a3: environmental exchange

Question 0

describe the functional division of the respiratory system?

Answer 0

conducting portion: nose, pharynx/larynx, trachea, bronchi, terminal bronchioles
exchange portion: respiratory bronchioles, alveoli, aveolar ducts & sacs

Question 1

describe the structural division of the respiratory system?

Answer 1

UPPER: nose, nasal cavity, pharynx
LOWER: larynx, trachea, bronchi, bronchioles and alveolie

Question 2

describe basic wall plan of tracheobronchial tree(inner most to outer most)

Answer 2

mucosa - epithelium, basment membrane, lamina propria plus smooth muscle and glands to secrete
submucosa - ring like hyaline cartilage
adventitia - connective tissue

Question 3

what is mucosa?

Answer 3

epithelium with an underlying CT of a tube connecting to outside of the body

Question 4

main, predominant tissue in alveoli?

Answer 4

elastic fibres/CT

Question 5

general trend in respiratory wall structure?

Answer 5

general reduction in wall thickness and complexity with decreasing distance from gas exchange surfaces

Question 6

what are some important trends in varying wall structure?

Answer 6

epithelial cells: pseudostratified -> simple
goblet cells: high -> low numbers..disappear @ tertiary bronchioles
cilia: reduction of surface covered..disappear @ respiratory bronchioles
cell height: columnar -> cuboidal -> squamous decrease in height
cartilage: ring shaped(trachea) -> plates & islands(bronchi)..disappear @ bronchioles downwards
glands: decrease in number..disappear @ bronchioles

Question 7

if you inhale something where is it most likely to end up?

Answer 7

right primary bronchi to inferior lobe

Question 8

difference between right and left lung?

Answer 8

right lung has 2 fissures(horizontal, oblique) and 3 lobes(inferior, middle, superior)
- liver extends extends upwards pushing dome of diaphragm on the right side slightly higher than left
left lung has one fissure(oblique) and 2 lobes(superior, inferior)
- has cardiac notch, where apex of heart extends into

Question 9

what is the hilum?

Answer 9

point of attachment of vessels

Question 10

relationship of lungs and pleura?

Answer 10

membrane lining the chest cavity and lungs.
cushion lungs
smooth movement of lungs within chest cavity: secrete fluid
allow alveoli to take in more air when breathing

Question 11

what is the inter alveolar septum ?

Answer 11

wall between adjacent alveoli, contains extensive capillary network

Question 12

what is COPD? and how does it compromise respiratory function?

Answer 12

chronic obstructive pulmonary disease “narrowing of the airways”
severely compromises air conduction to and from respiratory surfaces

Question 13

whats the most common cause of COPD?

Answer 13

smokinggg

Question 14

how do irritants/smoke/toxins cause in the lungs?

Answer 14

(1) Inflammation of walls of bronchi and bronchioles -> thickening of walls -> narrowing of lumen -> reduced air flow
(2) Increasing mucus clogs lumen -> narrowing air flow
(3) Destruction of elastic fibres in alveoli -> reduction of alveoli recoil -> reduced ability to expel air and reduce surface area for gas exchange

Question 15

what are the requirements of ventilation?

Answer 15

patent air pathways(open and free from obstruction)

generation of a reversible flow

Question 16

how is patency of airways achieved?

Answer 16

• rigid wall structure(bone in upper, cartilage in trachea and bronchi)
• hydrostatic pressure
• pulmonary surfactant

Question 17

what is hydrostatic pressure?

Answer 17

outward pull on the walls of smaller air pathways(terminal/respiratory bronchioles alveolar ducts) holds them open

Question 18

what is pulmonary surfactant?

Answer 18

decreases alveolar surface tension

-> less inward pull on alveoli during expiration -> less effort required to stretch alveoli and expand lungs

Question 19

describe the relationship between lung volume and pressure:

Answer 19

increase in V -> decrease in P -> inflow of air

decrease in V -> increase in P -> outflow of air

Question 20

atmospheric air pressure =

Answer 20

760mmHg

Question 21

alveolar pressure =

Answer 21

758mmHg inhalation

762mmHg expiration

Question 22

how do muscles contribute to volume of lungs?

Answer 22

contraction of muscle = EXPANSION in volume of thoracic cavity

• external intercostal muscles
• diaphragm

Question 23

how does lung tissue contribute to volume of lungs?

Answer 23

elastic recoil of lungs and relaxation of previously contracted muscles reduced volume of thoracic cavity

Question 24

role of pleura in ventilation?

Answer 24

surface tension of pleura fluid adheres pleural membranes -> lungs pull outwards when thoracic volume increases pleural fluid produces bond between parietal and visceral pleura preventing collapse of lungs

Question 25

intrapulmonary pressure refers to pressure within _____?

Answer 25

alveoli of the lungs

Question 26

is inspiration active or passive process?

Answer 26

active, due to contraction of diaphragm and external intercostal muscles

Question 27

differences between normal and forced labour ventilation?

Answer 27

forced/labour ventilation uses an extra set of muscles during expiration internal intercostal muscles depress ribs increase intra-thoracic pressure abdominal muscles increase intra-abdominal pressure

Question 28

what is the blood air barrier?

Answer 28

respiratory membrane of the interaveolar septum

Question 29

state malfunctions of air modification:

Answer 29

environmental overload eg. smoking | cystic fibrosis

Question 30

main changes to air before it reaches gas exchange site:

Answer 30

FILTERED: remove debris and/or pathogens WARMED: to that similar of body temp HUMIDIFIED: so gas exchange surfaces don't dry out

Question 31

where is air filtered?

Answer 31

vibrissae (nose hairs) sticky mucus traps fine particles -> transferred to pharynx dust cells(alveolar Macrophages) engulf any particles that reach alveoli

Question 32

how is the removal of pathogens in air achieved?

Answer 32

defence cells in lumina propria | muco-ciliary escalator

Question 33

where is air humidified?

Answer 33

seromucous glands(saturate air with water vapour)

Question 34

where is inspired air warmed?

Answer 34

venous plexus in nasal mucosa | heat transferred from warm blood in superficial vessels to colder air in nostrils

Question 35

breathing through the nose rather than the mouth is advantageous because?

Answer 35

air is warmed upon inhalation

Question 36

consequences of smoking on respiratory system?

Answer 36

- direct toxic affects on CILIA -> inability to clear mucus and trapped pathogens -> smokers cough - rapid replacement of epithelial cells - excess mucus production and accumulation -> more prone to bacterial infection -> reduced diameter of airways

Question 37

requirements of efficient gas exchange in lungs

Answer 37

air must have been modified large surface area thin barrier mechanisms to drive exchange eg. conc gradient, gas solubility

Question 38

how is larger surface area achieved in lungs?

Answer 38

interalveolar septum -> extensive surface area and minimum distance between air in alveoli and blood

Question 39

what does henry's law state?

Answer 39

increase pressure on gas and solution more gas molecules will dissolve in solution until equilibrium is reached decrease pressure on gas and solution and gas molecules will come out of solution until new equilibrium is reached

Question 40

daltons law states?

Answer 40

in a mixture of gases such as air, the total pressure is equal to the sum of the individual partial pressures of the gases in the mixture

Question 41

is the partial pressure of oxygen greater in atmospheric air or alveoli?

Answer 41

atmospheric!

Question 42

describe the structure of respiratory membrane:

Answer 42

thin layer of surfactant type 1 alveolar epithelial fused basal laminae capillary endothelial cells

Question 43

how are variations in the volume of the lungs brought about?

Answer 43

contraction of muscles elastic recoil of lungs thoracic cage compliance

Question 44

role of pleura in ventilation?

Answer 44

bond between parietal and visceral pleura prevents lung collapse

Question 45

what does the visceral pleura cover?

Answer 45

surface of lungs

Question 46

what does the parietal pleura cover?

Answer 46

thoracic cavity

Question 47

what maintains the patency of the trachea?

Answer 47

ring shaped cartilage

Question 48

what drives expiation?

Answer 48

recoil of elastic fibres

Question 49

role of external intercostal muscles?

Answer 49

pulls ribs superiorly pushes sternum anteriorly increases dimensions of chest

Question 50

list the order of which air passes during inspiration:

Answer 50

``` external nares nasopharynx trachea primary bronchi bronchioles alveolar ducts ```

Question 51

why is the diameter of the afferent arteriole bigger than efferent arteriole?

Answer 51

to maintain high blood pressure in the glomerulus

Question 52

the _______ the partial pressure of gas, the more it can be dissolved in solution, the greater the rate of exchange

Answer 52

higher

Question 53

coal miner with chronic cough, has black deposits in lungs, which cell type is most likely to contain the deposited material?

Answer 53

alveolar macrophages

Question 54

what are podocytes?

Answer 54

cells specialised for filtration

Question 55

where are podocytes found?

Answer 55

in the visceral layer of the glomerular capsule

Question 56

in the GIT where is stratified squamous epithelial found?

Answer 56

oesophagus

Question 57

in the GIT where is segmentation found?

Answer 57

small intestine

Question 58

in the GIT where is pits with abundant goblet cells found?

Answer 58

colon

Question 59

in the GIT where is rugae found?

Answer 59

stomach

Question 60

in the GIT where is mechanical and chemical digestion found?

Answer 60

stomach

Question 61

in the GIT where is abundant submucosal mucous glands found?

Answer 61

duodenum

Question 62

in the GIT where is both villi and pits found?

Answer 62

small intestine

Question 63

in the GIT where is modified Muscularis external layer found?

Answer 63

both stomach and colon

Question 64

what is reabsorbed at the proximal convoluted tubule?

Answer 64

h2o sugar protein

Question 65

flow of filtrate and urine though urinary system, in order:

Answer 65

nephron, renal papillae, calyces, renal pelvis, ureters, urinary bladder, urethera

Question 66

the action of ADH on principal cells of the distal convoluted tubule(DCT) is to?

Answer 66

increase insertion of aquaporin-2 vesicles into apical membranes

Question 67

what is the major digestive enzyme in saliva?

Answer 67

amylase

Question 68

what controls the motility of the gastrointestinal tract?

Answer 68

myenteric plexus

Question 69

where is the glomeruli located in the kidney?

Answer 69

cortex of the kidney

Question 70

where is distal convoluted tubules located in the kidney?

Answer 70

cortex of kidney

Question 71

where is vasa rectus located in the kidney?

Answer 71

medulla of kidney

Question 72

where is major and minor calyces located in the kidney?

Answer 72

renal sinus

Question 73

where is nephron loop(loop of henle) located in the kidney?

Answer 73

medulla of kidney

Question 74

where is proximal end of ureter located in the kidney?

Answer 74

renal hilus

Question 75

what are the muscular activities of the digestive system regulated by?

Answer 75

hormones parasympathetic and sympathetic neurons contents of digestive tract intrinsic nerve plexus

Question 76

what is the function of conchae and meatuses in the respiratory tract?

Answer 76

maximise contact between air and air modification mechanism

Question 77

what is the function of respiratory epithelium in the respiratory tract?

Answer 77

filtering of air

Question 78

what is the function of nasal vibrissae in the respiratory tract?

Answer 78

filtering of air

Question 79

what is the function of mucosal venous plexus in the respiratory tract?

Answer 79

warming of air

Question 80

what is the function of serous acini of seromucous glands in the respiratory tract?

Answer 80

humidification of air

Question 81

what is the function of mucous acini of seromucous glands in the respiratory tract?

Answer 81

filtering of air

Question 82

what is the function of dust cells in the respiratory tract?

Answer 82

filtering of air

Question 83

what does surfactant do in the respiratory system?

Answer 83

decrease surface tension at the air-epithelial interface

Question 84

what histological feature distinguishes a bronchus within the lungs from the trachea?

Answer 84

irregular plates of hyaline cartilage

Question 85

what is peristalsis?

Answer 85

regular contractions of the muscularis externa that pushes food through entire GIT

Question 86

what are the folds of the small intestine which increase surface area for diffusion called?

Answer 86

villi

Question 87

what is the function of the large intestine?

Answer 87

water balence of digestive system

Question 88

a patient excretes a large volume of very dilute urine on a continuing basis, this could be due to?

Answer 88

absence of ADH

Question 89

what does the renal corpuscle consist of?

Answer 89

the glomerulus and the glomerular capsule