The urinary system Flashcards
1
Q
urinary system consist of
A
-two kidneys
-two ureters
-one urinary bladder
-one urethra
2
Q
Function of the urinary system
A
- elimination of waste products of metabolism
- filters 180L of fluid daily
- removes waste products of metabolism and drugs/toxins
- regulates blood osmolality
- regulates blood ions
- regulates blood pH
- produce the hormone erythropoietin
3
Q
osmolality
A
total concentration of solutes
4
Q
erythropoietin
A
-promotes red blood cell production
5
Q
Location of the kidneys
A
-just above the waist
-between the parietal peritoneum and the posterior wall of the abdomen (retroperitoneal)
6
Q
Why is the left kidney more superior than the right kidney
A
-the right kidney is crowded by the liver
7
Q
Why is the left kidney more superior than the right kidney
A
-the right kidney is crowded by the liver
8
Q
structure of the kidney
A
bean shaped
9
Q
hilum
A
-notch on medial margin where ureter exits
-entering/exiting are blood vessels, nerves, and lymphatic vessels
10
Q
What are the three tissues surrounding the kidneys
A
- renal fascia
- adipose capsule
- fibrous capsule (renal capsule)
11
Q
renal fascia
A
-outermost layer composed of dense fibrous connective tissue
12
Q
adipose capsule
A
middle layer cushions kidney against blows
13
Q
fibrous capsule (renal capsule)
A
-innermost layer
-covers external surface of kidneys
-protects kidneys from infections in surrounding tissue
14
Q
cortex of the kidney
A
-superficial region
-light colored
-granular
15
Q
medulla of the kidney
A
-deep to cortex
-dark red/brown color
16
Q
renal pyramids of the kidneys
A
-triangle-shaped
-collectively make up the medulla
17
Q
papilla of the kidneys
A
-apex of each pyramid
-point towards hilum
18
Q
base of the kidneys
A
-base of each pyramid
-point toward cortex
19
Q
medullary rays of the kidney
A
-lines within pyramids
-consist of straight tubules and collecting ducts
20
Q
renal columns of the kidney
A
-cortex like material located between renal pyramids
21
Q
renal pelvis of the kidney
A
-funnel shaped tube continuous with ureter leaving the hilum
22
Q
major calyces
A
-branching extension of the renal pelvis
23
Q
minor calyces
A
-major calyces form minor calyces
-cup shaped structure that enclose each renal papilla
24
Q
Flow of urine in the kidneys
A
- renal papilla
- minor calyx
- major calyx
- renal pelvis
- ureter
- urinary bladder
- urethra
25
nephron
-functional unit of the kidney
-contains both vascular and non-vascular components
26
glomerulus
-ball of capillaries containing blood to be filtered
-all substances except proteins and red blood cells pass through the glomerulus
27
glomerular (Bowman's capsule)
-consist of parietal layer and a visceral layer
-the visceral layer consist of podocytes (foot cells) that terminate in the foot processes
28
filtration slits
-the clefs or openings between the foot processes are called this in bowman's capsule
29
capsular space
-where filtrate enters through these slits
30
renal corpuscle
-consists of the glomerulus and glomerular capsule
31
renal tubule
-tubule extending from the glomerular capsule to the collecting duct
-contains the proximal convoluted tubule (PCT), nephron loop (loop of Henle), descending limb (thin), ascending limb (thick). and distal convoluted tubule (DCT)
32
distal convoluted tubule
-carriers its contents into the collecting duct
33
collecting duct
-travels to the renal papilla and releases the newly formed urine into the minor calyx
34
Function of nephrons
1. glomerular filtration
2. tubular reabsorption
3. tubular secretion
35
glomerular filtration
-creates protein and blood cell free filtrate from blood
-water and solutes move from the glomerulus into the glomerular capsule, the result is a solution called the filtrate
36
tubular reabsorption
-the movement of certain components of the filtrate from the nephron tubule to the blood flowing through the peritubular capillaries and vasa recta
-filtrate contains ions, nutrients, and waste but the nutrients and most ions must be returned to the blood (124 ml of 125 ml will be reabsorbed)
-only 1 ml of filtrate is eliminated as urine
-specific amount of each substances absorbed depends on body's needs at that time
-process of reabsorption is accomplished by passive and active transport mechanisms
37
tubular secretion
-the addition of substances directly into the filtrate from the blood
-these substances were not part of the filtrate. and added from peritubular capillaries called tubule cells
38
cortical nephron
-type of nephron that accounts for 85% of all nephrons
-no vasa recta blood vessels associated with this nephron
39
juxtamedullary nephrons
-type of nephron that accounts for 15% of all nephrons
-glomerulus located next to cortex/medulla border
-deeply penetrates the medulla
-has a long nephron loop
-vasa recta blood vessels are associated with this nephron
-plays a role in producing concentrated urine
40
afferent arteriole
-feeds the glomerulus
41
efferent arteriole
-drain the glomerulus
42
peritubular capillaries
-surround the proximal and distal convoluted tubules
43
vasa recta
-are associated with the juxtamedullary nephrons
-long straight chains that run parallel to the nephron loops and deeply penetrate the medulla
44
List the Renal blood vessels
1. renal artery
2. segmental arteries
3. Interlobar arteries
4. Arcuate arteries
5. Cortical radiate arteries
6. cortical radiate veins
7. Arcuate veins
8. Interlobar veins
9. renal veins
45
Interlobar arteries
-located in the renal columns
46
Arcuate arteries
-form arches over the bases of the renal pyramids
47
cortical radiate arteries
-supply blood to the cortex
48
What is the end product of a functioning nephron
-urine
49
What are three processes that occur which result in urine formation
1. Glomerular filtration
2. Tubular reabsorption
3. Tubular secretion
50
filtration
-forcing of fluid and dissolved substances through a membrane by outward forces
51
renal corpuscle
-adapted for filtering
-consist of a very porous membrane
-contains glycoproteins (neg charge) in the basement membrane
-extensive capillary network
-increased surface area
52
Why does the efferent arteriole have a smaller diameter than afferent arteriole
b/c the blood pressure in the glomerulus is very high
53
Factors that affect the rate of filtration
1. hydrostatic pressure in glomerular capillaries (HP gc)
2. Forces that oppose filtration
3. P (EFF) = effective filtration pressure
4. The net filtration pressure (NFP)
5. Glomerular filtration rate
54
hydrostatic pressure in glomerular capillaries (HP gc)
- HP gc is essentially glomerular blood pressure
- HP gc is the dominant force driving filtration
55
colloid osmotic pressure in glomerular capillaries
-pressure exerted by proteins in blood plasma
56
hydrostatic pressure in the capsular space HPcs
-pressure exerted by filtrate against the wall of the glomerular capsule
57
P (EFF) = effective filtration pressure
-net result of three contributory pressures (HP gc, OP gc, and HP cs)
P (EFE) = net filtration pressure (NFP)
-OP = osmotic pressure
CS = capsular space
HP = hydrostatic pressure
58
NFP- net filtration pressure
-outward pressure - inward pressure
= (HP gc) - (HP cs + OP gc)
= (55) - (15+30)
= 10 mmHg
-directly results in the GFR: glomerular filtration rate
59
Glomerular filtration rate
-the volume of filtrate formed each minute by the combined activity of all the millions of glomeruli of the kidneys
60
The glomerular filtration rate is directly proportional to...
1. net filtration pressure
2. total surface area for filtration
3. filtration membrane permeability
61
How much filtrate does an adult kidney produce
- 180 L (47 gallons) of filtrate per day
-equates to a normal GFR of 120-125 ml of filtrate per minute
-most of the filtrate is reabsorbed and returned to the blood
62
How can glomerular filtration rate be determined by
-renal clearance of inulin (rarely performed)
-estimated by blood creatinine levels (routinely performed)
63
renal clearance of inulin
-the volume of plasma from which the kidneys can completely remove inulin within a minute
64
Substances reabsorbed in the PCT
-glucose
-amino acids
-sodium
-chloride
-water ( most water in filtrate reabsorbed along with other substances by osmosis)
65
Substances reabsorbed in the descending limb
-water is reabsorbed here passively (osmosis)
-not permeable to NaCl and other solutes
66
Substances reabsorbed in the ascending limb
-not permeable to water
-permeable to NaCl
67
substances reabsorbed in the DCT
-aldosterone regulates the sodium reabsorbed here
68
substances reabsorbed in the collecting duct
-water reabsorption regulated by ADH
-approx 10% water reabsorbed here
-sodium reabsorption and potassium secretion regulated by aldosterone
-hydrogen ions and bicarbonate ions are reabsorbed or secreted to maintain proper blood pH
69
What is secreted during tubular secretion
-NH4 (ammonium)
- H+ (hydrogen ions = protons)
- K+ (potassium)
- creatine (from creatine phosphate in muscle)
- metabolites (breakdown products) of drugs like penicillin
