Respiratory System

Question 1

Why do we need to breathe?

Answer 1

To acquire oxygen for cellular respiration.

Question 2

Breathing

Answer 2

→ Inspiration (taking air into the lungs)

→ Expiration (breathing air out of the lungs)

Question 3

External Respiration

Answer 3

Exchange of O2 and CO2 between air and blood

Question 4

Internal Respiration

Answer 4

Exchange of O2 and CO2 between blood and cells of the surrounding tissue

Question 5

Cellular Respiration

Answer 5

Series of chemical reaction that take place in cells (mainly mitochondria).
→ Overall goal is to take sugar molecules (i.e. glucose) and extract the chemical energy found in the bonds of the molecule

General Equation:
C6H12O6 + 6(O2) → Enzymes → 6(CO2) + 6(H2O) + Energy

Question 6

Challenges with Bigger Organisms

Answer 6

→ The bigger you are the more oxygen you need!
→ Larger and complex organisms must have a large surface area to exchange the gas.
↪ Worms use their moist skin as the surface area to exchange gas. It must stay moist to work!
↪ Frogs use both skin and lungs…

Question 7

Pleural Membrane and Diaphragm

Answer 7

→ The human respiratory system is lined with two membranes called the pleural membranes.
→ They rest on the diaphragm, a muscular layer that separates the thoracic cavity from the abdominal cavity. The diaphragm plays a role in exhalation and inhalation.
→ The main function of pleural membranes is to hold the two lungs within their pleural cavity. This allows the lungs to expand during breathing and helps avoid friction and tissue damage.

Question 8

Nasal Cavity

Answer 8

→ Air enters the body through the nose, is warmed, filtered, and passed through the nasal cavity.
→ Foreign particles are prevented from entering the nasal cavities by tiny hairs lining the passageways as well as the mucus

Question 9

Pharynx

Answer 9

Cavity shared with the digestive system where air is passed through.

Question 10

Epiglottis

Answer 10

Essentially a one-way valve for air. Our esophagus and trachea are connected to one singular tube, that tube can either have air or consumables. The epiglottis makes sure that no food or drink enters the larynx.

→ Made of Elastic Cartilage
→ Apart of Pharynx

Question 11

Larynx

Answer 11

Voice box located in the upper part of the trachea.

→ The vocal cords are two bands of tissue that extend across the opening of the larynx. They vibrate as air is forced across them to produce sound.
→ Following puberty the larynx in male increases in size, creating a deeper sound in their voice.
→ Getting an infection and sickness can have an effect on the larynx changing the sound of your voice (eg. laryngitis).
→ made of muscles and cartilage

Question 12

Trachea

Answer 12

Most commonly referred to as the windpipe. This is the main airway to the lungs.
↪ Extends from Larynx to the bronchi

The trachea has multiple cartilaginous rings to keep it open as if it was soft, it would collapse from the difference in pressure that the lungs create.
↪ These cells still help the trachea maintain some flexibility to bend

Goblet cells (some are ciliated) line the trachea. The mucus produced by goblet cells traps debris that may have escaped the filters in the nasal cavity. The debris is swept away by the cilia.

If a large piece of debris (food or liquid) enters the trachea a cough is what results to send that piece out

Question 13

Bronchi

Answer 13

The trachea splits into the right and left Bronchus.

These are airways that lead to the lungs.

Reinforced with cartilage rings to prevent their collapse and are lined with ciliated goblet cells to filter out any debris

→ Made of columnar epithelial

Question 14

Bronchioles

Answer 14

These are pipes that get smaller and smaller until they reach the alveoli through the alveolar ducts.
→ Do not have cartilage rings
→ Smooth muscle tissue surrounds the bronchioles so that they can contract and expand

→ Made of columnar epithelial

Question 15

Alveoli

Answer 15

Bunched up in sacs called Alveolar sacs. These are responsible for gas exchanges.

Each of the Alveoli has capillaries around them.
→ Each of the Alveoli is lined with simple squamous epithelial.
→ The oxygen and CO2 exchange through diffusion.

→ When the lungs are inflated the alveoli are bulb shaped and when deflated they collapse on themselves.

Alveoli measure between 0.1 to 0.2 μm in diameter. Alveoli are surrounded by a network of thin-walled capillaries.

This relationship (alveoli and capillaries) allows for the exchange of gases. Each lung contains about 150 million alveoli. This would be about 40 times the surface area of our bodies or the size of a tennis court.

Both of the lungs contain about 700 million alveoli

Question 16

Gas Exchange: External Respiration

Answer 16

→ Occurs between the alveoli and the capillaries

→ When cells go to alveoli, they have more CO2 and less O2 while the alveoli have more O2 and less CO2. The differences in concentrations triggers diffusion.
↪ O2 diffuses from the alveoli to the capillary
↪↪ The oxygenated blood goes to the circulatory system where it is distributed throughout the body
↪ CO2 diffuses from the capillary to the alveoli
↪↪ The CO2 rich air in the alveoli is exhaled

Question 17

Gas Exchange: Internal Respiration

Answer 17

→ Occurs between the cells and tissues from all over the body and the capillaries

→ Capillaries are usually in O2 concentration and low in CO2 concertation near tissue. On the other hand, the cells in the body have a relatively low O2 level and high CO2 level (as a result of cellular respiration).
↪ O2 will diffuse from the capillary to the body cells
↪↪ The oxygenated cells will use the O2 for cellular respiration
↪ CO2 will diffuse from the body cells to the capillary
↪↪Deoxygenated blood will move to the heart to be pumped to the lungs to be exhaled (CO2 is a waste product for humans)

Question 18

Breathing

Answer 18

Definition: The process of taking in air and expelling it from the lungs.

→ Remember that air will always flow from a area of high pressure to an area of low pressure
→ The two muscles that control inhalation and exhalation in humans are:
↪ Diaphragm
↪ Intercostal Muscles (located between the ribs)

Question 19

Breathing: Inhalation

Answer 19

INHALATION (taking air into the lungs)

The intercostal muscles contract:
Ribs move up and out

Diaphragm contracts:
It moves downward

Together, these increase the volume of the thoracic cavity (chest cavity)
Increase in volume = decrease in pressure

Air moves into the lungs from the external environment, as the air moves from high(er) pressure to low(er) pressure

Question 20

Breathing: Exhalation

Answer 20

EXHALATION (moving air out of the lungs)

The intercostal muscles relax:
Ribs move back in

Diaphragm relaxes:
It moves back upwards

Together, these decrease the volume of the thoracic cavity
Decrease in volume = increase in pressure

Air moves out of the lungs to the external environment, as the air moves from high(er) pressure to low(er) pressure

Question 21

Tonsillitis

Answer 21

an infection of the tonsils cause by virus or bacteria

Question 22

Laryngitis

Answer 22

An inflammation of the larynx that can cause the voice to become raspy or hoarse

Question 23

Pneumonia

Answer 23

A disease that causes inflammation in one or both lungs; it is usually caused by a viral infection or a bacterial infection.

Question 24

Bronchitis

Answer 24

A respiratory disease that causes the inflammation of the mucous membrane of the bronchi; it is classified as either acute (due to infection) or chronic (due to irritant).

Question 25

Asthma

Answer 25

A lung disease that cases chronic inflammation of lungs and overproduction of mucus in lungs. This can be triggered by irritants or stress.

Question 26

Emphysema

Answer 26

A chronic respiratory where alveoli loose their elasticity which effect the lungs ability to expel air.

Question 27

Cystic Fibrosis

Answer 27

A genetic disease that causes a thick build-up of mucus in the lungs, resulting in infection, inflammation and damage to the lung tissue.

Question 28

Carcinoma

Answer 28

A tumor made up of rapidly multiplying cells.

Question 29

Metastasis

Answer 29

The spread of cancerous cells from their original site to other parts of the body.

Question 30

Diagnosis: Respiratory System

Answer 30

Computed Axial Topography: A specialized X ray technique that is used for imaging organs and other tissues in the body, also known as CAT or CT scan.

Two-photon microscopy: A technique that uses photons to form images of living tissue with a depth of up to 1mm

Bronchoscopy: An endoscope is passed to the lungs via the mouth and it allows doctors to repair damaged blood vessels, biopsy and remove tumors