Unit 1 Lecture 1: Respiratory Structure and Function

Question 1

Main Purpose of the Respiratory System

Answer 1

Obtain O2 for the cell’s to use and eliminate the CO2 the body’s cell produce

Question 2

The Respiratory System encompasses two separate but related process which are…?

Answer 2

1. Internal Respiration - inside the cell; consume O2 and produces ATP
2. External Respiration - Outside of the cell itself between the external environment and the cells of the body

Question 3

What are the four steps for external respiration?

Answer 3

1. Ventilation/Breathing: Movement of air into and out of the lungs
2. O2 and CO2 are exchanged between air and alveoli and blood within pulmonary capillaries by means of diffusion
3. Blood transports O2 and Co2 between the lungs and tissues
4. O2 and Co2 exchanged between tissues & blood by process of diffusion across systemic (tissue) capillaries

Note: Pulmonary capillaries are wrapped all around the alveoli to increase SA and help with diffusion of air

Question 4

If 21% of atmospheric oxygen is inhaled in along with 0.03% CO2, upon exhalation what percentage of O2 and Co2 would you estimate the body to have?

Answer 4

The body would release about 15% oxygen because it uses some of it for the cells and the percentage of CO2 is 4.4% because the cells release metabolic waste products

Question 5

What did the Wasserman Gears of Life represent?

Answer 5

There are gears representing “lungs,” “heart blood,” “Muscle” showing that they work in unison

Note: When exercising these gears move faster

Question 6

What are some non-respiratory functions of the respiratory system?

Answer 6

• Enhances the venous cavity by increasing volume of air you intake which in turn decreases the pressure of the thoracic cavity to let the air flow in
• Lungs provide a reservoir of blood for the left heart, helping to equalize outputs of the left and right ventricles

Question 7

What is the main respiratory muscle?

Answer 7

Diaphragm; Inspiratory Muscle

Question 8

In terms of anatomy, the lungs contain what?

Answer 8

Airways and alveoli (includes bronchi which end with alveolus)

Question 9

The chest wall includes structures apart of respiration which are:

Answer 9

Thorax and abdomen
* Contains muscle that contract and generate air flow

Note: Uses Boyle’s Law (change in pressure and volume and they are inversely related)

Question 10

What is the reason for the bronchi splitting into several branches?

Answer 10

To have multiple alveoli and allow for increased SA for gas exchange

Question 11

Which structure indicates the beginning of the conducting zone?

Answer 11

Trachea

Question 12

Where in the system does gas exchange occur?

Answer 12

Specifically in the alveoli where gases (O2 and Co2) are exchanged

Question 13

Which part of the airway is lined with smooth muscle?

Answer 13

Specifically the bronchioles (outer part)

Question 14

When the airways branch there are two changes occuring when branching. These changes are…?

Answer 14

1. Radius (branches smaller than others)
2. Change airflow rates

Question 15

What is found inside of the airway and what does it help with?

Answer 15

• Cilia: helps with warming the air that is inhaled so that it’s not irritating
• Mucus secreted; byproduct of lymphatic system

Cilia also traps foreign particles by pushing them upwards

Question 16

What are the pores of Kohn?

Answer 16

Found in walls between adjacent alveoli permit airflow between adjoining alveoli; collateral ventilation

Question 17

The Lungs have a large quantity of elastic connective tissue. What does that mean in terms of how the lung feels?

Answer 17

The lungs would feel and be more elastic in nature

Note: Elastic in nature makes sense as it is supposed to expand and deflate

Question 18

The muscle surrounding the airways are innervated by the ANS. What can the innervation allow for?

Answer 18

Constriction and dilation of the bronchioles

Note: There are different types of medications like puffers to help force the bronchioles to dilate

Question 19

What structure in the airways is sensitive to certain hormones and local chemical?

Answer 19

Bronchioles

Question 20

What are bronchodilators?

Answer 20

Dilates bronchioles which are innervated by smooth muscle; chemical

Question 21

What is a beta 2 agonist?

Answer 21

Found in inhalers and it is a chemical that binds to specific beta 2 receptors to restrict them and dilate the bronchioles

Question 22

What are the alveoli known for and what are the different types of alveoli?

Answer 22

• Known for their gas exchange
• Type 1 Alveolar and Type 2 Alveolar Cells

Question 23

What are type 1 alveolar cells?

Answer 23

Surround the alveoli as a wall essentially and is very thin which allows for easy gas exchange

Question 24

Where is the intersitial space located?

Answer 24

Between the alveoli and the pulmonary capillaries

0.5 micrometres

Question 25

What are Type 2 alveolar cells?

Answer 25

• Secretes pulmonary surfactant; reduces surface tension in alveoli to help maintain good level of pressure in all the alveoli

W/o the surfactant some alveoli will expand and others will deflate
Fun fact: Babies (fetus) make their own surfactant by week 34-36 so being born before that, they need to have a breathing tube attached to allow for all alveoli to get equal pressure

Question 26

What are alveolar macrophages and where are they located?

Answer 26

Alveolar macrophages are guarding the lumen; protector of alveoli and they are located within the alveoli

Question 27

In the chest wall we have two classes of muscle: Inspiratory and expiratory muscles. Which of the two is more active than the other and why?

Answer 27

Inspiratory muscle are very active/busy while expiratory muscles can be active. Essentially when you use your inspiratory muscles to breathe in, expiratory muscles aren’t really used as much since the inspiratory muscles just need to stop contracting

Therefore, expiratory is not as active due to this and the fact that the lungs are elastic in nature so they themselves will want to go back to normal without having to wait for the muscles to help

Question 28

List the Inspiratory Muscles and Expiratory Muscles used in ventilation?

Answer 28

Inspiratory: Sternocleidomastoid, Scalenes, External Intercostals, Parasternal Intercostals, Diaphragm

Expiratory: Internal Intercostals, External abdominal obliques, Internal abdominal obliques, Rectus and transversus abdominus

Question 29

What type of situation would involve the expiratory muscles to be more active?

Answer 29

Going beyond natural recoil of lungs by forcefully exhaling; need the expiratory muscles to push the lungs and deflate them

The Lungs naturally want to recoil which is why you usually don’t see the expiratory muscles working to push air out

Question 30

Explain how air entering the lungs causes a change in volume and pressure

Answer 30

When air is entering into the body there’s an increase in volume for the amount of air going into the alveoli and this in turn causes intra-alveolar pressure to decrease which results in higher volume of air in the lungs

Question 31

The relaxation of what structures causes the size of the chest cavity to decrease?

Answer 31

Relaxation of the diaphragm (main inspiratory muscle), muscles of the chest wall, and elastic recoil of alveoli

Question 32

During expiration when volume decreases what happens to pressure?

Answer 32

Intra-pleural pressure and intra-alveolar pressure increases as volume decreases due to the expiratory muscles contracting which allows for air to be driven out

Pressure becomes greater than atmospheric pressure which then can be released