RESPIRATORY Flashcards
(45 cards)
FUNCTIONS OF RESPIRATORY CENTRE (6)
- Gas exchange
- Regular blood pH
- Smell
- Filter warm and moisten air
- Produce sound
- Excretes water and heat
Name conducting zone vs respiratory zone
Conducting zone
* nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
Respiratory zone (external respiration or gas exchange occurs)
* respiratory bronchioles. Alveolar ducts, alveolar sacs, alveoli
Describe the pharynx + functions
- skeletal muscles with mucous membranes
- comprised of naso/oro/laryngopharynx
- part of conducting airways
Functions - passage for food and air
- resonating chamber for speech sounds
- houses the tonsils
describe larynx structure and position
- Short tube of cartilage
- Lined by mucous membrane
- Connects pharynx to trachea
function of thyroid cartilage
forms anterior wall of the larynx
epiglottis, made from what, does what
- Elastic cartilage
- Partial section is free to move up and down with swallowing to protect larynx
- Food diverts down into oesophagus
Cricoid cartilage, made from what, does what
- Ring of hyaline cartilage
- Forms inferior wall of larynx
Trachea structure and function
- Passageway for air anterior to oesophagus
- Divides into left and right bronchi
- Lined with mucous membrane (cilia and goblet cells)
- Supported by cartilage
Describe bronchioles structure
progressively become smaller
cartilage decreases and then dissapears
smooth muscle cells are no longer present past the bronchioles
decrease of cilia
decrease of goblet cells = decrease mucous
parietal vs visceral pleura
- Parietal pleura- outer layer, attached to wall of thoracic cavity and diaphragm
- Visceral pleura- inner payer, attached to the lungs
lobes of lungs
right - 3 lobes
left 2 lobes
how much fluid in intrapleural space
18mls
alveoli structure and function
lined with epithelium
covered with surfactant
respiratory pattern medulla vs pons
Medulla
* Controls rhythm
* Both inspiratory and expiratory areas
Apneustic
* Area in lower pons
* Increases time of inhalation
Pneumotaxic
* Area in upper pons
* Help turn off inspiration to…decrease time of inhalation, increase respiratory rate
What stimulates our medulla for respiratory drive
Cortical influences
* Impulses from hypothalamus and limbic system stimulate respiratory centre
Chemoreceptor regulation
* Located in medulla
* Responds to H+ and PCO2 levels in CSF
this is a negative feedback system
Pulmonary ventilation, describe inhalation and exhalations relationship to atmospheric pressure
Inhalation occurs when pressure in lungs is LESS than the atmospheric pressure
Exhalation occurs when the pressure in the lungs is GREATER than the atmospheric pressure
Muscles of ventilation, inspiratory vs expiratory
Quite unforced inhalation
* Diaphragm and external intercostals
* Diaphragm = decreased pressure so air can flow in
Quiet exhalation is a passive process
* Begins when diaphragm and intercostals relax
* Due to elastic recoil of chest wall and lungs
* Volume decreases which forces air out
Ventilation pressure changes
At rest, inhalation, exhalation
comparing atmospheric pressure and alveolar pressure
At rest
* Atmospheric pressure = 760mmhg
* Alveolar pressure = 760mmhg
Inhalation
* Atmospheric pressure = 760mmhg
* Alveolar pressure = 756 mmhg
Exhalation
* Atmospheric pressure = 760mmhg
* Alveolar pressure = 762mmhg
Boyles Law define and relate to ventilation
relationship between pressure and volume
decrease volume = increase pressure and vice versa
* This happens when the muscles of inhalation cause the chest and lungs to expand on the command of the medulla oblongata (intrapulmonary pressure then falls to 758mmHg)
Daltons Law define and relate to gas exchange
The total pressure exerted by a mixture of gases is the sum of the pressures exerted by each gas in the mixture
* The partial pressure is proportional to the percentage of that gas in the mixture
* This is important in determining the movement of oxygen and co2 between the atmosphere and the alveoli, alveoli and blood and blood and cells.
* Each gas operates independently and diffuses from a higher PP to an area of lower PP
Henrys Law
The amount of gas that is dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid when the temperature is kept constant.
Increased temp = decreased solubility
O2 and nitrogen solubility is less than CO2 meaning very little can enter circulation at normal pressures
% of gases inspired at atmospheric pressure
- Nitrogen = 78.6%
- Oxygen = 20.0%
- Carbon dioxide =0.04%
- Water vapour = 0.46%
External respiration vs internal respiration brief description
aka pulmonary gas exchange
- Diffusion of O2 from air in alveoli to blood in pulmonary capillaries
- Diffusion of CO2 from pulm caps back to alveoli and then exhaled
internal = systemic gas exchange
= exchange of O2 and CO2 between systemic capillaries and tissues
Tidal volume vs minute volume
TV= volume of one breath
MV= rr x tidal volume
