respiratory Flashcards
catabolism of glucose
co2, water, energy(ATP) in the presence of oxygen
what is breathing
the process of exchanging o2 from the atmosphere with co2 from the body
two main features that differentiate organisms respiratory systems
habitat
level of organisation
respiration in coelenterates,sponges,flatworms
cell surface, gaseous exchange with gases dissolving in water passing through cells as they do not have blood vessels to transport gases.
respiration in earthworms
moist cuticle. the cuticle is the outermost covering and used for the diffusion of gases. it is thin moist and vascular
respiration in insects like cockroach
network of tubes- the tracheal system to transport atmospheric air within the body. they have small openings called spiracles through which air enters and leaves the body.
respiration in lower aquatic arthropods
eg: cray fish,prawn ,molluscs like unio
they have special vascular structures like gills(plate like filamentous and highly vascular) which are bathed with water for exchange of gases
respiration in vertebrate fishes
gills
respiration in amphibians
gills(tadpole )
moist skin,lungs,buccal cavity(frogs and toads)
respiration in birds mammals and reptiles
lungs
why do aquatic animals have a faster rate of breathing than terrestrial animals
because the amount of dissolved oxygen is fairly lower in water than air and also that aquatic organisms like the fishes obtain oxygen from water present in the dissolved state.
turtles breathe air from
cloaca
what is fermentation
it is also called anaerobic respiration
eg:in yeast, glucose forms ethyl alcohol and co2. in bacteria,endoparasites, mature RBC and muscles, glucose is converted to lactic acid.
whats the respiratory passage
the flow of air from the outside to the internal surface of the lungs
the flow of air in the respiratory passage
external nostrils nasal chamber internal nares nasopharynx glottis(part of the larynx) trachea primary bronchi secondary bronchi tertiary bronchi bronchioles
alveolar ducts
atria
alveolar sac
alveoli
external nostrils
holes in the nose above the upper lip
nasal chambers
pseudostratified ciliated columnar, non-ciliated brush border columnar, cuboidal and goblet cells lining
mucus from the goblet cells trap dust
moisture to make the air humid
brings the temperature of the incoming air up to body temp
internal nares
posterior openings of nasal cavities that lead to the nasopharynx
nasopharynx
only air passes through
opens into the trachea through the glottis(opening to the upper part of the larynx)
larynx
voice box
cartilage
the upper part of the trachea
opening called glottis
cartilages of larynx
- thyroid cartilage: most prominent,c shaped, incomplete dorsally ,called Adam’s apple(hyaline)
- cricoid cartilage: lies below the thyroid cartilage, signet ring-shaped(hyaline)
- arytenoid cartilages: two pyramid-shaped cartilages on the posterior wall of the larynx,attached to vocal cords(hyaline + elastic)
- corniculate: two conical nodules of elastic-fibrocartilage which lie at the apices of arytenoid cartilages
- cuniform: two elongated club-shaped of elastic fibro-cartilage which lie above and anterior to corniculate cartilages. these connect the epiglottis to the arytenoid cartilage
- epiglottis: leaf-like single cartilage that projects into the pharynx
what is the thyrohyoid membrane
broad flat membrane attached to the hyoid bone above and thyroid cartilage below
vocal cords present in the larynx
one pair of false vocal cord above the true vocal cords. they do not participate in sound production
one pair of inner true vocal cords which produce sound
vocal cords in men
well developed, thick and longer
trachea
windpipe
a straight tube extending up to the mid-thoracic cavity
lined by incomplete POSTERIORLY cartilaginous rings to prevent it from collapsing during inspiration
pseudostratified ciliated columnar mucus-secreting cells
where does the trachea divide into primary bronchi
5th thoracic vertebrae
what do bronchi divide into
divide to form terminal branching called bronchioles(lobular-terminal-respiratory). supported by incomplete cartilaginous rings(NOT IN BRONCHIOLES)
alveoli
thin-walled irregular walled balloon like structures well supplied with blood vessels. the exchange of gases takes place here.
number of alveoli in both lungs combined
300-500 million
surfactant active agent
lecithin secreted by type 2 alveolar epithelial cells, reduces the surface tension between the alveolar fluid and air. it prevents collapsing of the lungs’ alveoli
position of the lungs
dorsally by the ventral column and ventrally by the sternum, laterally by the ribs
it’s closed below by the diaphragm
what is the diaphragm
dome-shaped structure made up of muscles and separates the thoracic and abdominal cavity
membranes enclose the lungs
two membranes called pleura
the outer pleura membrane is in close contact with the thoracic cavity and the inner pleura membrane is in close contact with the surface of the lungs
space between the two membranes is called the pleura cavity filled with pleura fluid
function of pleural fluid
lubricates the membranes so there is no friction and the membranes may slide over each other
colour of the lungs
pink at birth
greyish when older due to deposition of carbonaceous materials
right lung vs left lung
the right lung is shorter but wider due to accommodating for the liver and the left lung is longer but narrower as accommodating for the heart
the left lung is divided by an oblique fissure, dividing it into 2 lobes, the left inferior and left superior
the right lung is divided into 3 lobes, the right inferior,right middle and right superior
each lobe has segments which are further divided into lobules
10 segments in the right and 8 in the left
weight of each lung
625R
565L
the conducting part of the respiratory pathway and its function
external nostrils nasal chamber internal nares nasopharynx glottis(part of the larynx) trachea primary bronchi secondary bronchi tertiary bronchi bronchioles
they conduct air,clear the air, moist the air, warm the air
the exchanging part of the respiratory pathway and its function
alveolar ducts
atria
alveolar sac
alveoli
diffusion of gases
steps involved in respiration
breathing diffusion of gases b/w lungs and blood transport of gases diffusion of gases between blood and tissue utilisation of o2
biochemical reaction of respiration
c6h12o6(present inside cells)+o2–>
6co2+6h2o+energy(utilised in performing activities)
the two stages of the mechanism of breathing
inspiration
and expiration
how does air move in and out of lungs
pressure gradient, from high to low pressure
inspiration
contraction of the diaphragm and external intercostal muscles in the anterior-posterior and dorsal-ventral axis
increase in the volume of the thoracic cavity
a decrease in pressure in the lungs
expiration
relaxation of the diaphragm and external intercostal muscles in the anterior-posterior and dorsal-ventral axis
a decrease in the volume of the thoracic cavity
an increase in pressure in the lungs
forceful expiration
contraction of inner internal costal muscles, pulling the ribs down and inwards
contraction of abdominal muscles, therefore, compresses the abdomen and pushes the content towards the diaphragm
the volume of the thoracic cavity decreases and pressure increases.
what are hiccups
jerky incomplete inspiration sound which occurs due to sudden spasmodic contraction of the diaphragm and sudden closure of the glottis
it is due to the irritation of sensory nerve endings in the digestive tract
whats snoring
the noise produced during sleep, it is the rough rattling inspiratory sound produced by the vibration of vocal cords and the partial blockage of the respiratory tract by the tongue
rate of breathing in a normal healthy person
12-16 times per minute
what is a spirometer
estimate the volume of air involved in breathing movements which helps in the clinical assessment of pulmonary functions
what are respiratory volumes
the amount of air which our lungs can hold at a certain condition tidal volume inspiratory reserve volume expiratory reserve volume residual volume
tidal volume(TV)
normal breathing
the volume of air inspired and expired
500ml
lowest respiratory volume
inspiratory reserve volume(IRV)
the additional or extra volume of air, a person can inspire on forceful inspiration
2500-3000ml
expiratory reserve volume(ERV)
the additional or extra volume of air, a person can expire on forceful expiration
1000-1100ml
residual volume(RV)
air that remains in the lungs after forceful expiration
1100-1200ml
doesn’t let the alveoli collapse on themselves
respiratory capacities
addition of two or more respiratory volumes inspiratory capacity expiratory capacity function residual capacity vital capacity total lung capacity
inspiratory capacity
the total volume of air a person can inspire after a normal expiration
TV+IRV=500+2500
expiratory capacity
the total volume of air a person can inspire after a normal inspiration
TV+ERV=500+1000
function residual capacity
the volume of air that will remain in the lungs after a normal expiration
ERV+RV=1000+1100
vital capacity
maximum volume of air a person can breathe
ERV+IRV+TV=1000+2500+500
total lung capacity
the total volume of air present in the lungs and respiratory tracts after a maximum inspiration
ERV+IRV+TV+RV=1000+2500+500+1100
hering-Breuer reflex
in the bronchi and bronchioles, stretch receptors are present, they prevent the overstretching of lungs, nerve impulses are sent via the vagus nerve to inhibit the inspiratory area. as a result, expiration begins
the protective and preventive mechanism for over-inflation of lungs.
the trachea is lined with incomplete rings of
hyaline cartilage
the thoracic cage is made up of
ribs, sternum and thoracic vertebrae
how does diffusion of gases take place
from a region of higher partial pressure to a region of lower partial pressure
factors affecting the rate of diffusion of gases
- solubility: gases having high solubility diffuse at a faster rate . co2 diffuses 25 times faster than o2
- partial pressure: from higher to lower
- thickness of membrane: thicker the membrane, lesser the diffusion
the alveolar capillary membrane
3 layers(0.2mm total thickness)
thin squamous epithelium of alveoli that lines it
endothelium lining of alveolar capillaries
basement substance between these 2 layers
partial pressure of o2 in atmosphere and alveoli
159 and 104 respectively
the partial pressure of o2 in tissues/deoxy blood and oxy blood
40 and 95 respectively
the partial pressure of co2 in atmosphere and alveoli
0.3 and 40
the partial pressure of co2 in tissues/deoxy blood and oxy blood
45 and 40
what happens in pneumonia
accumulation od lymph and mucus in alveoli which impairs the exchange of gases
how is oxygen transported
in dissolved form through plasma(3%) as oxyhaemoglobin(97%) by RBC
what is one unit of oxyhaemoglobin made of
one molecule of haem,4 molecules of oxygen, globulin proteins
what causes o2 to bind with haemoglobin in the first place
the high partial pressure difference between alveoli and the deoxy blood capillaries
what makes the oxygen dissociate from haemoglobin
decrease in the partial pressure of o2 in blood causes weakening of bond and moves towards tissues where there is lower partial pressure of oxygen
increase in acidity
decrease in pH
high temperature
amount of haemoglobin in 100 ml of blood
15g
the capacity of 1g of haemoglobin to combine with o2
1.34 ml o2/ g of haemoglobin
oxygen level in arteries and venules
20ml and 14.4 ml/100 ml of blood
under strenuous exercise, the o2 level falls to
the level falls to about 4.4ml/100ml of blood, approximately 15 ml of o2 is transported by Hb during exercise
oxygen dissociation curve
relationship between pO2 and(vs) percentage saturation of Hb with o2 is known as O2 dissociation curve
when is the haemoglobin in the blood 50% saturated with o2(P50)
when pO2 is 25mm Hg
indication of a shift to the right in the oxygen dissociation curve
dissociation
indication of a shift to the left in the oxygen dissociation curve
association
factors responsible for a shift to the right in the oxygen dissociation curve
low partial pressure of oxygen
high partial pressure of co2( 40mm saturation point)
high H+ ion concentration and decrease in pH(acidic)
high temperature
where does the shift to the right in the oxygen dissociation curve occur
tissues
factors responsible for a shift to the left in the oxygen dissociation curve
the high partial pressure of oxygen
the low partial pressure of co2
less h+ ion concentration( high pH)
low temperature
where does the shift to the left in the oxygen dissociation curve occur
alveoli
shape of o2 dissociation curve
sigmoid
what is bohrs effect
with a rise in pCO2 and fall in pH, decreases oxygen affinity and decreasing oxygen affinity to Hb
therefore raising P50
what does increase in diphosphoglyceric acid do
shift the HbO2 curve to the right
who has higher affinity for o2, foetal or adult haemoglobin
foetus
why does foetus haemoglobin have a higher affinity for oxygen
it binds BPG less strongly
why is myoglobin affinity for o2 curve hyperbolic
it only has one fe2+ group
what is carbon monoxide poisoning
carboxyhaemoglobin
stable compound with no place for oxygen
headache, dizziness,nausea,death
250 times more stable than oxygen binding
SARS
severe acute respiratory syndrome
causative agent, coronavirus member of the influenza
Feb 26,2003,china
what is the respiratory pigment present in earthworms and nereis
haemoglobin
cyanosis
colour of skin and the mucous membrane becomes bluish when there is a deficiency of oxygen in blood
hypoxia
oxygen shortage in tissues
4 types of hypoxia
- anaemic hypoxia: oxygen is reduced due to anaemia
- cytotoxic hypoxia: cyanide poisoning. utilization of o2 is impaired in the body cells
- stagnant hypoxia: due to heart failure, reduced pumping of the heart.
- hypoxic hypoxia: insufficient oxygen in the air at high altitudes
transport of co2
- dissolved form through plasma: 7%. it gets dissolved in the blood plasma and is carried in solution to the lungs.
- as bicarbonate ions:70% co2 diffuses into rbcs and binds with water to form carbonic acid which dissociates to give hydrogen and bicarb ions.
- by carbaminohaemoglobin:20-25% , co2 binds with the globulin part of the haemoglobulin
enzyme for facilitating forming bicarbonate ions in RBCs
carbonic anhydrase
bicarbonate ion reaction from tissues to blood
co2+h2o->h2co3->h+ + hco3-
bicarbonate ion reaction from blood to lungs
h+ + hco3- ->h2co3->co2+h2o
factors that affect the binding of co2 with Hb
in tissues: high pco2, low po2
in alveoli: low pco2 and high po2
amount of co2 delivered by the blood to alveoli
4ml per 100 ml of blood
hamburgers phenomenon
at tissue level, the Hco3- ions diffuse out into the plasma and cl- ions enter the RBC
at alveoli level: the Hco3- ions diffuse into the RBC from the plasma and the cl- ions move out
Haldane effect
effect of oxyhaemoglobin formation or dissociation
oxyhaemoglobin is a strong acid which releases hydrogen ions. this causes the formation of H2CO3
due to increase acidity, co2 loses its power to bind with haemoglobin
