CH 27 Flashcards
Urinary system
1
Q
Organs of the urinary system
A
- Kidneys
- Ureters
- Urinary bladder
- Urethra
2
Q
Function of urinary system
A
Remove waste products from blood and maintain homeostasis
- Storage
- Expulsion
- Regulation of blood volume
- Regulation of erthryocyte production
- Regulation of acid-base balance
3
Q
Filtered waste products
A
Filtrate, becomes processed to become tubular fluid
4
Q
Urine
A
Filtrate processed by kidneys
5
Q
Storage
A
Urinary bladder is muscular sac that stores urine
6
Q
Expulsion
A
Urine is transported from urethra to urinary bladder and expels it from the body
7
Q
Micturation/ urination
A
Expulsion of urine from urinary bladder
8
Q
Regulation of blood volume
A
Kidneys control the volume of interstitial fluid and blood under direction of certain hormones
Thus by affecting changes in blood volume, the kidneys also indirectly change blood pressure
9
Q
Regulation of erthryocyte production
A
As kidneys filter blood, they also indirectly measure oxygen levels in the blood
10
Q
Erythropoietin (EPO)
A
Hormone secreted by kidney cells when blood oxygen levels drop
Acts on stem cells in bone marrow to increase erythrocyte production, allowing blood to transport more oxygen
11
Q
Regulation of ion levels
A
Kidneys help control the blood ions balance such as sodium, potassium, phosphate, calcium by eliminating it in urine
12
Q
Regulation of acid-base balance
A
Kidneys alter blood level of hydrogen (H+) and bicarbonate (HCO3-) ions by eliminating varying amounts of ions
13
Q
Kidneys
A
- Lateral to spine T12-L3
- Right kidney bigger and lower than left
- Retroperitoneal
- Kidney bean colored (reddish-brown) and kidney bean shaped
- Center of concave side is hilum where vessels, nerves, and ureters are attached
14
Q
Function of kidneys
A
Filtration of blood:
- Removal of blood
- Regulation of systemic blood pressure
- Regulation of blood volume
- Regulation of blood pH
- Regulation of water and electrolyte levels in body fluids
- Secretion of erthyropoeitin
- Synthesis of vitamin D along with skin and liver
15
Q
Tissue that protects and supports the kidneys
A
- Perinepheric fat/ adipose capsule
- Renal fascia
- Paranephric/ pararenal fat
16
Q
Perinepheric fat/ perirenal fat/ adipose capsule
A
Closest to kidney; provides cushion to protect from trauma
17
Q
Renal fascia
A
Deep fascia which supports the kidney in abdominal cavity; dense irregular CT that holds the kidney in place
18
Q
Paranephric/ pararenal fat
A
More cushioning lateral to kidneys
19
Q
Regions of the kidney
A
- Fibrous/ renal capsule
- Cortex
- Medulla
- Major and minor calyces
- Renal pelvis
- Uriniferous tubules
- Renal lobe
- Renal sinus
20
Q
Fibrous/ renal capsule
A
Directly adheres to outer surface of kidney; dense irregular CT that maintains the kidney’s shape, protects it from trauma, and helps prevent infectious pathogens from entering the kidney
21
Q
Cortex
A
Outer lighter area of kidney
22
Q
Medulla
A
Inner darker area of kidney
23
Q
Components of renal medulla
A
- Renal columns
- Renal pyramids
- Renal papilla
24
Q
Renal column
A
Extensions of the renal cortex between renal pyramids; subdivide the kidney into renal pyramids
25
Renal pyramids
Subdivision of renal medulla; 8-15/kidney
26
Renal papilla
Apex (point) of renal pyramid
27
Renal lobe
1 renal pyramid and surrounding cortex
8-15/kidney
28
Minor calyces
Funneled-shaped space that carries urine out of each renal pyramid
8-15/kidney
29
Major calyces
Larger space formed by the union of minor calyces
2-3/kidney
30
Renal pelvis
Large-funnel shaped space formed by the union of the major calyces
Collects urine and transports it to the ureter
31
Renal sinus
Space around calyces that contains loose/areolar CT, adipose CT, blood vessels, and nerves; continuous with hilum
Houses renal artery, renal vein, lymph vessels, nerves, renal pelvis, and renal calcyes
32
Urine pathway through regions of kidney
minor calyces
major calyces
renal pelvis
ureter
33
Nephron
- Functional unit of kidney
- Filters blood and forms urine
- 1.25 million/ kidney
34
Parts of nephron
- Renal corpuscle
- Renal tubules
- Collecting duct/ tubule
35
Renal corpuscle
Enlarged, bulbous portion of nephron
36
Components of renal corpuscle
- Glomerular capillaries
- Bowman's/ glomerular capsule
37
Glomerular capillaries/ glomerulus
Fenestrated capillaries: capillaries with fenestrations (pores) that blood plasma and dissolved substances leaks through to be filtered
38
Bowman's/ glomerular capsule
Epithelial capsule surrounding the glomerulus
39
Components of Bowman's/ glomerular capsule
- Visceral layer
- Capsular space
- Parietal layer
40
Visceral layer of Bowman's/ glomerular capsule
Formed by specialized cells called podocytes
41
Podocyte components
- Pedicels
- Filtration slit
- Slit membrane
42
Pedicels
Foot-like processes that wrap around the glomerular capillaries to support the capillary wall
43
Filtration slits
Thin spaces that separate pedicels and are covered with membranes; restricts passage of most small proteins
44
Filtration membrane
Porous, thin, negatively charged structure formed by the glomerulus and visceral layer of the glomerular capsule; Substance must pass through this "filter" to become filtrate
45
Filtration membrane layers
Innermost (closest to lumen) --> outermost:
- Endothelium of glomerulus
- Basement membrane of glomerulus
- Visceral layer of glomerular capsule
46
Endothelium of glomerulus
Fenestrated to allow blood plasma and its dissolved substance to be filtered while restricting the passage of large structures such as formed elements (erythrocytes, leukocytes, platelets)
47
Basement membrane of glomerulus
Porous membrane that that restricts passage of large plasma proteins while allowing smaller structures to pass through
48
Parietal layer of Bowman's/ glomerular capsule
Simple squamous ET
49
Capsular space
Actual space between visceral and parietal layers of glomerular capsule where filtrate enters
50
Renal tubules
- Proximal convoluted tubule (PCT)
- Nephron loop/ loop of Henle
- Distal convoluted tubule (DCT)
51
Proximal convoluted tubule (PCT)
- Lined with simple cuboidal ET with tall microvilli that markedly increase its reabsorption capacity (lumen looks fuzzy)
- Cells reactively resorb all nutrients (including glucose and amino acids) as well as most vitamins, plasma proteins from tubular fluid to enter the blood in peritubular capillaries to be returned to general circulation
- About 60-65% of water from tubular fluid is resorbed by osmosis
- Secretes some H+ ions into tubular fluid
52
Distal convoluted tubule (DCT)
- Lined with simple cuboidal ET with no microvilli (lumen looks clear)
- Secrete ions (H+, K+) in tubular fluid
- Resorbs water and Na+ ions
53
Once tubular fluid leaves the DCT, it enters the ______ that empty into _______
collecting tubules; collecting ducts
54
Collecting duct
- Collects urine from different nephrons
- Simple cuboidal in tubules
- Simple columnar near renal papilla
55
Nephron loop AKA loop of Henle
- Tubule that forms a loop
- Resorbs water and solutes (Na+, Cl-) from tubular fluid
- Secretes H+ in tubular fluid
- Thick limbs lined with simple cuboidal ET
- Thin limbs lined with simple squamous ET
56
Limbs of nephron loop
- Ascending limb
- Descending limb
57
Descending limb
- From cortex into medulla
- Thick then thin
58
Ascending limb
- From medulla back to cortex
- Thin then thick
59
Once tubular fluid leaves the collecting duct, it enters the _________ and becomes urine
papillary ducts
duct opening at renal papilla (tip of renal pyramids) and enters the minor calyces
60
Tissue lining renal calyces and renal pelvis
transitional ET
61
Formation of urine
- Filtration
- Reabsorption
- Secretion
62
Filtration
- Blood is filtered
- Occurs in glomerulus
63
Reabsorption
- Occurs in renal tubules
- Movement of substances like glucose from renal tubules into surrounding blood capillaries
- Returns wanted nutrients and such back into blood circulation
64
Secretion
- Occurs in renal tubules
- Movement of unwanted substances like toxins from surrounding blood capillaries into renal tubules to be eventually to be excreted
65
2 types of nephrons
- Cortical nephrons
- Juxtamedullary nephrons
66
Cortical nephron
- 85% of all nephrons
- Located primarily in cortex
- Relatively short nephron loops
67
Juxtamedullary nephron
- 15% of all nephrons
- Located primarily in medulla
- Have long nephron loop surrounded by vasa recta
- Form a more concentrated urine during times of dehydration (vomiting, diarrhea)
68
Vasa recta
"straight vessels"; Capillary network surrounding nephron loop of juxtamedullary nephrons where materials are resorbed and returned to blood; specialized part of peritubular capillary
69
Juxtaglomerular apparatus (JGA)
- In all nephrons
- Controls glomerular filtration rate (GFR): rate at which filtrate moves
- Controls systemic blood pressure
70
Components of juxtaglomerular capsule (JGA)
- Juxtaglomerular cells
- Macula densa
71
Juxtaglomerular cells AKA granular cells
- Smooth muscle cells in wall of afferent arteriole
- Secretes renin in blood if blood pressure drops, a vasoconstrictor enzyme that will constrict blood vessels to increase systemic BP
72
Macula densa
- Specialized ET cells in DCT
- Detects changes in concentration of filtrate and signals juxtaglomerular cells
- Only on tubule side next to afferent arteriole, are narrower and taller than other DCT cells
73
Blood supply to kidney
- Renal artery
- Segmental artery
- Lobar artery
- Interlobar artery
- Arcuate artery
- Interlobular artery
- Afferent arteriole
- Glomerulus
- Efferent artery
- Peritubular capillary and vasa recta
- Interlobular vein
- Arcuate vein
- Interlobar vein
- Renal vein
- IVC
* no segmental or lobar vein
74
Renal artery
- Receives blood from kidneys
- Arises and extends from lateral region of descending abdominal aorta at level of first or second aorta
75
Segmental artery
- Up to 5
- Branch from renal artery within renal sinus
76
Lobar artery
- Receives blood from segmental arteries
77
Interlobar arteries
- Receives blood from lobar arteries
- In renal columns
78
Arcuate arteries
- Branching of interlobar arteries
- Located parallel to base of medullary pyramid
79
Interlobular arteries
- Branching of arcuate arteries
- Project into cortex
80
Afferent arteriole
Extension of interlobular arteries into small branches; afferent= toward: carry blood to glomerulus
81
Glomerulus
Capillary network as the afferent arteriole enters the renal corpuscle
82
Efferent arteriole
Receives blood from the glomerulus; branch into peritubular capillaries or vasa recta; efferent= to take away or exit: takes blood away from glomerulus
83
Peritubular capillaries
Are intertwined with convoluted tubules, primarily reside in cortex; peri=around
84
Interlobular veins
Receives blood from peritubular capillaries and vasa recta
85
Arcuate veins
Union of interlobular veins that project parallel to base of medullary pyramids
86
Interlobar veins
Union of arcuate veins
87
Renal vein
Unions of interlobar veins in the renal sinuses; Leave the kidney via the hilum and drain into the IVC
88
Interlobar vessels
Located between lobes of kidneys
89
Arcuate vessels
Forms vessel arcs at corticomedullary junction
90
Interlobular vessels
Located between smaller lobules of kidney cortex
91
Urinary tract
- Ureters
- Urinary bladder
- Urethra
92
Ureters
- Carries urine from kidneys to urinary bladder
- Travel from renal pelvis to posterolateral wall of bladder
- Last few inches are horizontal
- Retroperitoneal
93
Walls of ureters
- Mucosa: transitional ET
- Muscularis: inner longitudinal layer and outer circular layer (opposite of GI tract)
- Adventitia
No submucosa
94
Urinary bladder
- Stores urine
- Located immediately posterior to pubic symphysis in floor of pelvis
- In females: lies anteroinferior to uterus and anterior to vagina
- In males: lies anterior to rectum and superior to prostate gland
95
Wall of bladder
- Mucosa: transitional ET with rugae
- Submucosa: dense irregular CT, supports urinary bladder wall
- Muscularis: complex pattern of muscle fibers and difficult to determine layers
- Adventitia: areolar CT
96
Detrusor
Muscle of bladder wall
97
Internal urethral sphincter
Formed by detrusor muscle; at neck of urinary bladder; involuntary smooth muscle that encircles the urethral opening
98
Trigone
Triangular area formed by opening of ureters and urethra; lacks rugae so does not expand when bladder fills with urine; funnel that directs stored urine to urethra
99
Urethra
- Begins at neck of urinary bladder
- Carries urine outside of the body
100
2 sphincter muscles
- Internal urethra sphincter
- External urethra sphincter
101
External urethra sphincter
- Formed by urogenital diaphragm
- Skeletal muscle (voluntary)
- Located at floor of pelvis
102
Wall of urethra
-Muscosa: transitional ET near bladder, stratified squamous ET near external orifice, males may have pseudostratified and stratified columnar ET
- Muscularis: smooth
- Adventitia: areolar CT
103
Female urethra
Has single function of transporting urine to exterior of body
104
Male urethra functions
Urinary and reproductive functions: transports urine and semen
105
Regions of male urethra
- Prostatic urethra
- Membranous urethra
- Spongy urethra
106
Prostatic urethra
Travels through the prostate gland
107
Membranous urethra
Travels through external urethral sphincter (urogenital diaphragm)
108
Spongy urethra
Travels through corpus spongiosum of penis
