiratory quotient

rate of CO2 production/rate of O2 consumption

in what 2 forms is oxygen transported

bound to hemoglobin

dissolved in plasma

what percent of the time is oxygen transported by hemoglobin

98.5

how many oxygen are bound to hemoglobin at a time

4

what does the oxy hemoglobin dissociation curve show

the relationship between PO2 and the capacity for oxygen to bind to hemoglobin

what is the binding and release of oxygen from hemoglobin dependent on

partial pressure of oxygen PO2

what drives the diffusion of oxygen into the blood where it binds to Hb

when the lung PO2 is greater than blood PO2

what drives the release of oxygen from Hb

when the tissue PO2 is less than blood PO2

what is the bohr effect

a shift in the oxy hemoglobin dissociation curve to the right

what causes the bohr effect

decreased blood pH (increased H+)

increased blood PCO2

increased temperature

(all associated with exercise)

what occurs during the bohr effect

Hb molecules release more oxygen at any given PO2

each gram of hemoglobin binds how many ml of oxygen

1.34

arterial blood is healthy adults is what percent saturation

97-98

what is hypoxia

lack of adequate oxygen at the tissue level

what is hypoxia caused by

anemia

hypoxemia

what is anemia

lowered ability of blood to carry oxygen due to low rbc count or hemoglobin concentration