XI: Chapter 17- Breathing and gaseous exchange Flashcards
What are nasal conchae?
6 bony projections in the lateral wall of respiratory part
What works as an air conditioner for nose?
Conchae
Which bones form the conchae?
Maxilla, ethmoid and nasal bone
Internal nares open into
Nasalpharynx
How many cartilages are present in the larynx? Name them.
9 Thyroid Cricoid Arytenoid (paired) Corniculate/cartilage of Santorini (paired) Cuneiform cartilage (paired) Epiglottis
Which is the largest cartilage of larynx?
Thyroid cartilage
Which cartilage forms adam’s apple in males?
Thyroid cartilage
Which cartilage of larynx is C shaped?
Thyroid cartilage
Which cartilage of larynx is signet ring shaped?
Cricoid cartilage
Which cartilage of larynx is pyramid shaped?
Arytenoid cartilage
What is the shape of epiglottis?
Leaf shaped
Which cartilages in larynx are hyaline cartilage?
Thyroid, cricoid, arytenoid
Which cartilages in larynx are elastic cartilage?
Cartilage of santorini, cuneiform cartilage, epiglottis
Vocal cords are attached to which cartilage ?
Arytenoid cartilage of larynx
What is the function of false vocal chords?
Provide moisture to true vocal chord
The anterior vocal chords are
False vocal chords
How many cartilage rings are present on trachea? What type of cartilage are they?
16-20 hyaline cartilage rings
At the level of which vertebrae does the trachea divide into bronchi?
5th thoracic
How are the right and left bronchus different?
Right- shorter, ventral
Left- longer, horizontal
How many secondary bronchii does the right bronchus divide into?
3
How many secondary bronchii does the left bronchus divide into?
2
How many right tertiary bronchii are present?
10
How many left tertiary bronchii are present?
8
Which is the conducting part of the respiratory tract?
From external nares upto terminal bronchiole
Incomplete cartilage rings are present in which part of respiratory tract?
Trachea to initial bronchiole
How many types of cells are present in alveoli of lungs?
Pneumocyte 1, pneumocyte 2 (clara cells) and dust cells
What is the function of pneumocyte 1?
Responsible for actual gaseous exchange with blood
What is the function of pneumocyte 2?
Produce surfactant to prevent collapsing of alveoli
What is the diametre of trachea?
2 cm
How many alveoli are present in one lung?
300 million
Ventrally, the lungs are protected by
Sternum and ribs
Dorsally, the lungs are protected by
Vertebrae and ribs
Laterally the lungs are protected by
Ribs
Posteriorly the lungs are protected by
Diaphragm
How many fissures are present in the right lung?
3 lobes, 2 fissures
How many fissures are present in the left lung?
1 fissure, 2 lobes
What covers the lungs?
Double layered pleura
Normal inhalation required the contraction of
Radial/phrenic muscles of diaphragm and 11 pairs of external intercostal muscles
What makes the lung expand along the anterior-posterior axis?
Diaphragm
What makes the lungs expand along the dorso-ventral axis
External intercostal muscles
What is the respiratory rate in humans?
12-16 per minute
What process happens during forceful expiration?
Active process
Internal intercostal muscles and abdominal muscles contract
Pulmonary volumes are assessed by a
Spirometre
How much of the tidal volume actually reaches the alveoli?
350 ml
What is the inspiratory reserve volume?
2500-3000 ml
What is the expiratory reserve volume?
1000-1200 ml
What is the value of residual volume?
[Breathing]
1200 ml
What is inspiratory capacity?
Maximal volume of air that can be inspired after normal expiration. (3000ml -3500ml)
What is functional residual capacity?
Volume of air that remains after normal expiration (Expiratory reserve volume+residual volume)
What is vital capacity?
Maximum volume of air that can be inspired after a forceful expiration.
What is more soluble in blood- CO2 or O2?
CO2
What is the partial pressure of oxygen in alveoli?
104
What is the partial pressure of oxygen in oxygenated blood?
95
What is the partial pressure of oxygen in tissues?
40
What is the partial pressure of carbon dioxide in Alveoli?
40
What is the partial pressure of carbon dioxide in oxygenated blood?
40
What is the partial pressure of carbon dioxide in tissue>
45
Across how many layers do gases have to diffuse in alveoli?
3- simple squamous epithelium of alveoli
basement membrane
endothelium of blood capillary
What is the oxygen content in 100ml of oxygenated blood?
20ml
One molecule of haemoglobin can at max carry how many molecules of oxygen?
4
What is the amount of oxygen delivered to tissue by blood in resting condition?
5ml
What is the amount of oxygen delivered to tissue by blood during streneous exercise?
15ml
What percentage of oxygen is present in dissolved state in blood?
3%
What does shifting of oxygen dissocisation curve to the right signify?
Dissociation of haemoglobin (more oxygen available)
Increase in diphosphoglyceric acid cause the oxyggen dissocisation curve to
Shift to right
What is bohr’s effect in context to oxygen dissocisation curve?
Reduced affinity of oxyhaemoglobin with dioxygen in response to increase acidity.
What is the difference between foetal haemoglobin and maternal haemoglobin?
Foetal haemoglobin has higher affinity for dioxygen than maternal blood.
How many oxygen molecules can myoglobin bind to?
1
What is hamburger’s effect/chloride shift?
Bicarbonate ions move from RBC to plasma and Cl- from plasma into RBC
What is Haldane’s effect?
Oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin which increases the removal of carbon dioxide.
Which breathing is abdominal breathing?
Normal breathing
Which breathing is thoracic breathing?
Forced breathing
What type of breathing is found in pregnant women?
Thoracic breathing
How long does inspiration and expiration last?
2s, 3s respectively
Where is the main respiratory cente located?
Medulla
What is the main respiratory centre of brain called?
Respiratory rhythm centre
WHat groups of neurons are present in respiratory rhythm centre?
Dorsally respiratory group and ventrally respiratory group
What is the function of dorsally respiratory group?
Initiates repiration
How does dorsally respiratory group of nerves bring about expiration?
Stops sending signals to muscles for 3 seconds, muscles relax => expiration
Which part of respiratory rhythm centre controls normal breathing?
Dorsally respiratory group
Which part of respiratory rhythm centre controls forceful breathing?
Ventrally respiratory group
What modifies respiratory rhythm centre of medulla?
Pontine centres
WHat are the parts of the pontine centre?
Pneumotaxic and apneustic
What is the role of pneumotaxic centre?
Switch off centre of inspiration
Which centre of brain inhibits medullary respiratory centre?
Pneumotaxic centre
Which centre of brain can increase respiratory rate?
Pneumotaxic centre
What is herring brewer reflex?
Protective reflex to prevent lungs from overinflation. Stretch receptor in bronchi are stimulated by overinflation of lungs which stimulate pontine centre to increase respiratory rate.
Baroreceptors of bronchi send signals to pneumotaxic centre by which nerve?
Vagus nerve
Where are the central chemoreceptors for breathing present?
Medulla
Where are peripheral chemoreceptors situated?
carotid and aortic bodies
What can the peripheral chemoreceptors sense?
partial pressure of CO2 and acidity in the blood of aorta and carotid artery
What can the central chemoreceptors in humans sense?
partial pressure of CO2 and acidity of CSF in 4th ventricle of brain
What is the condition of difficulty in breathing while in horizontal position called?
Orthopnoea
What is hypoxia?
Low oxygen concentration in tissues
Histotoxic hypoxia is caused by
Cyanide poisoning
What is carbon monoxide poisoning called?
Asphyxia
Blood becomes cherry red in case of
Asphyxia
Spiracles of cockroaches are equivalent to which part of human body?
Nostrils
How can mammals eat while breathing?
Because of negative pressure breathing
Brown lungs disease is caused by
Inhalation of cotton dust
What kind of respiration is found in aquatic arthropods?
Branchial respiration
RBCs contain a minute amount of carbonic anhydrase and plasmsa contains a very high amount of carbonic anhydrase. True/false?
False
RBCs contain a very high amount of carbonic anhydrase and plasmsa contains minute amount of carbonic anhydrase.