Breathing 1 Flashcards
explain the structure of the nasal chamber
I pair of external nostrils ( dirhynous condition)
Nasal chambers are seperated by hyaline cartilage
The naterior part of th e nasal chamber is formed by the nasal vestibule( formed by the invagination of skin during embryonic development), it bears hair sebaceous glands that help in the removal of foreign particles.
The posterior part is made of 3 bones called nasal conchae. at several places these bones have outgrowths called turbinals to make passage long and spiral, to lengthen passage for air flow ( humidify air, bring to room temp, clean air)
expain the stricture of pharynx
The nasal chamber opens into the pharyns via nasopharynx.
the pharynx is made up of 3 parts:
i) nasopharynx from nasal chamber
(ii) Oropharync from mouth
iii) laryngeopharynx/hypopharynx present bfr the larynx
opening of food pipe is c/a gullet
opening of the larynx is caled glottis
explain the structure of larynx
Larynx is the sound producing organ in which two types of vocal cords are present
(i) False
(ii) True
False vocal cords provide moisture to the true vocal cords. Whereas true vocal cords are
helpful in phonation (Sound production)
what is trachealis muscle
it is a voluntary muscle that is prevent on the dorsal side of the trachea. it helps in dilating the trachea during forceful respiration
explain the lungs
The pleural layer has 2 membranes
i) outer/parietal pleura- close with the thoracic lining(ribs)
ii)inner/visceral pleura- close with lung surface/ alveoli
The left lung is bilobed and has a notch called the cardiac notch where the heart is placed. The two lobes of the long is seperated by an oblique fissure.
The space between the 2 lungs where the heart is placed is called as the mediastinum.
The right lung is trilobed demarcates by the oblique fissure and horizontal fissure.
Mammalian lungs are solid and spongy without muscles so power of self contraction and self
relaxation is not present in mammalian lungs.
describe diaphragm
The diaphragm is a dome shaped muscle, it is a chracteristic feature of mammals.
also c/a as phrenic muscle
Phrenic nerve is for diaphragm contraction.
It is the muscular structure which separate thoracic cavity from abdominal cavity.
m/o radial muscles
helpful forbreathing, parturition, micturition and defacation (b/c helps in creating pressure diff)
describe alveoli
Alveoli are structural and functional units of
lungs.
Alveoli consist of two types of cells called
pneumocytes.
Pneumocytes I are smaller cells and helps in
gaseous exchange whereas pneumocytes II are
larger cells which secrete a phospholipid
LECITHIN.
Lecithin act as a surfactant reduces the surface tension of alveoli and keep alveoli always remain
open for efficient gaseous exchange. Deficiency of lecithin in alveoli causes respiratory distress
syndrome.
On the outer side of alveoli yellow fibrous connective tissue is present. The total number of
alveoli present in both the lungs of man is 300 million.
which parts form the thoracic chamber/ thoracic cage?
airtight chamber:
- dorsally- vertebral column
- ventrally sternum
- laterally ribs
- anterior clavicle
- posterior diaphragm
what are the intercostla muscles
Spaces between two pair of ribs are called
intercoastal spaces. Whereas muscles in these
spaces are called intercoastal muscles. There
are two types of intercoastal muscles
(a) External intercoastal muscles (EICM)
(b) Internal intercoastal muscles (IICM)
explain the time taken per breathing cycle
i) inspiration- active - 2s
ii) expiration-passive- 3s
for 1 breathing cycle= 5s
no of cycles per minute= 12-16 breaths per minute
explain the mechanism of breathing
i) inspiration
- diaphragm- contracts
- eicm- contracts
thoracic volume increases, pulmonary volume increases, so pressure decreases
ii) exspiration
- diaphragm relax
- eicm- relax
thoracic volume decreaes, pulm. volume, decreasesm so pressure increases
iii) forcible exppiration’/abdominal breathing
- diaphragm -relax
eicm- relax
iicm- contrac
abdominal muscle- contract
so forcible expiration is active while just expiration is a passive process.
Abdominal breathing due to diaphragm mainly.
In fever breathing rate increases.
When CO2 concentration increases in blood breathing rate becomes faster.
Breathing rate in infants is greater than adults.
Eupnoea :- It is the state of normal breathing. In man rate of normal breathing is 12-16 per
minute. In infants rate of breathing is 44 per minute. Rate of breathing is slowest while
sleeping.
Bradypnoea or Hyponoea :- It is the state of slow breathing.
Rapid breath or hypernoea :- It is the state of fast breathing.
Apnoea - It is the state of stoppage of breathing temporarily.
Dyspnoea - It is the state of painful breathing due to pleurisy.
Asphyxia - It is the state of suffocation due to high CO2 concentration or low O2 concentration.
what are expiratory muscles
abdominal muscles and iicm
what is dead space
air present in the conducting part of the respiratory system is called as dead space air.
150ml of air
which instrument can measure respiratory volume
spirometer
it cant measure residual volume
most of the residual volume occurs in alveoli
explain the binding of oxygen
Hb4+O2—->Hb4O8
atAlveoli
atTissues
1 gm of haemoglobin transports 1.34 ml of oxygen. 100 ml (1 dL) of blood contains
normally 15 gm of haemoglobin, so 100 ml blood transports approximately 20 ml of
oxygen.
thereis approx. % 5Lof blood in the human body. 1L of oxygen is carried in one full cycle.
In a conducting cycle blood gives its 25% O2 to tissues.
oxygen dissociation curve
A graph is plotted between O2 concentration
and percentage saturation of haemoglobin
with this curve is called oxygen dissociation
curve.
Dissociation curve is sigmoid shape.
This curve is highly useful in
studying the effect of factors like,
H+
concentration, temperature on
binding of O2 with Haemoglobin.
Shift to left means that increase in
affinity between O2 and Hb.
Shift to Right means that decrease in
affinity between O2 and Hb and
dissociation of oxyhaemoglobin.
% saturation of Hb= no of molecules of o2 binded to Hb/ no of moelcules of o2 that can combine with Hb x 100%
explain bohr effect and haldane effect
bohr effect= right shift= tissue level
- breakdown of HbO2
- metabolism increases
- temperature increase
- H+ ion conc increase, pH decrease
- pCO2 increase
- bisphosphoglycerate increases
haldane effect= left shift= lung/alveoli
- formation of HbO2
- metabolism decreeases
-temperature decreases
- h+ ion conc decreaes pH increases
- pCO2 decrease
- BPGA decrease
what is
(i) methemoglobin
(ii) oxyhaemoglobin
(iii) carboxyhaemoglobin
(iv) carbaminohaemoglobin
(v) myoglobin
(i) Haemoglobin generally has iron in +2 oxidn state. If iron atom is present as +3 oxidn state, it is called methemoglobin. o2 doesnot bind to methemoglobin. oxidised haemoglobin
(ii) oxygen+ Hb
(iii) CO + Hb
(iv) CO2+ Hb
(v) oxygen storage molecule in muscle cell
explain co2 transport
The majority of bicarbonate ions (HCO3
the plasma along a concentration gradient. In the plasma HCO3
–) formed within the erythrocytes diffuse out into
– combine with Na+ and
form Sodium bicarbonate (NaHCO3). Nearly 70% CO2 transported by plasma as NaHCO3
form.
In response of HCO3
–, chloride ions (Cl–) diffuse from plasma into the erythrocytes to
maintain the ionic balance. Thus, electrochemical neutrality is maintained. This is called
Chloride shift or Hamburger Phenomenon. The chloride ions react with with the K+ present in the rbc to form KCl. ( to prevent accumulation of Cl-)
The H+ presnt in the RBC reacts with Haemoglobin to form haemgolobinic acid. This acid is a weak acid. It behaves as a buffer and maintains the pH of blood.
what stimulates the dissociation of carbaminohaemoglobin.
This dissociation is stimulated by oxyhaemoglobin. This CO2 freed from blood goes into
atmosphere. The effect of oxyhaemoglobin on the dissociation of these compounds is
known as Haldane effect. In this reaction oxyhaemoglobin acts like a strong acid i.e, it
frees H+ in the medium.
define the folllowing
Anoxia - It is the lack of O2 supply to tissues.
Hypocapnoea - It is the state of reduced CO2 concentration in blood.
Hypercapnoea - It is the state of increased CO2 concentration in blood.
Acapnia : Stoppage of breathing due to very low CO2 in blood.
Hypoxia : O2 deficiency in body tissues.
Reasons of hypoxia :
(a) Anaemia
(b) Low O2 in atmosphare
(c) High CO2 in atmosphere
Anaemic hypoxia (CO poisoning) : CO binds haemoglobin 200 to 300 times faster than
oxygen to form stable carboxyhaemoglobin.
(i) amt of co2directly dissolved in plasa
(ii) amt of co2 present in plasma in dissolved state
(i)7%
(ii)77%
affinity of haemoglobin complex
co- 200/300 times more affinity than o2
co2- 20/25 times more affinity than o2
