Excretory products and their elimination Flashcards
1
Q
Which six things are accumulated by animals? Either by metabolic activities or by other means like excess ingestion.
A
Ammonia, urea, uric acid, carbon dioxide, water and ions
2
Q
The three major forms of nitrogenous wastes excreted by the animals are called
A
Ammonia, urea and uric acid
3
Q
The most toxic nitrogenous form which requires large amounts of water for its elimination is
A
Ammonia
4
Q
The least toxic nitrogenous form which can be removed with a minimum loss of water
A
Uric acid
5
Q
The process of excreting ammonia is
A
Ammonotelism
6
Q
Many bony fishes, aquatic amphibians and aquatic insects are _______ in nature.
A
Ammonotelic
7
Q
Ammonia is generally excreted by diffusion across body surfaces or through gill surfaces (in fish) as
A
Ammonium ions
8
Q
_______ necessitated the production of lesser toxic nitrogenous wastes like urea and uric acid for conservation of water.
A
Terrestrial adaptation
9
Q
Mammals, many terrestrial amphibians and marine fishes mainly excrete urea and are called
A
Ureotelic animals
10
Q
Reptiles, birds, land snails and insects excrete nitrogenous wastes as?
A
Uric acid
11
Q
Nitrogenous waste like uric acid is excreted in the form of____
A
Pellet or paste
12
Q
Reptiles, birds, land snails and insects excrete nitrogenous wastes as uric acid is called
A
Uricotelic animals
13
Q
What are the excretory structure in Planaria?
A
Protonephridia or flame cells
14
Q
Protonephridia or flame cells are the excretory structures in ___,___,___ &___
A
Platyhelminthes, rotifers, some annelids and the cephalochordate – Amphioxus
15
Q
Protonephridia are primarily concerned with ____ and _____ regulation i.e osmoregulation.
A
ionic, fluid volume
16
Q
Ionic and fluid volume regulation known as?
A
osmoregulation-
17
Q
The tubular excretory structure of earthworms & some annelids is called
A
Nephridia
18
Q
The excretory structures of most of the insects including cockroaches is called
A
Malpighian tubules
19
Q
Name the organ which performs the excretory structures in crustaceans like prawns.
A
Antennal glands or green glands
20
Q
In humans, kidneys are situated between the levels of ________ thoracic and _________ lumbar vertebra.
A
last thoracic and third lumbar vertebra
21
Q
Kidneys are situated close to the
A
Dorsal inner wall of the abdominal cavity
22
Q
The length of each kidney of an adult human is
A
10-12 cm
23
Q
The width of each kidney of an adult human is
A
5-7 cm
24
Q
The thickness of each kidney of an adult human is
A
2-3 cm
25
The average weight of each kidney of an adult human
120-170 g
26
Towards the centre of the inner concave surface of the kidney is a notch called
hilum
27
Inner to the hilum is a broad funnel shaped space called
renal pelvis
28
Renal pelvis has projections called
calyces
29
There are two zones inside the kidney
an outer cortex and an inner medulla
30
The medulla is divided into a few conical masses are called
medullary pyramids
31
The cortex extends in between the medullary pyramids as renal columns is called
Columns of Bertini
32
How many complex tubular structures are present in each kidney?
One million
33
Complex tubular structures in kidneys called
nephrons
34
The functional units of kidney are
nephrons
35
Each nephron has two parts known as
the glomerulus and the renal tubule
36
A tuft of capillaries formed by the afferent arteriole
Glomerulus
37
Glomerulus is formed by
afferent arteriole
38
Afferent arteriole is a fine branch of _______ artery.
renal
39
Blood from the glomerulus is carried away by
efferent arteriole
40
The renal tubule begins with a double walled cuplike structure called
Bowman’s capsule
41
The glomerulus is enclosed by
Bowman’s capsule
42
Glomerulus along with Bowman’s capsule, is called the
malpighian body or renal corpuscle
43
The renal tubule continues further to form a highly coiled network known as
proximal convoluted tubule
44
The hairpin shaped part of the tubule is known as
Henle’s loop
45
Henle’s loop has a ____ & ____ limb.
descending and an ascending limb
46
The ascending limb continues as highly coiled tubular region called
distal convoluted tubule (DCT)
47
The DCTs of many nephrons open into a straight tube called
collecting duct
48
The Malpighian corpuscle, PCT and DCT of the nephron are situated in the ___ of the kidney.
cortical region
49
The loop of Henle of the nephron is situated in the ___ of the kidney.
medullary region
50
Nephrons in which the loop of Henle is too short and extends only very little into the medulla are called
cortical nephrons
51
Nephrons in which the loop of Henle is very long and runs deep into the medulla are called
juxta medullary nephrons
52
The efferent arteriole forms a fine capillary network around the renal tubule called
peritubular capillaries
53
A minute vessel of this network runs parallel to the Henle’s loop forming a
‘U’ shaped vasa recta
54
In which nephrons, vasa recta is absent or highly reduced?
cortical nephrons
55
What are the three main processes involved in Urine formation?
glomerular filtration, reabsorption and secretion
56
The first step in urine formation is?
filtration of blood
57
The first step in urine formation is carried out by
glomerulus
58
The filtration of blood is carried out by the glomerulus and is called
glomerular filtration
59
Amount of blood filtered by the kidneys per minute
1100-1200 ml
60
Blood filtered by the kidneys per minute constitute roughly ____ of the blood pumped out by each ventricle of the heart in a minute.
1/5th
61
The glomerular capillary blood pressure causes filtration of blood through 3 layers
the endothelium of glomerular blood vessels, the epithelium of Bowman’s capsule and basement membrane between these two layers
62
The epithelial cells of Bowman’s capsule called _______ are arranged in an intricate manner
podocytes
63
Podocytes are arranged in an intricate manner so as to leave some minute spaces called
filtration slits or slit pores
64
almost all the constituents of the plasma pass onto the lumen of the Bowman’s capsule except
proteins
65
The amount of the filtrate formed by the kidneys per minute is called
glomerular filtration rate (GFR)
66
GFR in a healthy individual in a minute is approximately
125 ml/minute
67
GFR in a healthy individual in a day is approximately
180 litres per day
68
A special sensitive region formed by cellular modifications in the distal convoluted tubule and the afferent arteriole at the location of their contact called
juxta glomerular apparatus (JGA)
69
A fall in GFR can activate the JG cells to release
renin
70
Which hormone can stimulate the glomerular blood flow and thereby the GFR back to normal?
renin
71
Amount of urine released per day by an individual is
1.5 litres
72
Nearly __ of the filtrate has to be reabsorbed by the renal tubules
99%
73
The process of reabsorbing the filtrate by the renal tubule called
reabsorption
74
Which cells in different segments of nephron perform reabsorption either by active or passive mechanisms?
tubular epithelial cells
75
Substances like glucose, amino acids, Na+, etc, in the filtrate are reabsorbed by _______ transport.
active
76
the nitrogenous wastes are absorbed by
passive transport
77
Reabsorption of water in the initial segments of the nephron occurs
passively
78
Name the three substances secreted by the tubular cells into the filtrate during urine formation
H+, K+ and ammonia
79
PCT is lined by _____ epithelium
simple cuboidal brush border epithelium
80
What per cent of electrolytes and water are reabsorbed by PCT segment?
70-80 per cent
81
PCT helps to maintain the ____ of the body fluids
pH and ionic balance
82
PCT helps in the selective secretion of ___, ___ & ___ into the filtrate
hydrogen ions, ammonia and potassium ions
83
Reabsorption is minimum in which segment of nephron?
ascending limb of henle’s Loop
84
Ascending limb plays a significant role in the maintenance of
high osmolarity of medullary interstitial fluid
85
The descending limb of loop of Henle is ____ to water
permeable
86
The descending limb of loop of Henle is almost impermeable to ____
electrolytes
87
The ascending limb is _____ to water
impermeable
88
The ascending limb allows transport of electrolytes ____ or ____
actively or passively
89
As the concentrated filtrate pass upward, it gets diluted due to the passage of electrolytes to the____
medullary fluid
90
___ of Na+ and water takes place DCT
Conditional reabsorption
91
Conditional reabsorption of ____ & ____ takes place in DCT
Na+ and water
92
DCT is also capable of reabsorption of ________ and selective secretion of hydrogen and potassium ions.
HCO3–
93
DCT is capable of selective secretion of
hydrogen and potassium ions and NH3
94
Long duct extends from the cortex of the kidney to the inner parts of the medulla called
Collecting Duct
95
Large amounts of water could be reabsorbed from Collecting Duct to produce a
concentrated urine
96
Collecting Duct allows passage of small amounts of urea into the
medullary interstitium
97
Collecting Duct plays a role in the maintenance of pH and ionic balance of blood by the selective secretion of
H+ and K+ ions
98
Structures like ___ & ____ play a significant role in producing a concentrated urine in mammals
Henle's loop and vasa recta
99
The flow of filtrate in the two limbs of Henle’s loop is in opposite directions and thus forms a
counter current-
100
The flow of blood through the two limbs of vasa recta is in ___ pattern
counter current
101
The proximity between the Henle’s loop and vasa recta, as well as the counter current in them help in maintaining an ____ towards the inner medullary interstitium
increasing osmolarity
102
Osmolarity in the cortex
300 mOs mol L–1
103
Osmolarity in the inner medulla
1200 mOs mol L–1
104
Osmotic gradient is mainly caused by
NaCl and urea
105
NaCl is transported by the______ which is exchanged with the _____
ascending limb of Henle’s loop; descending limb of vasa recta
106
NaCl is returned to the interstitium by the
ascending portion of vasa recta
107
Small amounts of urea enter the _____ of the ascending limb of Henle’s loop
thin segment
108
Transport of substances facilitated by the special arrangement of Henle’s loop and vasa recta is called the
counter current mechanism
109
Counter current mechanism helps to maintain a _____ in the medullary interstitium
concentration gradient
110
Human kidneys can produce urine nearly ___ concentrated than the initial filtrate formed
four times
111
The functioning of the kidneys is efficiently monitored and regulated by ____ mechanisms
hormonal feedback
112
Hormonal feedback mechanisms which monitor and regulate the functioning of the kidneys involve
hypothalamus, JGA and to a certain extent, the heart
113
Osmoreceptors in the body are activated by changes in ___, ____ & ___
blood volume, body fluid volume and ionic concentration
114
An excessive loss of fluid from the body can activate osmoreceptors which stimulate the hypothalamus to release
antidiuretic hormone (ADH)
115
Antidiuretic hormone(ADH) is also known as
vasopressin
116
The hypothalamus release antidiuretic hormone (ADH) from the
neurohypophysis
117
ADH facilitates water reabsorption from latter parts of the tubule, thereby preventing
diuresis
118
Increase in blood pressure can increase the _____ & thereby ____
glomerular blood flow & GFR
119
A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the
JG cells
120
renin which converts _____in blood to angiotensin I and further to angiotensin II
angiotensinogen
121
Angiotensin II is a powerful _____
vasoconstrictor
122
Angiotensin II activates the ____ to release Aldosterone
adrenal cortex
123
Aldosterone causes reabsorption of ___ & ___ from the distal parts of the tubule
Na+ and water
124
An increase in blood flow to the atria of the heart can cause the release of
Atrial Natriuretic Factor(ANF)
125
dilation of blood vessels called
vasodilation
126
ANF can cause vasodilation and thereby decrease the ____
blood pressure
127
ANF mechanism acts as a check on the______
renin-angiotensin mechanism
128
Urine formed by the nephrons is ultimately carried to the_____
urinary bladder
129
Urine is stored in urinary bladder till a voluntary signal is given by the_______
central nervous system
130
The CNS passes on motor messages to initiate the relaxation of the _____ causing the release of urine
urethral sphincter
131
The process of release of urine is called
micturition
132
The neural mechanisms causing the process of release of urine is called
micturition reflex
133
pH of urine
6
134
On an average, what amount of urea is excreted out per day?
25-30 gm
135
Analysis of urine helps in ___ of many metabolic disorders
clinical diagnosis
136
The presence of glucose in urine is called
Glycosuria
137
The presence of ketone bodies in urine is called
Ketonuria
138
The presence of glucose and ketone bodies in urine are indicative of
diabetes mellitus-
139
Which organs other than kidney help in the elimination of excretory wastes?
lungs, liver and skin
140
What amount of CO2 is removed by human lungs?
200mL/min
141
The largest gland in our body is?
liver
142
Name six bilecontaining substances secreted by Liver
bilirubin, biliverdin, cholesterol, degraded steroid hormones, vitamins and drugs
143
Name two glands in the skin which can eliminate certain substances through their secretions
sweat and sebaceous glands
144
Name three substances present in the sweat
NaCl, small amounts of urea & lactic acid
145
Name three substances eliminated by sebaceous glands
sterols, hydrocarbons and waxes
146
Sebaceous glands eliminate certain substances through
sebum
147
Malfunctioning of kidneys can lead to accumulation of urea in blood, a condition called
uremia
148
Urea from the body can be removed by a process called
hemodialysis-
149
During the process of haemodialysis, the blood drained from a convenient artery is pumped into a dialysing unit called
artificial kidney
150
An anticoagulant which is added in the blood before pumping it into a dialysing unit
heparin
151
The ultimate method in the correction of acute renal failures
Kidney transplantation
152
Stone or insoluble mass of crystallised salts (oxalates, etc) formed within the kidney
Renal calculi
153
Inflammation of glomeruli of kidney
Glomerulonephritis
