(F) Lec 4: The Urinary System Flashcards
Familiarize the renal functions
- Regulation of balance between water and electrolytes and the acid-base balance
- Excretion of metabolic wastes along with excess water and electrolytes in urine
- Excretion of bioactive substances, drugs
- Regulation of arterial blood pressure by secretion of renin
- Secretion of erythropoietin
Enumerate the parts of the system
- Kidneys
- Ureters
- Urinary bladder
- Urethra
Location (gross anatom) of the kidney
- Posterior abdomen under cover of the ribs
- Retroperitoneal
Two main parts of kidney
Hilum and capsule
Concave part of kidney where the ff can be found:
- Blood vessels
- Lymph vessels
- Renal pelvis
Hilum
Convex, thin, and fibrous part of the kidney
Capsule
Parts of renal parenchyma
Cortex and Medulla
Renal parenchyma;
- Outer, darker
- Renal corpuscles
- Tubules
Cortex
Renal parenchyma;
- Straight structures
- Renal pyramids
- Renal columns
- Medullary rays
- Renal papilla
Medulla
Part of renal circulation which is closely associated with nephron components
Vasculature
Names according to location and shapes
BVs
Functional unit of kidney
Nephron
Two main parts of nephron
Renal corpuscle
Renal tubule
Part of nephron;
- Bowman’s capsule
- Glomerulus
Renal corpuscle
Part of nephron;
- Proximal Convoluted Tubule (PCT)
- Loop of Henle
- Distal Convoluted Tubule (DCT)
- Connecting tubules and Collecting ducts
Renal tubule
Types of nephron
Cortical and juxtamedullary
Type of nephron;
- Located almost completely in the cortex
Cortical
Type of nephron;
- Lie close to the medulla
- 1/7 of total
- Have long loops of Henle
Juxtamedullary
Refers to mass of capillary loops found in the renal corpuscle
Glomerulus
Layers of Bowman’s capsule
Visceral and Parietal
Part of renal corpuscle that receives filtered fluid
Capsular/Urinary space
Two poles in the renal corpuscle
Vascular and Tubular pole
Layer of Bowman’s capsule;
Simple squamous
At the tubular pole, the epithelium changes back to simple cuboidal
Characteristic feature of the PCT
Parietal layer
Cells found in the visceral layer of the Bowman’s capsule
Podocytes and pedicels
Cells in visceral layer;
- Stellate epithelial cells
- Cell body give rise to 1o processes
- 2o foot processes
Podocytes
Cells in visceral layer;
- Interdigitate forming elongated spaces
- Filtration slit pores
Pedicels
The slit pores of the pedicels are bridged by what?
semipermeable diaphragm called slit diaphragm
Poles;
- Afferent arteriole enters and efferent arteriole leaves
- Afferent arteriole divides into 2-5 capillaries of the glomerulus
Vascular
Poles;
PCT begins
Tubular/Urinary pole
Enumerate the filtration barrier
Fenestrated capillary endothelium
Glomerular basement
Filtration slit diaphragms
Filtration barrier;
- Block blood cell and platelets
Fenestrated capillary endothelium
Filtration barrier;
- Basal laminae of capillary
+ podocyte - Restricts large proteins &
organic anions
Glomerular basement membrane
Filtration barrier;
- Restricts small proteins and some anions
Filtration slit diaphragms
Refers to:
- Physical support of
capillaries within
glomerulus - Between capillaries that
lack podocytes
Mesangial cells
Refers to:
- Longer than DCT
- Mainly cortical
- Lumen a fuzz-filled
appearance - Specialized for both
reabsorption and
secretion
PCT
Simple cuboidal cells with:
- Long microvilli (brush
borders) - Abundant mitochondria
- Very acidophilic cytoplasm
& central nuclei
PCT
Refers to:
- PCT extends down to the
medulla as thick
descending limb and
continues as tthis - U-shaped with thin descending & ascending limbs
Loop of Henle
LE of loop of Henle
Simple squamous
Loop of Henle becomes what?
Thick ascending limb
Refers to the structure that is simple cuboidal extending back into the cortex
Thick ascending limb
Refers to:
- Short microvilli
- More empty lumens
- Rate of Na+ absorption
is regulated by
aldosterone (from
adrenal glands)
DCT
LE of DCT
Simple cuboidall
Juxtaglomerular apparatus;
Specialized sensory
structure
* Regulates glomerular
blood flow and keeps
GFR constant
* DCT contacts arteriole
* Become more columnar
and closely packed
Macula densa
Juxtaglomerular apparatus;
- Tunica media of afferent
arteriole - Smooth muscles
become modified to
granular cells - Secretes Renin
JG granular cells
Role of this secretion is the regulation of blood pressure and electrolyte balance
Renin
Juxtaglomerular apparatus;
- Extraglomerular
mesangial cells - Supportive,
contractile, and
defensive functions
Lacis cells
LE of collecting tubules
Simple cuboidal to columnar epithelium (it merges with columnar cells of collecting duct)
LE of collecting ducts
Simple columnar
Hormone that makes CD more
permeable to water during dehydration
ADH
Refers to:
- Single layer of small
basal cells resting on a
very thin basement
membrane - Intermediate region:
one to several layers of
columnar cells
Transitional Epi
Transitional Epithelium has which kind of cells in the superficial layer?
Umbrella or Dome cells
Layer of TE when distended
2-3
Layer of TE when empty
4-5
Refers to:
- A form of stratified epithelium
- Found only in the urinary tract of mammals
- Highly specialized to
- Accommodate a great degree of stretch
- Withstand the toxicity of urine
TE
CT is found in which layer of the ureter?
Adventitia
Layer of ureter
2 layers of
Smooth muscle; distal becomes 3
layers
Muscularis
Layer of ureter
transitional
epithelium
* Lumen very narrow,
easily obstructed
Mucosa
T or F: Ureter has submucosa
False
LE of mucosa of urinary bladder
TE
Specific subtype of tissue of LP of urinary bladder
DICT
Layer of urinary bladder
- LE; transitional
- Lamina propria: DICT
Mucosa
Layer of urinary bladder
- DICT
- Highly vascularized
Submucosa
Layer of urinary bladder
Detrusor
Muscularis
Arrangement of detrusor
- Inner longitudinal
- Middle circular
- Outer longitudinal
Organ in the system where detrusor is found
Urinary bladder
Length of female urethra
4 - 5 cm
Length of male urethra
20 cm
Refers to:
- Purely a urinary organ
- Initially with transitional epithelium
- Then by SSE and some areas of PSCE
- Middle part is surrounded by the external
striated muscle sphincter
Female urethra
LE of female urethra
Then by SSE and some areas of PSCE
Urethra in males is passageway for what
Semen and urine
Parts of male urethra
- Prostatic
- Membranous
- Spongy
Part of male urethra;
- 3 to 4 cm long
- Transitional
epithelium - Urothelium
Prostatic
Part of male urethra;
- Short segment that
passes through an
external sphincter of
striated muscle - Stratified columnar and
pseudostratified
epithelium
Membranous
Part of male urethra;
- 15 cm long
- Enclosed within erectile
tissue of the penis - Stratified columnar and
pseudostratified
columnar - Distally: stratified
squamous epithelium
Spongy
Mucosa of male spongy urethra
Lacuna of Morgagni
Refers to irregular outpocketings found in spongy urethra of male
Lacuna of Morgagni
LE of spongy urethra
stratified or
pseudostratified
columnar
* Distal: SSNKE
Refers to:
- External opening
- Lined by stratified
squamous epithelium - Becomes continuous with
the epithelium of the
glans
Urethral meatus
Urethra is lubricated by mucous secretions from?
- Para-urethral glands
- Bulbo-urethral glands of
Cowpe
LE of membranous urethra of males
Stratified columnar and
pseudostratified
epithelium
LE of prostatic urethra of males
Uroepi
Corpus cavernosum and spongiosum are found in which part of male urethra
Spongy