Name a few organs?? the respiratory system consists of
Oral and nasal cavities
Lungs (tubes that lead to lungs)
Chest Structures
Two actions of the respiratory system (intake and out take of what?)
Intakes O2 for delivery to the blood
Eliminates CO2 from the blood
What is Ventilation?
Mechanical process that moves air into and out of lungs (think *air vent)
What is Gas Exchange?
Exchange of gases between the air and blood in the lungs, and between blood and other tissues of the body
What is Oxygen Utilization?
Use of oxygen in cell respiration
Name the 6 parts in the respiratory system
Nose/Mouth
Pharynx (throat)
Larynx (voicebox)
Trachea (windpipe)
Bronchus
Lung
Name and state the order of the parts within the Lungs:
Left/Right Primary bronchi -----> bronchioles -----> terminal bronchioles -----> respiratory bronchioles -----> alveolar ducts ----- alveolar sacs
What are the three parts within the Upper Airways?
Nose/mouth
Pharynx
Larynx
What's within the conducting zone?
All structures through which air passes before reaching the respiratory zone
3 actions of the conducting zone
CONDUCTS air to the respiratory zone
warms and humidifies inspired air
filters and cleans air
What is the Respiratory Zone?
Region where gas exchange occurs, comprising the respiratory bronchioles and alveolar sacs
(think *respiratory zone COMPRISES respiratory bronchioles)
The _______ zone transports air to the ______ zone
conducting; respiratory
How many alveolar sacs does most gas exchange occur in?
8 million
______ and ______ have rings of cartilage
trachea; bronchi
What are bronchioles surrounded by?
Smooth muscle
What determines how easily airflow can occur?
The relaxation/contraction of smooth muscle lining the airways (bronchodilation vs. bronchoconstriction)
Where is the intrapleural space (pleural cavity) located?
Between the parietal and visceral pleura (epithelial membrane)
think *VIP:
V.isceral
I.ntrapleural
P. Parietal
What does intrapleural space contain?
A thin layer of fluid that acts a lubricant
What are the 4 protective mechanisms?
Nasal hairs/Mucus
Mucus escalator
Bronchoconstriction
Macrophages
Nasal hairs and mucus...
trap particles
Mucus escalator...
keeps lungs clear (ciliated cells in airways carry mucus and particulate matter into the pharynx to be swallowed)
Bronchoconstriction
responds to irritation
prevents particulate matter from entering alveoli
Macrophages
(WBCs) in airways and alveoli engulf/destroy inhaled particles and bacteria
*protections us from infections
Air _____ moves from ___ pressure region to ____ pressure region
passively; high; low
What is the movement determined by? (continuing from last question)
Intra-alveolar and atmospheric pressures
Intra-alveolar Pressure = ? = ?
Palv = pressure inside lungs
Atmospheric Pressure = ? = ?
Patm = 760 mmHg at sea level
If Palv < Patm, what occurs?
Inspiration (air moves into lungs where pressure is lower)
If Palv > Patm, what occurs?
Expiration (air moves out of lungs)
*think expiration = exhalation
What determines the pressure in lungs?
Volume of lungs (Boyle's Law: P1V1 = P2V2)
Increase lung volume ______ Palv, resulting in ______
reduces; inspiration
Decreased lung volume _______ Palv, resulting in _____
increases; expiration
What is inspiration?
Movement of air from external environment through airways into alveoli during breathing; inhalation
What occurs during inspiration?
Parasternal & external intercostals contracts
Diaphragm contracts and is lowered
Lung volume increases which decreases Palv
What is expiration?
Movement of air from the alveoli to the external environment during breathing; exhalation
What occurs during expiration?
Inspiration muscles relaxes
Diaphragm relaxes
Lung volume decreases
Tidal Volume:
The amount of air moved in or out of the airways in a single breathing cycle
Inspiratory/Expiratory reserve volumes:
The additional volume that can be inspired or expired
The Tidal Volume, Inspiratory and Expiratory quantities sum to the lung's ______.
Vital capacity
Residual Volume
The amount of air that must remain in the lungs to prevent alveolar collapse
What is alveoli?
Clusters of epithelium-lined air sacs
What does each clustered alveoli include in regards to blood vessels?
An abundance of pulmonary capillaries
Why does aveoli having pulmonary capillaries so important... what does it allow?
It assures that the ventilated air is within range to the "pulmonary" blood
It allows efficient gas exchange between the air and the body
Type 1 alveolar cells:
form most of the epithelium
Type 2 Alveolar Cells:
secrete a detergent-like substance called surfactant
What does surfactant do?
Decreases surface tension in alveoli to prevent alveolar collapse
Partial Pressure
pressure of each individual gas
Oxygen from alveoli...
moves into capillaries -----> transports to tissues -----> enters ISF -----> enters cell
Carbon dioxide from the cell...
enters ISF ---> then capillaries ---> transports to alveoli by the bloodstream
In regards to partial pressures of gases, what occurs in the lungs?
The concentration gradients favors inward (toward blood) diffusion of oxygen and the outward (toward alveolar air) diffusion of carbon dioxide
State what happens during Neural Control of Respiration
Motor neurons cyclically stimulate skeletal muscle contraction/relaxtion
What chemoreceptors are in the Chemical Control of Respiration?
Peripheral chemoreceptors in heart
Central chemoreceptors in medulla oblongata of brain
What is the main function for chemical control of respiration?
detects changes in PO2, PCO2, [H+] to keep them constant
What serves as a buffer for H+?
Bicrabonate (HCO3-)
Hypoventilation =
Dcecrease/Inadequate ventilation
Hyperventilation =
Increased ventilation
What occurs during HYPOventilation?
PCO2 increases
reaction proceeds to the right, pH decreases
What occurs during HYPERventilation?
PCO2 decreases
reaction proceeds to left, pH increases
What causes PCO2 to increase in the cells of the body?
Metabolic processes in the cells
What "informs" the respiratory center to increase the rate of ventilation?
Chemoreceptors that responds to increased carbon dioxide levels in the blood and resulting decreased pH
How much mL of O2 does blood carry?
20 mL of O2 per 100 mL of blood
State the percentages of blood in regards to O2 Transport in blood
1.5% is dissolved as a gas in plasma and RBCs
98.5% is bound to hemoglobin in RBCs
Hemoglobin molecule:
4 globins bound to 4 hemes
What is in the center of each heme
One atom of iron that can combine with one O2 molecule
Where does the loading and unloading of O2 occur?
Loading = pulmonary capillaries unloading = Systemic capillaries
State the percentages in regards to CO2 transport in blood?
10% dissolved as a gas in plasma and RBCs
20% as a carbaminohemoglobin
70% is tranported as HC03-
What happens to ventilation during exercise?
Increases to keep up w/ increased metabolism so oxygen, carbon dioxide and pH remain constant
Increase O2 delivery to skeletal muscles
PCO2 decreases while pH increases