The respiratory system

Question 1

What is the Respiratory System?

Answer 1

The respiratory system is responsible for the intake of oxygen and removal of carbon dioxide, facilitating gas exchange between the body and the external environment.

Question 2

Respiratory System Functions

Answer 2

The primary functions include:
Ventilation (breathing): Moving air in and out of the lungs.
Gas exchange: Oxygen enters the bloodstream, and carbon dioxide is removed.
Regulation of blood pH: By controlling CO2 levels.
Sound production: In the larynx during speech.

Question 3

Key Organs and Structures

Answer 3

Nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, and lungs.

Question 4

Nasal Cavity

Answer 4

Passage where air comes in
CILIA - Covered with cilia that act like filters capturing particles
MUCUS - moistened the air coming
BLOOD CAPILLARIES - warms incoming air

Question 5

Pharynx

Answer 5

Connects nasal cavity to larynx and esophagus
Branches into larynx and esophagus
Common passage way (food and air)

Question 6

Trachea

Answer 6

Is covered with cilia/mucus (like in nasal cavity) helping to filter out any unwanted particles
The trachea is supported by “C” shaped cartilage rings ( helps trachea be open)

Question 7

Bronchioles

Answer 7

The bronchi branch into smaller airways called BRONCHIOLES
Don’t contain cartilage
Covered with smooth muscle that constrict/relax

Question 8

Inspiration

Answer 8

Diaphragm contracts and goes down (flat)
Intercostal muscle contracts, moving ribs out and up
These actions make thoracic capacity larger (decrease pressure in lungs)
Air comes in lungs because pressure in atmosphere is greater than pressure inside, forcing air to come in the lungs (high➡️low pressure)

Question 9

Diaphragm

Answer 9

Sheet of muscle that separates thoracic cavity from abdominal cavity
Assists in ventilation
When relaxed is in a dome shape

Question 10

Intercostal Muscles

Answer 10

Help move ribs up/down and out/in

Question 11

Larynx

Answer 11

Contains 2 thin elastic filaments (vocal chords)
When breathing there is a large gap between the 2 chords
When speaking, muscles around the larynx contract and bring the chords closer ( the passage of air through the narrow space makes the chords vibrate)

Question 12

Epiglottis

Answer 12

Enlarged piece of cartilage
A flap that covers the larynx when food is being swallowed, forcing food to enter the esophagus and not the trachea

Question 13

Bronchi

Answer 13

The trachea forks into two smaller pathways BRONCHI
Each pathway enters one lung
Contains “O” cartilage rings

Question 14

Alveoli

Answer 14

The bronchioles end in tiny little sacs called ALVEOLI
Each alveoli is surrounded by blood capillaries
Site for gas exchange [oxygen moves from area high concentration (air) to area of low concentration (blood)]
Carbon dioxide goes through this process as well
The walls of the alveoli are only one layer of cells, allowing rapid gas exchange

Question 15

Lungs

Answer 15

R lung = 3 lobes (superior - middle - inferior lobe)
L lung = 2 lobes (superior - inferior lobe)
Surrounded by pleura (layers of tissue)

Question 16

Boyles law

Answer 16

Gasses move from an area of high concentration, to a area of low concentration
⬆️ volume = ⬇️ pressure
⬇️ volume = ⬆️ pressure

Question 17

Expiration

Answer 17

Diaphragm relaxes (dome shape)
Intercostal muscle relax, making ribs fall down and in
Volume in thoracic cavity decreases making pressure increase (air moving from high➡️low pressure)
Therefore air is being pushed out (pressure inside is greater than pressure in atmosphere)

Question 18

There is a high pressure of ____ in the atmosphere, while there is a high pressure of ______ _______ in the bodies tissues

Answer 18

There is a high pressure of oxygen in the atmosphere, while there is a high pressure of carbon dioxide in the bodies tissues

Question 19

Oxygen transport

Answer 19

During inspiration oxygen moves from atmosphere to alveoli
Oxygen gets transported around by help of hemoglobin (Hb)
When oxygen get attached to hemoglobin it becomes oxyhemoglobin (HbO2)
When oxyhemoglobin arrives at the capillaries, oxygen is released from the hemoglobin and enters tissues (low pressure of oxygen in tissues)

Question 20

Carbon dioxide transport

Answer 20

Carbon dioxide needs to move from tissue to atmosphere

Question 21

Gas exchange

Answer 21

1. During inspiration oxygen is taken to lungs
2. When oxygen is at alveoli, diffuses from thin walls and enters pulmonary capillaries)
3. When oxygen enters blood, it jumps onto hemoglobin (4O2 + Hb) = HbO2
4. HbO2 travels in blood to tissues (high concentration of CO2 because of cellular respiration)
5. At tissue-blood interface, O2 from Hb and diffuses into tissues (high➡️low concentration). In tissue O2 mixes with glucose making energy, But also makes CO2 as bi-product
6. CO2 diffuses into RBC and must be expelled by the body, when CO2 is in the RBC it combines with H2O to form carbonic acid with the help of carbonic anhydrase
7. Carbonic acids quickly dissociates into H* and HCO3
8. The H* can bind with Hb, so extra H* that bind to Hb. Help remove O2 from the Hb, so that it’s free to enter tissue
9. Once blood reaches lungs O2 (inspiration) dislodges H* from Hb and cycle starts again

Question 22

Tidal volume

Answer 22

The volume of air inhaled and exhaled in a normal (resting) breathing movement

Question 23

Inspiration reserve volume

Answer 23

Additional volume of air that can be taken in, beyond regular/ tidal volume

Question 24

Expiratory reserve volume

Answer 24

Additional volume of air that can be forced out of the lungs, beyond regular/tidal exhalation

Question 25

Residual volume

Answer 25

Amount of gas that remains in lungs/passage ways even after a full exhalation
(This air never leaves the respiratory system, if did lungs and respiratory system would collapse)
This air has little value for gas exchange

Question 26

Vital capacity

Answer 26

maximal volume of gas exhaled during a forced exhalation after a forced inhalation.

Question 27

Total lung capacity

Answer 27

the maximal volume of gas in the lungs after a maximal inhalation

Question 28

Spirometer

Answer 28

Instrument used to measure lung volume

Question 29

Increase in body activity ➡️ Increase in ______ rate ➡️ Increase in cellular respiration

Answer 29

Increase in body activity ➡️ Increase in breathing rate ➡️ Increase in cellular respiration

Question 30

What starts a change in the rate of breathing?

Answer 30

High levels of carbon dioxide
This CO2 is detected by the medulla oblongata in the brain (control bodies reflex)
Medulla oblongata sends out nerve signals to initiate faster movement of diaphragm/intercostal muscle

Question 31

There are chemoreceptors present in the _______ and _______

Answer 31

There are chemoreceptors present in the carotid and aorta
These receptors send signals to the medulla oblongata to increase breathing rate (by increasing contractions of diaphragm/intercostal muscle)

Question 32

Hypoxia (altitude sickness)

Answer 32

Body first response is increase in breathing rate (bring more oxygen to alveoli)
Body will also produce more red blood cell ( when back to normal altitude, the extra RBC will allow for exceptional endurance, but the RBC will drop after a few weeks)