RESPIRATORY Flashcards
What does pseudostratified mean?
epthelium consisting of closely packed cells whcih appear to be arranged in layers but all fo which are attached to a basemment membrane.
what does olfactory mean?
relating to the sense of smell
what does patent mean?
open/unobstructed/allowing free passage
what is the optimal condition of air?
warm, clean, moist
what relationship do we want blood and air to have for gas exchange?
close together but still seperated
what 5 things does the respiratory system need to be effective?
- surface for gas exchange
- path for air to flow to gas exchange surface
- ability to breathe ai in and out
- olfaction
- be able to produce sound
what are the main components of resp system?
upper resp tract, LRT, thoracic cavity, joints, resp muscle.
what are the main components if the URT?
nose, nasal cavity, paranasal sinuses, pharynx
what are the main components of the LRT?
larynx, trachea, bronchus, bronchioles, respiratory bronchioles, alveoli
what are the alveoli?
sites of gas exchange
alveoli is resp region, nasal cavity to bronchioles is:
conducting region
what is the oral cavity for?
passage of fod and air
what does the epithelium do along the resp tract?
- changes for function
- makes air optimal condition
what kind of epithelium does the conducting region have?
respiratory epithelium
what kind of epithelium does the areas where air and food travel have and why?
stratifies squamous to protect from abrasion
what kind of epithelium does sites of gas exchange have?
simple squamous so it can be very thin
what kind of epithelium does olfacating areas have?
olfactory mucosa
what is respiratory eptihelium?
psuedostratifid ciliated columnar epithelium. goblet cells within hold and produce mucus.
where is resp epithelium found?
nasal cavity, part of pharynx, larynx, trachea, bronchi.
what do goblet cells do?
- produce mucus, trap debris, moisten air, cilia push dirty mucus to throat so it is swallowed
why do people have a running nose in the cold?
cili require a certain temp to work - in the cold they will stop working.
why do people cough/have a runny nose when they are sick?
when people are sick, they produce more mucus so the cilia cannot keep up, we have to help the mucus move by coughing
what is smokers cough?
smoke kills cilia and therefore they arent able to move the mucus normally and so they have to cough more.
what is the upper resp tract function?
- conducting passage
- prepares air for resp membrane/ gas exchange (warm, moist, clean)
- smell and sound/speech
what are the parts of the pharynx?
- nasopharynx
- oropharynx
- laryngopharynx
what is the primary passageway for air?
the nose
what is the nose primarily made of? why?
cartilage, it mainitains patent airways
what is another name for the nostrils?
external nares
what is the accessible part of the nose called?
vestibule
what is the nose lined with?
skin
what are the nose hairs called? what do they do?
vibrissae - they filter inhaled air
what is the nasal septum made of?
anterior - cartilege
posterior - bone
what do the internal nares open into?
nasal pharynx
what bones form the roof of the nasal cavity?
ethmoid and sphenrid bones
what is conchae and where is it?
3 projections (superor, middle, inferior) on lateral walls
what does conchae do and what is it made of?
- circulates air within the space (turbinate)
- makes more surface area for warming humidifying olfaction.
- is covered by resp epithelium and goblet cells
where is olfactory mucosa found?
on an area on the roof of the nasal cavity. it contains smell/olfactory receptors.
what is nasal mucosa and what is its function?
lining of the nasal cavity. epithelium sits on lamina propia. has a plexus of thin walled veins.
helps warm the air that comes in (radiation)
what happens when air temp drops in the nasal cavity?
the vascular plexus dilates = greater heat transfer. nose bleeds generally originate from bleeding here.
what is a sinus?
air filled cavity within a bone.
what does paranasal mean?
surrounding nose
where are the paranasal sinuses found?
within frontal, sphenoid, ethmoid, and maxillary bones.
what are paranasal sinuses lined with?
respiratory mucosa
where do paranasal sinuses drain to?
pharynx
what is the function of paranasal sinuses?
- lightens skull
- increases sa to clean/moisten air
- sound resonance
what are blocked sinuses?
infected mucus can block drainage.
what is the pharynx?
muscular funnel shaped tube shared by resp and digestive systems.
what are the three regions of the pharynx?
- nasopharynx (air ONLY)
- oropharynx
- laryngopharynx
where is the nasopharynx?
posterior to the nasal cavity, from the posterior nares to the soft palate.
how is food blocked from the nasal cavity?
the uvula and soft palate block the nasopharynx during swallowing
where do the auditory tubes drain from and to?
from the middle ear to the nasopharynx
where are the pharyngeal tonsils (adenoids)?
on the posterior wall of the nasal cavity/nasopharynx.
which part of the pharynx is food and which part is air?
- nasopharynx (air ONLY)
- oropharynx (air and food)
- laryngopharynx (air and food)
what lines the oropharynx?
stratified squamous epithlium to protect against abrasion.
what lines the laryngopharynx?
stratified squamous epithlium to protect against abrasion.
where is the oropharynx?
posterior to the oral cavity, from soft palate to hyoid bone.
what two tonsils are found in the oropharynx?
palatine tonsils (visible) and lingual tonsils (under tongue).
where is the laryngopharynx?
from hyoid bone to opening of larynx/begninning of esophagus. ends at level where resp and digestive tracts diverge.
what has right of way in laryngopharynx?
food - swallowing is prioritised.
what kind of eptihelium is found in the oropharynx, laryngopharynx and vestible of nose?
stratified squamous epithelium
what are the components of the LRT?
larynx, trachea, bronchi, bronchioles, alveoli
what are the functions of the LRT?
conducts air to/from site of gas exchange
completes cleaning/warming/humidifying of the air and blood
has a large sa for gas exchange
what is the only thing that passes through the larynx?
air only
where is the larynx?
from the hyoid bone to the trachea, anterior to the esophagus
what protects and maintains the airways in the larynx?
cartilege
what is cartilege’s function in the larynx?
to protect and amintain open airways
what is the epiglottis?
a flap that closes over airway to stop food from entering during swallowing.
hat is the adams apple and what does it do?
laryngeal prominence, protects larynx etc
what si the glottis?
the voicebox
what are the two types of folds attached to the voicebox?
vocal folds, and vestibular folds.
what do vocal folds do?
‘true vocal cords’, air = vibration = noise. the thicker the folds the deeper the voice (thicker folds in males).
what do vestibular folds do?
‘false vocal cords’, superior to vocal cords, prevent forgeign materials from entering. produce very deep sounds when used (rarely - you have to be trained to use them).
where is the trachea?
anterior to the esophagus between larynx and primary bronchi
what is the fucntion of the trachea?
maintain patent airways and clean/warm/humidfy air
how does the trachea maintain patent airways?
c shaped cartilege rings (lets esophagus open)
ends of c connected by smooth muscle
m,any elastin fibres in lamina propie/submucosa layers.
what in the trachea allowes for coughing and how?
the ends of the c connected by smooth muscle (trachealis) for coughing when they contract.
how does trachea clean/warm/humidfy air?
resp epithelium
what is the mucociliary escalator and what does it do?
removes debris from the pharygnx to be swallowed and digested. is made up of cilia hairlike structures that move mucus.
where is the mcus from and what does it coat?
from goblet cells and mucus glands to coat surface of epithelium
how many lobes are in each lung and why?
right side has 3 lobes
left side has 2 lobes
this allows room for the heart
what is the hilum?
where the bronchi and blood vessels enter the lungs
what is the coastal surface?
outer surafe of lungs against ribs
what does the bronchial tree consist of?
trachea - 1st bronchi - 2nd (lobar) bronchi (one per lobe) - 3rd (segmental) bronchi - broncioles - branching - branching x 16 - terminal bronchioles (end of conducting).
what is the trachea made of (3)?
resp eptihelium
C shaped rings
trachealis muscle at posterior
what is the 1st bronchi made of?
resp epithelium
cartilege rings and smooth muscle to complete
what are the 2nd and 3rd bronchis amde of?
resp epithelium that starts to decrease in height, goblet cell numbers decrease, cartilege plates.
what are broncioles made of?
cuboidal epithelium, no cartilege but thick smooth muscle for bronchoconstriction and bronchodilation.
what is the function of terminal bronchioles?
each supplies a pulmonary lobule
how does cartilege change as it goes from the LRT?
ring in larynx, C is trachea, plates in bronchi, none in bronchioles.
how does the epithelium change as it goes down the LRT?
resp mucosa that decreases in height by the 2nd bronchi. Cuboidal in bronchioles, no goblet cells present.
what is in the respiratory zone?
pulmonary lobules made of many alveoli (air sacs) like bunches of grapes.
150 million alveoli in each lung.
what are alveoli covered in?
the external surface is covered in fine network of pulmonary capillaries.
what are alveoli walls made of?
they are very thin, made of simple squamous epithelium on a thin basement membrane
what is alveoli structure?
pocket like (open on one side) covered in cap network
what are alveoli made of?
two types of pheumocytes - squamous and cuboidal.
what do the squamous pheumocytes do in the alveoli?
form resp membrane/blood air barrier in cappilary wall and shared basement membrane.
what do the cuboidal pheumocytes do in the alveoli?
they are scattered amongst the squamous pheumocytes. they secrete surfactant (a complex lipoprotein) that reduces the surface tension of alveoli fluid.
what does surfactant do in the alveoli?
it is secreted by cuboidal pheumocytes in the alveoli and it is a complex lipoprotein that reduces the surface tention of the alveoli fluid.
what do roaming macrophages do?
remove debris that makes it to the alveoli
what is where the capillary meets the alveoli wall?
respiratory membrane (gas exchange membrane).
what is the respiratory membrane?
the membrane between the cap network and the alveoli wall - the blood air barrier
what is the resp membrane made of?
alveolar cell layer, fused basement membrane of alveolar, epithelium capillary endothelium layer, capillary endothelium layer, red blood cells.
what are all body cavities lined with?
serous membranes
what are serous membranes?
double layers of secretory tissue with fluid between layers.
what is a visceral layer?
on organ
what is a parietal layer?
on the body wall
what is the serous membrane in the thoracic cavity called?
pericardium, pleura
what is the serous membrane in the abdominopelvic cavity called?
peritoneum
what does the thoracic cavity contain (membranes)?
mediastinum (heart, vessels, pericardium) pleural cavities (lungs x 2)
what arer the boundaries of the thoracic cavity?
anterior - sternum posterior - thoracic vertebrae x 12 lateral - ribs x 12 superior - base of neck inferior - diaphragm
where are the lungs seperate in the pleural cavity?
so that if one lung stops working the other can contiue.
what safe guards the lungs if one stops working?
the fact that they are seperated in the pleural cavity.
what is ventilation driven by?
pressure changes in the thoracic cavity.
pressure is inversely proportionate to volume - what does this mean?
if we change the volume of the thoracic cavity, we change the pressure.
what is inspiration?
volume increases
what is expiration?
volume decreases
what is boyles law?
p = 1/-V pressure is measured by collisions. the smaller the more the collisons, which means more pressure. air will move to lower air pressure.
air will move to
lower air pressure
what do we need in order to breathe to make air move?
a pressure gradient
what is the air pressure between breathes?
there is no pressure gradient between inside and outside of the cavity
explain air pressure to breathe in:
when volume is increased (inhilation) the pressure is decreased, so air flows in to the low pressure environment inside.
explain air pressure for exhalation:
the volume is decreased and therefore the pressure is increased, therefore air flows out to the lower air pressure environment of outside.
what are the anterior thoracic joints?
sternumn to ribs:
- sternocostal
- costochondral
- interchondral
what are thoracic joints made of?
costal cartilege , synovial joints, cartilaginous joints
what is the sternocostal joint?
synovial joint except for first rib which is cartilagenous, between sternum and cartilege
what is the costochondral joints?
cartilagenous attaching ribs to cartilege
what are the interchondral joints?
synovial attaching from costochondral to other cartilege.
what are the posterior thoracic joints?
the articulation between thoracic vertebrae and ribs.
- costotransverse
- costovertebral
what type of joints are posterior thoracic joints?
synovial joints
what are the costotransverse joints?
the synovial joints between ribs and transverse vertebrae
what are the costcovertebral joints?
between rib and body of vertebrae
what are the muscle of respiration and what do they do?
move the rib cage to allow us to breathe. there are the primary inspiratory muscles - diaphragm and intercostals and the accessory msucles that are onky active when needed.
what is the diaphargm?
a sheet of skeletal muscle that seperates thorax from abdomen
explain the contracts of the diaphragm and breathing.
dome shape when relaxed - exhalation. flattened when contracted - inhilation
what does the contraction of the diaphragmn do?
expands the thoracic cavity, compresses the abdominopelvic cavity, decreases the air pressure in the thoracic cavity.
how do the intercostal muscles attach?
diagonally between neighbouring ribs
what do external intercostals do?
lift ribcage and expand cavity. when inspiration is quiet and forced.
what do internal intercostals do?
depress rib cage and decrease cavity. only when expiration is forced.
what do accessory respiratory muscles do?
- increase cavity volume for forced inspiration
- decrease cavity volume for forced expiration
- only in forced breathing.
what are accessory muscles attached to?
thoracic cage.
what muscles are involved in inspiration and what do they do?
diaphargm contracts/flatterns
external intercostals contract/lift ribs
what happens with muscles in forced inspiration?
as well as the normal*, plus accessory muscles contract to expand thoracic cavity further.
*diaphargm contracts/flatterns
external intercostals contract/lift ribs
what muscles are involved in expiration?
diaphragm relaxes/dome shapes, external intercostals relax (no longer lifting rib cage).
what happens with muscles in forced expiration?
as well as normal*, plus internal intercostals contract to depress ribs and accessory muscles contract to further decrease cavity volume.
*diaphragm relaxes/dome shapes, external intercostals relax (no longer lifting rib cage).
how do lungs expand as cavity does?
- lung tissue is elastic and is always trying to recoil.
- the pheura makes the lungs stick to the thoracic wall
- lungs decrease in expiration and increase in inspiration.
what makes the lungs ‘stick’ to the thoracic wall?
the fluid bond that the pleural fluid provides.
what are the two forces that have to be overcome to take a breath
- stiffness of the lungs
2. resistance of the airways to the lungs
explain how the stiffness of the lungs is an opposing force to breathing and how it is combatted:
- the lungs must expand to take in air
- the lungs are very compliant
- sa tension holds lungs in place
explain how the resistance of airways to the lungs is an opposing force to breathing and how it is combatted:
- air needs to be moved from outside to the alveoli
- the resp tract is putting resistance on the movement of air.
what is pulmonary fibrosis and how does it happen?
thickening and scarring of the alveoli so that it doesnt stretch. less vital capacity and pressure.
caused by ongoing stress or chemical damage.
how is alveoli linign related to surface tension?
the fluid they are lined with exert surface tension. the walls of alveoli are v thing which enhances this effect.
how does surface tension effect alveoli?
it tries to compact them in but they need to be able to expand.
what reduces ST in alveoli? what happens if it is not reduced?
surfactant produced by alveoli that disrupts ST. failure to produce this surfactant results in difficulty expanding lungs and reduced oxygen intake.
what is resp distress syndrome?
when premature babies fail to produce surfactant in alveoli meaning ST cannot be decreased and therefore they cant fully expand and they dont get enough oxygen.
what solves airway resistance?
there is resistance on air as it moved from outside to the bronchi/bronchioles/alveoli. this is combatted by changing the radius of the bronchioles (bronchiconstriction and bronchidilation)
what is asthma?
over bronchiconstriction.
what is spirometry?
a spirometer measures the volume of inspired/exhaled air and how much a person is breathing.
what are the five spirometry trace volumes?
tidal volume TV inspiratory reserve volume IRV expiratory reserve volume ERV residual volume RV minimal volume MV
what is tidal volume?
volume of air moved in and out during normal quiet breathing
what is inspiratory reserve volume?
extra volume that can be inspired with maximal inhilation.
what is expiratory reserve volume?
extra volume that can be exhaled with maximal effort.
what is residual volume?
volume remaining in the lungs after maximal exhalation.
what is minimal volume?
volume remaining in lungs if they collapsed.
what are the four spirometry trace capacities?
- vital capacity
- total lung capacity
- inspiratory capacity
- functional residual capacity
what is vital capacity?
Total volume of air you can move in and out of your lungs. Inspiratory reserve AND expiratory reserve AND tidal volume. Total volume of air you can move in and out of your lungs.
what is total lung capacity?
vital capacity AND residual volume. total volume in lungs when theyre filled to the absolute maximum.
what is inspiratory capacity?
inspiratory reserve AND tidal volume. total volume of air you can breathe in from rest
what is functional residual capacity?
expiratory reserve AND residual volume. the volume remaining in lungs after normal exhalation.
what does the forced expiratory volume (FEV) one second test show?
- how much of the vital capacity comes out in the first second.
- it can show if someone has a disease causing resistance to airflow eg. asthma
what is the normal ratio of FEV to vital capacity?
normally 80% of the vital capacity is expired in the FEV one sec test. less than 70% indicates airway obstruction.
what can spirometry help determine between?
obstructive and resistrictive issues
what are restrictive respiratory issues?
reduced lung capacity
eg. asthma, chronic bronchitis
what are obstructive respiratory issues?
resistance to airflow, reduced lung compliance, insuffient surfactant release.
eg. fibrosis
what is the equation for how much we breathe in and out/resp min volume?
VE = VT x f
resp minimum vol = tidal volume x resp rate
L/min. L/breath (breathing strength). breaths/min (breathing speed)
what does dead space mean?
not all air that is breathed in goes to the alveoli
what is the equation for alveoli ventilation (l/min)
VA = (VT - VD) x f
alveoli ventilation = (tidal volume breathing strength - dead space) x resprate breathing speed
how do you get more air to the alveoli?
increase the tidal volume while keeping breathing speed constant. tiny breaths dont help.
what is daltons law?
the pressure of a mixture of gases is the sum total of the pressures of each individual gas. (not all air is useful to us)
what is the goal of moving gas across membranes?
to move gas back and forth between thr alveoli and capillaries.
to transport inhaled O2 to capillaries.
to transport CO2 to alveoli to be exhaled.
how do gases move across the membranes between alveoli and the capillaries?
diffusion.
what are the three determinants of diffusion rate?
- sa of membranes
- thickness of membranes
- pressure difference between the 2 sides
what is alveolar ventilation?
how much air reaches alveoli
what makes the surface area of alveoli the way it does?
the bulbous structure of alveoli and the high density of capillaries creates a large SA for gas exchange.
what is emphysema?
a disease when alveoli areas are expanded and damaged resulting in a reduction of surface area which mean less contact between air and capillaries which means less oxygen exchange. This often occurs in smokers.
why are gas exchange membranes thin and what happens if they arent?
they need to be thin so that gas exchange happens with ease. fibrosis or scar tissue causes membrane to thicken.
what is erythropoesis?
athletes training at high altitudes mean that there is less atmospheric O2 which means less blood O2 whihc means they learn to function on less O2
what are the three 02 pressures to consider?
atmospheric O2
alveolar O2
blood O2
how does exericse effect alveolar ventilation and alveolar O2 levels?
how strongly we are breathing and how much exercise we get increases O2 need so when the blood is returned it needs more blood from the alveoli.
what are the two ways oxygen is tranported?
- dissolved O2
- bound to haemoglobin in RBCs
why is dissolved in blood not the main way that oxygen is transported?
o2 dissolved poorly in warm blood. only 3ml per L of blood so 15mL in total since the body has 5l of blood. this is far less than the 250mL needed.
how many ml of oxygen is needed in the body?
250ml
how many o2 can haemoglobin bond?
- when the first has been bonded, the rest bond easier. the haemoglob curve of saturation can change depending on conditions.
how does exercise effect the haemoglobin curve and release of oxygen?
it produces heat and a decrease in pH which pushes haemoglobin cruve to the right and encourages it to release more O2 so skeletal muscle can be replenished. so exercise = low affinity for haemoglobin binding.
how is CO2 transported back to the outside world from inside the body?
carbonic anhydrase converts CO2 to carbonic acid bicarb then moves into the plasma where it easily dissolves and is carried to the lungs and converted back to CO2 carried across alveoli and breathed out.
what two things combine to make carbonic acid?
CO2 and H2O
why does exercise release more O2 (chem)?
carbonic acid dissociates into bicarb and h+ which lowers pH and blood gets more acidic.
exercise = more CO2 = more acidic blood
which helps haemoglobin to release more O2 to replenish tissue’s reserves.
why is it important that breathing is controlled?
we need to maintain normal levels of O2 and CO2 for metabolic and biochemical stability.
what kind of receptors send afferent signals to control breathing?
chemorecptors, baroreceptors, lung stretch receptors, protective receptors.
which is the most important receptor for breathing and what does it do?
chemoreceptors . they monitor CO2. it is the build up of CO2 rather than the lack of O2 that causes us to need to breathe.
what is barorecptor’s relationship with artial bp like?
seesaw relationship between arterial blood pressure and respiratory minute volume.
how do inflation/deflation/protective reflexes work?
- as the lungs inflate/deflate they sent afferent input to the brain.
- the brain sends efferent input to prevent them from stretching too far either way.
- receptors also detect irritation and brain signals to sneeze or cough.
what causes a sneeze?
inflation/deflation/protective reflexes send afferent signals of irritation and the brain sends efferent signals to sneeze.
