Respiratory System

Question 1

What does the Upper respiratory tract do?

Answer 1

aids in the passage of air
Moistens the warm air before it reaches our lungs

Question 2

What makes up the upper respiratory tract

Answer 2

Nasal cavity
Pharynx- nasopharynx, oropharynx and laryngopharynx
Larynx

Question 3

Describe the nasal cavities structure and function

Answer 3

Internal chambers in the nose
Where air is inhaled, warmed and humidified

Question 4

Describe the structure of nasal conchae and function

Answer 4

Scroll-shaped bones
That protrude and firn spaces which air passes
Conchae swirl air around allowing time to humidify, warm and clean air before it enters the lungs

Question 5

Describe the epithelial cilia and mucous membrane function in the nasal cavity

Answer 5

Seromucous, other glands and goblet cells produce mucous that along with cilia traps unwanted large particles which we cough or swallow when it reaches the pharynx

Question 6

What is the purpose of the epithelial lining

Answer 6

Contains glands/goblet cells which secrete mucus to trap particles
Ciliates cells waft foreign particles towards the pharynx where they can be swallowed
Phagocytotic cells engulf an destroy bacteria and debris trapped by mucus

Question 7

larynx function

Answer 7

voice box

Question 8

pharynx function

Answer 8

dual function as passageway for air travelling to and from the lungs and swallowing food and drink down the oesophagus

Question 9

what happens to the epiglottis when breathing

Answer 9

stays up and air passes freely between laryngopharynx and larynx

Question 10

what happens to the glottis and epiglottis when eating

Answer 10

when eating glottis closes and epiglottis folds backwards covering the entrance to the larynx so food and liquid don’t enter the trachea to lungs

Question 11

What makes up the lower respiratory tract?

Answer 11

Bronchial tree:
Trachea
Divides into two primary bronchi
Hilum
Divide into two/right secondary bronchi and three/left
Tertiary bronchi
Bronchioles
Alveoli
Alveolar sacs

Question 12

Describe the structure of the trachea

Answer 12

Cylindrical tube, has c-shaped cricoid cartilaginous tubes prevent airway collapse
Lined with ciliated epithelial cells containing goblet cells which secrete mucus

Question 13

Describe the structure of bronchi

Answer 13

Structured by cartilage

Question 14

Describe the structure of bronchioles

Answer 14

Structured by smooth muscle
Under the control of autonomic nervous system can cause bronchodilation and brochoconstriction

Question 15

Describe the structure of alveolus

Answer 15

One layer of squamous epithelial cells (type 1 cell) also contains type 2 cells (cuboidal) which secrete pulmonary surfactant, a phospholipid what keeps the membrane moist and the alveolus patent
Covered by a network of pulmonary capillaries, each wall is one cell thick
macrophages line alveolar surface

Question 16

Describe the relationship between alveolar and the pulmonary blood vessels

Answer 16

The meet point between the walls of the alveolus and wall of capillary is called the respiratory membrane
Gas exchange occurs via diffusion
The large surface area plus very thin wall = efficient gas exchange

Question 17

describe the pleura and pleural cavity

Answer 17

pleura consists of a closed sac of serous membrane which contains a small amount of serous fluid called pleural fluid
the visceral and parietal pleura refer to the two layers of the pleura cavity

Question 18

describe the role of pleura

Answer 18

the lungs can expand and recoil within the pleural sac, lubricated by the pleural fluid

Question 19

describe the conducting zone

Answer 19

from nostril to start of bronchioles
no gas exchange

Question 20

describe intercostal muscles

Answer 20

11 pairs between 12 pairs of ribs
supplied by intercostal nerves and arranged in two layers: external and internal

Question 21

describe the function external intercostal muscles

Answer 21

lift the rib cage up and out in inspiration

Question 22

describe the function of internal intercostal muscles

Answer 22

used when expiration becomes active, i.e. exercise

Question 23

describe the diaphragm

Answer 23

dome-shaped muscular structure

Question 24

Describe Inspiration

Answer 24

Active (needs energy), simultaneously, diaphragm contracts and moves downwards and external intercostal muscles contract which expands the thoracic cavity and the rib cage is moved upwards and outwards, causing the lung tissue to be pulled upwards and outwards with the ribs and downwards with diaphragm as pleura membrane is all connected
causes lungs to expand and pressure within alveoli and air passage to decrease, drawing air into lungs

Question 25

Describe expiration

Answer 25

Passive, diaphragm and external intercostal muscle relax, so downwards and inwards movement of rib cage so volume of thoracic cavity is reduced and pressure inside lungs increases so Air is expelled .

Question 26

describe how accessory muscles are used in forced inspiration

Answer 26

muscles contract and pull rib cage upwards boosting the action of the external intercostal muscles

Question 27

describe how accessory muscles are used in forced expiration

Answer 27

shortens the expiration time, increases the speed and force of exhalation and allows respiratory rate to rise sometimes the abdominal muscles are used, which compress the abdominal organs increasing the upward pressure on diaphragm and helping to force air out of lungs

Question 28

describe the physiological variables affecting breathing

Answer 28

elasticity: the amount of stretch of the lung and ability to return to normal compliance: how easy it is for the lungs to stretch airway resistance: how easy it is for air to move through the airways

Question 29

describe the role of surfactant

Answer 29

reduce friction and decrease surface tension within the alveoli and makes it easier for the alveoli to expand and contract

Question 30

describe the mechanics of inspiration

Answer 30

movement of rib cage and flattening of diaphragm increases lung volume causes drop in airway pressure air rushes in lungs expand max air is lung volume

Question 31

define tidal volume

Answer 31

amount of air that moves into the lung in one respiratory cycle

Question 32

define functional residual capacity/ residual volume

Answer 32

amount of air left in the lungs at the end of expiration

Question 33

describe the mechanics of expiration

Answer 33

relaxed diaphragm relaxes the chest muscles causes rib cage to compress lungs and decrease space as u breath out lungs return to original shape due to elastic recoil

Question 34

define inspiratory reserve volume

Answer 34

extra volume of air over and above the normal tidal volume that can be inhaled into the lungs during max inspiration

Question 35

define inspiratory capacity

Answer 35

amount of air that can be inspired with max effort

Question 36

define expiratory reserve volume

Answer 36

additional volume of air that can be expelled over and above the normal tidal volume during max expiration

Question 37

define peak expiratory flow

Answer 37

measured with peak flow meter and record max speed of air flow during forced expiration

Question 38

define vital capacity

Answer 38

the max amount of air that can be moved in and out of the lungs

Question 39

describe the gas exchange taking place during respiration in alveoli and tissues

Answer 39

lungs: high partial pressure of oxygen in alveoli so oxygen binds to haemoglobin in blood blood: low partial pressure of oxygen in blood so carbon dioxide binds to haemoglobin in blood

Question 40

describe transport of CO2

Answer 40

10% as dissolved gas 30% combined with Hb 60% as bicarbonate ions

Question 41

describe neural control of ventilation

Answer 41

receptors (peripheral chemoreceptors, central chemoreceptors and pulmonary mechanoreceptors) > respiratory control centre (medulla, pons) > impulse travels via spinal cord > effectors (respiratory muscles, diaphragm)

Question 42

describe the central chemoreceptors role

Answer 42

central- brain stem neurons respond to changes in pH in cerebral spinal fluid = levels of CO2 in blood maintaining stable pH ensures stable CO2 levels

Question 43

describe the peripheral chemoreceptors role

Answer 43

peripheral- sensitive to pCO2 and low arterial pO2