Urinary System Flashcards
0
Q
Juxtaglomerular cells combine with ____ cells to form the Juxtaglomerular apparatus in the kidney.
A
Macula Densa cells
1
Q
- The renal medulla is composed of tissue called ______.
A
Renal pyramid.
2
Q
Which of the following is not in the sequence of proper kidney blood flow? The starting point is the renal artery and the finishing point in the renal vein?
A
Interlobular vein
3
Q
Which is found in the highest concentration in the urine?
A
Urea
4
Q
The primary function of the ascending loop of Henle in the kidney is?
A
The active reabsorption of chloride ions
5
Q
Besides the kidneys what systems make up the urinary system?
A
The urinary bladder, the paired ureters, and the urethra.
6
Q
The adrenaline gland top of the kidney is functional to the kidney.
A
False
7
Q
What are the three supportive tissues that surround each kidney?
A
The renal fascia, the perirenal fat capsule, and the fibrous capsule?
8
Q
What are the three distinct regions of the kidney?
A
The cortex,the medulla, and the pelvis
9
Q
The walls of the calyces, pelvis, and ureter contains smooth muscles that contract rhythmically to propel urine along its course by Peristalisis.
A
True
10
Q
What are nephrons?
A
Structural and functional units of the kidney that carry out the processes that form urine.
11
Q
What does each nephron consist of?
A
They consist of a glomerulus and a renal tuble.
12
Q
The renal tubule has a cup shape end the glomerular capsule or Bowmans capsule, which is blind and completely surrounds the glomerulus.
A
True
13
Q
What surrounds the glomerulus?
A
The glomerular capsule or bowman’s capsule.
14
Q
Collectively the glomerular capsule and the enclosed glomerulus are called the
A
Renal corpuscle
15
Q
The endothelium of the glomerulus capillaries is fenestrated, which makes them exceptionally porous.
A
True
16
Q
What is filtrate
A
Plasma derived fluid or raw material that the renal tubules process to form urine
17
Q
What is the parietal layer of the glomerular capsule composed of?
A
Simple squamous epithillium
18
Q
The visceral layer of the glomerular capsule is composed of what cells?
A
Podocytes
19
Q
Filtrate enters the capsular space through what foot processes?
A
Filtration slits
20
Q
What are the remaining parts of the renal tubule and in what order does filtrate move through the renal tuble?
A
The proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule
21
Q
Filtrate enters the collecting ducts from the proximal convoluted tuble
A
False
22
Q
Filtrate from the renal corpuscle passes through the PCT first and then the DCT.
A
True
23
Q
What type of cells form the walls of the PCT and do they contain microbiolo
A
Formed from cuboidal epithelial cells with a large mitochondria, and surfaces contains dense microvilli
24
The loop of Henle contains both descending and ascending limbs.
True
25
The defending limb is continuous with the distal tubule
False
26
The thin segment is located in which limb?
The descending limb and is composed of simple squamous epithelium.
27
The as sending limb contains which segment?
The thick segment that is composed of low columnar epithelium
28
The thin segment is only found in the descending limb.
False sometimes can be found in ascending limb
29
The epithelial cells of the DCT like those of the PCT are cuboidal epithelium and confined to the cortex but are thinner and almost entirely lack microvilli.
True
30
What are the two types of cells seen in the collecting ducts?
Intercalated cells and principal cells
31
Principal cells play a major role in maintaining body's water and NA balance
True
32
Intercalated cells maintain the body's ___
Acid-base balance of the blood
33
What are the two major groups of Nephrons?
Cortical and Juxtamedullery nephrons
34
Cortical nephrons represent 85% of the nephrons
True
35
Where are cortical nephrons are located where?
They are located entirely in the Cortex except for small parts of thier loops of Henle that dip into the outer medulla.
36
Where are the Juxtamedullary nephrons located?
Originate close to the cortex-medulla junction
37
The Juxtamedullary nephrons play an important role in?
The kidneys ability to produce concentrated urine
38
What are the two capillaries associated with the renal tubule?
The glomerular and peritubular capillaries.
39
The glomerular capillaries do not run parallel and are not specialized for filtration.
False
40
Why does the glomerulus have high blood pressure ?
The arterioles have high resistant vessels and the affe rent arteriole has a larger diameter than the the efferent forcing the fluid into the glomerular capsule.
41
Most of the filtrate is re absorbed in the renal tubule and and returned to the blood in the glomerular capillary beds
False
42
What is the function of the peritubular capillaries?
Low pressure porous capillaries that readily absorb so lutes and water from the renal tubule cells as they are reclaimed from the filtrate.
43
What are the vasa recta and what is their role
The vasa recta contain bundles of long straight vessels that play a role in forming the concentration of urine.
44
The glomerulus capillary bed reclaims most filtrate
False
45
The glomerulus produces the filtrate and the peritubular capillaries reclaim most of the filtrate
True
46
What are granular cells or Juxtaglomerular cells?
They are enlarged smooth muscle cells with prominent secretory granules containing renin, which act as mechanoreceptors that sense blood pressure.
47
What are macula densa cells and what is their role?
Macula densa cells are closely packed cells of the ascending limb of the loop of Henle that lie adjacent to the granular cells that act as chemoreceptors and that respond to NaCl content of the filtrate
48
What does the filtration membrane consist of and where is it located?
It lies between the blood and the interior of the glomerular capsule that allows free passage of water and solutes smaller than plasma. And contain three layers the fenestrated endothelium of the glomerular capillaries, the visceral layer of the membrane composed of podocytes that have filtration slits and the basement membrane.
49
Which cells engulf and degrade macromolecules stuck in the filtration membrane?
Glomerular mesangial cells
50
What are the 3 major processes involved in urine formation and the adjustment of blood composition
Glomerular filtration by the glomeruli, tubular reabsorption and tubular secretion
51
What are the three processes that maintain the bodies volume and chemical make up of the blood?
1) the cell and protein free blood are put into a separate container the renal tubules and collecting ducts 2) the kidneys reclaim filtrate by tubular reabsorption 3)maintaining chemical balance by tubular secretion
52
Why are filtrate and urine different
Filtrate contains everything found in blood plasma except protiens, while urine contains mostly metabolic wastes and unneeded substances.
53
What is glomerular filtration?
It is a passive process in which hydrostatic pressure forces fluids and solutes through a filtration membrane?
54
Why is the glomerulus a much more efficient filter than other capillary beds
Because filtration membrane has a large surface area and is thousand times more permeable to water and solutes. As well as has a higher filtration pressure so that water,glucose, amino acids, and nitrogenous wastes pass freely into the glomerulus capsule from the blood.
55
What is the net filtration pressure?
The net filtration pressure are the forces acting upon the glomerular bed and is responsible for filtrate formation
56
What is glomerular hydrostatic pressure (HPg)?
It is essentially the glomerular blood pressure and is the chief force pushing water and solutes out of the blood and across the filtration membrane.
57
HPg is opposed by what two forces?
Colloid osmotic (oncotic) pressure of the glomerular blood (OPg) and capsular hydrostatic pressure (HPc)
58
What is the glomerular filtration rate (gfr)?
GFR is the volume of filtrate formed each minuet by the combined activity of the glomeruli of the kidneys.
59
What are the factors governing the filtration rate of the glomerular capillary bed?
Total surface area available for filtration, filtration membrane permeability and NFP.
60
GFR is not directly affected by NFP.
False
61
GFR is affected by both intrinsic and extrinsic control?
True
62
Intrinsic controls act locally to maintain GFR, while extrinsic controls by the nervous and endocrine systems to maintain blood pressures.
True
63
Intrinsic controls take precedence over intrinsic controls
False
64
What is the process used to adjust the resistance to blood flow in the kidney despite fluctuations to systemic blood pressure?
Renal auto regulation
65
What are the two types of controls that control renal auto-regulation/intrinsic controls?
Myogenic mechanism and the tubuloglomerular feedback mechanism
66
What is the myogenic mechanism and how is it an intrinsic control?
Myogenic mechanism is the tendency of the vascular smooth muscle to contract when stretched. During increasing systemic blood pressure it causes the afferent arteriole to constrict and prevent blood flow to protect the glomerulus against damaging levels of blood pressure. During low systemic blood pressure it causes dilation of the afferent arteriole and raises glomerular hydrostatic pressure.
67
What cells direct the tubuloglomerular feedback mechanism?
Macula densa cells because they are located in the walls of the ascending limb of the loop of Henle and respond to NaCl filtrate concentration
68
What happens during GFR increase / decrease to the tubuloglomerular feedback mechanism?
When GFR increases the macula densa cells release ATP in order to cause intense constriction of the afferent arteriole hindering blood flow to the glomerulus which decreases NFP and GFR to allow for proper filtration. When GFR decreases the macula densa cells inhibit ATP causing vasodilation if the afferent arteriole allowing more blood flow to the glomerulus thus increasing NFP and GFR.
69
GFR is constantly maintained between what pressures?
Between 80 and 180 mmHg
70
Intrinsic controls are used to regulate pressure during hypovolemic shock.
False
71
What is the purpose of the extrinsic controls?
To regulate systemic blood pressure
72
When extracellular fluid is normal which system prevails?
The intrinsic controls or renal autoregulatory mechanisms
73
During extreme circumstances which system will prevail?
Neural sympathetic nervous system takes over under the extrinsic controls
74
How does the sympathetic nervous system control GFR?
By releasing neuroepinephrine that act on the alpha-adrenergic receptors on vascular smooth muscle strongly constricting afferent arterioles, thereby inhibiting filtrate formation indirectly tripping the renin angiotensin mechanism. It also directly stimulates granular cells to release renin.
75
What is the renin mechanism?
Causes the release of the hormone renin
76
What is renin?
A hormone that acts directly on angiotensinogen, a plasma globulin made by the liver converting to angiotensinogen 1, which covert to angiotensinogen 2 by the angiotensinogen converting enzyme ACE.
77
What are the five ways that angiotensinogen 2 act to stabilize systemic blood pressure and extracellular fluid volume?
1) as a potent vasoconstrictor to raising mean arterial blood pressure. 2)by stimulating the reabsorption of sodium by acting on the renal tubules and triggering the release of aldosterone from the renal cortex causing blood pressure to rise.3)by Stimulating the hypothalamus to release anti diuretic hormone and activates the hypothalamic nerve center to increase blood volume.4)increases fluid reabsorption by decreasing peritubular hydrostatic pressure allowing more fluid to be absorbed.5) targets glomerular mesangial cells causing them to contract and reduce the GFR by decreasing the total surface area of the glomerular capillary
78
What are some of the factors that trigger renin release collectively or independently?
Reduced stretch of the glomerular cells,stimulation of the glomerular cells by input from activated macula densa cells, and direct stimulation of the granular cells.
79
What is tubular reabsorption?
It's a selective transepithelial process that begins as soon as filtrate enters the proximal convoluted tubule
80
Substances are absorbed by which routes?
They can be absorbed by either the transcellular or paracellular route
81
How do substances get reclaimed from tubular reabsorption?
In this route the filtrate enters the luminal membrane,the cytosol,and then through the basolateral membrane of the tubule and then the epithelium of the peritubular capillaries.
