Anatomy/physiology

Front 1

5 basic functions of respiratory system

Back 1

Extensive area for gas exchange. Regulation of blood pH. Producing speech sounds and providing olfactory sensations. Protection of respiratory system.

Front 2

How is speech produced by the respiratory system?

Back 2

Movement of air over the vocal cords.

Front 3

Why does the respiratory system need protection?

Back 3

It is the perfect environment for bacteria. The air in there is moist and has a constant supply of oxygen.

Front 4

What is the bypass of the respiratory system and why is it needed?

Back 4

A person can breathe through their mouth. It acts as compensation when illness makes nose breathing difficult.

Front 5

What makes up the upper airways?

Back 5

The nose, nasal passageway and the pharynx.

Front 6

What is the purpose of the nose and nasal passageways?

Back 6

It is the primary air passage way. Its shape allows control of our passage. It is the beginning of respiratory defence.

Front 7

What is the structure of the nose and the nasal passageway?

Back 7

It consists of bone and cartilage, covered by connective tissue and skin. This acts as a form of protection. The nose is filled with cilia and mucus. They filter warm/humidifies the air (in preparationfor the lower respiratory system) and filter/catch particles in the air.

Front 8

What is the pharynx and its purpose?

Back 8

This is the connection between the digestive and respiratory system. It is designed so air and food can pass through.

Front 9

What are the lower airways?

Back 9

The larynx, trachea, lungs and bronchi.

Front 10

What is the larynx and its structure?

Back 10

It is where the vocal cords are located. It contains no bones, only cartilage (for flexibility and protection). A decrease in cartilage and an increase in smooth muscle as you move down (this gives involuntary control for constriction and dilation for controlling air). It leads to the trachea.

Front 11

What is the trachea also caned and what is it attached to?

Back 11

The trachea is the windpipe. It extends from the larynx to the primary bronchi, where it splits into the left and right primary bronchi.

Front 12

What is the structure of the trachea?

Back 12

It is made of connective tissue and smooth muscle and is reinforced by C-shaped rings of cartilage. The cartilage rings act as protection and allows movement when the heart moves/food is swallowed ao also enables reduction/increase in air volume.

Front 13

Purpose of the vast amount of cilia and goblet cells in the trachea?

Back 13

The goblet cells produce mucus. the cilia in moves the mucus upwards to be swallowed. This creates a mucus-cilia elevator, if this breaks down there is no protection for the respiratory system.

Front 14

what is the structure of the bronchi?

Back 14

It is made of smooth muscle (for volume intake). The right bronchus is larger (most blockages occur here). There are 3 levels: primary,secondary and tertiary bronchi. The walls contain progressively less cartilage (decrease in cartilage = increase in smooth muscle).

Front 15

What is the bronchial tree?

Back 15

Where airways enter the lungs primary bronchi their branches form a bronchial tree.

Front 16

What is the anatomy of the thorax?

Back 16

It is bounded at the neck with the spinal column, ribs and sternum making up the wall (also contains lots of connective tissue with elastic properties). It is separated from the abdomen by the diaphragm.

Front 17

What is the pleural sac?

Back 17

It is a serous membrane that is double-folded. It contains the lungs (and associated membranes) and it is contained in the thorax.

Front 18

What is the pleura?

Back 18

The pair of serous membranes in the thorax that envelop the lungs. They are known as the pleural cavities.

Front 19

What separates the 2 pleural cavities?

Back 19

The mediastinum, a bundle of connective tissue.

Front 20

What is the anatomy of the pleura?

Back 20

Each lung occupies a single pleura. The consist of 2 layers : the parietal pleura and visceral pleura(both secrete pleural fluid).

Front 21

What is the parietal pleura?

Back 21

It covers the inner surface of the thoraic wall.

Front 22

What is the visceral pleura?

Back 22

It covers the outer surfaces of the lungs and extend into fissures between lobes.

Front 23

What is the purpose of the pleura?

Back 23

It encases and protects the lungs (from expansion) and also allows a reduction of pressure.

Front 24

What is the term for the disease state of the pleura?

Back 24

Pleurisy.

Front 25

How many lobes does the right lung have?

Back 25

3

Front 26

How many lobes does the left lung have?

Back 26

2.

Front 27

What is the bronchial tree?

Back 27

The branching system of bronchi and bronchioles, conducting air from the trachea to re alveoli.

Front 28

The lungs are protected by the pleural sac and are pressurised.

Back 28

Blank.

Front 29

What is the conducing zone?

Back 29

The low resistance pathway that transports and prepares air for gas exchange. It is also where respiratory defence occurs. NO GAS EXCHANGE OCCURS HERE.

Front 30

What does the conducting zone consist of?

Back 30

The nasal cavity, trachea, bronchi, bronchioles and terminal bronchioles.

Front 31

What leads to scar tissue formation in the lungs and why is this detrimental?

Back 31

Infection in the lung. Scar tissue does not function (other than for protection).

Front 32

What is the respiratory zone?

Back 32

The site of gas exchange.

Front 33

What does the respiratory zone contain?

Back 33

Respiratoy bronchiole ( connected to individual alveoli), alveolar ducts, alveolar sacs (which contain alveoli).

Front 34

What is the structure of alveoli?

Back 34

The alveolar walls contain capillaries and very small intestinal spaces, the blood is seperate from air within the alveolus by an extremely thin barrier (0.2 micrometres). There are approximately 300 million in the lungs and their total surface area is the size of a tennis court. This makes them specialised for rapid gas exchange.

Front 35

What do alveoli contain?

Back 35

Type 1 alveolar cells, type 2 alveolar cells and alveolar macrophages.

Front 36

What are type 1 alveolar cells?

Back 36

Flat squamous epithelial cells that make up 95% of the alveolar surface. They allow rapid gas diffusion. These cells are liable to damage but can repair to a point.

Front 37

What are type 2 alveolar cells?

Back 37

Cuboidal septal cells. They are scattered between type 2 cells and make up 5% of the alveolar surface. They Have a main functions: produce surfactant and repair alveolar epithelium (type I cells).

Front 38

What is the purpose of alveolar macrophages?

Back 38

Also known as dust cells. They are the last line of defence and engulf anything that shouldn't be there.

Front 39

What is surfactant?

Back 39

It is a phospholipid that coats the alveoli. It reduces surface tension and prevent alveoli collapse during exhalation (allowing lungs to expand). Without it surface tension would be 10X greater.

Front 40

What is Infant Respiratory Distress Syndrome (IRDS)?

Back 40

Premature (before 8 months) babies lungs lack sufficient surfactant, as it is not produced until 8 months in foetal life. This results in alveoli collapse.

Front 41

What are the main respiratory defences?

Back 41

The nasal cavity warms/fiIters air. Mucous escalator. The structure of the respiratory epithelium changes throughout respiratory tract. Alveolar macrophages.

Front 42

Why must the pharyngeal epithelium must protect itself?

Back 42

It must protect itself from abrasion and chemical attack as the pharyna must conduct air to the larynx and convey food to the oesophagus.

Front 43

What causes a breakdown of respiratory defence?

Back 43

The presence of irritants (cigarette smoke). Aggressive pathogens (tuberculosis). Inherited congenital defects that affect mucus production/transport ( cystic fibrosis).

Front 44

What is pulmonary ventilation?

Back 44

It is the physical movement of air into and out of the respiratory tract, that is to maintain alveolar ventilation to ensure a suppy continuous of oxygen.

Front 45

What are the 2 phases of ventilation and what causes them?

Back 45

Inhalation (Inspiration) and exhalation (expiration). Ventilation is driven by changes in volume, which result in a pressure change.

Front 46

What are the main rules regarding volume and pressure change?

Back 46

A change in volume causes a change in pressure. A larger volume results in a lower pressure, while a smaller volume results in a higher pressure. Air will flow from high to low pressure.

Front 47

How is volume and pressure changed during ventilation and why is it important?

Back 47

Muscles of respiration charge thoracic volume and thus pressure. Air flow from outside the body into the alveoli is due to pressure differences.

Front 48

What pressures are important in ventilation?

Back 48

Atmospheric pressure (Patm). Alveolar (interpumonay) pressure (Palv). Intra peral pressure (Pip). Transpulmonary pressure (Pip).

Front 49

What is atmospheric pressure (Patm)?

Back 49

Pressure exerted by weight of gas in atmosphere on Objects on earth surface (760mmHg, sometimes described as 0mmHg).

Front 50

What is alveolar (intrapulmonary) pressure (Palv)?

Back 50

Pressure inside respiratory tract (at alveoli), normal breathing difference is very small.

Front 51

What is intrapleural pressure (Pip)?

Back 51

Pressure within the pleural sac (in the space between parietal and visceral pleura). Usually less than atmospheric pressure (normally -6mmHg but can reach -18mmHg during powerful inhalation)

Front 52

What is transpulmonary pressure (Ptp)?

Back 52

The differences in pressure. Ptp = Palv - Pip.

Front 53

What is Boyles Law?

Back 53

Pressure of a gas is inversely proportional to its volume.

Front 54

How does Boyles law relate to the respiratory system?

Back 54

Pressure changes result from charges in dimension of chest wall and lungs. In smaller spaces the particles suffer more collisions with the container's walls.

Front 55

What pressure changes cause inhalation?

Back 55

Alveolar pressure (Palv) < Atmospheric pressure (Patm). The driving force fo air flow is negative. Air flows inwards.

Front 56

What pressure changes occur in exhalation?

Back 56

Alveolar pressure (Palv) > Atmospheric pressure (Patm). Driving force for air flow is positive. Air flows outward.

Front 57

What is lung compliance?

Back 57

A measure on how easily the lungs expands and contracts. Low compliance means a greater force is required to fill/empty the lungs. High compliance means it is easier to expand the lungs ax given change in transpulmonary pressure.

Front 58

What factors affect lung compliance?

Back 58

Connective tissue structure of the lungs. Level of surfactant production. Mobility of thoracic cage.

Front 59

How does connective tissue structure affect lung compliance andwhaatisdislase state associated with it?

Back 59

Loss or supporting tissue resulting from alveolar damage increases compliance. Emphysema.

Front 60

How does level of surfactant production affect long compliance and what disease state can be associated with it?

Back 60

Collapse of alveoli on exhalation is prevented by surfactant. Inadequate surfactant reduces compliance. IRDS.

Front 61

How does mobility of the thoracic cage affect lung compliance and what disease state can be associated?

Back 61

Reduction of compliance can result from any disorder affecting articulations of ribs/spinal column. Arthritis.

Front 62

What is the respiration cycle?

Back 62

An inhalation followed by an exhalation. There are 10-15 respiratory cycles per minute.

Front 63

How much air enters the lungs per min and how much blood flows through the pulmonary capillaries at rest and during exercise in normal adults?

Back 63

At rest, ~4L fresh air enters the lungs per min and 5L of blood flows through the pulmonary capillaries. During heavy exercise airflow increases by ×20 and blood flow increases by ×5.

Front 64

What triggers breathing ?

Back 64

The most important trigger is proton concentration in cerebral fluid. The second most important one is PCO2 (partial pressure of carbon dioxide) in the body. Oxygen needs is the third most important trigger.

Front 65

During a normal inhalation, how much air is breathed in at rest?

Back 65

500ml.

Front 66

What are the mechanisms of inhalation?

Back 66

The chest expands. The ribs more out (inspiratoy intercoastal muscles contract) and the diaphragm contracts. The thorax expands. Pip becomes more sub atmospheric (transpulmonary pressure increases). Lungs expand. Palv becomes sub atmospheric. Air flows into the alveoli.

Front 67

What is the mechanism of exhalation?

Back 67

The diaphragm and me inspiratory intercoastal muscles relax. The chest wail recoils inward. Trans pulmonary pressure moves back towards pre-inspiration valve. Lungs recoil to pre-inspiration size. Air in alveoli becomes compressed. Palv becomes greater than Patm. Air flows out of the lungs.

Front 68

What are in muscles of inhalation and when are they used?

Back 68

They are the intercoastal muscles. There are 2 types: inspiratory (internal) and expiratory (external). They are the accessory muscles. Inspiratory one used during normal breathing and expiratory are used during forced breathing.

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Front 69

What are the pressure changes in normal breathing (inhalation)?

Back 69

(Indicated as mmHg below / above -760mmHg) Alveolar = -3 , Intrapleural = -6. Transpulmonary = +3.

Front 70

what are the pressure changes in normal breathing (exhalation)?

Back 70

(Indicated as below or above -760mmHg. Alveolar = +3. lnlrapieural = -3. Transpulmonary = +6.

Front 71

What are the aeessory muscles of inspiration and there purpose?

Back 71

Sternocleidomastoid, elevates the sternum. Scalenes group, elevate the upper ribs. Pectoralis minor.

Front 72

What are the principle muscles of inspiration and their purpose?

Back 72

External intercoasts and interchondral part of internal intercoasts elevate the ribs. Diaphragm done descends to increase the vertical dimension of the thoracic cavity and elevates the lower ribs.

Front 73

What are the muscles of expiration in normal (quiet) breathing?

Back 73

Expiration resvts from passive, elastic recoil of the lungs, rib cage and diaphragm.

Front 74

What are the muscles of expiration in active breathing?

Back 74

Internal intercoastals (except intvchondrai part) pull the ribs down. Abdominal, pull the ribs down and compress abdominal contents (thus pushing diaphragm upwards).Quadratus lumborum, pulls the ribs down.

Front 75

What are lung volumes?

Back 75

Tidal volume (TV), Inspiratoy reserve volume (IRV), Expiratory reserve volume (ERV) and Residual volume (RV).

Front 76

What are lung capacities?

Back 76

Functional residual capacity (FRC), vital capacity (VC) and Total lung capacity (TLC).

Front 77

What is tidal volume?

Back 77

The volume of air inspired) expired with each breath. ~500ml.

Front 78

What is inspiratory reserve volume?

Back 78

The volume of air forcefully inspired. ~ 3000mI.

Front 79

What is residual volume?

Back 79

The volume of air remaining in the lungs after maximal expiration. ~ 1200ml.

Front 80

What is functional residual capacity?

Back 80

ERV + RV . It is the volume of air remaining in lungs after normal expiration. ~2400ml

Front 81

What is vital capacity?

Back 81

IRV + TV + ERV. It is the maximum volume of air that a person can expel after maximum inspiration. ~4700ml.

Front 82

What factors make gas exchange efficient?

Back 82

A small distance between capillaries and lungs. Requires a concentration gradient for rapid transfer. A difference in partial pressures, as it is difficult for gas to pass into solution.

Front 83

Why does infection in the lungs make gas exchange inefficient?

Back 83

Inflammation makes the distance too large for gases to transfer over.

Front 84

Where does gas exchange occur in the body?

Back 84

Pulmonary ventilation ensures cells supplied with oxygen and removes carbon dioxide arriving from the bloodstream. Gas exchange occurs between the blood and alveolar air across respiratory membrane.

Front 85

What gases do we breathe in?

Back 85

Nitrogen, oxygen, water vapour and carbon dioxide.

Front 86

What is atmospheric pressure?

Back 86

It represents the combined effects of collisions of all gas molecules in the air.

Front 87

What is the partial pressure of a gas (P)?

Back 87

It is the pressure of a gas' contribution to pressure in a mixture of gases. It is directly proportional to the gas' concentration. All partial pressures added together equal the total pressure exerted by a gas mixture.

Front 88

What causes diffusion in partial pressure of gases?

Back 88

Net diffusion occurs from high to low partial pressures and is affected by temperature.

Front 89

Describe Daltons law

Back 89

Each gas contributes to total pressure in proportion to its relative abundance.

Front 90

What causes diffusion between liquids and gases?

Back 90

When under pressure, gas molecules to move into a solution. At equilibrium, gas molecules into/out of a liquid at the same rate (gases like to be at equilibrium but a difference is required for gas exchange).

Front 91

Describe Henrys Law.

Back 91

At a given temperature the amount of a particular gas in solution is directly proportional to its partial pressure (higher temperature means gas moves out of the solution more easily.

Front 92

What determines actual amount of gas in solution?

Back 92

Solubility of a gas in a particular liquid at a given temperature and pressure. Dissolved gas content is reported as mI gas per 100ml (1dl).

Front 93

What are the solubility of oxygen, nitrogen and carbon dioxide in the body fluids?

Back 93

Carbon dioxide is very soluble, oxygen is less soluble and nitrogen has limited solubility.

Front 94

What is decompression sickness (the bends)?

Back 94

High sea pressures forces nitrogen to move into solution into the body fluids. When the body depressurises (when moving quickly to lower pressures) it causes the dissolved gas to come out of solution to create bubbles in the body.

Front 95

Describe factors of normal diffusion at respiratory membranes.

Back 95

There is a substantial difference in partial pressure across the respiratory membrane. Gases are lipid soluble, there is a large surface area, coordinated blood flow and airflow (these directed to certain areas of the lungs). Gas exchange occurs over small distance (averagely 0.5 micrometres). Surfactant is present.

Front 96

Draw a diagram of partial pressure of oxygen and carbon dioxide changes in the body.

Back 96

Hint 96

Normally blood in the lungs has a lower partial pressure of oxygen than the atmosphere and lungs, so air moves into the blood. The blood has a higher partial pressure of carbon dioxide than in the lungs so it moves out of the blood.

Front 97

What factors affect gas exchange?

Back 97

Damage to tissue or scar tissue. Cold temperatures increases membrane distance. Tumour growth reduces surface area.

Front 98

How are the states of oxygen and carbon dioxide changed for gas exchange?

Back 98

when inhaling, carbon dioxide mixes with gas in lungs (partial pressure of carbon dioxide increases). For gas exchange to occur, oxygen must be a gas and carbon dioxide must be liquid. Blood moves constantly so gas can't equilibrate. The blood has low oxygen so it moves from alveoli into the blood and is diluted. It also has high carbon dioxide which acts as the driving force for it to move out of solution ( the difference doesn't have to be large).

Front 99

Oxygen is insoluble, so how is it transported?

Back 99

Erythrocytes help carry it through haemoglobin. Haemoglobin consists of 4 haem groups (each haemoglobin unit can bind to 4 oxygen molecules . Oxyhaemoglobin). Each Erythrocyte has ~280million haemoglobin (can compensate for oxygen loss).

Front 100

Describe an oxygen dissociation curve .

Back 100

It is difficult to bind the first oxygen so a high pressure is required and as more oxygen birds the higher the affinity for it is. If partial pressure increases (lungs) the reaction shifts to the right and more oxygen gets bound to haem. If partial pressure of oxygen decreases (tissues) the reaction shifts to the left and more oxygen is released.

Front 101

What is the Bohr effect?

Back 101

A drop in pH causes a shift in the oxygen dissociation curve. As it causes the shape of Haemoglobin to change in a way that makes them well use oxygen reserves more readily. This effect is caused by primarily carbon dioxide.

Front 102

How does temperature effect haemoglobin saturation?

Back 102

When temperature rises haemoglobin releases more oxygen. The presence of carbon dioxide and large amounts of heat indicates metabolism occuring.

Front 103

What is carbon monoxide (CO) poisoning?

Back 103

CO competes with oxygen for the binding sites on haem units. It has a stronger affinity than oxygen, the bond it forms with haem is extremely durable (essentially makes the haem unit inactive for respiratory purposes). If CO molecules are 0.1% of inhaled air, human survival is impossible without medical intervention. A high partial pressure of oxygen is needed to push the CO off the haem.

Front 104

What methods of carbon dioxide transport are there?

Back 104

Carbon dioxide is generated by aerobic metabolism in peripheral tissues and it has an impact on blood pH. Upon entering the blood stream it is: converted to bicarbonate (70%), bound to protein portion of haemoglobin within erythrocytes (23%) or dissolved in plasma (7%).

Front 105

How is carbon dioxide converted into bicarbonate in the blood?

Back 105

Carbons dioxide combines with water to form carbonic acid (accelerated by carbonic annydrase). Carbonic acid is unstable so its intermediates dissociate into bicarbonate and proton. The bicarbonate is transported out of the erythrocyte into the blood's plasma in exchange for a chloride ion. In the lungs this reverses (chloride ion for bicarbonate) and the proton dissociates from the haemoglobin and binds to it forming carbonic acid. The carbonic acid quickly dissociates into carbon dioxide by carbonic anhydrase and is expelled from the lungs through exhalation.

Front 106

How is respiration controlled normally?

Back 106

Cellular absorption and generation rates are matched by the capillary rates of delivery/removal.

Front 107

How is respiration controlled when there is an imbalance?

Back 107

Homeostatic mechanisms intervene such as changes in blood flow and oxygen delivery regulation at a local level, as well as changes in rate of respiration under control of the respiratory centre.

Front 108

How is gas transport and alveolar function regulated locally?

Back 108

The rate of oxygen delivery and efficiency of oxygen pickup at lungs is regulated largely at a local level. Local factors (like differences in partial pressures) coordinate lung perfusion and alveolar ventilation.

Front 109

Describe local regulation of gas transport/alveolar function in peripheral tissues.

Back 109

If peripheral tissues become more active. In the interstitial fluid the partial pressure of oxygen reduces, while the partial pressure of carbon dioxide increases. This creates a differences between partial pressures in tissues and arriving blood, so more oxygen is delivered and more carbon dioxide is removed.

Front 110

Why is partial pressure of carbon dioxide need to be maintained?

Back 110

Blood pH must be 7.35 -7.45 (outside this range enzymes and proteins denature). A rise or fall in partial pressure of carbon dioxide indicates pH changes. Breathing rate changes to help control partial pressure of carbon dioxide.