What is the function of the respiratory system
To deliver O2 to the blood and take CO2 away from the blood
Describe and identify two levels of gas exchange
Internal respiration (cellular respiration) and external respiration (exchange of O2/CO2 between body and atmosphere)
4 Processes involved in external respiration
Pulmonary Ventilation (movement of air in and out of lungs)
Exchange of O2/CO2 between blood and lungs
Transportation of O2/CO2 between lungs and tissues by blood
Exchange of O2/CO2 between blood and tissues by diffusion
6 Other functions of the respiratory system
Balance PH of blood (CO2 in carbonic acid)
Vocalization
Defense against pathogens (mucosal elevator)
Respiratory pump (venous return of blood to heart)
Activate plasma proteins
How many lobes make up each lung
Left lung has two lobes and the right lung has three lobes
Structures and functions of the upper airway
Air passages in head and neck that create path for airflow.
O2 enters nasal/oral cavity
O2 travels to pharynx
diverges with food
O2 enters larynx
Two zones of the respiratory tract
Conduction zone creates path for airflow into respritory zone
Respiratory zone is where O2/CO2 move in and out of blood
What is the importance of goblet and ciliated cells
Goblet cells secrete mucus to trap pathogens
Ciliated cells move in whiplike fashion to push mucus up and out of lungs
Smoking’s effect on ciliated cells and mucosal elevator
Smoking paralyzes ciliated cells so the mucosal elevator cant function
Structures of the respiratory zone
Respiratory Bronchioles and Alveoli
Function of respiratory bronchioles
lead to alveoli
How do gas molecules pass into blood
O2 diffuses from high to low concentration across one layer of type 1 cells, through respiratory membrane, into capillary
6 components of the chest wall
12 pairs of ribs
sternum (breast Bone)
thoracic vertebrae
Intercostal muscles (external and internal)
Diaphragm
Pleura - layer of epithelial cells that surround the lungs
What is pneumothorax and its cause
Presence of air/gas in pleural space (between lungs and pleura) caused by air leaking from lungs, caused by traumatic injury
Pressure gradient during inspiration
Palv < Patm
Pressure gradient during expiration
Palv > Patm
Alveolar Pressure
Palv (pressure of air inside alveoli)
Atmospheric Pressure
Patm (pressure of the air outside the body)
Intrapleural pressure
Pip (Pressure between lungs and pleura)
Transpulmonary pressure
difference between Pip and Palv
Muscles involved inspiration (inhalation)
external intercostals
diaphragm
Muscles involved in expiration (exhale)
During quiet expiration the muscles relax
during active breathing, contract abdominal and internal intercostal muscles
two factors that affect pulmonary ventilation
Lung compliance
airway resistance
Define low lung compliance
how easy the lungs expand, tuberculosis creates scar tissue that affects compliance
Asthma
Spastic contraction of smooth muscle in bronchiole walls
Allergies
Histamine causes bronchi to contract and produce more mucus
Diffusion across alveoli and blood
down the concentration gradient (high to low concentration)
3 factors that rate of diffusion depends on
rate of diffusion increases as concentration increases
rate of diffusion increases as surface area increases
rate of diffusion increases as permeability of the membrane increases
Partial Pressure
determined by fractional concentration on gas and total atmospheric pressure
Concentration of O2 in air
21%
Concentration of N2 in air
79%
Patm
760mm/hg
2 factors that determine solubility of gas in liquid
solubility of the gas (co2 is more soluble than o2)
increase in partial pressure = increase in solubility of gas
What are the bends
when a SCUBA diver surfaces too quickly and the nitrogen bubbles form because of the rapid decrease in pressure
Pulmonary edema
Accumulation of excess fluid in the alveoli, between type I cells
Why is alveolar press’ different than atmospheric press’
o2 immediately diffuses from alveoli into bloodstream
Atmospheric air mixes with remaining co2 in lungs
Inspired air mixes with water vapor in lungs
Why does partial pressure vary depending on the location on respiring tissue
it depends on how much the tissue is working
3 factors that determine alveolar Po2 and Co2
Po2 and Pco2 of atmosphere
volume of air reaching alveoli /minute
rate of metabolism of respiring tissue
hyperpnea
rate of alveolar ventilation increase as needs for o2 increase
Hypoventilation
if Po2 fails to increase with need
Hyperventilation
happens if Pco2 gets to low
Inspiratory Reserve volume
Max volume of air inspired after quiet inspiration (3000ml)
Expiratory Reserve Volume
max volume of air expired after quiet expiration (1000ml)
Tidal Volume
Volume of air inspired/expired in quiet breath (500ml)
Residual Volume
Volume of air in lungs after max expiration (1200ml)
Inspiratory capacity
max volume of air that can be inspired after quiet expiration
Vt + IRV
Vital Capacity
Max volume of air that can be expired after max inspiration
Vt + IRV + ERV
Total Lung Capacity
max volume of air lungs can hold
Vt + IRV + ERV + RV