respiratory system Flashcards
what are the 3 functions of the respiratory system
supply the body with o2 excretory organ (co2, h20, ketone bodies, heat) maintain PH of body fluids
how many lobes does the right lung have
3
superior, middle, inferior
how many fissures (lobes divided by fissures) does the right lung have
2
oblique and horizontal
how many lobes does the left lung have
2
superior, inferior
how many fissures (lobes divided by fissures) does the left lung have
1
oblique
what surrounds the lungs
pleura (2 parts) visceral pleura (covering lung) parietal pleura (covering chest cavity)
according to position, what parts make up the upper respiratory tract
nose, nasal cavity, paranasal sinuses, pharynx, larynx
according to position, what parts make up the lower respiratory tract
trachea, bronchi (primary, secondary and tertiary), bronchioles, alveoli
according to function, what makes up the conducting zone
nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
according to function, what makes up the respiratory zone
respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
what are the functions of the nasal cavity
warms, cleanses, humidifies inhaled air, detects oudors, modifies the voice,
what are the 3 parts of the nasal cavity
conchae (blood filled folds)
meati (channel between conchae)
paranasal air sinus (holes in bone, sinuses)
where is the pharynx and what does it do
extends from the nose to the larynx.
passageway for air and food, warms and humidifies air
where is the larynx and what does it do
connects laryngopharynx with trachea (made up of 9 pieces of cartilage)
maintains an open airway and where voice box located
what happens during swallowing
larynx pulled up, epiglottis moves down to cover laryngeal inlet (trap door)
where is the trachea and what is it made up of
below the larynx
made up of cartilage ring, smooth muscle and respiratory mucosa
what are the 6 parts of the bronchial tree top to bottom
trachea primary bronchi secondary bronchi (3 in right lung, 2 in left) tertiary bronchi bronchioles terminal bronchioles
do both bronchi and bronchioles have cartilage
no, just bronchus has cartilage
does the pulmonary (lung) artery carry oxygenated or deoxygenated blood to the lungs
deoxygenated - carries it from the heart to the lungs to be oxygenated
what do the pulmonary (lung) veins do
carry oxygenated blood to the heart
what do bronchial arteries do
supply lung tissue with blood (don’t supply alveoli -capillaries supply alveoli)
what do pulmonary veins do
carry oxygenated blood to the heart
what is pulmonary ventilation
the exchange of air between the atmosphere and the alveoli of the lungs
what muscles are involved in quiet inspiration - sat down, relaxed
diaphragm (80%) external intercostals (20%)
what nerve is responsible for initiation of breath
phrenic nerve
what is involved in quiet expiration
passive process based on elasticity of lungs
what is involved in forced inspiration
scalenes (muscles in the neck) sternocleidomastoid (sides of the neck - Deadre Rasheeds!) pectoralis minor (muscle in upper part of chest) pectoralis major (chest)
what is involved in forced expiration
internal intercostals oblique and rectus abdominis muscles (abdomen) quadratus lumborum (connects pelvis to spine)
how does movement of chest wall help air to enter and leave the lungs
pressure differences between the atmosphere and the alveoli created by pressure difference in thoratic cavity and contraction and relaxation of respiratory muscles
what is respiratory pressure
always related to atmospheric pressure 760 mmHg (mm of mercury) at sea level (the pressure exerted by the air or gases surrounding the body) - if no atmospheric pressure air would not go into lungs
intrapleural (space between two membranes, filled with fluid) pressure (Pip) is how much lower than intrapulmonary pressure (pressure within the lungs). what does this mean
intrapleural pressure is 4mmHg lower than intrapulmonary pressure which prevents the lungs from collapsing
what happens when you breathe in
rig cage expands/moves up and out, diaphragm flattens, pressure goes down due to larger space, draws air in down pressure gradient
what is Boyles Law
when the temp of a gas is constant the pressure varies inversely with its volume - as volume increases, pressure decreases e.g during inspiration
what is pulmonary compliance
the ease with which the lungs can be expanded
during inhalation bronchioles enlarge - what happens to the resistance to airflow
it decreases
during exhalation, as the bronchioles deflate what happens to the resistance to airflow
it increases
how is lung function assessed - 3 ways
chest sounds (presence of mucus) pulmonary functions test using peak flow spirometer (device which measures amount of air entering and leaving the lungs)
what is FVC
Forced vital capacity - deep breath followed by rapid maximal exhalation, peak flow (>70% in healthy person)
what is FEV
Forced expiratory volume - volume exhaled during the first second of a forced expiratory maneuver
what is Henry’s law
amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in air
how much of oxygen is carried bound to haemoglobin
- 5% - Each haem portion of Hb can carry 4 molecules of O2
1. 5% carried in plasma
what factors effect the affinity of hb for oxygen and how do they effect the oxygen-haemoglobin dissociation curve
temperature carbon dioxide how acidic the blood is structure of hb as oxygen affinity for hb decreases partial pressure decreases (?)
what is partial pressure
the pressure that one gas in a mixture of gases would exert if it were the only gas present
how is carbon dioxide transported
70% as bicarbonate (HCO3-) ion in plasma
23% bound to Hb in RBC’s
7 % in plasma
what is the formula for carbon dioxide transport
CO2 + H20 ↔ H2CO3 ↔ H+ + HCO3-
Carbon Dioxide + water ↔ carbonic acid ↔ Hydrogen + bicarbonate
controls breathing as reversable
if CO2 levels increase (e.g emphysema) what happens, what can this lead to
increases CO2, PH of blood decreases as more carbonic acid is formed. can lead to respiratory acidosis (PH < 7.35)
if CO2 levels decrease (e.g panic attack) what happens, what can this lead to
PH of blood increases (less carbonic acid) as more carbonic acid is converted into CO2 (?) Can lead to respiratory alkalosis (PH>7.45)
what is internal respiration
exchange of oxygen between blood and cells/tissues
what is external respiration
exchange of oxygen between environment and internal body
how is breathing controlled
CNS pons and medulla - repetitive stimuli are sent form the respiratory control centres (pontine centres) in the pons (brain) to the ventral respiratory group (VRG) in the medulla to Dorsal Respiratory group
what factors influence rate and depth of breathing - 4 things
changing demands: exercise
altitude
disease
changing levels of co2, o2, h+
What are the two types of chemoreceptors which help detect changes in chemical and what do they do
1) peripheral chemoreceptors: detect changes in O2. aortic bodies, carotid bodies, medicate 30% of the response to CO2
2) central chemoreceptors: detect changes in CO2, in medulla monitor cerebrospinal fluid and mediate 70% of the response to CO2
what can happen to patients who retain CO2 for example COPD patients
their chemoreceptors adapt to constantly high paCO2 (hypercania) so a decrease in paco2 becomes their main respiratory stimulus (hypoxic drive). If given air enriched with O2 it takes away their hypoxic drive, their breathing slows and paco2 increases even more so
what increased paCO2 level triggers a response
> 43mmHg
what decreased paCO2 level triggers a responce
<37mmHg
what happens if O2 levels (PaO2 levels) increase eg breathing in oxygen-rich gas
generates free radical which are toxic and can lead to coma and death
what happens if O2 levels (PaO2 levels) decrease
must drop below 60mmHg before ventilation is increased otherwise central chemoreceptors switch off
What are the key regulators of breathing
CO2 and H+
What is hypoxia
Hypoxia (also known as Hypoxiation or Anoxemia) is a condition in which the body or a region of the body is deprived of adequate oxygen supply.
