Respiratory system

Question 1

What is the position of the lungs?

Answer 1

• The thoracic cage which encloses the heart and lungs.

- Boundaries are vertebral column, ribs, sternum and diaphragm.

Question 2

Why do we need respiration?

Answer 2

• We need oxygen!!
• Cells produce energy for maintenance, growth, defence and division.
• Cells use O2 and produce CO2.

Question 3

Describe 5 functions of the respiratory system?

Answer 3

• Provides gas exchange surface area between air and circulating blood.
• Moves air to and from exchange surfaces.
• Protects respiratory surfaces.
• Produces sound.
• Participates in olfactory sense.

Question 4

What does the respiratory tract consist of?

Answer 4

• Consists of conducting portion; from nasal cavity to terminal bronchioles.
• Consists of respiratory portion; the bronchioles and alveoli.

Question 5

What is the alveoli?

Answer 5

-Air-filled pockets within the lungs where all gas exchange takes place.

Question 6

Describe the upper respiratory tract?

Answer 6

• Nasopharynx = contains tonsils and openings to left and right auditory tubes.
• Oropharynx = communicates with oral cavity.
• Laryngopharynx = extends from hyoid bone to entrance of larynx and esophogus.

Question 7

Describe the trachea?

Answer 7

• Also the windpipe.
• Extends from ricoid cartilage where it branches into right + left pulmonary bronchi.
• 15 to 20 tracheal cartilages to strengthen and protect airway.

Question 8

Describe the bronchi?

Answer 8

• Right and left primary bronchi.

- The right is larger and descends at a steeper angle.

Question 9

Describe the lungs?

Answer 9

• Each lung in pleural cavity.
• The base of each rests on the diaphragm.
• Lungs have lobes separated by deep fissures.
• Right = THREE lobes!!
• Left = TWO lobes!!
• Primary bronchus branches in to secondary bronchi, then to tertiary.
• Each lung surrounded by membrane called pleura and in pleural fluid.
• Each bronchiole delivers to a single pulmonary lobule.

Question 10

The lungs and autonomic control?

Answer 10

• ANS regulates smooth muscle, diameter of bronchioles, airflow, dilation of bronchioles.
• Bronchoconstriction; caused by ANS activation, histamine release (allergic reaction).

Question 11

What is pneumonia?

Answer 11

• Causes fluid to leak into alveoli.

- Compromises function of respiratory membrane.

Question 12

Explain the blood supply to the lungs?

Answer 12

-Capillaries supplied by bronchial arteries, provide oxygen and nutrients to tissues of conduction passageways of lung.

Question 13

Name the 3 processes of external respiration?

Answer 13

• Pulmonary ventilation.
• Gas diffusion.
• Transport of O2 and CO2.

Question 14

What is pulmonary ventilation?

Answer 14

-Causes volume changes that create changes in pressure.
Summary:
-Diaphragm contracts, thoracic cavity volume increases, internal pressure in lungs fall and so air flows into the lungs.

Question 15

Name the respiratory muscles?

Answer 15

• Diaphragm
• External intercostal muscles
• Accessory respiratory muscles

Question 16

Name the muscles of active exhalation?

Answer 16

• Internal intercostal
• Transverses thoracis muscles
• Abdominal muscles

Question 17

What occurs during pulmonary ventilation?

Answer 17

• Physical movement of air into and out of the lungs.
• Maintains right amount of air in and out.
• Brings in O2 and CO2.
• Gas exchange.
• Lungs give off heat and H2O vapour.

Question 18

Describe the stages of inspiration?

Answer 18

• Contracting the diaphragm moves it downwards.
• Expands thoracic cavity.
• Pulls pleura (attached to lungs).
• Lungs expand
• Air drawn into lungs.

Question 19

Describe the stages of expiration?

Answer 19

• Diaphragm relaxes and moves upwards.
• Reduces thoracic cavity.
• Pushes pleura.
• Lungs go back to resting size.
• Air pushed out of lungs.

Question 20

What happens to the accessory muscles during in and ex?

Answer 20

• External intercostal muscles move ribs up and out aiding INspiration!!
• Internal intercostal muscles move ribs down and in during EXpiration!!

Question 21

Abreviations for calculations?

Answer 21

• Pulmonary ventilation (PV) = total amount of air moved in or out each minute.
• Tidal volume (TV) = ‘size’ of each breath.
• Respiratory rate (RR) = number of breaths per min.

PV = TV x RR

Question 22

Extra in and ex?

Answer 22

• Extra inspiration = inspiratory reserve volume.

- Extra expiration = expiratory reserve volume.

Question 23

What is residual volume?

Answer 23

• RV is when some air is still present in the lungs after maximum expiration.

Question 24

How to calculate vital capacity (volume available)

Answer 24

VC = IRV + ERV + TV

Question 25

Respiratory calculations?

Answer 25

- Tidal volume = normal breathing. - Vital capacity = ERV + TV + IRV. - Inspiratory capacity = TV + IRV. - Expiratory capacity = TV + ERV. - Total lung capacity = VC + RV.

Question 26

What is anatomic dead space?

Answer 26

Volume of air remaining in conducting passages. | This is because not all air reaches alveolar exchange surfaces.

Question 27

What do red blood cells do?

Answer 27

- Transport O2 to and CO2 from peripheral tissues. | - Remove O2 and CO2 from plasma, allowing gases to diffuse into blood.

Question 28

How is oxygen transported?

Answer 28

- O2 binds to iron ions in haemoglobin (Hb) molecules. - Each RBC has about 280 million HB molecules. - Each binds four O2 molecules.

Question 29

How is carbon dioxide transported?

Answer 29

- It can be converted to carbonic acid. - Bound to protein portion of haemoglobin. - Dissolved in plasma.

Question 30

Describe carbon monoxide?

Answer 30

- Binds strongly to haemoglobin. - Takes the place of O2. - Can result in carbon monoxide poisoning (death).

Question 31

Where is respiration controlled?

Answer 31

- Involuntary centers in brain stem; regulate respiratory muscles. - Voluntary centers in the cerebral cortex.

Question 32

Voluntary control of respiration?

Answer 32

- Strong emotions; can stimulate respiratory centers in hypothalamus. - Emotional stress can activate sympathetic division of ANS. - Anticipation of stenuous excercise; can increase respiratory rate.