Structural and Functional Organization of the Urinary System Flashcards
1
Q
What are the components of the urinary system
A
two kidneys, two ureters, one urinary bladder, and one urethra
2
Q
What is the study of anatomy, physiology, and disorders of the kidneys?
A
Nephrology
3
Q
What is the branch of medicine that deals with the male and female urinary system?
A
urology
4
Q
What are the 5 functions of the kidneys?
A
Regulation of ion levels
regulation of blood volume and pressure
regulation of blood pH
Production of hormones
Excretion of wastes
5
Q
How do the kidneys regulate blood pressure
A
secrete renin, which activates the renin-angiotensin-aldosterone pathways, by adjusting blood flow into and out of the kidneys, and by adjusting blood volume.
6
Q
how do kidneys regulate blood pH?
A
by excreting variable amounts of H+ in the urine, and conserve HCO3.
7
Q
What are the two hormones produced by the kidneys?
A
Calcitirol and Erythopoietin.
8
Q
what is calcitriol?
A
active form of Vitamin D, helps regulate calcium homeostasis.
9
Q
What does erythropoietin do?
A
stimulates production of red blood cells
10
Q
what do the kidneys excrete as waste?
A
ammonia and urea
bilirubin
creatinine
uric acid
foreign substances
11
Q
Where do the kidneys lie?
A
L3-T12, between peritoneum and back wall of the abdominal cavity, on either side of the vertebral column
12
Q
Which kidney is lower?
A
right kidney
13
Q
what is the indentation on the medial border of the kidney?
A
renal hilum
14
Q
what goes in and out of the renal hilum?
A
the ureter leaves from here and blood vessels, lymphatic vessels, and nerves enter and exit.
15
Q
what is the connective tissue sheath that helps maintain the shame of the kidney and serves as a barrier against trauma?
A
the renal capsule
16
Q
what surrounds the renal capsule and cushions the kidney, anchoring it to the posterior abdominal wall?
A
adipose tissue
17
Q
what are the two main interior regions of the kidneys?
A
renal cortex
renal medulla
18
Q
what fills the spaces between the cone shaped renal pyramids inside the medulla?
A
renal columns, which are extensions of the renal cortex.
19
Q
urine formed in the kidneys passes through what?
A
papillary ducts w in the renal pyraminds into cuplike structures called minor calyces.
20
Q
how many minor calyces does each kidney have?
A
8-12
21
Q
how many major calyces do kidneys have?
A
2-3
22
Q
what is the renal pelvis?
A
collects urine from the major calyces, drains into a ureter which transports urine into the bladder.
23
Q
How much blood at any given time is in the kidneys?
A
20-25% of the cardiac output, 1200 milliliters of blood per minute.
24
Q
The arteries that flow INTO the kidney eventually reduce to what smaller vessel?
A
afferent arterioles, into the tangled capillary network called the glomerulus
25
the capillaries of the glomerulus reunite to form what?
efferent arteriole
26
after leaving the glomerulus, the efferent arterioles form a network around what?
the kidney tubules. these peritubular capillaries form peritubular veins.
27
What is the name for the functional units of the kidneys?
the nephrons
28
all the smaller veins (e.g. peritubular> interlobular>arcuate> and interlobar veins) ultimately drain into what?
the renal vein.
29
two parts of the neprhon:
renal corpuscle
renal tubule
30
what is filtered fluid called that passes into the renal tubule?
glomerular filtrate
31
two parts that make up the renal corpuscle?
glomerulus and the glomerular (Bowmans) capsule
32
three main sections of the renal tubule.
in the order that fluid passes through it:
proximal convoluted tubule
loop of Henle
distal convoluted tubule
33
which part of the renal tubule extends into the renal medulla
the loop of henle
34
what are the basic processes performed by the nephrons and collecting ducts?
glomerular filtration, tubular reabsorption, and tubular secretion.
35
what is the first step in urine production?
glomerular filtration.
36
where does filtration occur crossing the wall of glomerular capillaries?
glomeruli
37
at what point does the filtered fluid that has undergone tubular reabsorption and tubular secretion get called urine?
when it enters the minor and major calyx.
38
what is the space between the renal corpuscle and the glomerular capsule called?
capsular space
39
what forms the filtration membrane?
the podocytes (inner wall of the glomerular capsule) and the glomerular endothelium.
40
what forms the outer layer of the glomerular capsule?
simple squamous epithelial cells
41
what creates the pressure that causes filtration in the kidneys?
the blood pressure in the glomerular capillaries.
42
what are the two pressures that oppose glomerular filtration?
blood colloid osmotic pressure
and glomerular capsule pressure (due to the fluid in the capsular space and renal tubule)
43
normal blood pressure is greater than the two opposing pressures of the glomerular capillaries, producing a net filtration of how much mmHg?
10mmHg
44
how many liters daily does net filtration pressure force into the capsular space for males and females?
150 L daily for females, 180 L daily for males
45
formula for net filtration pressure
NFP= glomerular capillary BP - (blood colloidal osmotic pressure + glomerular capsule pressure)
46
what helps raise the blood pressure in the glomerular capillaries?
the fact that the efferent arteriole is smaller in diameter than the afferent arteriole
47
what process helps keep net filtration pressure steady to maintain normal glomerular filtration?
changes in the diameters of the afferent and efferent arterioles (constricted afferent = decrease, constriction of efferent = increase)
48
what is the amount of filtrate that forms in the both kidneys every minute called?
glomerular filtration rate (GFR)
49
GFR rate in adults
105 ml/min in females, 125 ml/min in males
50
what happens if the GFR is too high?
needed substances pass so quickly through the renal tubules that they are unable to be reabsorbed and pass out of the body as urine.
51
what happens if GFR is too low?
waste products are not adequately secreted
52
what hormone increases GFR?
Atrial Natriuretic Peptide (ANP). it promotes loss of sodium ions and water in urine
53
what secretes ANP?
cells in the atria of the heart if it is stretched more, as occurs when blood volume increases.
54
what happens with greater sympathetic stimulation of the kidneys?
the afferent arterioles are constricted reducing GFR, Net Filtration, and urine output, conserving blood volume and permits greater blood flow to other body tissues (as in hemorrhaging or excercise)
55
at what point does filtered fluid become tubular fluid?
once it enters the proximal convoluted tubule.
56
what percentage of glomerular filtrate actually leaves the body in urine?
1%. the fluid that actually drain into the renal pelvis.
57
what type of cells along the renal tubules and colleting ducts carry out tubular reabsorption?
epithelial cells
58
proximal convoluted tubule cells make the largest contribution to reabsorbing, by reabsorbing what?
65% of filtered water, 100% of filtered glucose and amino acids, and large quantities of ions ( sodium, potassium, chloride, bicarbonate, calcium, and magnesium)
59
how does reabsorption of solutes into the peritubular capillaries promote reabsorption of water?
water moves by osmosis into the peritubular capillaries following the concentration gradient of solutes in the peritubular capillaries.
60
where are the cells that "fine tune" reabsorption for homeostatic balances of water and ions?
cells located distal to the proximal convoluted tubule.
61
what are the two ways that tubular secretion happens?
passive diffusion and active transport processes.
62
what are the secreted substances?
Hydrogen Ions (H+) potassium (K+) ammonia (NH3) urea, creatinine and certain drugs such as penicillin.
63
what is a waste product that is produced when amino groups are removed from amino acids?
Ammonia
64
what cells convert ammonia to urea?
liver cells.
65
to eliminate acids, the cells of the renal tubules secrete what ion into the tubular fluid?
H+|
66
what are the most important hormonal regulators of ion reabsorption and secretion?
Angiotensin II and aldosterone
67
what does angiotensin II enhance reabsorption of in the proximal convoluted tubule?
Sodium and Chlorine
68
What hormone simulates the tubules cells of the distal convoluted tubules and collecting ducts to reabsorb more Na+ and Cl- and secrete more K+?
aldosterone
69
what stimulates the adrenal cortex to release aldosterone?
angiotensin II
70
what hormone increases glomerular filtration rate but also plays a minor role in inhibiting the reabsorption of Na+?
Atrial natriuretic peptide
71
what is the major hormone that regulates water reabsorption?
antidiuretic hormone (ADH)
72
when the concentration of water in the blood decreases by as little as 1%, osmoreceptors located where stimulate the release of ADH from the posterior pituitary?
hypothalamus
73
lower than normal levels of Ca in the blood stimulates the parathyroid glands to release what hormone?
Parathyroid hormone (PTH)
74
in addition to stimulating cells in the distal convoluted tubules to reabsorb more Ca in the blood, what else does PTH do?
inhibits HPO4 (phosphate) reabsorption, promoting phosphate excretion.
75
what is the normal volume of urine eliminated per day in a normal adult?
1-2 Liters. water is 95% of it.
76
in addition to urea, creatinine, potassium, and ammonia, what are the other typical solutes normally prese in urine?
uric acid, sodium, chloride, magnesium, sulfate, phosphate, and calcium ions.
77
what are the structures that transport and eliminate urine?
Ureters, Urinary Bladder, and Urethra
78
what prevents backflow of urine when pressure build up in the bladder during urination?
the ureters passing under the urinary bladder for several centimeters.
79
what condition could happen if the "backflow valve" of the ureters passing under the bladder is not operating?
cystitis (urinary bladder inflammation)
80
what are the three layers of the ureters?
mucosa
smooth muscle
areolar connective tissue (containing blood vessels, lymph vessels, and nerves)
81
what holds the urinary bladder in position?
folds of peritoneum.
82
what is the average urinary bladder capacity?
700-800 mL
83
what are the three layers of smooth muscle in the muscular layer of the urinary bladder called?
detrusor muscle
84
the peritoneum of the bladder covers which surface of the bladder?
the peritoneum.
85
what allows for a marked advantage of for any organ that must accommodate a variable volume of fluid?
transitional epithelium. (containted in the inner layer of the ureters and bladder)
86
which urethral sphincter is voluntary and which is involuntary?
the internal urethral sphincter is involuntary.
87
when the volume of urine in the urinary bladder exceeds how many ml, do the stretch receptors in ins wall transmit nerve impulses into the spinal cord?
200-400 mL
88
what is the micturition reflex?
parasympathetic impulses from spinal cord contract detrusor muscles and relax internal urethral sphincter.
simultaneously, the spinal cord inhibits somatic motor neurons, relaxing external urethral sphincter
89
what will usually occur prior to the micturition reflex happening?
you will have a sensation of fullness that initiates a desire to urinate.
90
fluid makes up what percentages of total body mass in lean adults?
between 55% and 60%
91
what do you call intracellular fluid and what fraction of your body fluid is kept there?
cytosol. 2/3rds.
92
what percentage of ECF is interstitial fluid?
80%
93
what percentage of ECF is blood plasma?
20%
94
what are other ECF that are grouped with interstitial fluid?
lymph
CSF
Synovial
aqueous humor and vitreous body in the eye
endo- and perilymph
pleural, pericardial, and peritoneal fluids
95
what separates each cells intracellular fluid from the surrounding ICF?
plasma membrane
96
what separates the ICF from blood plasma?
blood vessel walls
97
what percentage of total body mass does water make up?
45-75%
98
what is closely interrelated with fluid balance in the body?
electrolytes
99
the main source of body water are ingested liquids, about _____ mL, and moist foods, about ________ mL from the GI tract. which totals to about ______ mL/day.
1600, 700, 2300
100
how much water in the body is the result during chemical reactions, or "metabolic water"
200
101
total daily water gains is about how many mL?
2500
102
what governs the urge to drink?
the hypothalamus at the thirst center
103
what percentage of fluid loss triggers mild dehydration?
2%
104
what two things stimulate the thirst center?
osmoreceptors in the hypothalamus and angiotensin II in the blood.
105
what is the main factor that determines body fluid volume?
urinary salt, NaCL
106
what are the three hormones that regulate the extent of renal Na+ and Cl- reabsorption?
Atrial natriuretic peptide (ANP), angiotensin II , and aldosterone.
107
what is the major hormone that regulates water loss?
antidiuretic hormone (ADH)
108
what stimulates the release of ADH?
increase in osmotic pressure of body fluids ( a decrease in the water concentration of the fluids)
109
what does ADH do?
promotes insertion of water channels into the plasma membrane of cells in the collecting ducts of the kidneys.
110
in contrast to ADH, what does the intake of plain water do to osmotic pressure?
plain water decreases the osmotic pressure of blood and interstitial fluid.
within minutes, ADH secretion shuts down, water channels are removed from cell membranes and as a result more water is lost in urine.
111
osmotic pressure increase in interstitial fluid will make your cells do what?
shrink
112
a decrease in osmotic pressure in interstitial fluid will make your cells do what?
swell.
113
what are the most abundant extracellular fluid?
Sodium ions. (Na+})
114
what are the most prevalent anions in extracellular fluid?
Chloride ions
115
what are the most abundant intracellular cations?
potassium (K+)
116
how does K+ help regulate the pH of body fluids?
when K+ moves in or out of cells, it is often exchanged for H+.
117
what controls the renal collecting ducts to secrete more K+ and therefore controls its levels in the blood plasma?
aldosterone
118
where is 98% of the calcium in adults?
skeleton and teeth
119
in body fluids, calcium is mainly what?
an extracellular cation.
120
what are the two main regulators of Ca2 in the blood plasma?
PTH and calcitriol.
121
how does PTH regulate Ca2?
PTH stimulates osteoclasts in bone tissue to release Ca2 (and phosphates) from bone matrix. PTH enhances reabsorption of Ca2 from glomerular filtrate back into blood and increases calcitriol.
122
how does calcitriol (the form of vitamin D that acts as a hormone) help regulate Ca2?
increases Ca2 absorption from the GI tract.
123
when electrolytes break apart they form ions. what are the four general functions of those ions from that process?
control osmosis of water
maintain the acid base balance
carry electrical current
serve as cofactor needed for optimal activity of enzymes.
124
why is the maintenance of an acid-base balance in the body of critical importance?
the three dimensional shape of all body proteins, which enables them to perform specific functions, are very sensitive to minor changes in pH.
125
pH of a healthy systemic arterial blood?
7.35 and 7.45
126
what are the three mechanisms that the removal of H+ is dependent on?
buffer systems, exhalation of carbon dioxide, and kidney excretion of H+ in urine.
127
what are the principal buffer systems of the body.
protein buffer system
Carbonic Acid-Bicarbonate Buffer system
phosphate buffer system
128
which buffer system has a carboxyl group that releases H+, and an amino group that combines with H+, able to buffer both acids and bases?
protein buffer system
129
which buffer system can act as a weak acid or a weak base?
Carbonic Acid-Bicarbonate Buffer System
130
Which buffer system is high in intracellular fluid and is an important regulator of pH in the cystosol?
Phosphate Buffer system
131
when blood acidity increases (increase in H+, decrease in pH #) is detected by chemoreceptors located where? in turn stimulates the inspiratory area where?
chemoreceptors in the medulla oblongata and in the aortic and carotid bodies. which stimulates inspiratory area in the medulla oblongota.
132
what is the only way to eliminate most acids that form in the body? (hint: it's also the slowest mechanism for it)
kidney excretion of H+
133
what is the defined acidity of blood in acidosis?
7.35
134
what is the effect of acidosis on the body?
depression of the CNS through depression of synaptic depression. If pH falls below 7, individuals become disoriented, comatose, and may die.
135
alkalosis is defined as blood over which pH value?
7.45
136
effects of alkalosis on the body:
nervousness, muscle spasms, convulsions, over excitability of the CNS, and death.
137
what is the term for when hypoventilation or hyperventilation can help bring blood pH back to normal range?
respiratory compensation.
138
what will kick in if someone has altered blood pH due to respiratory causes?
renal compensation.
139
what is the effectiveness and speed at which respiratory compensation works?
occurs within minutes and reaches it maximum within hours.
140
what is the speed at which renal compensation takes to become effective?
may begin in minutes, but it takes days to reach maximum effectiveness
141
which population is more susceptible to several fluid and electrolyte disorders?
older population
