Chapter Quiz Flashcards
Tubuloglomerular Feedback - Avian
1
Q
Provides an expandable reservoir for urine, which is continuously flowing from pelvis of the kidney through ureters.
A
Urinary Bladder Functions
2
Q
Emptying of urinary bladder when filled with urine
A
Micturition
3
Q
Passage of Urine from Kidney to Bladder
A
Collecting Ducts - Pelvis of Kidney - Bladder through the Ureters
4
Q
Each (?) is innervated by both sympathetic and parasympathetic nerves
A
Ureters
5
Q
Increases frequency of Urine
A
Parasympathetic Stimulation
6
Q
Decreases frequency of Urine
A
Sympathetic Stimulation
7
Q
Prevents reflux of urine from bladder
A
Ureterovesicular Valve
8
Q
Accommodation power of Urinary Bladder
A
150 mmH20
9
Q
What happens when inhibition of spinal centres of micturition and by contraction of external sphincter which surrounds the external part of the urethra. The desire to urinate arises from stimulation of receptors in the wall of the bladder by stretch and contraction of musculature.
A
Voluntary opposition of Urination.
10
Q
Inhibited by internal sphincters and cause contractions of whole bladder and are main motor nerves.
A
Parasympathetic nerves
11
Q
Present in bladder walls that are stimulated during contraction of urinary bladder.
A
Receptors
12
Q
Elevated level of waste products in the blood, usually nitrogen-containing compounds like urea and creatinine.
A
Uremia or azotemia
13
Q
Toxic condition that occurs due to retention of urea in the blood.
A
Uremia or Azotemia
14
Q
Other term for Uremia
A
Azotemia
15
Q
Are symptoms of uremia or azotemia
A
Lethargy, depression, nausea, vomiting, deep breathing, dizziness, coma and convulsions.
16
Q
Increased urine formation
A
Diuresis
17
Q
Increased excretion of urine, due to deficiency in ADH
A
Polyuria
18
Q
Reduced excretion of urine
A
Oliguria
19
Q
Complete cessation of urine formation
A
Anuria
20
Q
Difficult or painful micturition
A
Dysuria
21
Q
Slow dropwise painful discharge of urine, caused by spasm of urethra and bladder.
A
Stranguria
22
Q
Measurement of kidney’s ability to remove substances from the plasma.
A
Renal clearance
23
Q
Parameters in renal clearance
A
RBF, RPF (Renal Plasma Flow), GFR, FF
24
Q
Used to express ability of kidneys to clean or clear the plasma of various substances.
A
Plasma clearance
25
Ratio of substance plasma to ml : into urine ml/min
Usually 1:1, plasma substance:mg of each substance: secretion to urine
26
Excellent measure of kidney function and the clearance rate of different substances are determined by analyzing the concentration of substance simultaneously in plasma and urine and measuring the rate of urine formation.
Plasma Clearance
27
Substance to measure GFR must be freely filtered at the glomerulus, should not be reabsorbed or secreted by tubular epithelium when it enters the nephron.
Inulin, inulin clearance
28
Fructose polysaccharide that is commonly used in estimation of GFR
Inulin
29
Another polysaccharide for estimation of GFr
Mannitol
30
In clinical conditions for measuring GFr and kidney functions, freely filtered and not reabsorbed. Some species, only 10% is secreted by the tubules. Exception for birds
Creatinine clearance
31
Substance used in measurement of RPF
Para Amino Hippuric Acid (PAH)
32
Total amount of substance in the plasma that passes through the kidneys each minute
Plasma load
32
Fraction of plasma load that is filtered as GF
Tubular load
33
Formed by passive water reabsorption from the tubules while many solutes in the tubular fluid are absorbed by active process.
Concentrated urine
34
Formed by absorption of solutes alone and excretion of water in the urine
Dilute urine
35
Normal osmolality of GF when it enters the proximal tubule
300 ml osm/L
36
High permeability to H20 and no permeability to solutes
Descending limb of Loop of Henle
37
No permeability to H20, highly permeable to Na, Cl, and moderately permeable to urea
Ascending thin limb of Loop of Henle
38
Permeable to sodium, chloride, low permeability to water and urea
Ascending thick limb of loop of henle
39
Permeable to sodium, chloride and low permeability to H20 and Urea
Distal tubule
40
Sodium reabsorption varies with aldosterone stimulation, H20 and urea by anti-diuretic hormone.
Cortical collecting tubule, outer medullar collecting duct and inner medullary collecting duct
41
Operated by Loops of Henle in counter current mechanism
Counter current multiplier
42
Operated by Vasa Recta
counter current exchanger
43
Counter current system in which transport between the outflow and inflow is entirely passive.
Countercurrent Exchanger
44
Mechanism for concentration of urea in the medulla.
Recirculation of urea
45
*High Level of ADH increases permeability of distal tubule
*High osmolarity of the renal medullary fluid
Requirements for Concentrated Urine
46
Synthesized in the cell bodies of hypothalamic nuclei (supraoptic nuclei) and transported to nerve fiber endings in the posterior lobe of the pituitary where it is stored in the secretory granules.
ADH ( anti-diuretic hormone)
47
Adrenal cortex regulates K+ and Na+ concentration. It acts on tubules causing Na+ reabsorption and K+ excretion. Aldosterone increases Na+ reabsorption from distal tubules by increasing Na+ transport protein; salt free diet causes increased aldosterone secretion resulting in increased Na reabsorption.
Aldosterone
48
Activated by reduced circulating blood volume as in hemorrhage. Decreased sodium concentration in the distal convoluted tubule and sympathetic stimulation also causes release of renin.
Renin-Angiotensin System
49
Ca2+ and PO4 excretion in urine is regulated at the proximal tubule by the action of parathyroid and thyrocalcitonin from thyroid. Parathyroid hormone (PTH) causes decrease in PO4 reabsorption and increase in PO4 excretion in urine.
Parathyroid Hormone
50
Myocardial cells of the atria release the ANP when the atria are stretched during high volume of blood.
Atrial natriuretic peptide
51
* Increases the GFR by causing vasodilatation of afferent arterioles and vasoconstriction of efferent arterioles.
* Inhibits angiotensin II stimulated absorption of Na+ and water in proximal tubules.
* Reduces water reabsorption in collecting tubules.
* Inhibits aldosterone release.
* Decreases the response of the collecting tubules and collecting ducts to ADH.
Atrial natriuretic peptide
52
produced from kidney regulates erythropoiesis.
Erythropoietin
53
Produced from kidney
Renin
54
From kidney, acts as blood pressure lowering agents
Prostaglandin
55
Normal Blood PH
7.4
56
. Maintenance of normal blood and extracellular pH within the narrow limits is essential for homeostasis. The pH usually refers to the hydrogen ion (H+) concentration and has a widespread effect on the function of the body systems. Any disturbance in the H+ ion concentration leads to imbalance of pH.
Acid base balance
57
Three primary buffer systems are involved in regulation of H+ ion concentration in the body fluids to prevent alkalosis or acidosis–
Regulation of hydrogen ion concentration
58
Three primary buffer systems
* Chemical acid base buffer systems
* Respiratory regulation of acid base balance
* Renal control of acid base balance
59
When there is a change in the H+ ion concentration, the body fluids react immediately to minimize the change. Chemical buffers act by converting either strong acids or bases into weaker acids or bases
Chemical acid base buffer systems
60
* This is the most important buffer system in the body. Bicarbonate combines with H+ ions to form carbonic acid in the tubular fluid, which then dissociates to CO2 and H20. The CO2 formed is removed by the lungs and the HCO3– formed in the cells is reabsorbed from the filtrate to the blood.
Bicarbonate
61
* It plays a major role in buffering renal tubular fluid and ICF. The two main elements of the phosphate buffer are HPO42- (base) and H2PO4– (weak acid). Hydrogen ions from strong acids are captured by converting a weak base to a weak acid and strong base captured by conversion of a weak acid to a weak base.
Phosphate buffer
62
* It is an intracellular buffer present in high concentrations in the blood. Hemoglobin molecule forms the second most important blood buffer and is present in the form of proteinate ions (Hb–). These basic ions, with their weak acids (HHb) form a buffer pair. When an acid is added to the blood
Protein buffer
63
* Ammonia is formed by the hydrolysis of glutamine in the presence of enzyme glutaminase in the tubular cells which freely diffuses into luminal fluid and continues with H+ ions to form NH4+ ions. This NH4+ ions combines with chloride ions and is excreted as ammonium chloride in the urine.
Ammonia buffer system
64
* The respiratory system acts as the second line of defense against acid base disturbances. An increase in PCO2 of ECF, decreases the pH, while a decrease in PCO2, increases the pH. Therefore, by adjusting the PCO2, the lungs effectively regulate the H+ ion concentration of the ECF.
Respiratory regulation
65
* An increase in ventilation removes CO2 from ECF thereby reducing the H+ ion concentration. Similarly, a decrease in ventilation, increases CO2 thus increasing H+ ion concentration in ECF.
Respiratory regulation
66
* Arterial PCO2 is (?) to alveolar ventilation, i.e., if alveolar ventilation falls, PCO2 rises. Therefore, relatively small changes in ventilation has a profound effect on H+ ion concentration and pH.
Inversely proportional
67
acts as a typical negative feedback controller of H+ ion concentration.
Respiratory system
68
* Increase in what concentration above the normal, stimulates the respiratory system and alveolar ventilation increases. This decreases the PCO2 in ECF and reduces H+ ions concentration back to normal.
H+ concentration
69
* The kidneys regulate acid-base balance by excreting either an acidic or basic urine. Excretion of either an acidic or a basic urine removes acids or basic from the ECF. Large numbers of HCO3– ions are filtered in the urine and if they are excreted into the urine, it removes base from the blood. Similarly, large numbers of H+ ions are secreted into the urine, and if they are excreted, it results in loss of acid from the blood. If more HCO3– ions are filtered than the H+ secreted, there will be net loss of base from ECF.
Renal control of acid base balance
70
Kidneys regulate ECF H+ ions through?
o Tubular Secretion of H+ ions
o Reabsorption of filtered bicarbonate ions
o Combination of excess H+ ions with phosphate and amino buffers
71
H+ ions are secreted in the proximal tubule, thick ascending loop of Henle and distal tubule by sodium hydrogen counter transport.
Tubular secretion of H+ ions
72
This occurs by means of active transport of sodium ions into the cell and H+ ions from the tubular cell into the tubular lumen against the concentration gradient provided by sodium-potassium ATP pump. For each H+ ion secreted, what ion is reabsorbed?
HCO3 Ion
73
When CO2 diffuses into the tubular cells, formed by metabolism, CO2 combines with water, forms (?) which dissociates into HCO3– and H+ ions. H+ ions are secreted from the cell into the lumen by sodium-hydrogen counter transport.
H2CO3
74
The sodium moves into the cell by concentration gradient established by sodium-potassium ATPase pump in the basolateral membrane. H+ ions are also secreted in the distal tubule and collecting ducts and transported through H+ pump by
H+ATPase Mechanism
75
The filtered bicarbonate ions are not easily reabsorbed across the tubular membrane. The bicarbonates combines with H+ ions to form (?) which then dissociates to form Co2 and H2O. This CO2 moves across the tubular membrane and diffuses immediately into the tubular cell.
H2CO3
76
* When excess of H+ ions are secreted, only a small fraction of it is excreted in the ionic form (H+) in the urine and the remaining H+ ions combines with buffers such as phosphate and ammonia buffer in the tubular fluid as urine can be acidified to a pH of about (?)
4.5
77
* The phosphate buffer system is composed of HPO42- and H2PO4 –. Both are concentrated in the tubular fluid because of poor reabsorption. Excess H+ ions combines with HPO42- to form H2PO4 which in turn are excreted as sodium salt (?)
Na2HPO4
78
is synthesized from glutamine which is actively transported into the tubular epithelial cells.
Ammonium Ion
79
* This buffer system is composed of ammonia (NH3) and ammonium ion (NH4+).
Combination of excess H+ with ammonia buffer system
80
Inside the cell, (?) is metabolised to form NH4+ and two HCO3 – ions. The NH4+ is secreted into the tubular lumen by countercurrent mechanism in exchange for sodium which is reabsorbed
Glutamine
81
Therefore, for each molecule of glutamine metabolised in the proximal tubule, (?) NH4+ ions are secreted into the urine and (?) HCO3 – ions are reabsorbed into the blood.
2 and 2
82
* In the collecting tubule, formation of NH4+ ions occurs by a combination of NH3 (ammonia) with H+ ions and then excreted as NH4+. The collecting ducts are permeable to NH3 and form NH4+. Hydrogen ions react with NH3 and form NH4+. For each NH4+ excreted, one (?)– reabsorbed in to the blood.
HCO3
83
* The pH of the ECF is determined by the rate of conjugate base to their weak acids. The total amount of buffer base in whole blood including HCO3, Hb and other bases of lesser importance is called buffer base (B.B). These bases are known as metabolic components determining blood pH.
Acid Base balance disturbances
84
* The gain of strong acid or loss of base from the ECF is known as (?) . (?) will be present in metabolic acidosis.
Metabolic acidosis, Acidemia
85
o Diabetes mellitus in which (?), (?), (?) are produced.
B-Hydroxy butyric acid, acetone, acetoacetic acid
86
failure of HCO3– reabsorption and loss in the urine.
Renal acidosis
87
pancreatic juice containing HCO3 is not reabsorbed and is lost.
Diarrhoea
88
* The (?) stimulates secretion of H+ ion by the renal tubule. This ensures reabsorption of all HCO3 ions from tubular fluid and the excess H+ ions will begin to acidify the urine. For each H+ ion secreted, one (?) will be reabsorbed into the plasma. This holds good for short-term stress and in severe conditions, therapeutic action is required
Acidemia, HCO3
89
* This process involves the gain of base (OH or HCO3 ions) or loss of strong acid by ECF.
Metabolic alkalosis
90
Metabolic alkalosis is present in:
o Persistent vomiting, in which gastric acid is lost from the body.
o K+ deficiency in which renal tubules secretes large amount of H+ ions into urine.
o Injection of HCO3 solutions
91
Renal tubules secretes large amount of H+ ions into urine
K+ deficiency
92
consists of decreased secretion of pH ions and so increased excretion of HCO3– ions.
Renal correction
93
* If excretion of CO2 by the lungs falls below the rate of CO2 production in the body, respiratory acidosis develops.
Respiratory acidosis
94
* There will be an increase in blood PCO2 (hypercapnia) and the primary defect will be in the inability of lungs to expire CO2 at a normal rate.
Respiratory acidosis
95
Respiratory acidosis occurs due to?
o Depression of respiratory centres in CNS.
o Abnormality of chest wall or respiratory muscles which prevents enlargement of thorax.
o Obstruction to gas movement in lungs.
96
* A rise in PCO2 causes increase in H2CO3 and buffer reaction prevents the fall of pH caused by rise in H2CO3.
Respiratory acidosis
97
* Renal compensation then follows. Low pH stimulates secretion of H+ into urine with a rise in plasma HCO3– .
Respiratory acidosis
98
* When alveolar hyperventilation occurs, the expiration of CO2 may exceed the rate of its production within the body and respiratory alkalosis develops.
Respiratory alkalosis
99
Low Plasma PCO2
Hypocapnia
100
caused by abnormal stimulus to respiratory centres either directly as in NH3 toxicity or through hypoxemia acting through peripheral chemoreceptors.
Hyperventilation
101
* Regulation of fluid by the body is necessary to maintain homeostasis. If the water or electrolyte equilibrium is affected, many body functions fail to proceed at normal rates.
Fluid and electrolyte balance
102
major constituent of all living things. Most of the ions and molecules that make up living matter have chemical and physical relationships with water.
Water
103
present in three different compartments namely, intracellular fluid and extracellular fluid, which in turn is divided into interstitial fluid and plasma.
Body fluid
104
* In a lean animal, (?) of water is present intracellular, (?) in the interstitial spaces and (?) in the blood plasma. Apart from this, water is also present in the transcellular fluids such as in CSF, aqueous humor of the eye, synovial fluids, urine, bile etc.
50%, 15%, 5%
105
* If a (?) solution is added, water would begin to shift into the plasma, while, an addition of hypotonic NaCl solution shifts the water into the cell.
hypertonic NaCl
106
* The total amount of water in the body almost remains relatively constant. The body gains water either by ingestion or as end product of cellular metabolism. Similarily loss of water occurs in urine, from the skin, expired gases, faeces etc.
Water Balance
107
An electrolyte in any chemical that dissociates to ions when dissolved in a solution. Ions can be positively charged (cations) or negatively charged (anions). The major electrolytes found in the body are sodium, potassium, calcium, magnesium, chloride, phosphate, sulphate and bicarbonate. The primary electrolytes of the ECF are sodium, chloride and bicarbonate and in the ICF are potassium and phosphates.
Electrolytes
108
major cation of ECF. About 45% of sodium stored is found in ECF, 45% in the bone and the remaining intracelullarly. It plays an important role in the excitability of muscles and neurons and in regulating the fluid balance in the body.
Sodium
109
major cation of intra cellular fluid and about 89% of the total body content of potassium is present in the ICF. Potassium is important for the functioning of excitable cells and in the regulation of fluid levels within the cells.
Potassium
110
Potassium concentration is regulated by
Aldosterone
111
The sodium ions are balanced electrically with the chloride and bicarbonate ions. The chloride ions are regulated secondarily to sodium and bicarbonate ions.
Chloride and bicarbonate
112
The excretion or reabsorption of sodium ions is accompanied by chloride ions. Similarily, chloride ions are excreted along with the bicarbonate ions to maintain electroneutrality in the ECF. The bicarbonate ion is unique in that it is formed or removed rapidly by the body. Bicarbonates are formed and removed by carbon dioxide.
Chloride and bicarbonate
113
* In the birds, the ureters transport the urine to the cloaca, which is the common collection site for digestive, reproductive and urinary organs. There is no urinary bladder in birds.
Excretion in birds
114
Differences in bird renal system
o Presence of two major types of nephrons which are functionally different.
o Presence of renal portal system.
o Formation of uric acid instead of urea as the end product of nitrogen metabolism.
o Post renal modification of the urine in the ureter.
115
2 Major types of Nephrons
Reptilian and Mammalian
116
nephrons that are located in the cortex and it lacks the loop of Henle. It has no capacity to concentrate the urine, i.e., there is no tubular transport system and whatever solute and water is present in the filtrate, directly passes to the cloaca.
Reptilian
117
nephrons that have well defined loop of Henle. It has the capacity to concentrate the urine. In this tubular transport system is present.
Mammalian
118
provides an extra branch of blood flow to the renal tubules along with peritubular capillaries.
* Venous blood from portal vein gives one branch to the kidney and this branch provides the microcapillaries which perfuse the tubules along with peritubular capillaries.
Renal portal system
119
* The metabolic end product of protein and amino acids in reptiles and birds
Uric acid
120
(?) formed in liver and also in kidneys from ammonia. (?) is freely filterable at the glomerulus, and it is also secreted by the tubules.
Uric acid
121
* Tubule secretion accounts for (?) of total uric acid eliminated.
90%
122
provide a greater quantity of blood to the tubules for the secretion of uric acid by the tubules. Since greater quantity of uric acid is available in the tubules, which exceeds the solubility, the uric acid is precipitated. It passes through the tubules in the precipitated form and appears in the urine as a white coagulum. Since the uric acid is not in solution, it does not contribute to osmotic pressure, and thus avoids obligatory water loss.
Renal portal system
123
* The post renal modification of urine is possible in the birds when the urine reaches the cloaca water is drawn back to colon and cecum due to
antiperistalsis movement of colon
124
is similar to that of the mammals. In addition to the action of ADH on the tubular cells it also controls the functioning of reptilian and mammalian type of nephrons.
Renal response to ADH
125
is mixed with mucus and mucus facilitates the carrying of uric acid in the urine.
Precipitated uric acid
126
Mixed with faeces that is cream coloured and contain thick mucous
Bird urine
127
