Chapter 14: Breathing and exchange of Gases

Question 1

__________ an Italian anatomist, was born in 1822, began his scientific career studying the cardiovascular system of reptiles

Answer 1

Alfonso Corti
(1822-1888)

Question 2

Alfonso Corti turned his attention to the mammalian___________, in 1951

Answer 2

Auditory system

Question 3

Alfonso Corti published a paper describing a structure located on the basilar membrane of the cochlea containing hair cells that convert sound vibrations into nerve impulses, the _____________

Answer 3

Organ of Corti

Alfonso Corti died in 1888

Question 4

_____________ is utilised by the organisms to indirectly break down simple molecules like glucose, amino acid, fatty acids etc

Answer 4

Oxygen (O₂)

Question 5

________________ which is harmfulalso released during the break down of simple molecules

Answer 5

Carbon dioxide (CO₂)

Question 6

O₂ has to be continuously provided to the cells and CO₂ produced by the cells have to be released out. This process of exchange of O₂ from the atmosphere with CO₂ produced by the cells is called _____________, commonly known as ____________

Answer 6

breathing
respiration

Question 7

Lower invertebrates like sponges, coelenterates, flatworms exchange O₂ with CO₂ by _______________ over their entire body surface

Answer 7

simple diffusion

Question 8

Earthworms use their ___________ and insects have a network of tubes (_______________) to transport atmospheric air within the body

Answer 8

moist cuticle
tracheal tubes

Question 9

Special vascularised structures called gills(___________________) are used by most of the aquatic arthropods and molluscs

Answer 9

branchial respiration

Question 10

Vascularised bags called ____________ (pulmonary respiration) are used by the terrestrial forms for the exchange of gases. among vertebrates, fishes use ___________ whereas amphibians,reptiles, birds and mammals respire through Lungs

Answer 10

Lungs

gills

Question 11

Amphibians like frogs can respire through their moist skin known as __________________

Answer 11

Cutaneous respiration

Question 12

the nasal chamber opens into the ______________ a portion of which is common passage for food and air

Answer 12

Pharynx

Question 13

The pharynx opens through the Larynx region into the ___________

Answer 13

Trachea

Question 14

Larynx is a cartilaginous box which helps in sound production and hence called the _______________

Answer 14

sound box (larynx)

Question 15

During swallowing glottis can be covered by a thin elastic cartilaginous flap called ________________ to prevent the entry of food into the Larynx

Answer 15

epiglottis

Question 16

Trachea is a straight tube extending up to mid-thoracic cavity, which divides at the level of ______thoracic vertebra into a right and left primary _____________

Answer 16

5^th
bronchi

Question 17

Each Bronchi undergoes repeated divisions to form the secondary and tertiary bronchi ending up in very thin terminal ______________

Answer 17

Bronchioles

Question 18

The tracheae, primary, secondary and tertiary bronchi and intitial bronchioles are supported by incomplete ______________ rings

Answer 18

cartilaginous

Question 19

each terminal bronchioles give rise to a number of very thin, irregular-walled and vascularised bag-like structures called ___________

Answer 19

alveoli

Question 20

Humans have two lungs which are covered by a double layer___________, with ___________ fluid between them

Answer 20

Pleura

Pleural fluid

Question 21

External nostrils up to the terminal bronchioles constitute the conducting part whereas the alveoli and their ducts form the ________________________ part of the respiratory system.

Answer 21

respiratory or exchange

conducting part:- transport the atmospheric air to the alveoli

Exchange part:- the site of actual diffusion of O₂ and CO₂ between blood and atmospheric air

Question 22

The lungs are situated the the ____________ chamber, which is formed dorsally the the vertebral column, ventrally by the sternum, laterally by the ribs and on the lower side by the dome shaped _______________

Answer 22

thoracic chamber

Diaphragm

Question 23

Respiration involves 5 steps
1. Breathing or pulmonary ventilation in which _______
2. Exchange at the surface of ___________
3. Transport of gases by ____________
4. Exchange of gases at __________ level
5. Cellular respiration as ___________

Answer 23

1.atmospheric air is drawn in CO₂ rich alveolar air is released out
2. Alveoli
3. Blood
4. tissue
5. **utilisation of O₂ by the cells for catabolic reactions and resultant release of CO₂

Question 24

Breathing involves two stages ,____________ during which atmospheric air is drawn in and ___________ by which the alveolar air is released out

Answer 24

Inspiration
expiration

Question 25

**Inspiration** can occur if the pressure within the lungs(intra-pulmonary pressure) is _____________ than the **atmospheric pressure** i.e., there is a **negative pressure** in the lungs with respect to atmospheric pressure

Answer 25

**less than**

Question 26

**Expiration** takes place whin the **intra-pulmonary pressure** is ____________ than the atmospheric pressure

Answer 26

**higher**

Question 27

The **diaphragm** and a specialised set of muscles-**external and internal intercostals** between the ___________, help in generation of pressure gradient

Answer 27

**Ribs**

Question 29

Inspiration is initiated by the **contraction** of ____________ which increases the volume of **thoracic chamber**

Answer 29

**diaphragm**

Question 30

An increase in the **pulmonary volume** decreases the intra-pulmonary pressure to less than the _______________ which forces the air from outside to move into the lungs

Answer 30

**atmospheric pressure**

Question 31

On an average, a healthy human **breathes** _____________ times/minute

Answer 31

**12-16**

Question 32

The volume of air involved in breathing movements can be estimated by using a ____________ which helps in clinical assessment of pulmonary functions

Answer 32

**spirometer**

Question 33

______________ is volume of air inspired or expired during a **normal respiration**. it is approx. _________mL. a healthy man can inspire or expire approximately ___________mL of air per **minute**

Answer 33

**Tidal Volume (TV)** **500 mL** **6000 to 8000 mL**

Question 34

___________________ is additional **volume** of air , a person can inspire by a **forcible inspiration**. This averages _________ mL to ___________ mL

Answer 34

**Inspiratory Reserve Volume (IRV)** **2500** to **3000**mL

Question 35

____________________ is additional **volume** of air , a person can expire by a **forcible expiration**. This averages __________ mL to __________ mL

Answer 35

**Expiratory Reserve Volume (ERV)** **1000** to **1100** mL

Question 36

_____________ is volume of air **remaining in the lungs** even after a **forcible expiration**. This averages ___________ to __________ mL

Answer 36

**Residual Volume** **1100** to **1200** mL

Question 37

_______ types of **respiratory volumes** namely 1. **Tidal volume (TD)** ________________ mL 2. **Inspiratory Reserve Volume (IRV)** ______________ mL 3. **Expiratory Reserve Volume (ERV)** _____________mL 4. **Residual volume (RV)** ____________mL

Answer 37

**6000 to 8000** mL **2500 to 3000** mL **1000 to 1100** mL **1100 to 1200** mL

Question 38

________________ **capacity** is the **total volume** of air a person can **inspire** after a **normal expiration**

Answer 38

**Inspiratory capacity (IC)** = **TV + IRV** This includes tidal volume and inspiratory reserve volume

Question 39

________________ **capacity** is the **total volume** of air a person can **expire** after a **normal inspiration**

Answer 39

**Expiratory capacity (EC)** = **TV + ERV** This includes tidal volume and Expiratory reserve volume

Question 40

________________ **capacity** is the volume of air that will **remain** in the lungs after a **normal expiration**

Answer 40

**Functional Residual capacity (FRC)** = **ERV + RV**

Question 41

_____________ **capacity** is the maximum volume of air a person can **breathe in** after a **forced expiration** or the maximum volume of air a person can **breath out** after a forced inspiration

Answer 41

**Vital Capacity (VC)** **VC** = **ERV + TV + IRV**

Question 42

Total lung Capacity (TLC) is the **Total Volume** of air accommodated in the lungs at the end of a **forced inspiration** This includes __________ , ___________ , ___________ and _______________

Answer 42

**RV** **ERV** **TV** **IRV** or **vital capacity** + **Residual volume**

Question 43

___________ are the primary sites of exchange of **gases**. Exchange of gases also occur between **blood** and **tissue**

Answer 43

**alveoli**

Question 44

**Pressure** contributed by an **individual gas** in a **mixture of gases** is called _____________ and is represented as **pO₂** for **oxygen** and **pCO₂** for **carbon dioxide**

Answer 44

**Partial pressure**

Question 45

Partial pressure of **pO₂** in **atmospheric air** is __________ mm Hg Partial pressure of **pCO₂** in **atmospheric air** is __________ mm Hg

Answer 45

**159** **0.3**

Question 46

Partial pressure of **pO₂** in **alveoli** is __________ mm Hg Partial pressure of **pCO₂** in **alveoli** is __________ mm Hg

Answer 46

**104** **40**

Question 47

Partial pressure of **pO₂** in **deoxygenated blood** is __________ mm Hg Partial pressure of **pCO₂** in **deoxygenated** is __________ mm Hg

Answer 47

**40** **45**

Question 48

Partial pressure of **pO₂** in **oxygenated blood** is __________ mm Hg Partial pressure of **pCO₂** in **oxygenated** is __________ mm Hg

Answer 48

**95** **40**

Question 49

Partial pressure of **pO₂** in **Tissues** is __________ mm Hg Partial pressure of **pCO₂** in **Tissues** is __________ mm Hg

Answer 49

**40** **45** note opposite to deoxygenated blood

Question 50

As the solubility of **CO₂** is ____________ times higher than that of **O₂**, the amount of **CO₂** that can diffuse through the diffusion membrane per unit difference in partial pressure is much higher compare to that of **O₂**

Answer 50

**20-25**

Question 51

The **diffusion membrane** is made up to **three** major layers 1. The thin **squamous epithelium** of _________ 2. The **endothelium** of alveolar ______________ 3. The **basement substance**

Answer 51

**alveoli** **Capillaries**

Question 52

Blood is the medium of transport of **O₂** and **CO₂**. About _______ % of **O₂** is transported by **RBCs** in blood. The remaining _____% of **O₂** is carried in dissolved state through the **Plasma**

Answer 52

**97 %** **3 %**

Question 53

______ % of **CO₂** is transported by **RBCs** whereas **70 %** of it is carried as __________. About ______% of **CO₂** is carried in a dissolved state through **plasma**

Answer 53

**20 -25 %** **bicarbonate** **7 %**

Question 54

**Haemoglobin** is a red coloured **iron** containing pigment present in the __________. **O₂** can bind with haemoglobin in a reversible manner to form ______________

Answer 54

**RBCs** **oxyhaemoglobin**

Question 55

Each **Haemoglobin** molecule can carry a **maximum** of _________ molecules of **O₂**

Answer 55

**four**

Question 56

In alveoli, where there is high **pO₂** , low **pCO₂**, lesser **H⁺** concentration and lower **temperature**, the factors are all favourable for the formation of __________________

Answer 56

**oxyhaemoglobin**

Question 57

In the tissues, where low **pO₂**, high **pCO₂**, high **H⁺** concentration and higher temperature exist, the condition are favourable for dissociation of _____________ from the **oxyhaemoglobin**

Answer 57

**oxygen**

Question 58

Every **100 mL** of oxygenated blood can deliver around ______ mL of **O₂** to the tissues under normal physiological conditions

Answer 58

**5 ml**

Question 59

**CO₂** is carried by haemoglobin as ____________________ (about **20-25** per cent)

Answer 59

**carbamino-haemoglobin**

Question 60

**RBCs** contain a very **high concentration** of the enzyme, ______________ and minute quantities of the same is present in the plasma too

Answer 60

**carbonic anhydrase**

Question 61

At the **tissue site** where partial pressure of **CO₂** is high due to **catabolism**, **CO₂** diffuses into blood (RBCs and plasma) and forms __________ and __________

Answer 61

**HCO₃^-** **H⁺**

Question 62

At the alveolar site where **pCO₂** is low, the reaction proceeds in the opposite direction leading to the formation of _______ and __________

Answer 62

**CO₂** **H₂O**

Question 63

**CO₂** trapped as _________________ at the tissue level and transported to the alveoli is released out as **CO₂**

Answer 63

**bicarbonate**

Question 64

Every 100 ml of **deoxygenated blood delivers approximately ______% of **CO₂** to the **alveoli**

Answer 64

**4 ml**

Question 65

Specialised centre present in the _____________ region of the brain called **respiratory rhythm centre** is primarily responsible for respiratory rhythm

Answer 65

**Medulla**

Question 66

Another centre present in the **pons** region of the brain called ________________ centre can **moderate** the functions of the **respiratory rhythm centre**

Answer 66

**Pneumotaxic centre**

Question 67

______________ is a difficulty in **breathing** causing wheezing due to inflammation of **bronchi** and **bronchioles**

Answer 67

**Asthma**

Question 68

_______________ is a chronic disorder in which **alveolar walls** are damaged due to which **respiratory surface** is decreased. One of the major causes of this is _________________

Answer 68

**Emphysema** **Cigarette smoking**

Question 69

____________________ Disorder is especially those involving **grinding** or **stone breaking**, so much dust is produced , long exposure can give rise to **inflammation** leading to **fibrosis** (proliferation of fibrous tissue) and thus causing serious lung damage

Answer 69

**Occupational Respiratory Disorders**

Question 70

Nearly **70 %** of carbon dioxide is transported as **bicarbonate** (**HCO₃^-**) with the help of the enzyme _________________

Answer 70

**carbonic anhydrase**

Question 71

**20 -25 %** of carbon dioxide is carried by **haemoglobin** as _____________________

Answer 71

**Carbamino- haemoglobin**