Respiratory system Flashcards
upper respiratory tract
Nose, nasal cavity, paranasal sinuses and pharynx
lower respiratory tract
Larynx, trachea, bronchi, bronchioles and alveoli
2 zones
conducting zone- only passage no exhange of has
respiratory zone- exhange of gas
nasal cavity
three turbinate bones (nasal conchae) and nasal meatuses
the roof of the nasal cavity contains
sensory cells of the olfactory mucosa to help with smell sensatio
concahe
increase the surface area and produce a turbulent airflow to delay it for warming, humidifying and cleaning the air to protect the lungs.
goblet cells
secrete mucus, which can trap dust, debris and pathogens.
cilia
unison towards the pharynx to remove the mucus with damaging foreign particles.
paranasal sinus
hollow cavities in the facial bones, continuous with the nasal cavity. They warm, humidify, and filter air, lighten the skull and enhance voice resonance.
pharynx 3 types
nasopharynx- warm and humidtify air
oropharynx- common path for food and air
laryngopharynx- opens to anterior larynx and posterior oseophagus
larynx
voice box
thyroid cartlidge supports
epiglottis closes when swallowing prevents food entering lungs
vocal chords- membranous tissue
trachea
It is supported and kept open always by incomplete C-shaped hyaline cartilage rings. An elastic connective tissue and smooth muscle (trachealis muscle) completes the ring at the back. These soft tissues protect the oesophagus posterior to the trachea and allow it to expand during swallowing.
alveoli
Type I alveolar cells/pneumocytes, made of thin simple squamous epithelia to facilitate easy diffusion of gases.
close proximity to pulmonary capilaries for gases exchange
lungs
left- 2 lobes- cardiac notch
right- 3 lobes
hilum- entry of vessels
respiration
provides every cell with oxygen and removes co2
ventilation
continuous movement of fresh air rich in oxygen and removing carbon diozide
inhilation/ exhilation
inhilation
bringing air rich in 02 into lungs
exhalation
exspiring air rich in co2 from the lungs
ventilation mechanics
air moves from high pressure to low pressure
inhale pressure inside lungs must increase
exhale pressure iside lungs must increase
intraveolar pressure
pressure inside the lungs
p1 x v1=
p2 x v2
change lung pressure
skeletal muscles covering lungs
fluid in pleural cavity keeps lungs at a particular pressureso lungs adhere to the cavity
expand lungs during rest
inspiration is a … procces
active
diaphragm
dome shaped at rest
increase throacic volume/ decrease pressure
extrenal interchostal muscles
lift ribs up and down
forced inspiration
scalenes
sternoclionmastoid
trapizeus
quiet exspiration
is a passive proccess- no muscle contraction
decrease thoracic volume and increase throacic pressure
internal intercostal muscles
depress the rib cage
abdominal muscles
compress abdomin to decrease throacic volume
inspiration
At beginning of inspiration
* No pressure difference between atmosphere and lungs
* Intrapleural pressure is subatmospheric
2. Inspiratory muscles contract and intrathoracic volume ↑
3. Intrathoracic and Intrapleural pressure ↓
4. Lungs expand and alveolar volume ↑
5. Alveolar pressure ↓ and becomes subatmospheric
6. Air moves into the lungs due to pressure gradient
7. At the end of inspiration
* Intra-alveolar pressure becomes the same as atmospheric
pressure
* Intrapleural pressure is more -ve than at the beginning of
inspiration
expiration
At the beginning of expiration
* Intra-alveolar pressure is same as atmospheric pressure
* Intrapleural pressure is highly subatmospheric
2. Inspiratory muscles relax → intrathoracic volume ↓
3. Intrapleural pressure ↑
4. Lungs recoil and alveolar volume ↓
5. Alveolar pressure ↑ and becomes higher than atmospheric
pressure
6. Air moves out of the lungs
7. By the end of expiration
* Intra-alveolar pressure becomes the same as atmospheric
pressure
* Intrapleural pressure is less -ve than at the beginni
external respiration
passive diffsuion
gas exchange between the gas in the blood and gas in the lungs
across alveoli membrane
concentration
internal repiration
gas exhage between blood and cells of the body
type 1 pneumocytes
these cells are thin and squamous, ideal for gas exchange. They share a basement membrane with pulmonary capillary endothelium, forming the air-blood barrier where gas exchange occurs
20ml of oxygen in
every 100ml of blood
98 percent on haemagoblobin
haemaglobin
4 globin protein chains
each haem group
can bind 1 oxygen atom
oxyhaemaglobin
red bright
has oxygen
deoxyhaemaglobin
dark red
no oxygen
tissue have high concentration in tissue
lower ph
decrease oxygen binding affinity
increase in temperature
lowers oxygen affinity
carbon dioxide reactions
CO2 + H20 = H2CO3 = H + + CO3-
reaction goes right from tissue to blood
reaction goes to the left in lungs
CARBON DIOXIDE REACTION CAN BE INCREASED BY
carbonic anhydrase
controls respiration
PCO2 pressure that is high which is important for normal
if it is less then 40mmg then breathing could stop all togehter
hypercapnia
increased CO2
INCREASES H2CO3
INCREASE H+
caused by decreased oxygen delivery and co2 removal
decreased gas exchange
causes comma death dereased CNS actiivty
hypocapnia
decreased CO2
need to hyperventilate to increase CO2 removal
increase CNS activity
carbon dioxide travels in blood via
bicarbonate in blood
spirometry
lung functioned test
tidal volume
Amount of air inhaled during a normal breath
Expiratory reserve volume (ERV)
Amount of air that can be exhaled after a normal exhalation
Residual volume (RV)
Air left in the lungs after a forced exhalation
Vital capacity (VC)
Maximum amount of air that can be moved in or out of the lungs in a single respiratory cycle
respiratory minute volume
TV X RR
control of airways
during intense physical activity- increase enrgy expenditure
diameter of airways- autonomic nervous system
airflow during inspiration/ exhalation
turbulent flow vs lament flow
control of bronchiole diameter
parasympathetic nervous system cause smooth muscle to contract and bronchioles to contract and increase resistance to air flow decrease air into lungs
sympathetic nervous has no ability on there bronchioles
luminar flow
no resistance
turbulent flow
increased resistance
dorsal respiratory group
in medulla
fires signals for 2 seconds rest 3 seconds for expiration
venteral repsiratory group
medulla
controls both inspiration and expiration in forced breathing
pneumtaxic center
pons
controls rate and depth of breathing
C3 C4 C5 FOR DIAPHRAGM
RESPIRATORY REFLEXES
baroreceptors activated in hypoxia decrease breathing rate in BP is high
centeral chemoreceptors- activated when have high level of hydrogen ions and rising carbon dioxide levels
mechanoreceptors- decrease tifal volume increase breathing rate
age changes
Arthritic changes in the costovertebral joints and costal cartilages stiffening the thorax and decreasing compliance during inspiration.
Elastic tissue is replaced by scar tissue reducing lung compliance and vital capacity.
Emphysema destroys alveolar surfaces and reduces surface area available for gas exchange with ageing, particularly in smokers.
Physical activity and avoiding smoking can maintain exercise tolerance as you age.
