Ch. 7 - Respiration Flashcards
What is the main question regarding the function of the respiration system?
How does the respiratory exchanges stuff with environment?
What are the two main functions of the respiratory system?
Ensure that:
- oxygen is brought to each cell in the body
- carbon dioxide is removed from the body
What are two requirements of respiration?
- The surface area (respiratory surface) must be large enough for the O2/CO2 exchange to occur fast enough to meet the body’s needs
- Respiration must take place in a moist environment so that the O2 and CO2 are dissolved in water
What are the two basic processes of breathing?
- Inspiration (inhalation, breathing in)
- Expiration (exhalation, breathing out)
What is inspiration?
Move air from the external environment to the lungs inside the body.
What is expiration?
Moves air from the lungs back to the external environmen
What are the three main stages of respiration?
External, Internal, Cellular
What is external respiration? What’s the conditions?
Exchange O2 and CO2 between the air and the blood.
Cool, and neutral
What is internal respiration? What’s the conditions?
Exchange of O2 and CO2 between the body’s tissue cells and the blood.
Warm, and acidic.
What is cellular respiration?
Series of energy-releasing chemical reactions that take place inside the cells.
Is the final stage of respiration.
Is the sole means of providing energy for all cellular activities, and helps bodies maintain homeostasis.
C6H12O6 + 6O2 -> ATP + 6CO2 + 6H2O
What does the nasal cavity do?
Warms, moistens, and cleans the air entering the system.
What does the pharynx do?
Common passage for air and food.
What does the epiglottis do?
Flap of tissue that covers opening to trachea, when food is swallowed.
What does the larynx do?
(Voice Box)
First part of trachea that is made of cartilage, ciliated, and containing the vocal cords.
What does the trachea do?
Ciliated tube supported by rings of cartilage.
What do the bronchi do?
Ciliated pair of tubes that lead into lungs, supported by cartilage.
What do the bronchioles do?
Ciliated tubes with muscular walls, capable of dilating or constricting.
(Not cartilaged)
What do the alveoli do?
Sac-like structures with thin walls surrounded by capillaries, site of gas-exchange.
What do the pleura do?
Two thin like membranes that hold the (stick) lungs to the inside of the thoracic cavity. Prevent collapse/deflation of lungs, just like pericardium.
What is the thoracic cavity?
The space inside the rib cage.
What do the ribs and intercoastal muscle?
Enlarge size of thoracic cavity when breathing to decrease air pressure.
What does the diaphragm do?
Muscle that contracts to enlarge the chest cavity.
What do cilia do?
Hair-like projections in the lining of trachea/bronchi/bronchiles, which sweep mucus and dirt (trap/clear/removal) out of the lings back up the nose/throat to be coughed/sneezed out.
What is the movement of air based on? In what conditions does air get drawn in and pushed out?
Air pressure.
Drawn in where air pressure is low.
Pushed out from where air pressure is high.
What are the full steps of inhalation?
- Intercoastal muscles and diaphragm contract, and the rib cage moves out/expands and the dome-shaped diaphragm flattens.
- Chest volume of the thoracic cavity increases and air inside the thoracic cavity is under less pressure than the external air pressure.
- In order to equalize the external and internal air pressure, air rushes in, causing lungs to expand.
When inhaling air, moves from an area of high pressure (external air) to an area of low pressure (lungs).
What is the volume of expansion limited to during inspiration?
- The equalizing pressure
- Elastic limit of the lung tissue.
What is the relationship of expiration and inhalation?
Expiration is the reverse of inspiration.
What are the full steps of expiration?
- Intercoastal muscles and diaphragm relax. (Ribs move in and diaphragm returns to the dome shape).
- Volume of thoracic cavity decreases, causing air pressure in the lungs to increase.
- Air rushes out
When exhaling, air moves from an area of high pressure (lungs) to an area of low pressure (external air).
Why is respiratory volume important?
Lung volume and therefore the amount of gas exchanged per breath can vary.
What is a spirograph?
A graph representing the amount of air that moves in and out of the lungs with each breath.
What is the tidal volume?
Volume of air that is inhaled/exhaled in a normal breath at rest.
~500 mL
(If we even think about breathing, we often take in more air than our tidal volume)
What is the inspiratory reserve volume?
Additional volume of air that can be inhaled.
What is the expiratory reserve volume?
Additional amount of air that can be forced out of the lungs.
What is the vital capacity?
Total volume of air that can be moved in air out of the lungs.
~5000 mL
VC= After a full inhalation, all air that’s exhaled.
What is the residual volume?
Amount of air that remains in the lungs and respiratory tract after fully exhaling. Ensures that lungs don’t collapse upon exhaling.
Residual ~1000 mL = Total Volume 6000mL - Vital Capacity 5000mL
How is breathing maintained and regulated?
Maintained and regulated by the medulla oblongata responding to chemoreceptors (the monitors, in carotid arteries/aorta)
What is monitored by the medulla oblongata?
Carbon dioxide and carbonic acid (H2CO2) levels.
What happens if carbon dioxide and carbonic acid (H2CO2) levels increase?
Medulla oblongata send at sympathetic nerve impulses to diaphragm and intercoastal muscles to increase breathing rate.
(Fight/flight)
What do things like morphine and barbiturates do the respiratory system?
- Decrease sensitivity to Co2
- May cause the breathing rate to fall (relaxation)
What do O2 receptors do? When do these things often occur?
(Chemoreceptors) Detect low levels of O2 and make the medulla send out sympathetic impulses.
This might occur during overdoses, assisted suicide, and euthanasia.
What is the negative feedback loop for CO2?
[High CO2] -> Chemoreceptors -> (send a chemical signal) Medulla -> (send sympathetic nerve impulses) -> Diaphragm/Intercoastal Muscles -> (increase breathing rate) [Low CO2]
Explain the process of external respiration, in detail.
- Where?
- As the blood moves away from the body tissues:
- As air moves through the lung capillaries:
Occurs between (in lungs) alveoli and capillaries next to them.
It is oxygen-poor and carbon-dioxide rich as it moves away from the body tissue.
As air moves through the lung capillaries:
O2 from air in alveoli diffuses into capillaries and CO2 diffuses out of the blood and is exhaled.
Explain the process of internal respiration, in detail.
- Where?
- Oxygen diffuses from the blood into:
Occurs between (in cells) capillaries and the body’s tissues.
O2 diffuses from blood into oxygen-poor tissues while CO2 diffuses from the tissues into the blood.
Where does O2 move from? (concentration)
Areas of [high] to [low]
How do you speed up O2 movement?
Happens faster when the [gradient] is larger.
Square brackets [] =
Concentration
How does O2 move into the blood? What type of cell does this and how many can it carry?
Once O2 diffuses into the blood, it combines with hemoglobin (Hb), which can carry 4 O2 molecules.
This makes oxyhemoglobin: Hb + O2 -> HbO2
What is the composition of air mostly?
N2 - 78%
O2 - 21%
CO2 - 0.04%
Can this reaction of hemoglobin and oxygen be reversed? What does it depend on?
Yes, it depends on the concentration gradient of O2 present.
Happens when oxyhemoglobin gets to tissues and O2 diffuses out.
What happens when the blood reaches the tissues during oxygen transport via hemoglobin?
- 95-98.5% of the hemoglobin present in blood form oxyhemoglobin under normal [O2] (~21%)
- When blood reaches the tissues, [O2] is very low, and the O2 breaks away from the Hb and diffuses into the tissues.
HbO2 -> O2 (to tissue) + Hb (back to lungs)
What are the three forms in which carbon dioxide diffuses out of the tissues into the capillaries?
- Blood plasma
- Hemoglobin
- Carbonic acid
Explain the process of how CO2 is carried by the blood plasma?
7% of CO2 is carried in here
- CO2 is soluble and is carried as dissolved gas in blood
Explain the process of how CO2 is carried by hemoglobin?
23% of CO2 is carried by hemoglobin that just released O2.
- Forms carbaminohemoglobin/carbhemoglobin
Explain the process of how CO2 is carried by carbonic acid?
- Most of CO2 (70%) reacts with water to form carbonic acid, which requires the enzyme carbonic anhydrase, found in RBCs
- Carbonic acid will immediately, readily ionize to form bicarbonate ions and hydrogen ions
- Bicarbonate ions will travel in this from in blood to the lungs (and HHb) where the reverse reaction occurs as H attaches back to HCO3, and eventually, releasing O2. Goes back to carbonic acid. Using carbonic anhydrase, converts back to CO2 and water, and released.
(H can be released in the kidneys by the HHb)
CO2 + H20 -> H2CO3 (aq) (carbonic acid) -> H+ + HCO3- (bicarbonate)
Why is it important for the reverse reaction to occur to decompose bicarbonate?
Formation of free H+ ions in the blood causes Hb to pick them up and form HHb (reduced hemoglobin). But, if there are too many H+ ions, there may not be enough free Hb molecules to pick them up.
Excess H+ lowers pH of blood (which is stronger acidity than HCO3), which is not good.
(Hb in this case acts as a buffer, so the pH doesn’t have that drastic of a change)
Why can we hold our breath longer normal if we hyperventilate?
Cause lots carbon dioxide removed, so diaphragm gets less impulses to breathe.
What are two upper respiratory tract infections? What is the upper respiratory tract?
Nose/Throat/Mouth/Trachea
Tonsilitis and Laryngitis
What is tonsillitis?
Infection of the tonsils (located in the pharynx)
What do tonsils help with?
- Prevent bacteria and other foreign pathogens from entering the body.
- Removal can increase the number of infections later on in life
- Can be removed if infections and breathing are impaired
- In past, children removed tonsils a lot, but now less common
What is laryngitis?
Inflammation of the larynx (of vocal cords)
What is the most common cause of laryngitis?
Viral infection…allergies/overstraining of voices also.
What heppns when the larynx is inflammed?
Vocal cords cannot vibrate as they normally do.
What are eight lower respiratory tract infections? What is the lower respiratory tract?
(Of mostly the bronchi and smaller)
- Bronchitis
- Pneumonia
- Pleurisy
- Emphysema
- Cystic fibrosis
- Asthma
- Lung Cancer
- Tuberculosis
What is bronchitis?
Disorder that causes the bronchi to be inflammed and filled with mucus, which is expelled by coughinh.
What is pneumonia?
Disease when alveoli in lungs are inflammed and filled with liquids.
What does pneumonia interfere with?
Gas exchange, and the body’s starved for oxygen.
What is pleurisy?
- Lung disorder caused by inflammation of pleural membrane, which is the membrane surrounding the lungs.
- Stabbing chest pain with every breath
What is emphysema?
Obstructive discorder whcih walls of alveoli break down and lose elasticity.
What does emphysema reduce? What does this cause?
Surface area for gas exchange = cause oxygen shortage in tissues. Exhalation difficult.
What is the solution to emphysema?
None, as effects are permanent, incurable. Oxygen tank doesn’t really work because you can’t increase rate of exchange, only concentration.
What is cystic fibrosis?
A serious genetic condition affecting the lungs.
What is cystic fibrosis caused by?
Abnormal genes.
What are the effects of cystoic fibriosis?
- Disrupts function of the cells living lining the passageway of lungs.
- Thick mucus lining of the lung passage makes breathing difficult.
What is asthma?
A chronic obstructive lung disease affecting bronchi and bronchioles.
What are the effects of asthma?
- Breathing is hard or impossible because of reduced airflow and inflamed airways
- Bronchial muscles tighten, and mucus increases
What is lung cancer?
Uncontrolled/invsaive growth of abnormal cells in the lungs.
What is the statistical impact of lung cancer in Canada?
Leading cause of cancer deaths for men and women.
What is carcinoma?
A malignant (evil) tumour formed from the multiplication of abnormal cells.
What are tumours?
A swelling of a part of the body, generally without inflammation, caused by an abnormal growth of tissue, whether benign or malignant.
Reduce surface area available for gas exchange, damage tissue, or produce toxin.
- 90% of lung cancers are in smokers
- Chewing tobacco = oral cancer damaging teeth/gums
What is a carcinogen?
Cancer-causing agent.
1. Have >60 in tobacco (like radon, formaldehyde, lead, vinyl chloride, urethane)
2. Radon element found in rocks and soil
3. Asbestos, a fire resistant mineral
What is tuberculosis?
Common, often deadly infectious diseased caused by mycobacteria.
- Attacks lungs (pulmonary), but also affects the nervous system.
Have we defeated tuberculosis?
Because of global travel, increased.
In third world countries, no. Lack of antibiotics.
If air enters the inter pleural space, what could happen?
A lobe of the lung can collapse.
