the repsiratory system

Question 1

respiration

Answer 1

exchange of gases between the atmosphere, blood and the
cells. Air is transported from the nasal cavity, down the pharynx, larynx and
trachea and through the bronchioles into the lungs.

Question 2

functions of the respiratory system

Answer 2

• move air to and from the body
• protects the airways by providing non-specific defences against pathogens
• maintains homeostasis
• speech

Question 3

quiet breathing vs forced breathing

Answer 3

Quiet breathing:
• Inspiration active (mainly diaphragmatic): shallow breathing involves intercostals.
• Expiration passive: elastic recoil of lungs and pressure from abdominal viscera.

Forced breathing (inspiration and expiration active):
• Involves accessory muscles of respiration: need to fix first and last rib. Abdominal muscles, pectoral muscles,
postural muscles

Question 4

Respiratory Mucosa

Answer 4

• Mucous membrane lines any area of the body that is exposed to the external environment.
• pseudostatified ciliated columnar

Question 5

Nasal Cavity

Answer 5

• It is very vascular (blood sinuses) so it warms the air.
  • Glands moisten the area.
  • Cleans and filters by cillia, mucus and hairs.

Question 6

Pharynx

Answer 6

Consists of the nasopharynx, oropharynx and laryngopharynx.

- They serve as pathways for the movement of food, liquid and air from the mouth

Question 7

Larynx

Answer 7

• epiglottis

- larynx

Question 8

trachea

Answer 8

respiratory epithelium

Question 9

Lungs

Answer 9

Have two completely separate independently functioning structures (3 right lobes and 2 left lobes).

Question 10

Pleura

Answer 10

Pleura is a double-sided thin membrane which surrounds the lungs and ribs

Question 11

Bronchial tree and alveoli

Answer 11

Primary bronchi > secondary bronchi > tertiary bronchi > terminal bronchioles > respiratory bronchioles > alveolar duct > alveolar duct > alveolar sac > alveolus.

Question 12

Ventilation

Answer 12

refers to the removal of CO2.

Question 13

Perfusion

Answer 13

refers to the intake of O2

Question 14

alveolar gas exchange

Answer 14

Oxygen in the alveolus must pass through the respiratory membrane to the blood stream. The CO2 in the blood must travel through the respiratory membrane to be expired.
- Oxygen diffuses into a layer of water inside the alveolus which passesthrough the cell membranes into the blood stream.

Question 15

factors effecting alevolar gas exchange

Answer 15

• gas flows in the correct direction
• solubility
• respiratory membrane thickness
• ventilation perfusion coupling

Question 16

regulation of blood pH

Answer 16

bicarbonate buffer system hydrates CO2 to form carbonic acid that dissociates into H+ and HCO3

Question 17

bicarbonate buffer equation

Answer 17

H2O + CO2 ⟷ H2CO3 ⟷ HCO3- + H+
An increase in H+ concentration is a decrease in pH (acidic environment).
- A decrease in H+ concentration is an increase in pH (alkalic environment).

Question 18

Buffer:

Answer 18

chemical substance or system that minimises changes in pH by releasing or binding H+ ions

Question 19

Blood pH is regulated sequentially by

Answer 19

• Chemical buffers
• Respiratory centres
• Renal mechanisms

Question 20

Pulmonary circulation

Answer 20

98% of the blood which delivers venous blood to be oxygenated

Question 21

Bronchial circulation

Answer 21

2% which delivers systemic blood to lung tissues.

Question 22

Pulmonary arteries

Answer 22

run alongside the air passageways to removing deoxygenated blood from the heart.

Question 23

Pulmonary veins

Answer 23

surrounded by alveoli and transport oxygenated blood back to the heart

Question 24

breathing

Answer 24

mechanical process which moves air into and out of the lungs via the diaphragm. It is a passive process that occurs in response to the rhythmically changing volume of the thoracic cavity.

Question 25

inspiration and expiration

Answer 25

Inflation and deflation of lungs depends on the slight negative pressure in the pleural space that pulls the
lungs and chest wall out. At rest the system is in balance. It relies on negative pressure in the pleural cavity.
- Inspiration is an active process. Expiration is usually a passive process (elastic tissue).

Question 26

what controls the rate and depth of breathing

Answer 26

• pons and mendualla

Question 27

Ventral respiratory group (inspiration)

Answer 27

output activates intercostal
muscles (intercostal nerves) and activates the diaphragm (phrenic nerves). Inspiration neurons fire, expiration neurons are inhibited

Question 28

Dorsal respiratory group

Answer 28

issues output to the VRG to modify the respiratory rhythm to adapt to varying conditions (alters time between inspiration and expiration).

Question 29

Pontine respiratory group

Answer 29

regulates rate and depth of breathing (input from hypothalamus, limbic regions and cortex). It regulates
breathing during exercise and sleep

Question 30

why are VRG and DRG are acted upon by the PRG

Answer 30

so that transition from

inspiration to expiration is sped up or slowed down which makes each breath shorter and shallower or longer and deeper.

Question 31

Residual volume

Answer 31

amount of air that cannot be exhaled from the lungs even with maximal effort.

Question 32

Vital capacity

Answer 32

ability to fully ventilate the lungs in a breath

Question 33

Tidal volume

Answer 33

amount of air inhaled then exhaled

Question 34

Forced Vital Capacity

Answer 34

total volume of air moved

Question 35

Forced Expiratory Volume

Answer 35

volume exhaled in first second