Chp 8 Respiration Flashcards
Features of a respiratory surface
- it should have a large surface area
- it should be thin, highly vascular and permeable to allow exchange of gases
- it should be moist
Where does gaseous exchange in plants happen
Through small pores in the stem called lenticels
Organs in upper respiratory system
External nares, nasal cavity, internal nares, nasopharnyx, nose, throat and associates structures
Organs in lower respirator system
Larnyx, trachea, bronchi, bronchioles and lungs
The nasal is divided into a right chamber and left chamber by
Mesethmoid cartilage.
A nasal chamber is divided into
Vestibule(its skin has hair to trap the dust)
Respiratory part(conditioner)(warms the air, it is the middle thin wall)
Olfactory or sensory chamber(fir detection of smell)
Pharynx is divided into….
Nasopharynx , oropharynx and then laryngopharynx
The pharynx has a set of lymphoid organs called…
Tonsils
Larynx is also called….
Voice box.
Voice is produced when air passes between the vocal chords and modulations created by tongue, teeth, lips and nasal cavity
Trachea is internally Lined by….
Ciliated, pseudostratified epithelium and mucous glands that trap the unwanted particles preventing their entry through lungs
The division of bronchi
The primary bronchi divides into secondary and tertiary bronchi which leads into terminal bronchioles ending into alveoli
Protection membrane of lungs
Each lung is enclosed by a double pleural membrane, outer parietal and inner visceral membrane.
Between the two pleura is a pleural cavity filled with a lubricating fluid called pleural fluid
Alveoli
Each alveolus is surrounded by a network of capillaries of pulmonary artries and veins. There are about 700 million alveolus in the lungs.
They provide a respiratory surface for exchange of gas
What is the respiratory membrane
An alveolus consists of a tine layer of squamous epithelium rest on a basement membrane . It is associated with a dense network of capillaries . The wall of the capillary is also made of squamous epithelium.
They together make up the respiratory membrane
Transport of oxygen
Only 3% is transported in the dissolved state by the plasma
And 97% is bound to the haemoglobin present in the RBCs.
Act of haemoglobin
Haemoglobin acts as the respiratory carrier. It has high affinity for O2 and combines with it to form oxyhaemoglobin. Oxyheaemoglobin is transported to the tissues however the degree of saturation of hb with o2 depends upon the partial pressure of o2
What is the relationship between hbo2 saturation and oxygen tension called
Oxygen dissociation curve
Bohr effect
It is the shift of oxyhaemoglobin dissociation curve due to change in partial pressure of CO2 in blood
Haldane effect
In the alveoli where ppO2 is high and ppCO2is low oxygen binds with haemoglobin but in the tissues where ppO2 is lower and ppCO2 is higher haemoglobin does not hold as much O2.
It releases O2 for diffusion into the tissue cells
Transport of CO2
It is transported by RBCs and plasma in 3 forms
- by plasma in solution form 7%
- by bicarbonate ions 70%
- by red blood cells 23%
Carbonic anhydrase
In the RBCs co2 combines with water in the presence of zinc containing enzyme , carbonic anhydrase to form carbonic acid .
Chloride shift or hamburgers phenomenon
Carbonic acid being unstable immediately dissociates into HCO3 and H in the presence of the enzyme carbonic anhydrase leading to large accumulation of HCO3 inside the RBCs.it thus moves out of rbcs this would bring about in balance of the charge inside the rbs . To maintain the ionic balance or electrical neutrality cl diffuses into the rbcs . This movement of chloride acid is called….
What are respiratory centres
Steady rate of respiration is controlled by neurons located in the pons and medulla and are known as respiratory centres.
It is divided into 3 groups :a.neurones in the medulla (inspiratory centres)
b.ventro lateral group of neurones in medulla (inspiratory and expiratory centres) c.pneumotaxic centre located in pons (primarily limits inspiration)
Just remember
The respiratory centre has connections with cerebral cortex which means we can voluntarily change our pattern of breathing
1 atp=?
ADP+iP+7.3Kcal=ATP
iP=inorganic phosphate
ADP=adenosine di phosphate
