Unit 4 Material Flashcards
(278 cards)
1
Q
The respiratory system includes (3)
A
Ventilation, gas exchange between blood and lung and tissues, oxygen utilization to make ATP (cellular respiration)
2
Q
External respiration is
A
ventilation and gas exchange in lungs
3
Q
Internal ventilation is
A
oxygen utilization and gas exchange in tissues
4
Q
Gas exchange in the lungs occurs via
A
diffusion
5
Q
O2 concentration is higher in the ______ rather than the _______, so O2 diffuses into _____.
A
Lungs.
Blood.
Blood.
6
Q
CO2 concentration in the ______ is higher than in the ______, so CO2 diffuses out of the _______.
A
Blood.
Lungs.
Blood.
7
Q
The respiratory system is anatomically divided into
A
Conduction zone and respiratory zone
8
Q
Zone that gets air into the respiratory zone
A
Conduction zone
9
Q
Zone that is site of gas exchange
A
Respiratory zone
10
Q
Air sacs in the lungs where gas exchange takes place
A
Alveoli
11
Q
How many alveoli are there and why are there so many
A
300 million. To provide large surface area to increase diffusion rate.
12
Q
Alveoli form clusters at the end of
A
Respiratory bronchioles
13
Q
Type I alveolar cells
A
95-97% total surface area where gas exchange occurs
14
Q
Type II alveolar cells
A
Secrete pulmonary surfactant and reabsorb sodium and water, preventing fluid buildup
15
Q
Pathway of Air (10)
A
Air travels down the nasal cavity > pharynx > larynx (glottis and vocal cords) > Trachea > Right and left primary bronchi > Secondary bronchi > Tertiary bronchi > Terminal bronchioles > Respiratory zone > terminal alveolar sacs
16
Q
CH 16 SLIDE 9
A
Shows pics of conducting and respiratory zones
17
Q
Functions of the conducting zone (3)
A
Transports air to the lungs.
Warms, humidifies, filters, and cleans air.
Voice production in the laryx.
18
Q
Mucus traps small particles and cilia move it away from the lungs
A
Mucociliary escalator and mucociliary clearance.
19
Q
What does the thoracic cavity contain
A
Heart, trachea, esophagus, and thymus within the central mediastinum, and lungs
20
Q
This lines the thoracic cavity
A
Parietal pleura
21
Q
This covers the lungs
A
Visceral pleura
22
Q
Potential space between the parietal and visceral pleura
A
Intrapleural space
23
Q
What does the diaphragm separate
A
The thoracic and abdominal cavities
24
Q
CH 16 SLIDE 12
A
Thoracic cavity cross section
25
Air moves from area of ____ pressure to ______ pressure
Higher to lower
26
Pressure differences between the two ends of the conducting zone occur due to
changing lung volumes
27
Important physical properties of the lungs (3)
Compliance, elasticity, and surface tension
28
Pressure of air outside the body
Atmospheric pressure
29
Pressure in the lungs
Intrapulmonary or intraalveolar pressure
30
Pressure within the intrapleural space. Contains a thin layer of fluid to serve as lubricant
Intrapleural pressure
31
1 atmosphere is
1033.25 cm H2O = 760 mm Hg
32
Inspiration pressure
Intrapulmonary pressure is lower than atmospheric pressure. Generally about -1cm H2O
33
Pressure below that of atmosphere is called
Subatmospheric or negative pressure
34
Expiration pressure
Intrapulmonary pressure is greater than atmospheric pressure. Generally about +1cm H2O
35
Intrapulmonary pressure at inspiration
-1 cm H2O
36
Intrapulmonary pressure at expiration
+1 cm H2O
37
Intrapleural pressure at inspiration
-8 cm H2O
38
Intrapleural pressure at expiration
-5 cm H2O
39
Transpulmonary pressure at inspiration
+7 cm H2O
40
Transpulmonary pressure at expiration
+6 cm H2O
41
The difference between intrapulmonary and intrapleural pressure is called the
Transpulmonary pressure
42
Keeps the lungs against the thoracic wall and allows them to expand during inspiration
Intrapleural pressure
43
Boyle's law
States that the pressure of a gas is inversely proportional to its volume
44
An increase in lung volume during inspiration decreases intrapulmoanary pressure to subatomospheric levels...
air goes in
45
A decrease in lung volume during expiration increases intrapulmonary pressure above atmospheric levels
Air goes out
46
The premise that lungs can be expanded when stretched is called
Lung compliance. Change in lung volume per change in transpulmonary pressure
47
The ease in which lungs expand under pressure
Lung compliance
48
This is reduced by factors that produce resistance to distention such as the infiltration of connective tissue in pulmonary fibrosis
Lung compliance
49
Premise that lungs return to initial size after being stretched
Elasticity
50
Lungs are elastic because they have a lot of
Elastin fibers
51
Because lungs are stuck to the thoracic wall, they are always under
Elastic tension
52
Tension increases during inspiration and is reduced by
Elastic recoil during expiration
53
This resists distension
Surface tension
54
Exerted by fluid secreted on the alveoli
Surface tension
55
In surface tension, fluid is absorbed by active transport of ___ and secreted by active transport of ___
Na+ and Cl-
56
Raises the pressure of the alveolar air as it acts to collapse the alveolus
Surface tension
57
People with cystic fibrosis have a genetic defect that causes an impalance of fluid absorption and secretion
Surface tension
58
Law of Laplace
Pressure is directly proportional to surface tension and inversely proportional to radius of alveolus. Small alveoli would be at greater risk of collapse without surfactant
59
Surfactant is secreted by
Type II alveolar cells
60
Surfactant is consisted of
Hydrophobic protein and phospholipids
61
What does surfactant do
Reduces surface tension between water molecules by reducing the number of hydrogen bonds between water molecules. Prevents collapse. Allows a residual volume of air to remain in the lungs
62
Surfactant gets more concentrated as alveoli get smaller during
expiration
63
Acute respiratory distress syndrome (ARDS)
High risk for alveolar collapse due to septic shock, reduced compliance, and reduced surfactant. Not treatable with surfactant
64
Respiratory distress syndrome (RDS)
Premature babies may be born with a high risk for alveolar collapse because surfactant production begins late in fetal life. Treated with surfactant.
65
Muscles involved in breathing (4)
Diaphragm, external intercostal muscles, internal intercostal muscles, parasternal intercostal muscles.
66
Muscle that contracts in inspiration, relaxes in expiration.
Diaphragm.
Lowers in inspiration making cavity larger.
Raises in expiration, making cavity smaller.
67
Muscle that raises the rib cage during inspiration
External intercostal muscles
68
Muscle that lowers the rib cage during forced expiration
Internal intercostal muscles
69
Muscle that works with the external intercostal
Parasternal intercostal muscles
70
Muscles used for forced expiration
Scalenes, pectoralis minor, and sternocleidomastoid. And abdominal msucles
71
Quiet respiration occurs with the relaxation of what muscles
Inspiration muscles, which is a passive process
72
How does inspiration work?
Volume of thoracic cavity (lungs) increases vertically when diaphragm contracts (flattens) and laterally when parasternal and external intercostals raise the ribs.
Thoracic and lung volume increase > intrapulmonary pressure decreases > air in.
73
How does expiration occur?
Volume of thoracic cavity (and lungs) decreases vertically when diaphragm relaxes (dome) and laterally when external and parasternal intercostals relax for quiet expiration or internal intercostals contract in forced expiration to lower the ribs.
Thoracic and lung volume decreases > intrapulmonary pressure increases > air out.
74
CH 16 SLIDE 31
Mechanisms of Pulmonary Ventilation
75
How does spirometry work?
Breathing into and out of a device that records volume and frequency of air movement on a spirogram
76
What does spirometry measure? and what can it diagnose?
Lung volumes and capacity.
| Diagnose restrictive and obstructive lung disorders
77
Tidal volume is...
Amount of air expired or inspired in quiet breathing is called
78
Expiratory reserve volume is...
Amount of air that can be forced out after tidal volume is called
79
Inspiratory reserve volume is...
Amount of air that can be forced in after tidal volume
80
Residual volume is...
Amount of air left in lungs after maximum expiration
81
Vital capacity is...
Maximum amount of air that can be forcefully exhaled after a maximum inhalation
82
Total lung capacity is ...
Air in the lungs after a maximum inspiration
83
Inspiration capacity is...
Air that can be inspired after a normal expiration
84
functional residual capacity is...
Air left in the lungs after a normal expiration
85
Inspiration reserve volume + expiratory reserve volume + tidal capacity =
Vital capacity
86
Residual volume + expiratory reserve volume =
Functional residual capacity
87
Tidal volume x breaths per minute (~6L/min) =
Total minute volume
88
Restrictive pulmonary disorder
Lung tissue is damages. Vital capacity is reduced, but forceful expiration is normal
89
Example of pulmonary restrictive disorder
Pulmonary fibrosis
90
Obstructive pulmonary disorder
Lung tissue is normal. Vital capacity is normal, but forced expiration is reduced.
91
Examples of obstructive pulmonary disorder
Asthma; caused by inflammation, mucus, secretion, and construction of bronchioles.
Emphysema
92
Subjective feeling of shortness of breath
Dyspnea
93
Atmospheric pressure is measured using what
Barometer
94
At sea level, the atmospheric pressure is
760 mmHg
95
Dalton's law
The total pressure of a gas mixture is equal to the sum of the pressures of each gas in it
96
Partial pressure
The pressure of an individual gas; can be measured by multiplying the % of that has by the total pressure
97
O2 makes up 21% of the atmosphere, so partial pressure of O2 = 760 x 21% =
159 mmHg
98
Pdry is
PN2 + PO2 + PCO2 = 760 mmHg
99
Pwet (air gets out of lungs) is
PN2 + PO2 + PCO2 + PH2O = 760 mmHg
100
Pressure of water at 37 C is constant
47 mmHg
101
Partial pressure of O2 at sea level is
.21(760-47) = 150 mmHg
102
In the alveoli, the percentage of oxygen _____, and CO2 ____, changing the partial pressure of both
Decreases, increases
103
Henry's Law: The amount of gas that can dissolve in liquid depends on;
Solubility of the gas in the liquid.
Temperature of the liquid.
Partial pressure of the gases, determining factor.
104
CH 16 SLIDE 47
Relationship between Alveoli and capillaries
105
Blood PO2 only measures what
Oxygen dissolved in plasma, not bound to hemoglobins
106
Properly functioning lungs give systemic arterial blood PO2 less than 5 mmHg than
Alveolar air. Normal PO2 is 100 mmHg
107
CH 16 SLIDE 50
Partial pressure of Gas in Blood
108
The rate of blood flow through the lungs is equal to that through the systemic circuit
5.5 L/minute cardiac output
109
The pressure difference between the left atrium and the pulmonary artery is only
10 mmHg
110
Why is vascular pressure very low
Low resistance pathway.
| Reduces possibility of pulmonary adema.
111
Pulmonary arterioles construct when alveolar partial pressure O2 is __ and dilate when partial pressure O2 is __
Low, high.
112
Blood flow to alveoli is __ when they are full of Oxygen
Increased
113
Systemic arterioles constrict when partial pressure O2 is __
High. This ensure that only tissues that need oxygen are sent blood.
114
Voluntary breathing comes from what part of the brain
Cerebral cortex
115
Involuntary breathing comes from
The respiratory control centers of the medulla oblongata and pons
116
Motor neurons that innervate the diaphragm from the phrenic nerve and arise from
the cervical region of the spinal cord
117
Motor neurons that innervate the other breathing muscles arise form the
Thoroacolumbar region of the spinal cord
118
Medulla rhythmicity center
Contains inspiratory and expiratory neurons that stimulate or inhibit the phrenic nerve controlling respiratory muscles in a reciprocal way to produce the rhythmic pattern of breathing
119
What influences the activity of the medulla
The pons
120
The automatic control of breathing is influenced by feedback from chemoreceptors, which monitor...
pH of fluids in the brain and pH, CO2, and O2 of the blood.
121
Which ones senses changed in blood CO2 that lead to changes in brain pH since H+ can't cross BBB
Central chemoreceptors in medulla
122
Which sense blood CO2 and pH
Peripheral chemoreceptors in carotid and aorta arteries
123
When blood O2 is very low and actually has change, it's called...
Hypoxic drive and affects the carotid bodies
124
CH 16 SLIDE 60
Regulation of ventilation by the CNS
125
When ventilation is inadequate, CO2 levels rise and pH falls is called
Hypercapnia
126
If hyperventilation, CO2 levels fall and pH rises this is called
Hypocapnia
127
Oxygen levels do not change as rapidly because of oxygen reserves in
hemoglobin
128
Ventilation is controlled to maintain constant levels of
CO2 in the blood. Oxygen naturally follows
129
CH 16 SLIDE 62
Chemoreceptor Control of Breathing
130
Plasma O2 concentration is systemic arteries is about
0.3mL/100mL of blood
131
Total O2 content of blood depends on
PO2 and hemoglobin concentration
132
Most of the oxygen in blood is bound to
hemoglobin
133
each hemoglobin can carry ___ molecules of O2
4
134
___ million hemoglobin per RBC
280
135
Hemoglobin where iron is reduced from (Fe2+) and can bind with O2
Oxyhemoglobin/ rediced (deoxyhemoglobin) hemoglobin
136
Hemoglobin with oxidized iron (Fe3+) can bind do O2. Some drugs can cause this
Methemoglobin
137
Hemoglobin is bound with carbon monoxide; has stronger bond with CO and O2
Carboxyhemoglobin
138
When hemoglobin binds to oxygen in the lungs, it's called
Loading
139
When oxyhemoglobin drops off oxygen in the tissues, it's called
Unloading
140
High PO2 favors (unloading or loading)
loading
141
Strong bond favors _____ and inhibits ______
Loading, unloading
142
Oxygen remaining in the veins after unloading serves as
Oxygen reserve
143
22% oxygen unloading at
rest
144
39% oxygen unloading at
light exercise
145
80% oxygen unloading at
heavy exercise
146
pH and temperature change the affinity of hemoglobin for
O2; which ensures that muscles get more O2 when exercising.
147
Oxygen unloading is higher at ___ pH
Lower; Bohr effect
148
How do RBCs obtain their energy?
From the anaerobic metabolism of glucose...which created 2,3-DPG, increases unloading
149
When is 2,3-DPG created?
If a person is anemic or at high altitudes
150
CH 16 Slide 73
Factor chart that affects affinity of Hemoglobin for O2
151
Similar to hemoglobin, only 1 heme, so can only carry 1 oxygen molecule
Muscle hemoglobin
152
Where is muscle hemoglobin found?
In skeletal and cardiac muscles
153
Describe muscle hemoglobin affinity to O2
Higher affinity. Oxygen is only released when PO2 is very low.
154
Three ways in which carbon dioxide is carried in the blood
Dissolved in plasma, as carbaminohemoglobin attached to amino acid in hemoglobin, as bicarbonate ions
155
The enzyme that catalyzes the reaction to form carbonic acid
Carbonic anhydrase
156
Once bicarbonate ions is formed in the RBC, it diffuses where
plasma
157
H+ RBC attach to hemoglobin and attract
Cl-
158
What is the chloride shift?
The exchange of bicarb out of and Cl- into RBC
159
In pulmonary capillaries, increased PO2 favors the production of
oxyhemoglobin
160
The production of oxyhemoglobin makes H+ dissociate from hemoglobin and recombine with bicarb to form
Carbonic acid (H2CO3)
161
In low PCO2, carbonic anhydrase converts carbonic acid (H2CO3) back to
CO2 + H2O
162
pH of the blood ranges
7.34 - 7.45
163
Volatile acid
Carbonic acid because it can be converted and exhaled
164
Nonvolatile acids are buffered by...and are regulated by
Bicarbonate .
| Kidneys.
165
What is the major buffet run the blood
Bicarbonate ion
166
When blood pH falls below 7.35, it is called
Acidosis
167
caused by hypoventilation rise of CO2 which increases H+ (lowers pH)
Respiratory acidosis
168
Caused by excessive production of acids or loss of bicarbonate (diarrhea)
Metabolic acidosis
169
When blood pH rises above 7.45 it is called
Alkalosis
170
Caused by hyperventilation, pH increases
Respiratory alkalosis
171
Caused by inadequate production of acids or overproduction of bicarbonates, loss of digestive acids from vomiting
Metabolic alkalosis
172
Respiratory acidosis and alkalosis occurs with abnormal
CO2 concentration
173
Metabolic acidosis or alkalosis occurs with abnormal
bicarbonate concentration
174
Ventilation is insufficient, PCO2 is high, carbonic acid is high, and respiratory acidosis occurs
Hypoventilation
175
Rate of ventilation is faster than CO2 production. Less carbonic acid forms, PCO2 is low, and respiratory alkalosis occurs
Hyperventilation
176
A person with metabolic acidosis will hyper/hypoventilate to blow off CO2, H+ decreases, pH rises.
Hyperventilate
177
A person with metabolic alkalosis will hyper/hypoventilate, slowsslow down respiration, build up CO2, H+ increase, pH lowers
Hypoventilate
178
Ch 16 slide 91/92
Charts comparing respiratory acid-base
179
Kidneys function to regulate the extracellular fluid in the environment including (5)
Volume of blood plasma, wastes, electrolytes, oH, secrete erythopoieten
180
Where is urine made
In the kidney nephrons
181
Urine is transported using
peristalsis
182
Order of urine to exit the body
Made in kidney nephrons > drains into renal pelvis > down ureter to bladder > through urethra
183
Two distinct regions of the kidney
renal cortex and renal medulla (renal pyramids and columns)
184
Renal pyramids drain into
Minor calyx > major calyx > renal pelvis
185
the muscles that line the wall of the urinary bladder are called
Detrusor muscles
186
The internal urethral sphincter is what kind of muscle
Smooth muscle
187
The external urethral sphincter is what kind of muscle
skeletal muscle
188
Neurons in the S2-S4 normally inhibit parasympathetic nerves to the
detrusor muscles. called guarding reflex
189
Where is the micturition center located
in the pons
190
How many nephrons does each kidney have
more than a million
191
Consists of small tubules and associated blood vessels
Nephrons
192
Ch 17 Slide 9/10
Anatomy of the kidneys
193
Order of the renal blood vessels
Renal artery > Interlobar arteries > Arcuate arteries > Interlobular arteries > Afferent arterioles Glomerulus >
Efferent arterioles > Peritubular capillaries > Interlobular veins > Arcuate veins > Interlobar veins > Renal vein
194
What parts make up the renal corpuscle
Glomerular capsule and the glomerulus
195
Filtrate produced in the renal corpuscle passes into the
Proximal convoluted tubule
196
After filtrate passes through the proximal convoluted tubule, the fluid passes into the
descending and ascending limbs of the loop of Henle
197
After the loop of Henle, fluid passes into the
distal convoluted tubule and then into the collecting duct and then into the minor calyx
198
Two types of nephrons
Juxtamedullary (better at making concentrated urine), and cortical
199
Fenestrated capillaries of the glomerulus allow for what to happen
Large pores allow for water and solutes to leave but not blood cells and most plasma proteins
200
Filtrate must pass through
Capillary fenestrae, glomerular basement membrane, visceral later of the glomerular capsule composed of cells called podocytes
201
CH 17 SLIDE 17
Glomerular Corpuscle and Filtration Barrier
202
What is the major barrier for the filtration of plasma proteins in the glomerular corpuscle
Slits in the pedicles called slit diaphragm pores
203
Proteins in urine are caused by and is called
Defects in the slit diaphragm pores.
| called proteinuria
204
How does the fluid in the glomerular capsule get there (3)
hydrostatic pressure of the blood, colloid osmotic pressure, and very permeable capillaries
205
Net filtration pressure in the glomerular capillaries is
10 mmHg
206
What is the Glomerular Filtration Rate (GFR)
the volume of filtrate produced by both kidneys each minute (115-125mL = 180 L/day)
207
How long does it take for the total blood volume to be filtered
40 minutes
208
Extrinsic regulation of filtration rates occurs from
Sympathetic nervous system
209
Intrinsic regulation of filtration rate occurs from and is called
the kidneys; renal autoregulation
210
What happens to filtration with the sympathetic nervous system.
In F/F situation, vasoconstriction, which helps divert blood to heart and muscles, urine formation decreases to compensate for the drop in blood pressure.
211
What happens to filtration during renal autoregulation
GFR is constant even if BP fluctuates. Myogenic constriction.
Tubulogolmerular feedback
212
What is myogenic constriction?
Smooth muscles in arterioles sense an increase in blood pressure
213
What is tubuloglomerular feedback
Cells in the ascending limb of the loop of Henle (macula densa) sense a rise in water and sodium as occurs with increased blood pressure
214
Ch 17 Slide 25
Chart comparing Glomerular Rates regulation
215
What is reabsorption
The return of filtered molecules to the blood
216
where does 85% of reabsorption occur
In the proximal tubules of the descending hoop of Henle
217
Osmolality of filtrate in the glomerular capsule is equal to that of
Blood plasma (isoosmotic)
218
Na+ is actively transported in/out of the filtrate into the peritibular blood to set up a concentration gradient to drive osmosis
Out
219
Active transport in the proximal tubule
Cells have a lower Na+ concentration than filtrate, so Na+ diffuses into these cells and is then pumped out on the other side
220
Passive transport in the proximal tubule
The pumping of sodium into the interstitial space attracts negative Cl - out of the filtrate. Water follows Na+ and Cl- into the tubular cells and the interstitial space. Then into the peritubular capillaries
221
How much water is absorbed through the descending limb of the Loop of Henle
20% of water. The rest is absorbed in the nephron under the control of ADH
222
Fluid entering the loop of Henle is ____ to extracellular fluids
Isotonic
223
What part of the Loop of Henle sets up a gradient for the osmosis of water?
Ascending portion
224
NaCl is actively pumped into the interstitial fluid from the thick segment. Walls are not permeable to water. Surrounding fluid becomes concentrated at the bottom of the tube. Tubular fluid entering the descending loop of Henle becomes more hypotonic as it ascends the loop
Ascending Loop of Henle
225
is permeable to water but not salt. Water is drawn out of the filtrate and into the interstitial space where it is picked up by capillaries. As it descends, it becomes more solute concentrated
Descending loop of henle
226
Mechanism created between the two portions of the loop of Henle
Positive feedback. the more salt the ascending limb removes, the saltier the fluid entering it will be.
227
Countercurrent multiplication
the more salt the ascending limb removes, the saltier the fluid entering it will be.
228
Countercurrent mechanism steps
Interstitial fluid is hypertonic due to NaCl pumped out of the ascending limb.
Water leaves descending limb by osmosis, making the filtrate hypertonic going into the ascending limb.
More NaCl in the ascending limb can now be pumped out into the interstitial fluid.
The greater concentration of the interstitial fluid draws more water from the descending limb.
Filtrate in ascending limb now more concentrated.
Continues until the maximum NaCl concentration of the inner medulla is reached.
229
Ch 17 Slide 38
Diagram showing Countercurrent Exchange
230
What is the vasa recta
Specialized blood vessels around Loop of Henle which create the countercurrent system because it takes in salts from the descending region but lose them again in the ascending region. Keeps the salt in the interstitial space.
231
What pulls water down the ascending region of the vasa recta, which is removed from the interstitial space
High salt concentration at the beginning
232
Urea
Waster product of protein metabolism which contributes to countercurrent exchange
233
Where does urea come from?
Transported out of collecting duct and into interstitial fluid. Diffuses back into ascending limb and cycles around continuously. Helps set up solute concentration gradients.
234
Ch 17 slide 44
Puts it all together
235
Last stop in urine formation, impermeable to NaCl but permeable to water
collecting duct
236
Collecting duct and ADH path sequence
ADH binds to receptors on collecting duct cells > cAMP > protein kinase > vesicles with aquaporin channels fuse to plasma membrane
237
Where is ADH produced, stored, and released
Produced in hypothalamus. Stored and released from posterior pituitary gland. Release stimulated by increase in blood osmolality
238
Renal clearance - excretion
Just getting rid of stuff
239
Renal clearance - reabsorption
Everything that could get excreted, but doesn't. Returns stuff to the blood.
240
Renal clearance - secretion
Substances are moved form the peritubular capillaries into the tubules
241
Excretion rate =
(Filtration rate + secretion rate) - reabsorption rate
242
Excretion rate is used to measure
GFR (glomerular filtration rate), an indicated of renal health
243
Organic anion transporters and organic cation transporters are
membrane carriers specific to foreign substances that transport drugs into the tubules
244
Drug secreting carriers are polyspecific
overlap function
245
GFR =
(rate of urine formation x inulin concentration) / (inulin concentration in plasma)
246
What is para-aminohippuric acid (PAH)
An exogenous molecule injected for measurement of total renal blood flow
247
All PAH in the peritubular capillaries will be secreted by
OATs, so the time it takes to clear all PAH injected indicates blood flow to these capillaries
248
Ch 17 Slide 58
Renal clearance of PAH
249
Where is glucose completely reabsorbed
In the proximal tubule via secondary active transport, with sodium, facilitated diffusion, and simple diffusion
250
Glucose/Na+ cotransporters have a maximum and if maximum is reached, then the carriers are
saturated. Saturation spills glucose into the urine = glycosuria and is a sign of diabetes.
251
Kidneys match electrolyte excretion to
ingestion
252
Na+ healthy levels are important for
Blood pressure and blood volume
253
Control of K+ is important in
healthy skeletal and cardiac muscle activity
254
Aldosterone plays a big role in
Na+ and K+ balance
255
Aldosterone independent response
Increase in blood K+ triggers an increase in the number of K+ channels in the cortical collecting duct. Channels removed when blood K levels drop.
256
Aldosterone dependent response
Increase in blood K triggers adrenal cortex to release aldosterone. Increases K secretion in the distal tubule and collecting duct.
257
A rise in blood K directly stimulates production of aldosterone in the
adrenal cortex
258
A fall in blood Na indirectly stimulates production of aldosterone via the
renin-angiotensin-aldosterone system
259
Where is the juxtaglomerular apparatus located
Where the afferent arteriole comes into contact with the distal tubule
260
What does the juxtaglomerular apparatus sense
A decrease in plasma Na which results in a fall in blood volume
261
Granular cells secrete renin into the
afferent arteriole
262
Angiotensinogen is converted into angiotensin I by
the juxtaglomerular apparatus
263
What converts Angiotensin I into angiotensin II
Angiotensin-convering enzyme (ACE)
264
The juxtaglomerular apparatus stimulates the cortex to make what
Aldosterone. Promotes the reabsorption of Na from distal tubule and cortical collecting duct.
265
Low salt levels result in lower blood volumes due to inhibition of
ADH secretion
266
Renin is secreted by granular cells when they detect
Reduced blood volume
267
What is the macula densa
Part of the distal tubule that forms the juxtaglomerular apparatus
268
What does the macula densa do?
Sensor for tubuloglomerular feedback needed for regulation of glomerular filtration rate. Controlled via negative feedback
269
When there is more Na and H2O in the filtrate, a signal is sent to the afferent arteriole to
inhibit the production of renin
270
Increases in blood volume also increase the release of
atrial natriuretic peptide hormone from the atria of the heart when atrial walls are stretched
271
What does atrial natriuretic peptide do?
Stimulates kidneys to excrete more salt and therefore more water. Decreases blood volume and blood pressure.
272
B-type natriuretic peptide is secreted in response to
increased volume and pressure within the ventricles and it acts like ANP to promote diuresis
273
Reabsorption of __ stimulates the secretion of other positive ions; K and H
Na
274
Acidosis stimulates the secretion of __ and inhibits the secretion of __ ions and can lead to hyperkalemia
H and K ions
275
Alkalosis stimulates the secretion and excretion of more
K
276
Hyperkalemia stimulates the secretion of __ and inhibits the secretion of __ and can lead to acidosis
K and H ions
277
Kidneys maintain blood pH by reabsorbing bicarbonate and secreting __; urine is thus acidic
H
278
Proximal tubule uses Na/H pump to let __ out and __ in
Na; H
