Lecture Outline #25: Urinary System

Question 1

urinary system functions (3)

Answer 1

homeostatic functions
complicated filter mechanism
filtrate urine from kidneys to ureters

Question 2

urinary function: homeostasis

Answer 2

maintain correct balance of Na, K, Cl, and Ca ions (create the pH level)
assist in pH balance (urine should be acidic)
regulates blood pressure by adjusting blood volume which needs a certain osmotic pressure.

Question 3

urinary function: filter mechanism

Answer 3

retain valuable nutrients
excrete nitrogenous wastes

Question 4

urinary function: filtrate urine

Answer 4

ureters transfer urine into urinary bladder

Question 5

kidney location

Answer 5

paired organs on posterior wall of abdominal cavity
outside of peritoneal cavity: retroperitoneal
surrounded by pararenal adipose and renal capsule

Question 6

kidney structure: renal cortex

Answer 6

outer-most layer
primary function: filtration

Question 7

kidney structure: renal medulla

Answer 7

inner-most layer
primary function: contain BVs and drainage
contains: renal columns (blood supply to nephron) and renal pyramids (drainage)

Question 8

kidney structure: renal pelvis - cavity

Answer 8

tapers to form the ureter
contains minor calyces (right after renal papilla), major calyces (where minor calyces meet), and the actual renal pelvis (where major calyces meet)

Question 9

kidney structure: renal hilus

Answer 9

entrance for renal a.s and ANS n.s and exit for renal v., lymphatic vessels, and ureters.
contain the renal sinus located outside the kiney and surrounds renal pelvis and calyces, is a fat-filled depression

Question 10

kidney structure: lobes

Answer 10

renal pyramid + renal papilla + minor calyx = lobe
pyramid pokes into minor calyx via papilla
lobes are separated by renal columns which are composed of cortical tissue and act as a path for renal BVs from hilus to cortex

Question 11

renal BVs: arteries

Answer 11

renal a.s off abdominal aorta @ hilus outside major/minor calyces
- segmental a.s (where renal a.s separate, come up to renal columns
- interlobar a.s (go through renal columns)
- arcurate a.s (bend towards the merge of cortex & medulla)
- cortical a.s (extend through cortex)
- afferent arterioles
- glomerulus (capillary bed)

Question 12

glomerular/bowman’s capsule

Answer 12

surrounds glomerulus where blood filtrate (completely plasma) is and is pushed to proximal convoluted tubule

Question 13

glomerulus drained by

Answer 13

efferent arterioles - where blood plasma is leaked to maintain osmotic pressure, controlled by ANS
- this plasma is sent to nephron
blood plasma/filtrate passes to peritubular capillaries - recover 99% of blood/plasma/H2O

Question 14

kidneys drained by

Answer 14

peritubular capillaries
venules
interlobular v.s
arcurate v.s
interlobar v.s
renal v.s

Question 15

nephron

Answer 15

function unit kidney
1 million per kidney
complex plumbing
majority located in cortex = cortical nephrons
some in both cortex and medulla = juxtamedullary nephrons

Question 16

nephron - renal corpuscle (malphighain)

Answer 16

consists:
1. glomerular capsule
2. afferent arteriole
3. efferent arteriole
4. glomerular capillary bed

Question 17

glomerulus

Answer 17

covered by podocytes - regulate interdigitated pedicles to open/close
interdigital pedicles - course filter, secondary BP control (when hydrated, plasma leaks more but still don’t allow RBCs and big proteins past - if they do = problems)

Question 18

nephron - proximal convoluted tubule

Answer 18

collects filtrate from glomerular capsule
reclamation of water, all organic nutrients
1 tube per nephron

Question 19

nephron - loop of henle

Answer 19

descending limb - travels down to medullar
ascending limb - travels back to cortex
1 per nephron
reclamation of sodium, chloride, and water

Question 20

nephron - distal convoluted tubule

Answer 20

secretion of durgs, toxins
1 per nephron

Question 21

nephron - collecting duct

Answer 21

multiple nephrons dump into this
gathers the filtrate from many distal convoluted tubules
further reclamation of water
they combine/terminate to form renal papilla, where the filtrate is now urine

Question 22

kidney (through nephron) filtrate flow

Answer 22

renal corpuscle
proximal convoluted tubule
descending limb
ascending limb
distal convoluted tubule
collecting duct
renal papilla
minor calyx
major calyx
renal pelvis
ureter
urinary bladder
urethra
urethral orifice

Question 23

ureters

Answer 23

transfer via peristalsis urine from renal pelvis to urinary bladder
urine only retains cells from here
retroperitoneal location
made up of
- mucosa (epithelium) on inside
- muscularis (2 layers, active peristalsis) in middle
- adventitia (CT, serosa) on outside

Question 24

urinary bladder

Answer 24

hollow organ to store urine
walls made of 2 layers of m. - detrusor m. (involuntary smooth m., when contracts = urinate)
rugae on inner surface, increased SA when expands/flattens which stretches baroreceptors = urge to urinate)
retroperitoneal location - posterior to pubic symphysis
male - anterior to rectum
female - anterior to uterus

Question 25

urinary bladder - urethra, ureters, trigone

Answer 25

ureters enter posterolateral corners of bladder and open at the ureteral openings on trigone of bladder floor
trigone is the region of bladder floor that also has 1 urethral opening
urethra drains via internal urethral sphincter (internal smooth m.)

Question 26

urethra

Answer 26

transfers urine from bladder to outside body
passes through pelvis diaphragm via external urethral sphincter (voluntary skeletal m.)

Question 27

urethra - male division

Answer 27

1. prostatic urethra - passes through prostate gland
2. membranous urethra - goes through pelvis flood via external urethral sphincter
3. penile urethra

Question 28

UTIs

Answer 28

urinary tract infections, occur because bacteria more readily colonize bladder, ureters, and kidneys

Question 29

urogenital system

Answer 29

urinary + reproductive systems
- have a shared development and predictable malformation

Question 30

kidney malformations

Answer 30

fine as long as they work
ex - horseshoe kidneys, 4 of them

Question 31

urine comp

Answer 31

93-97% water
sterile
pH: 4.5-8

Question 32

urinalysis

Answer 32

physical and chemical assessment of urine
pregnancy detection

Question 33

pyelogram

Answer 33

x-ray image of kidneys and urine after injection of a radiopaque dye

Question 34

nephrolithiasis

Answer 34

renal calculi - kidney stones (not smooth or circular)
made of Ca/Mg salts and uric acid crystals that cause blockage of ureters

Question 35

diuretics

Answer 35

drugs that promote fluid loss in the urine (mainly to get alcohol out)

Question 36

hematuria

Answer 36

blood loss in urine
(blood in urine = problem)

Question 37

proteinuria

Answer 37

protein loss in urine

Question 38

dysuria

Answer 38

painful urination often associated with STDs