Urinary System Flashcards
(151 cards)
1
Q
What are the major functions of the urinary system?
A
Elimination
Excretion
Homeostatic Regulation of blood plasma
2
Q
What structures contribute to the elimination role of the urinary system?
A
Ureters
Bladder
Urethra
3
Q
What is elimination?
A
Discharge of waste products out of the body
4
Q
What structure contributes to the excretion role of the urinary system?
A
The kidney
5
Q
What is excretion?
A
Removal of organic waste products from body fluids, that produce urine
6
Q
What structure contributes to the homeostatic regulation of blood plasma role of the urinary system?
A
The kidney
7
Q
How does the kidney maintain homeostatic regulation of blood plasma?
A
- Regulates BV and BP
- Regulates plasma ion concentrations
- Stabilizing blood pH
- Conserves nutrients
8
Q
The kidneys produce urine from: A. liquids directly transported to kidneys after swallowing B. Products filtered from blood C. Water in digestive tract D. Excess fluids in the body E. Extracellular fluid
A
B. Products filtered from blood
9
Q
Everytime your heart beats, what percent of cardiac output goes to the kidneys?
A
25%
10
Q
If your BV goes up, you
A
have higher BP
Larger amount of urine
11
Q
If your BC goes down, you
A
Have lower BP
Absorb more water
Smaller and more concentrated amount of urine
12
Q
Smooth muscle ____ force urine toward the urinary bladder
A
Peristaltic contractions
13
Q
What is a ureter?
A
12 inch tube of smooth muscle where urine is sent following filtration
14
Q
What division of the ANS controls urination?
A
Parasympathetic stimulation
15
Q
What muscle is responsible for emptying the bladder?
A
Detrusor muscle
16
Q
Which urinary sphincter is involuntary: internal or external?
A
Internal
17
Q
Right before ejaculation, the _____ closes tightly to prevent semen and urine from mixing
A
Internal urinary sphincter
18
Q
After childbirth, women have more leakage because _____ is beat up after the baby leaves your body
A
the external urinary sphincter
19
Q
You gain control of the external urinary sphincter between ______ and _____ years old because synapses need time to form
A
2 and 3 years old
20
Q
Define urination (voiding)
A
Expelling urine from the urinary bladder through the urethra
21
Q
Urination is coordinated by the ________
A
micturition reflex
22
Q
What is the micturition reflex?
A
When your urinary bladder becomes stretched, you consciously sense bladder distentsion, and signals go to ANS to cause relflexive contraction of detrusor muscle
23
Q
What does the micturition reflex occur in response to?
A
Stretched bladder
Parasympathetic input
24
Q
Urination requires coupling the _____ with the _____
A
Micturition reflex
Relaxation of internal and external urethral sphincters
25
After overriding the signal to urinate, why does it take a second to finally urinate instead of immediately happening?
When you finally go to urinate, you have to relax the external urinary sphincter, and it takes a second for your body to understand that it is now open and to relax the internal urinary sphincter
26
The coupling of the micturition reflex refers to
The relaxation of both the internal and external urinary sphincters in order to urinate
27
Define incontinence
Inability to voluntarily prevent the release of urine
28
Incontinence is most common
among females
| especially after childbirth
29
Define urinary retention
Inability to voluntarily release urine
30
Urinary retention is most common
among males
| due to an enlarged prostate
31
Why does an enlarged prostate lead to urinary retention?
As the prostate grows, it pushes on the urethra so not as much urine can be expelled from the bladder, increasing the sensation of needing to urinate but being unable to
32
What are the two types of UTI's?
Urethritis
| Cystitis (inflammation of the bladder)
33
UTI's can occur anywhere along the urinary tract, but are most commonly found in
the urethra
34
Why are UTI's more common in females?
Shorter urethra
| Closer to vagina so easily exposed to pathogens during intercourse
35
What is the body's natural way of getting rid of UTI's?
Urination (flushes bacteria out)
36
The kidney contains how many nephrons and what is the nephron's job?
1.25 million
| To make urine
37
The renal medulla consists of collecting ducts that drain urine from
neprhron to calyces
38
Calyces drain urine into the
central renal pelvis
39
The renal pelvis drains urine into the
ureter
40
What three structures focus mainly on getting urine out of the body?
Ureters
Bladder
Urethra
41
What structures make urine?
Kidneys
42
Describe the general overview of the urine making process
25% of cardiac output comes into the renal artery, and blood travels up to the nephrons. Collectingducts take the urine and drain into the calyxes which then drain into the ureter.
43
Following the urine making process, cleaned up blood leaves through ___ and extra waste leaves through ____
renal vein
| ureter
44
The renal corpuscle is composed of
Bowman's capsule and the glomerulus capillary bed
45
The renal tubule consists of
PCT
Loop of Henle
DCT
46
What is filtrate?
Fluid pushed from glomerulus into capsular space
47
The renal corpuscle is responsible for
the production of filtrate from blood
48
The renal tubules are responsible for
- Reabsorption of organic nutrients and water and ions from filtrate into blood stream
- Secretion of waste products into filtrate
49
____ arterioles supply blood to the capillary bed of the glomerulus in the renal corpuscles
Afferent
50
____ arterioles collect blood leaving the glomerulus capillary bed
Efferent
51
______ capillaries surround the renal tubules
Peritubular
52
Peritubular capillaries are responsible for
Collecting nutrients, water, and ions reabsorbed out of filtrate
53
The glomerular capillary bed is unique because
It does not possess any venules
54
Because the glomerulus does not possess any venules, it is not a capillary bed that exists for ____
Oxygen delivery
55
The main goal of the glomerulus is for
Fluid to be pushed out to make filtrate
56
Trace the pathway of blood through glomerulus and peritubular capillaries
Oxygenated blood comes through afferent arteriole
Filtrate is formed
Oxygenated blood leaves through efferent arteriole
Oxygenated blood travels through peritubular capillary where item exchange occurs
Deoxygenated blood leaves via renal vein
57
What are the two types of nephrons?
Cortical nephrons and juxtamedullary nephrons
58
What type of nephrons make up the majority of all nephrons
Cortical nephrons
59
Compare cortical and juxtamedullary nephrons
Cortical: loop of henle are shorter; located in cortex
Juxtamedullary: Loop of henle longer; located in renal pyramids
60
Which type of nephron produces more concentrated urine?
Juxtamedullary nephrons
61
What causes water and solutes to move out of glomerular capillaries and into renal tubules?
Blood pressure
62
What is reabsorption?
The removal of water and solutes from filtrate into peritublar fluid
63
What is peritubular fluid?
Interstitial fluid surrounding renal tubule andperitubular capillaries
64
What is secretion?
Transport of solutes form the peritubular fluid into the filtrate
65
Blood pressure has to be ____ than factors that pull blood out of the nephron loop in order to make filtrate
greater than
66
Something that is reabsorbed travels through ____
peritubular fluid first then to peritubular capillary bed
67
Reabsorption and secretion occur via ________ across epithelial cells forming the wall of renal tubule
Epithelial cells
68
What are the three types of carrier mediated transport?
Facilitated diffusion
Active transport
Cotransport
69
The main type of transport used in reabsorption and secretion is
facilitated diffusion
70
Glucose is reabsorbed into the peritubular capillaries by hitching a ride with
Sodium
71
What are the characteristics of carrier proteins?
- Specific for a particular molecule
- Transport only in one direction
- Distribution of carrier proteins vary
- Can be controlled by hormones
72
Almost all of your glucose is reabsorbed in the_____
Proximal convoluted tubule
73
What is the transport maximum?
Carrier proteins have a renal threshold for reabsorption of substances in tubular fluid
74
When carrier proteins reach transport maximum what happens?
You have made all of the carrier proteins you can make and any excess that can no longer be reabsorbed is "lost" in urine
75
Protein creation is controlled by hormones in the
Distal convoluted tubule
76
If sodium levels drop what horomone is secreted to tell the kidneys to reabsorb more sodium?
Aldosterone
77
Presence of aldosterone tells your body to
Transcribe a sodium channel which is put in the membrane and sodium becomes reabsorbed in the blood
78
Diabetes means what for the kidneys?
High glucose exceeds transport maximum so it is lost in urine
Higher osmotic potential is present within the nephron so you secrete more water from the blood
79
Why don't plasma proteins and large molecules cross the glomerulus?
3 layers of glomerular filtration prevent them from crossing the barrier
80
What are the three layers of the glomerulus?
Capillary endothelium
Lamina densa
Podocytes
81
What is the function of podocytes?
Cover lamina densa of capillaries and produce filtration slits
82
Renal corpuscles have fenestrated capillary beds to
allow for easy exchange of materials
83
Materials are transferred from blood to nephron via
Filtration slits
84
The net filtration pressure is the sum of
opposing forces ( Blood pressure, Capsular Hydrostatic pressure, Blood osmotic pressure)
85
What is the equation for filtration pressure?
FP= BHP-CsHP-BOP
86
What is the blood pressure at the glomerulus and is it constant? What direction does it push fluid?
50 mmHg
yes
Pushes fluid out of glomerulus
87
What is the pressure of CHP? Is it constant? What direction does it push fluid?
15 mmHg
yes
Pushes fluid into glomerulus
88
What is the pressure of BOP? Is it constant? What direction does it push fluid?
25 mmHg
yes
Pushes fluid into glomerulus
89
What is the normal filtration pressure that the kidneys work to maintain?
10 mmHg
90
The kidneys produce how much filtrate per day?
180 L/day
91
Glomerular filtration rate is
The rate at which fluid is pushed out of glomerulus and filtered
92
GFR is effected by
- changes in blood pressure
- changes in blood osmotic pressure
- changes in fluid movement in renal tubules causing a build up of pressure in renal capsule
- blockage of filtration slits in glomerulus
93
Anything that alters the filtration pressure will alter
the GFR
94
When the GFR is effected by factors that alter net filtration pressure also cause changes in urine
output and composition
95
Low blood pressure will _____ filtration
Decrease
96
If you're dehydrated and your bp drops to 40 mmHg, what happens to GFR?
It falls to zero
97
What is glomerulonephritis?
Blockage of filtration slits by antigen- antibody complexes in the blood
98
What are the implications of glomerulonephritis?
Fluids cannot move out of capillaries
GFR decreases
Urine production falls
99
What is nephritis?
Inflammation of the kidney
100
What are the implications of nephritis?
Swelling causes increased capsular pressure so filtration rate slows
101
When the glomerulus is damaged
capillaries become very permeable
Plasma proteins and RBC's enter filtrate
Less net BOP pulling water into blood
Increase GFR and urine production
102
What is proteinuria
Plasma proteins appear in urine
103
What is hematuria
Blood cells appear in urine
104
What are the controlling factors of the GFR?
- Autoregulation
- Sympathetic ANS
- Renin-angiotensin
105
What hormones influence kidney reabsorption and secretion?
- PTH and Calcitonin
- Aldosterone
- Anti-diuretic hormone
106
The kidneys ________ afferent and efferent arteriole diameters in order to keep GFR constant despite changes in systemic BP
autoregulate
107
If BP decreases, how do the kidneys accomodate the drop in pressure?
- Dilate afferent arteriole
- Dilate glomerular capillaries
- Constrict efferent arteriole
108
If BP increases, how do kidneys accomodate the rise in pressure?
Constrict the afferent arteriole
109
What type of regulation can over-ride autoregulation of the kidneys?
Sympathetic ANS regulation
110
What effective does hypotensive (hemorrhaging) stress produce on the GFR?
strong vasoconstriction of afferent arteriole, reduced blood flow to glomerulus
111
What effect does overheating and exercise stress produce on the GFR?
- Blood is diverted away from kidney by vasodilation of arterioles in skin and skeletal muscles
112
Renin is released by the juxtaglomerular complex to stimulate a drop in filtration pressure which in turn
- Increases blood volume and BP
| - Triggers formation of angiotensin II
113
Trace the pathway of how Renin triggers the release of angiotensin II
Renin converts angiotensinogen to angiotensin I
Angiotensin I moves through lungs, meets ACE (enzyme)
ACE converts angiotensin I to angiotensin II
Angiotensin II increases blood volume and pressure
114
Nitrogenous wastes are made when we break down
proteins
115
Almost all of our ammonia is converted to
Urea
116
If urea is present in the body
Kidneys go into overdrive to put out as much urine as possible to get all of the urea out
117
What is the normal range of pH
4.5-8 (Avg 6)
118
What percent of normal urine is water?
93-97%
119
Proximal convoluted tubule's function is to
reabsorb nutrients and ions by carrier mediated transport
120
The PCT reabsorbs what percent of filtrate?
60-70%
121
The function of the descending limb of nephron loop is to
absorb water via osmosis
| Impermeable to solutes
122
Which limb is thicker?
Ascending
123
The ascending limb of nephron loop functions to
Reabsorb Na+ and Cl-
| Impermeable to water
124
What is the function of distal convoluted tubule and collecting ducts?
Depends on the levels of hormones
125
What is the function of the glomerulus?
To produce filtrate
126
Most reabsorption of nutrients at the PCT is done through
Carrier mediated transport
127
____ ions might be secreted out of blood if blood is too acidic to maintain normal pH
H+ ions
128
Increased osmolarity from NaCl transport from ascending limb results in increased movement of _______ from the descending limb
water
129
pH of blood is controlled by the varying amounts of _____ secreted or _____ reabsorbed
H+ secreted
| HCO3- reabsorbed
130
The presence of parathyroid hormone causes
Active reabsorption of Ca2+ ions to raise calcium levels
131
Presence of Calcitonin causes
Active secretion of Ca 2+ ions to lower calcium levels
132
Presence of Aldosterone causes
Active reabsorption of Na+ and Cl- in exchange for K+
133
Presence of ADH causes
Reabsorption of water
134
Aldosterone is released in response to
High K+
Low Na+
low BP
135
Aldosterone increases the synthesis of
Transport proteins for absorption of Na+ and secretion of K+
136
In the absence of aldosterone
Na+ reabsorption and K+ secretion is minimal in DCT and collecting ducts
137
ADH characteristics include
- Facultative water reabsorption
| - Creates water channels in the membrane to move water from DCT into blood
138
In the absence of ADH
water reabsorption is low in DCT and collecting ducts
139
Normal levels of ADH is enough to reabsorb ______ liters of the 27 L/day entering the DCT
25-26
140
ADH regulation is controlled primarily by
Osmoreceptors in hypothalamus
141
High levels of ADH are released in response to
high blood osmolarity
Low water content
Low BP
Low BV
142
Less ADH is released in response to
High water content in blood
Low osmolarity
High BP
High BV
143
Release of ADH can also effect the baroreceptors in the heart that respond to
blood pressure
144
If you are taking an ACE inhibitor or drink alcohol
you will supress ADH and excrete a low concentrated urine
145
What are the problems that result from micturition reflex
Incontinence
| Urinary retention
146
Urinary retention occurs as a result of
prostate gland hypertrophy (enlargement)
147
Incontinence is common after
childbirth
148
Kidney stones can be made of
Calcium, magnesium, or uric acid crystals
149
As we age, we lose functional nephrons and have a reduced sensitivity to
ADH
150
Reduced sensitivity of ADH leads to
incontinence because you aren't absorbing any water
151
One method of treating large kidney stones is
Shock wave lithotripsy
