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Bio IB > B3.1 gas exchange COPY > Flashcards

B3.1 gas exchange COPY Flashcards

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1
Q

what are 4 properties of surfaces that allow efficient gas exchange

A

large surface area
thin
moist
highly covered by capillaries

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2
Q

larynx

A

hollow muscular tube forming an air passage to the lungs and holding the vocal cords

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3
Q

trachea

A

a tube reinforced by rings of cartilage, extending from the larynx to the bronchial tubes and converting air to and from the lungs. The cartilage helps support the trachea while still allowing it to move and flex during breathing

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4
Q

ribs

A

bones involved in the protection of the thorax cavity

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5
Q

intercoastal muscle

A

muscles behind the rib that control the ventilation process

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6
Q

alveoli

A

many tiny air sacs of the lungs which allow for rapid gaseous exchnage (singular, alveolus)

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7
Q

pluramembrane

A

covers the surfaces of the lungs and prevent friction by secreting a lubricant called pleural fluid

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8
Q

bronchi

A

airway that conducts air into the lungs
branches into smaller tubes, known as bronchioles, lined with smooth muscles that can dialate or constrict

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9
Q

lung

A

spongy tissue made of alveoli and capillaries

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10
Q

diaphragm

A

dome shaped muscle that seperates the thorax from the abdomen and is invlved in the ventilation process

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11
Q

what is the alveolar epithelium

A

an example of a tissue where more than one cell type if present because different adaptations are recquired for the overall functio of the tissue
2 types of cells=
type 1P
type 2P

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12
Q

describe the type 1 pneumocytes

A

Structure: flattened, extreme thin cells that line the alveolus their shape maximizes surface area and minimizes distance for diffusion of gas into and out of blood

function: the cell responsible for the exchange that takes place in the alveoli

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13
Q

describe type 2 pneumocytes

A

strucutre:
rounded cells that are sporadicaly placed in the alveolus. contain many secretory vesicles (lamellar bodies) in the cytoplasm

function:
cell responsible for the production and secretion of surfactant, discharged by secretory vesciles to the alveolar lumen
the surfactant is a fluid that; coats the inner surface of the alveoli, allowing oxygen to dissolve and then diffuse into the blood of the capillaries
prevents that sides o the alveoli from sticking to each other when the air is exhaled

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14
Q

capillaries in terms of the alveolus

A

they fully surround the alveoli, cells that line the capillary= capillary epithelium, they are thin epithelial cells to maximise surface area for diffusion

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15
Q

whats the basement membrnae

A

a thin fibrous extracellular matrix of proteins that seperates the alveolus and capillary, provides structural support to the alveolus (helps maintain its shape)

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16
Q

what are the 4 muscles that change the movement of the ribcage

A

external intercostal muscles
internal intercotal muscles
diphragm
abdominal muscles

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17
Q

what does the movement of the ribcage affect

A

changes the volume of the thoraxic cavity which changes its pressure

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18
Q

what are the antagonistic muscles

A

external intercostal muscle
internal intercostal muscle

diaphragm
abdominal muscles

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19
Q

what happens during inspiration

A

abdominal muscles- relax
diaphragm- contract (flattens move downwards)
internal intercostal muscles- relax
external intercostal muscles- contract
ribcage movements- up and out
volume change- increases
pressure change- decreases, draws air in

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20
Q

what happens during expiration

A

abdominal muscles- contract ( pushes diaphragm up)
diaphragm- relax (doms up)
internal intercostal muscles- contract
external intercostal muscles- relax
ribcage movements- down and in
volume change- decreases
pressure change- increases draw air out

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21
Q

how can ventilaton be monitored in humans

A

via simple obeservation (coutning number of breathes per min)

chest belt and pressure meter (recording rise and fall of the chest)

spirometer (recording the volume of gas expelled per breath)

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22
Q

describe/ explain spirometry

A

involves measuring the amiunt (volume) and/ or seed (flow) at which air can be inhaled or exhaled

the spirometer detects the chnages in ventilation and presents the data (spirogram) on a digital display

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23
Q

describe how the actual spirometry process is performed

A

patient places clip on nose which keeps both nostrils closed
patient takes deep breath in, holds the breath for a few seconds and then exhales as hard as possible into breathing tube
patient repeats test at least 3 times

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24
Q

tidal volume

A

volume of air lungs can accomodate at rest

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25
vital capacity
volume of air lungs can accomodate whilst deep breathing = tidal volume + inspiratory reserve volume + experitory reserve volume
26
experitory reserve volume
max volume air that can be breathed out during deep breathing
27
inspiratory reserve volume
max volume of air that can be breather in during deep breathing
28
total lung capacity
vital capactiy + residual volume
29
residual volume
minimum volume of air present always in the lungs
30
compare inhaled with exhaled air
inhaled: more oxygen less co2 same n2 less water vapour exhaled: less oxygen more co2 same n2 more water vapour
31
how do you calculate ventilation rate
count number of breathes per min
32
suggest how total lung vlume at rest would differ for a patient with emphyema
decreaes (less surface area in alveolus)
33
what is the general/ simple nervous control system pathway
stimulus receptors sensory neurone relay neuorone ->CNS motor neurone effector response
34
what are the nervous control responses in ventilation rate
increase ventilation rate decrease ventilation rate
35
what are the effectors in both increase and decrease vent rate in nervous control of ventilation
diphragm external intercostal muscle internal intercostal muscle
36
whats the stimulus for an increase in ventilation rate
increase in co2 concentration in the blood this decreases the blood ph
37
whats the stimulus for an decrease in ventilation rate
at rest there is a decrease in co2 concentration in the blood normal blood ph or little alkali
38
what are the receptors in both increase and decrease vent rate in nervous control of ventilation
chemoreceptors (ph receptors) found in aortic and carotid arteries
39
where is the relay neurones in both increase and decrease vent rate in nervous control of ventilation located
in the medulla oblongata (BCC)
40
what are the motor neurones in both increase and decrease vent rate in nervous control of ventilation
phrenic nerve which acts on the diaphragm intercostal nerve acts on external and internal intercostal muscles
41
what are the sensory neurones in increase in vent rate reaction vs decrease in vent rate reaction
increase= sympathetic vagus nerve decrease= parasympathetic osopharyngeal nerve
42
explain body reaction for increased co2 in blood step 1
chemoreceptors detect increased co2 in the blood and lower ph, sending action potentials to the medulla oblongata
43
explain body reaction for increased co2 in blood step 2
the inspiratory centre of the medulla sends action potentials along nerves to the external intercostal muscles and diaphragm. Increasing their contractility rate
44
explain body reaction for increased co2 in blood step 3
the expiratory centre is inactive co2 concentration in blood decreases sending a negative feedback signal to the medulla, activating the expiratory centre, inhibitng the inspiratory centre further
45
explain body reaction for increased co2 in blood step 4 (last)
diaphragm contracts along with the external intercostal muscles
46
what happens to respiration during excercise
more aerobic and anaerobic respiration takes place high co2 in the blood produces lactic acid decrease ph blood detected by chemoreceptros in carotid arteries or aortic artereis electrical impulses sent t BCC in medulle obloongata (sympathetic) electrical impulses from bcc, causes diaphragam and intercostal muscles to produce a response through phrenic and intercostal nerves increase in ventiliation depth and rate increase blood ph
47
what happens to respiration at sleep
less aerobic and anaerobic respiration low co2 in blood neutra ph in blood detecter by chemoreceptors in carotid and arotic arteries electrical impulses sent to BCC in medulle oblongata (parasympathetic) electrical impulses sent from BCC towards diaphragm and intercostal muscles through phrenc and intercostal nerves decrease in ventilation depth and rate decrease in blood ph
48
explain general process of nervous control of ventilation
nervous system plas curcial role in regulting ventilation breathing contro centre (BCC) responsible for this, located medulle oblongata, which is a part of brainstem. Area integrates signals from various part of body to control rate and depth of breathing changes in blood levels of co2 and o2 and ph detected by specialized chemoreceptors, located in aorta and carotid arteries. they send signals to inspiratory control centre (Inside BCC0 via Vagus nerve and to experiatory control centre (inside BCCO via ossopharyngeal nerve motor signals from BCC sent to respiratory muscles. Phrenci nerve stimulates diaphragm, causing it to increase rate of contraction. Intercostal nerve activates the intercostal muscles, assist in expanding the ribcage sympathetic system ncreases breathing rate and depth during stress or exercises, while parasympathetic system slow breathing during rest and relaxation.
49
haemoglobin contains
2 alpha and 2 beta polypeptide chains 4 heme groups with 4 iron atoms in each polypeptide chain quaternary structure made of 4 teritiary structures conjugated protein structure because fold around non organic element= iron
50
what does it mean haemoglobin saturation
each iron i linked to one oxygen= oxyhaemoglobin, 4o2
51
explain each tissue on oxygen dissociation curve
0-30 mm Hg= exercising tissues 30-60 mm Hg= resting tissues higher pressures= lungs
52
53
haemoglobin has low affinity to O2
haemoglobin holds onto oxygen less tightly, meaning the oxygen can be lost or provided to other tissues, respiring tissues (that are in need of aerobic respiration and thus oxygen), haemoglobin in turn binds to co2 released by tissue forming carbaminoglobin
54
partial pressure O2
pressure exerted by O2 in mixture of gases at low pO2, haemoglobin is not fully saturated with oxygen, at high po2 full saturation occurs
55
whats the bohr shift
slight shift of o2 dissociation curve to the right to decrease haemoblogin affinity to oxygen mechanism which allows body to adopt the problem of supplying more oxygen to muscles undergoing strenous activity muscles generate carbon dioxide and lactic acid which lowers ph making haemoglobin let g of o2
56
explain structure of haemoglobin with low oxygen affinity
in between alpha and beta polypeptide chains adjacent to each other there is a strong hydrophobic bond diagonally between alpha and alph polypeptide chains there are many hydrogen bonds, but they are in general week, this stabilizes the dimers interaction with one above it in T-form= taute and tense, deoxy low in oxygen affinity
57
explain structure of haemoblogin with high oxygen affinity
R-form = relaxed oxy= high in oxygen affinity in between alpha and beta polypeptide chains adjacent to each other there is a strong hydrophobic bond diagonally between alpha and alph polypeptide chains there is one hydrogen bond, as oxygen disrupts the hydrogen bonds
58
name for when haemoglobin changes structure from T-form to R-form or vice versa
confrontational change
59
cooperative binding
confrontational change in hamemoglobin caused by oxygen binding the oxygen dissociation curve is caused by cooperative binding
60
what are the steps for cooperative binding
one o2 binds to a haemoglobin subunit o2 binding disrupts inter-dimer bonds increase in o2 affinity of remaining subunits
61
when is oxygen binding affinity low
when there is low saturation with oxygen
62
when is oxygen unloaded and loaded from haemoglobin
loaded in the lungs unloaded in tissues
63
saturation
percentage of haemoblogin binding sites in the bloodtsream occupied by oxygen
64
what is affinity
measure of how tightly haemoglobin attahches to oxygen high affinity= tight hold on oxygen low affinity= low hold, gives oxygen away
65
explain haemoglobin in alveoli capillaries
Partial pressure oxygen= high affinity of Hb for O2= high result= O2 attached Hb saturation= high
66
explain haemoglobin in respiring tissues
Partial pressure oxygen= low affinity of Hb for O2= low result= O2 released Hb saturation= low
67
compare adult Hb with fetal Hb
adult= made of 2 alpha, 2 beta subunits, lower o2 affinity fetal= made of 2 alpha, 2 gamma subunits, higher o2 affinity
68
compare oxygen dissociation curve for fetal and adult Hb
oxygen dissociation curve for fetal Hb is shifted to the left of adult Hb means that fetal Hb able to take up oxygen at lower partial pressure that adult Hb, has higher affinity for o2 fetus obtains oxygen through the placenta, oxygen dissociates from mothers Hb and is attahced to fetal Hb
69
what are the structures in the leaf
cuticle= waxy layer, impermeable to H2o and Co2 upper epidermis palisade mesophyll spongy mesophyll- full of air spaces vascular bundle= xylem ontop of phloem lower epidermis= contains guard cells and stoma
70
cuticle and upper epidermis
prevents water loss
71
palisade mesophyll
cells contain lots of chloroplasts; absorption of light for photosynthesis
72
vascular bundles
transport water to lead (xylem) and starch away (phloem)
73
spongy mesophyll
lossely packed, filled air spaces, surface for gas exchnage
74
lower epidermis and guard cells
guard cells open and close, control water loss via transpiration and allowing for gas exchange
75
stomata
pore, pore surrounded by pair of guard cells, change shape, open or close stoma
76
explain how guard cells change shape to open stomata
K+ ions enter the cell which establishes an osmotic gradient, this means water can enter the cell via osmosis. This increases the turgicity of the cell and tugor pressure as cell swells openng a hole between the guard cells= stoma, allowing co2 to enter the cell and water vapour to move out of the cell
77
explain how guard cells change shape to close stomata
K= ions move out of cell, establishes an osmotic gradient, water moves out of cell via osmosis, this decreases turgicity of the cell, decreasing tugor pressure, cell shrinks, closeing the stoma, co2 cant move into the cell and water vapour cant move out of the cell
78
how do you calculate mean stomatal density
1- FOV= FN (field number, 15 mm or 20mm or 25mm)/ (ME (eyepiece magnification always 10) *MO (10 40 or 100, objective magnification)) 2- FOV/2= radius 3- pi (3.14) * FOV radiusˆ2= area of FOV 4- divide mean number of stomata/ area of FOV
79
adaptations of leaves for gas exchange
thin and flat, large surface area= more efficient diffusion of gases in and out and absorption of sunlight waxy cuticle covers upper epidermis hydrophobic= protects against water loss
80
transpiration
loss of water vapour through leaves
81
evaporation in plants
loss o fwater out of leaf as water vapour when stomata are open is due to evaporation, when liquid exposed to air, molecules break off liquid become gas evaporation leads to transpirtion pull, upward movement of water due to continuoes evaporation
82
why does water vapour diffuse out of the leave
bigger concentration of water vapour in leaves than surrounding air
83
how do you measure the rate of transpiration
using a potometer, which measures rate of water uptake and indericetly transpriation, since whne one water molecule is absrobed one is lost via evaporation
84
how does light affect transpiration
plant transpires more rapidly in light, light stimulates opening of stoma, and warming up leaf
85
how does temperature affect transpiration
higher temperature= higher rate of transpiration
86
how does humidity affect transpiration
hgiher humidity lower rate of transpiration the higher the difference in concentration of water molecules from the air copared to the leaf the faster diffusion, highr diffusion causes more water molecules to be outside the leaf, thus weaker concentation gradient
87
how does wind affect transpiration
stronger wind= higher rate of transpiration wind removes water molecules from surroudning leaf cells, causes steeper concentration gradient

Bio IB (22 decks)

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