Chapter 26_AP2 Flashcards
Urinary System
1
Q
Urine is carried from the kidneys to the urinary bladder by the
A
ureter.
2
Q
Arrange the following structures in correct sequence:
1) ureter
2) renal pelvis
3) calyx
4) urinary bladder
5) urethra
A
3, 2, 1, 4, 5
3
Q
Blood vessels, nerves, and the ureter enter and leave the kidney at the
A
hilum.
4
Q
The structural and functional units of the kidney are called
A
nephrons.
5
Q
The juxtamedullary nephrons have?
A
Long loops of Henle
6
Q
The visceral layer of Bowman’s capsule is:
A
part of the filtration membrane and contains podocytes
7
Q
An obstruction in the afferent arteriole would reduce the flow of blood into the
A
glomerulus
8
Q
The filtration membrane consists of the
A
podocytes, capillary endothelium, and basement membrane
9
Q
Urine passes from the distal convoluted tubule (DCT) to the _____ and then to the minor calyx.
A
collecting duct.
10
Q
One feature of renal blood circulation that makes it unique is that
A
each nephron has at least two capillary networks
11
Q
Trace the path of a red blood cell from the renal artery to the glomerulus:
1) interlobar artery
2) interlobular artery
3) arcuate artery
4) afferent arteriole
A
1, 3, 2, 4
12
Q
The urinary bladder
A
stores urine until it is voided
13
Q
Skeletal muscle that surrounds the urethra as it extends through the pelvic floor forms the
A
external urinary sphincter
14
Q
Formation of filtrate depends on a
A
pressure gradient
15
Q
The active transport of substances from the capillaries into the kidney tubules is called tubular ______.
A
secretion
16
Q
The part of the cardiac output that passes through the kidneys is the
A
renal fraction
17
Q
Passage of proteins into Bowman’s capsule is prevented by
A
the size of the capillary pores, the size of the filtration slits in the podocytes, and the size of the proteins
18
Q
Decreased blood colloid osmotic pressure affects renal function by
A
increasing net filtration pressure
19
Q
The collecting duct becomes more permeable to water when
A
ADH production increases
20
Q
Hydrogen ions are secreted into the filtrate by both the
A
proximal and distal tubules
21
Q
The ability of the kidney to concentrate urine depends on
A
a high medullary concentration gradient
22
Q
A countercurrent mechanism is in
A
both the loop of Henle and the vasa recta
23
Q
The juxtaglomerular apparatus secretes
A
renin
24
Q
The kidneys produce renin when
A
the blood pressure in the afferent arteriole decreases
25
Atrial natriuretic hormone
is secreted when blood pressure increases
26
Autoregulation in the kidney involves changes in the degree of
constriction of afferent arterioles
27
When the tubular maximum for a substance is exceeded
the excess remains in the filtrate
28
When aldosterone is absent, sodium reabsorption in the nephron is
greatly decreased
29
Atrial natriuretic hormone increases
urine volume
30
List 6 functions of the urinary system
1. eliminates wastes
2. regulates blood volume
3. regulates ion concentration
4. regulates pH
5. red blood cell production
6. vitamin D production
31
The urinary system consists of:
kidneys, ureters, urinary bladder, and urethra
32
Location of the Kidneys:
lies behind the peritoneum on the posterior abdominal wall on each side of the vertebral column
33
Renal capsule:
fibrous connective
| tissue. Surrounds each kidney
34
Perirenal fat:
Engulfs renal capsule and acts as
| cushioning
35
Renal fascia:
thin layer of loose connective tissue that anchors kidneys and surrounding
adipose to abdominal wall
36
Hilum
Renal artery and nerves enter and
| renal vein and ureter exit kidneys; opens into renal sinus
37
renal sinus
cavity
filled with fat and loose connective
tissue
38
Cortex:
Outer area of kidney
39
Medulla:
Inner area of kidney; surrounds renal sinus
40
Renal columns
part of
cortical tissue that extends into
medulla
41
Renal pyramids
```
cone-shaped.
Base is boundary between
cortex and medulla. Apex of
pyramid is renal papilla,
points toward sinus.
```
42
Pelvis:
enlarged chamber
| formed by major calyces
43
Ureter:
exits at the hilum;
| connects to urinary bladder
44
Parts of the nephron:
Bowman’s capsule, proximal
tubule, loop of Henle
(nephronic loop), distal
tubule
45
Urine continues from the
| nephron to
collecting ducts,
papillary ducts, minor
calyses, major calyses, and the
renal pelvis
46
Renal corpuscle.
Bowman’s
capsule plus a capillary bed
called the glomerulus.
47
Glomerulus:
```
network
of capillaries. Blood
enters through afferent
arteriole, exits through
efferent arteriole.
```
48
Parietal layer:
```
outer.
Simple squamous
epithelium that becomes
cube-shaped where
Bowman’s capsule ends
and proximal tubule
begins
```
49
Visceral layer:
inner.
Specialized podocytes that
wrap around the
glomerular capillaries
50
Fenestrae:
window-like openings in
the endothelial cells of the
glomerular capillaries.
51
Filtrations slits:
```
gaps between the
cell processes of the podocytes.
Basement membrane sandwiched
between the endothelial cells of the
glomerular capillaries and the
podocytes.
```
52
Filtration membrane:
```
capillary
endothelium, basement membrane
and podocytes. First stage of urine
formation occurs here when fluid
from blood in capillaries moves
across filtration membrane into the
lumen inside Bowman’s capsule.
```
53
Afferent arteriole
supplies blood to glomerulus
54
Efferent arteriole
drains glomerulus
55
Afferent and Efferent arterioles have a layer of
smooth muscle
56
Macula densa
Specialized tubule cells of the distal tubule. The
| distal tubule lies between the afferent and efferent arterioles.
57
Proximal tubule:
simple cuboidal
| epithelium with many microvilli
58
Loops of Henle
Ascending limb and descending limb
59
Ascending limb
first part
simple squamous epithelium
and thin, distal part thicker and
simple cuboidal
60
Descending limb
first part
similar to proximal tubule.
Latter part simple squamous
epithelium and thinner
61
Distal tubule
shorter than
proximal tubule. Simple cuboidal,
but smaller cells and very few
microvilli
62
Collecting ducts:
```
form where
many distal tubules come together.
Larger in diameter, simple
cuboidal epithelium. Form
medullary rays and lead to
papillary ducts
```
63
Arterial supply:
1. Renal arteries branch from abdominal aorta
2. Segmental arteries branch from renal
3. Interlobar arteries ascend within renal
columns toward cortex
4. Arcuate arteries branch and arch over
the base of the pyramids
5. Interlobular arteries project into cortex and
give rise to afferent arterioles
64
The part of the circulation involved with urine formation
6. Afferent arterioles supply blood to glomerulus
7. Glomerulus
8. Efferent arterioles exit the renal corpuscle
9. Peritubular capillaries form a plexus around the proximal and distal tubules
10. Vasa recta: specialized parts of peritubular capillaries that course into medulla along with loops of Henle, then back toward cortex
65
Venous drainage
```
11. Peritubular
capillaries drain into
interlobular veins
and lead to
12. Arcuate veins
13. Interlobar veins
14. Renal veins
```
66
Filtrate
water, small molecules, ions that can pass through membrane; pressure forces it across filtration membrane
67
Renal blood flow rate
1176 mL/min
68
Renal plasma flow rate:
renal blood flow rate X fraction of
| blood that is plasma: 650 mL/min
69
Filtration fraction:
part of plasma that is filtered into lumen of
| Bowman’s capsules; average 19%
70
Glomerular filtration rate (GFR):
amount of filtrate produced
| each minute. 180 L/day
71
Average urine production/day:
1-2 L. Most of filtrate must be
| reabsorbed
72
Filtration membrane
filtration barrier. It prevents
blood cells and proteins from entering lumen of
Bowman’s capsule, but is many times more permeable
than a typical capillary
73
Filtration pressure:
pressure gradient responsible for
filtration; forces fluid from glomerular capillary across
membrane into lumen of Bowman’s capsules
74
Forces that affect movement of fluid into or out of the lumen of
Bowman’s capsule
Glomerular capillary pressure (GCP): blood pressure inside capillary tends to move fluid out of capillary into Bowman’s capsule
– Capsule hydrostatic pressure (CHP): pressure of filtrate already in the lumen
– Blood colloid osmotic pressure (BCOP): osmotic pressure caused by proteins in blood. Favors fluid movement into the capillary from the lumen. BCOP greater at end of glomerular capillary than at beginning because of fluid leaving capillary and entering lumen
75
High glomerular capillary pressure results from
Low resistance to blood flow in afferent arterioles
– Low resistance to blood flow in glomerular capillaries
– High resistance to blood flow in efferent arterioles: small diameter vessels
76
Changes in afferent and efferent arteriole diameter alter filtration
pressure
Dilation of afferent arterioles/constriction efferent arterioles increases
glomerular capillary pressure, increasing filtration pressure and thus
glomerular filtration
77
Autoregulation of GFR
Involves changes in degree of constriction in afferent arterioles
78
Sympathetic stimulation of GFR: norepinephrine
– Constricts small arteries and afferent arterioles
– Decreases renal blood flow and thus filtrate formation
– During shock or intense exercise: intense sympathetic stimulation, rate of filtrate formation drops to a few mm
79
Tubular reabsorption
occurs as filtrate flows through
the lumens of proximal tubule, loop of Henle, distal
tubule, and collecting ducts
80
Tubular reabsorption results because of:
```
– Diffusion
– Facilitated diffusion
– Active transport
– Symport
– Osmosis
```
81
Diffusion between cells:
```
from
lumen of nephron into interstitial
fluid
– Depends on rate of transport of same
solutes through the cells of the tubule
– K+, Ca2+, and Mg2+
```
82
Descending thin segment of loop of Henle is:
highly permeable to water and
moderately permeable to urea,
sodium, most other ions
(passive).
83
Ascending thin segment of loop of Henle is:
```
not
permeable to water, but is
permeable to solutes. Solutes
diffuse out of the tubule and
into the more dilute interstitial
fluid as the ascending limb
projects toward the cortex.
Solutes diffuse into the descending vasa recta.
```
84
Tubular Secretion
Moves metabolic by-products, drugs, molecules
not normally produced by the body into tubule of
nephron
85
Atrial natriuretic hormone
– Produced by right atrium of heart when blood volume increases stretching cells
– Inhibits Na+ reabsorption
– Inhibits ADH production
– Increases volume of urine produced
– Venous return is lowered, volume in right
atrium decreases
86
Tubular load
Total amount of substance that passes through filtration
| membrane into nephrons each minute
87
Tubular maximum
Maximum rate at which a
substance can be actively
absorbed
88
Urine Movement
Hydrostatic pressure forces urine through
| nephron
89
Ureters:
bring urine from
renal pelvis to urinary
bladder. Lined by transitional
epithelium
90
Urinary bladder:
```
hollow
muscular container. In pelvic
cavity posterior to symphysis
pubis. Lined with transitional
epithelium;
```
91
Trigone:
interior of urinary bladder. Triangular area between the
entry of the two ureters and the exit of the urethra. Area expands
less than rest of bladder during filling
