Respiratory System Flashcards
What does the air we breathe consist of?
Nitrogen, carbon dioxide, trace gases, and oxygen (most valuable)
In humans, what is the only means of obtaining oxygen?
Through the lungs
What is breathing?
Involves the movement of air between the lungs and the external environment. The process’s involved in breathing include both inspiration and cellular respiration
What is not breathing?
Yawning and hiccuping
What is yawning?
Stretching of the facial muscles
What is hiccuping?
Spasm of the diaphragm
What is respiration?
Involves all processes related to the exchange of oxygen and carbon dioxide including breathing, gas exchange , and cellular respiration
What is external respiration?
Involves the exchange of oxygen and carbon dioxide between the air and the cells of the lungs
What is internal respiration?
Involves the exchange of O2 and CO2 between blood and cells of the body
What is cellular respiration?
The exchange and the use of oxygen to make energy, and as a byproduct CO2 is produced
What is the role of the nasal cavity?
Filters the air with the help of cilia and mucous. It also moistens the air before it goes to the lungs
What is the pharynx?
Opens from the nasal cavity and branches into two structures
What is the esophagus?
Muscular tube that moves food to the stomach
What is the trachea?
The windpipe which is supported by c-shaped cartilaginous rings and covered with ciliated cells and mucous that act as a secondary filter
What is the epiglottis?
A flap of skin that covers the opening of the trachea to prevent food from entering the lungs while swallowing
What is the larynx?
The voice box, composed of two thin sheets of elastic ligaments that vibrate as air is forced out of them. Also called the vocal chords
What are bronchi?
Two tubes that branch from the trachea and carry air to the lungs
What are bronchioles?
Smaller branches off the bronchi that become progressively smaller until they reach the alveoli
What are alveoli?
Air sacs in the lung where gas exchange occurs
What are alveoli covered with?
A slippery lipoprotein ion called a surfactant
What does surfactant do?
Prevents the sacs from collapsing and sticking together
What do gases do in the alveoli?
Diffuse in and out according to concentration
What are five reasons that alveoli are a good site for gas exchange?
- Thin (faster)
- Moist (fluids move gases faster)
- High surface area (more spots for gas exchange)
- Warm (faster)
- Vascular (surrounded with a capillary making it the only possible sight)
What are pleural membranes?
Thin membranes surrounding the outer surface of the lungs. They are filled with fluid to reduce friction between the lungs and the chest cavity during inhalation
What is the diaphragm?
A large sheet of muscle that separates the organs of the thoracic cavity from those of the abdominal cavity
What happens to the diaphragm as the muscle contracts?
The diaphragm flattens decreasing pressure inside the chest cavity drawing air into the lungs
What happens to the diaphragm when the muscle relaxes?
The muscle becomes dome shapes
What are intercostal muscles?
Found between the ribs. As they contract the ribs are pulled outward and upward increasing the chest volume and contribute to inspiration
What determines the movement of gases into and out of the lungs?
A pressure difference between the atmosphere and the chest cavity
What is the relationship between pressure and volume?
They are inversely proportionate
Which way does gas move?
From high pressure to low pressure
What controls and regulates pressure inside the chest?
The diaphragm and intercostal muscles
What are the two ways the muscles control and regulate pressure inside the chest?
Inhale and exhale
What happens during an inhale?
The muscle contracts, the diaphragm flattens, ribcage lifts, increasing the chest volume, decreasing the pleural pressure; results in air moving into the lungs during inspiration; increased volume + decreased pressure
What happens during an exhale?
The muscle relaxes, the diaphragm becomes dome shaped, ribcage falls, decreasing the chest volume and increasing pleural pressure; results in air moving out of the lungs during exhalation; decreased volume + increased pressure
What does the diaphragm separate in order to regulate the pressure in the chest cavity?
The thoracic cavity from the abdominal cavity
During inspiration the intercostal muscles contract causing the ribs to move in which directions?
Up and out
During inspiration the diaphragm contracts causing it to move in which direction?
Downwards
During inspiration what happens to the volume of the chest cavity and lungs?
Increases
During inspiration what happens to the pressure in the chest cavity?
Decreases; lower than the atmospheric pressure
During inspiration in what way does the air move?
Air moves into the lungs
During expiration the intercostal the intercostal muscles relax causing the ribs to move in which directions?
Down and in
During expiration the diaphragm relaxes causing it to move in which direction?
Upwards/dome shaped
During expiration what happens to the volume of the chest cavity and lungs?
Decreases
During expiration what happens to the pressure in the chest cavity?
Increases; higher than the atmospheric pressure
During expiration in what way does the air move?
Air moves out of the lungs
What is the problem with a collapsed lung (stab wound)?
No pressure difference/equillibrium
What are the effects of high altitudes?
There is a low atmospheric pressure (thin air) therefore less O2 available, more air will be taken in (if pressure is too low the O2 cannot pass into alveoli), lose conciousness
Due to oxygen being only slightly soluble in the blood, what must it do in order to be transported?
Bind to hemoglobin (becomes oxyhemoglobin)
How much oxygen can blood carry as oxyhemoglobin?
20mL/100mL of oxygen
What does the amount of oxygen that combines with hemoglobin depend on?
The partial pressures of oxygen in the blood and in the tissues
What percentage of oxygen is transported by oxyhemoglobin?
97%
What percentage of oxygen is transported by plasma?
3%
What percentage of CO2 is carried in the plasma?
9%
What percentage of CO2 is carried as carbaminohemoglobin (HbCO2)?
27%
What percentage of CO2 is carried as carbonic acid or bicarbonate?
64%
What enzyme catalyzes this reaction?
Carbonic anhydrase
What does this reaction do?
Decreases the amount of carbon dioxide in the plasma, thus increasing the rate of diffusion of carbon dioxide from the cells to the blood
Once the blood is returned back to the lungs, what happens to the concentration of carbonic acid?
Becomes very high
What does the high concentration of carbonic acid encourage?
The diffusion of carbon dioxide out of the blood into the lungs
What happens to the oxygen in the alveoli when you inhale?
There is more oxygen in the alveoli than in the blood when you inhale
What happens to the oxygen in the alveoli?
Diffuses into the blood across the alveolar membranes
What transports the diffused oxygen?
In RBC’s as oxyhemoglobin or through the plasma
What happens to the oxyhemoglobin carried by the blood vessels?
Diffuses into cells at the capillary
What happens to the carbon dioxide when you exhale?
There is more carbon dioxide in the blood than in the alveoli
What happens to the carbon dioxide when you exhale?
The CO2 diffuses across the alveolar membranes into the alvoli
What is the CO2 transported as?
Plasma, carbaminohemoglobin, or carbonic acid and bicarbonate
Where do bicarbonate ions travel?
In the plasma
What type of function is breathing?
An autonomic function
What controls breathing?
Nerves from the medulla oblongata and the pons
What detects the levels of carbon dioxide (acid) and oxygen in the blood?
Chemoreceptors
What do chemoreceptors signal the brain to do?
Speed up (hyperventilate) or slow down (hypo-ventilate)
What are the two types of chemoreceptors?
CO2 receptors and O2 receptors
What are always looked at first?
CO2 receptors
When are CO2 receptors activated?
When high levels of Co2 or H2CO3 (carbonic acid) are found in the blood
When CO2 receptors are activated what do they do?
Send nerve impulses to the ribs and diaphragm to increase breathing movements (hyperventilation)
Where are oxygen receptors found?
In the carotid and aortic bodies in arteries
What do O2 receptors do if low levels of O2 are detected?
Send a message to increase big deep breaths (hypo-ventilation)
What is the purpose of hyperventilation?
Gets rid of CO2
What is the purpose of hypo-ventilation?
Gains back lots of O2
What is spirometry?
Measuring lung volume
What can be used to measure lung capacity?
A respirometer
What is tidal volume?
The amount of air expired or inspired during normal breathing; about 500mL
What is vital capacity?
The maximum volume of air that can be expired after maximum inspiration; about 4500mL
What is residual volume?
The remaining volume of air that cannot be forcibly expired; about 1200mL
Why is residual volume important?
Maintains breathing rates since this air is high in carbon dioxide
What can the respiratory system be compared to?
A big tree; the trachea is the trunk, the bronchi are the branches, the bronchioles are even smaller branches, and the site of gas exchange is the alveoli or the leaves
What is the order of the respiratory system during an inhale?
- Nose
- Pharynx
- Epiglottis
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Alveoli
What is the order of the respiratory system during an exhale?
- Alveoli
- Bronchioles
- Bronchi
- Trachea
- Larynx
- Epiglottis
- Pharynx
- Nose
What causes oxygen to unbound from hemoglobin at capillaries and tissues?
The acidic environment that is around tissues, muscles, organs, etc.
