exam 3 Flashcards
1
Q
gas exchange in respiration
A
exchange 1: atmosphere to lung (ventilation)
exchange 2: lung to blood
transport: transport gases in blood
exchange 3: blood to cells
2
Q
anatomy of airway
A
pharynx
larynx
trachea
bronchi
bronchioles
alveoli
3
Q
anatomy of airway
A
pharynx
larynx
trachea
bronchi
bronchioles
alveoli
4
Q
pharynx
A
passageway for ingested materials and air
5
Q
trachea
A
windpipe
flexible tube help by c-shape rings of cartilage
6
Q
larynx
A
contains the vocal cords
bands of connective tissue tightened or loosed by muscles to create sound when air passes
7
Q
bronchioles
A
small collapsible passageways
smooth muscle walls
branch until the reach the exchange surface (Alveoli)
total cross sectional diameter increases as they branch
8
Q
goblet cells
A
secreted by goblet cells
contain ciliated epithelial cells which move the mucus toward the pharynx
9
Q
alveoli
A
exchange surface of lungs
where O2 and CO2 move between air and blood
10
Q
type 1 alveoli
A
thin gas exchange cells
majority of alveolar surface
close association with pulmonary capillaries to permit gas exchange
0.2 um thick
11
Q
type 2 alveoli cells
A
produce surfactant
substance that acts to ease expansion of lungs during inspiration
12
Q
elastin fibers
A
connective tissue fibers between alveoli
contribute to elastic recoil
13
Q
pleural sac
A
membrane surrounding lungs
pleural tissue held by fluid
holds lungs against thoracic wall by intrapleural pressure
14
Q
intrapleural vs interpulmonary pressure
A
intrapleural is always less
15
Q
inspiration
A
external intercostal contacts
diaphragm contracts
chest wall and lungs expand
sterum moves up
16
Q
expiration
A
passive! due to elastic recoil
external intercostal relaxes
diaphragm relaxes
chest cavity and lungs contract
ribs and sternum decompress
17
Q
active expiration
A
internal intercostal muscles contract
abdominal muscles contract
18
Q
alveolar (interpulmonary) pressure during inspiration and expiration
A
low during inspiration
high during expiration
19
Q
resistance effect
A
decrease alveolar pressure during inspiration
increase alveolar pressure during expiration
increases energy required for breathing (normally 3%)
decrease compliance
20
Q
lung compliance
A
change in lung volume/change in transpulmonary pressure
21
Q
transpulmonary pressure
A
alveolar (interpulmonary) pressure - intrapleural pressure
22
Q
what affects compliance
A
intrinsic elastic properties
surfactant
23
Q
what affects compliance
A
intrinsic elastic properties
surfactant
24
Q
surfactant
A
made of phospholipids and proteins
secreted by type 2 alveoli cells
decrease surface tension!
25
surfactant effect on compliance
decrease surface tension
increase compliance
easier for lungs to expand
greater effect in smaller alveoli which equalizes pressure between large and small alveoli
26
tidal volume
volume of gas that moves in and out
500 ml per breath
27
functional residual capacity
2100 ml
volume left in system at end of expiration
28
expiratory reserve volume
extra 1100 we can force out using expiratory muscles
29
residual volume
remaining 1000 ml left after we force out extra air
30
inspiratory reserve volume
3000 ml air we can bring in if we breath deeper
31
total maximal inspiratio volume
3500
500 from normal tidal volume
extra 3000 from inspiratory reserve volume
32
vital capacity
total maximalvolume we can move in and out
4600
500 + 3000 + 1100
33
forced expiratory volume
volume actively expired in 1 second
typically 80% of todal
goes down as airway resistance increases
34
minute ventilation
tidal volume x breathing rate
amount of air moved in and out per minute
35
alveolar ventilation
takes into account dead space of tidal volume (150 ml)
amount of fresh air brought to alveoli per minute
= (tidal volume-dead volume) x breathing rate
36
respiratory quotient
1 molecule O2 consumed = 0.8 CO2 generated
37
normal alveolar ventilation per minute
approximately 12 breaths/min * 350 ml = 4200 ml
21% of volume is O2=882 ml/min of oxygen entering lungs
38
increase pCO2
dilate bronchioles
constrict pulmonary arteries
dilate systemic arteries
39
increase pO2
constrict bronchioles
dilate pulmonary arteries
constrict systemic arteries
39
gas exchange occurs by
simple diffusion
proportional to: concentration gradient, surface area
inversely proportional to: thickness, distance
40
atmospheric o2 alveolar pressure
160 mmHg vs 100 mmHg
difference because: dead volume, rapid diffusion between alveoli and pulmonary capillaries
41
normal arterial blood values
pO2= 95
pCO2 = 40
pH = 7.4
42
normal venous blood values
pO2 = 40
pCO2 = 46
pH = 7.37
43
what happens to arterial oxygen
2% dissolves in plasma
98% binds to hemogobin
44
exchange between alveoli and capillaries
occurs within first third of capillary length
45
hypoxia
less oxygen
46
asthma
causes hypoxia
increased airway resistance decreases alveolar ventilation
47
pulmonary edema
causes hypoxia
fluid in interstitial space increases diffusion distance
48
fibrotic lung tissue
causes hypoxia
thickened alveolar membrane slows gas exchange
49
emphysema
causes hypoxia
destruction of alveoli decreases surface area
50
binding of oxygen and hemoglobin
1 gram of hemoglobin combines with 134 ml of O2
each of 4 subunits can be oxygenated or deoxygenated
reversible, fast
Hb + O2 <-> HbO2
51
percent oxygenated substrate
percent of hemoglobin saturation of oxygen
52
hemoglobin concentration
150 g/liter
15%
53
what happens to CO2 in blood
7% remains dissolved
70% converted to bicarbonate and H+
23% binds to Hb
54
CO2 and Hb binding
forms cabaminohemoglobin
55
Hb-O2 curve shift to right
curve shifs to the right causes more O2 to be delivered to the tissue
56
what causes right shift of curve
increase of DPG
decrease pH
increase temp
57
what causes decrease pH which leads to curve shift to right
skeletal muscles are more active
acids build up of lactic acid
decrease pH
increase oxygen delivery
58
regulation of inspiratory muscles
phrenic nerve innervates diagphram
intercostal nerve innervates external intercostal
originate from cervical spinal cord (C3-C5)
59
what controls the nerves innervating inspiratory muscles
central rhythm generator located in medulla
60
central rhythm generator
generates oscillitaroy activity
which excites DRG and VRG
61
DRG and VRG
dorsal/ventral respiratory group
neurons that innervate motor neurons that control respiratory muscle
DRG fires I neurons
VRG fires both
62
pre-Botzinger nucleus
found in VRG
fires I neurons or E neurons
63
I neurons vs E neurons
I neurons: active during inspiration, silent during expiration
E neurons: silent during inspiration, active during expiration
64
where are peripheral chemoreceptor sites
cartoid bodies
aortic bodies
65
peripheral chemoreceptors respond to
changes in arterial blood
- significant decrease Po2 (Hypoxia)
- increased H+ (metabolid acidosis)
- increased pCO2 (respiratory acidosis)
66
central chemoreceptors
medulla oblongta
respond to changes in brain extracellular fluid
- increased pCO2 associated with changes in H+
67
blood brain barrier
CO2 can cross
H+ cant cross
68
peripheral vs central chemorceptors
low O2 only affects peripheral chemoreceptors
peripheral: increase arterial H+
central: increase ECF H+
69
what happens after chemorceptors fire
fire medulla inspiratory neurons (DRG and VRG)
fire neurons to diagphragm and inspiratory intercostals (phrenic and intercostal)
causes diagphragm and external intercostal to contract
breathign!
70
effect of exercise on ventilation
increase minute ventilation
decrease arterial co2
increase arterial H+
O2 stays same
feed forward mechanism because minute ventilation changes before others
71
sneezing
receptors in nose and pharynx stimulate deep inspiration and forced expiration
72
coughing
receptors in trachea stimulate deep inspiration and forced expiration
73
speech
requires fine control of respiratory muscles
74
2,3DPG
compound made from intermediate in glycolysis
increased levels of DPG in red blood cells with hypoxia
increased DPG shifts curve to right
75
breathing at high altitude
barometric pressure is low
alveolar O2 is low
hard to get O2
76
increase red blood cell count
if there is low o2=hypoxia
so kidneys release erythropoiten to produce erythrocytes
which increases hematocrit and blood volume
77
great increase in pulmonary ventilation
if there is low o2=hypoxia
so small increase in pulmonary ventilation
but kidney normalizes pH by secreting bicarbonate ion which increases ventilation by a lot
78
increase cellular metabolism
if there is low o2=hypoxia
but produce more cells, more mitochondria, more energy
79
increased vascularity of tissue
if there is low o2=hypoxia
but increase # of capillaries to make more o2
which also increases surface area for gas exchange between alveoli and blood
80
ways to acclimate to low po2
increase cellular metabolism
increase # RBC
increase vascularity of tissue
large increase of pulmonary ventilation
change O2-Hb curve
81
change O2=Hb curve
low O2=hypoxia=curve shift to left
over time 2,3-DPG brings curve back to the right
82
function of kidneys
regulate blood pressure, osmolality, electrolyte concentration, erythrocyte
maintain ph and h2o
excrete metabolic waste
produce glucose
83
urinary system
kidney
ureter
bladder
urethra
84
kidney anatomy
nephrons
bowmans capsule/proximal distal tubules: inner medulla
loop of henle/collecting ducts: outer cortex
85
nephrons
1 million per kidney
juxtamedullary (20%) long loop
cortical (80%)
86
renal autoregulation
myogenic mechnisms
tubuloglomerular feedback
87
path of urine
glomerulus
bowmans capsule
proximal convulted tubule
proximal straight tube
descending limb
ascending limb
distal convoluted tubule
cortical collecting duct
medullary collecting duct
renal pelvis
88
arterioles and capillaries of nephron
afferent arterioles
to glomerular capllaries
transition to efferent arteriole
to peritubular capillaries
89
excretion formular
filtration-reabsorption+secretion
90
filtration equation
net filtration pressure x Kf (filtration constant)
net filtration pressure: hydrostatic and osmotic pressure
filtration constant:how leaky capillary is
91
hydrostatic pressure
blood pressure
92
osmotic pressure
due to proteins being in plamsa but not in bowmans capsule
93
layers of filtration
1.capillary endothelial cells: more holes, coarsest level
2.basal lamina: noncellular matrix between endothelial cells
3.podocytes:filtration sites, finest level, specialized epithelial cells that line glomerular capillaries
94
GFR
normal glomerular filtration rate
125 ml/min=180 L/day
= V * Us/Ps
only works for a substance filtered but not secreted
95
clearance rate
how much blood is excreted (renal plasma flow) (600mL)
totally reabsorbed: clearance rate =0
96
filtration fraction
= GFR/RPF
97
reabsorption
most occurs in proximal tubule
regulated occurs in distal segment of nephron (collecting duct)
98
reabsorption pathway
transport molecules from lumen of tubules
across epithelial cells
into interstitial space
into peritubular capillaries
99
apical vs basolateral membrane
apical(Lumen: face tubular lumen, highly convoluted, large surface area
basolateral: face renal interstitial fluid
100
transport maximum
due to limited transporters or transport time
maximum rate at which a membrane can transport substance
101
Na+ reabsorption
enters lumen membrane through concentration gradient
crosses basolateral membrane by secondary conc. gradietn
102
glucose reabsorption
sodium enters lumen membrane down conc. gradient, SGLT protein pulls glucose with it
glucose diffuses basolateral membrane using GLUT
Na crosses baoslateral by secondary active transport
103
impermeability of water
collecting duct is impermeable to water
ascending limb: not permeable to water, permeable to sodium
descending limb: not permeable to sodium, permeable to water
104
permeability of collecting duct regulation
aquaporin 2 on apical membrane
ADH released into blood stream and acts on receptors on basolateral membrane
ADH binding activates cAMP
fusion of vesicle with membrane: insert AQ2 on apical membrane
105
where is ADH made
hypothalamus
106
osmosensors
located in hypothalamus
in close proximity to ADH
107
diabetes insipidus
central: problem with ADH syntheis or secretion
nephrogenic: problem with renal response to ADH
108
deeper into kidney
interstitial fluid becomes more hypertonic
109
plasma osmolarity and vasopressin
osmolarity increases
vasopressin (adh)increases
urine volume decreases
uring osmolarity increases
110
ADH secretion
decreased blood pressure
decreased atrial stretch
increased osmolarity
all increase vasopressin (ADH)
which inserts water pores
increase water reabsorption to convserve water
111
Na+ reabsorption
most in proximal tubule (2/3)
least in collecting tubule
none in descending loop
main transporter of apical membrane is Na/K/2Cl transporter
112
aldosterone
acts on collecting tubule
regulated by angiotensin 2 which is controlled by renin
aldosterone increases Na+ reabsorption and K+secretion
113
what controls renin
increase renal sympathetic nerves (b-adrenergic receptor)
decrease atrial presure
decrease GFR
114
control of plasma osmolality
regulating how much water there is to dilute or concnetrate solutes
115
mechanisms to regulate water
control of water loss by kidneys
control of water intake (thirst)
116
aldosterone
steroid hormone
released from adrenal cortex
acts on collecting ducts to promote na+ reabsorption and K+ secretion
117
absence of aldosterone
2% of filtered Na+ is excreted (a lot)
118
presence of aldosterone
all Na+ is reabsorbed
119
how does aldosterone control reabsorption of Na+
synthesizes new Na,K,ATPase molecule in basolateral membrane
stimulates insertion of Na+ channels in apical membrane
increases transcription/translation
120
what controls release of aldosterone
angiotensin acts on aldosterone releasing cells of adrenal cortex
121
renin
released from juxtaglomerular cells
lie next to macula densa
surround afferent and efferent arteriole
122
atrial natriuertic hormone
released from right atrium in response to stretch
promotes Na+ excretion
decreases Na+ reabsorption
increases GFR
inhibits renin secretion, aldosterone, and ADH
123
potassium homeostasis
regulation occurs by secretion at level of cortical collecting ducts
regulated by aldosterone because it increases Na/K channels, promote K+ secretion
124
calcium homeostasis
conc. in ECF is low
regulated at collecting duct
controlled via an endocrine feedback mechanism
controlled by PTH
low Ca = secrete PTH = increase Ca
promote Ca reabsorption
125
H+ homeostasis
buffer
respiration
kidneys
126
osmotic diuretics
ex: mannitol
provide large amount of filtered but not reabsorbed solute --> get excreted and bring water with them
127
aldosterone antagonists
ex: spironolactone
block aldosterone receptors which promotes Na+ excretion, bring water wih it
128
loop diuretic
ex: furosemide
inhibit Na+ transporter
