2. Histology of the Kidney and Urinary Tract Flashcards
The Kidney • Main function: • Filtration of blood supplied by the renal arteries. • Layers: • \_\_\_\_. • \_\_\_\_. • \_\_\_\_.
capsule
cortex
medulla
The Uriniferous Tubule: ____ + Collecting Duct
- Functional unit of the kidney: filtration, excretion, reabsorption.
- 1.3 million/kidney.
- Segments:
- Nephron:
- Renal corpuscle:
- ____
- Glomerulus
- Renal tubule:
- ____
- Loop of Henle
- ____
- Collecting tubule/duct:
- ____ segment.
- ____ medullary segment
- ____ medullary segment
• Composed of two parts ○ Nephron ○ Collecting tubule § Derive from diff \_\_\_\_ tissues § Differen,t but complementary functions
nephron
capsule of bowman
proximal convoluted tubule
distal convoluted
cortical
outer
inner
embryological
Cortical vs. Juxtamedullary Nephrons
• In kidney there are two tpyes of nephrons based on \_\_\_\_ inside the kidney ○ Cortical § Have \_\_\_\_ functional unit of nephron (from renal corpuscle to loop of henle until connects CT) > restricted to the \_\_\_\_ of the organ ○ JM § Part of nephron (glomerulus and P and DCT > located in cortext; but the loop of henle is in the \_\_\_\_) □ No glomeruli in the \_\_\_\_ ® Only \_\_\_\_, and sections of \_\_\_\_
location
full
cortex
medulla
medulla
The Kidney: Cortex and Medulla
• Cortex:
• Contains ____ and
____.
• Medulla:
• No ____.
• Mostly ____ and
ducts of the ____.
• Distinct morphologies
renal corpuscles nephron ducts renal corpuscles collecting tubules nephronq
The Renal Corpuscle
- Filtration unit.
- ____
- ____• Made of two substructures
○ Capsule of bowman
§ ____ takes place
○ Glomerulus
• Combine vessels, with the space where the filtrate will be in close apposition to the ____ enviroment (urinary space)
• Each corpuscle is composed of capsule of bowman that surrounds a space, that’ penetrated by ____ that divide into anastomsoing cap’s
○ Within - formation of ultrafiltrate into the urinary space > formation of ____ urine > blood leaves capillaires through the efferent arterioles
• In close proximity > will find parts of ____ itself
capsule of bowman glomerulus filtration external arterioles primary nephron
The Renal Corpuscle: Capsule of Bowman
- Parietal layer:
- Attached to the surrounding ____.
- ____ epithelium.
- ____ membrane.
- Visceral layer:
- Attached to the ____.
- Podocytes: ____ cells.
- ____ membrane.
- Urinary space (or Bowman’s space):
- Between ____ layers.
- Receives the ____ ultrafiltrate.
- Continuous with the lumen of the ____ at the urinary pole.• Parietal layer
○ Formed by squamous that surround the entire corpuscle
§ Secretes a basal lamina/BM
• Visceral layer
○ More interior layer
○ Formed by podocytes
§ The cell body ALWAYS looks into the ____ bt visceral and parietal layers
□ The urinary space - the space that gets the ultrafiltrate from the capillaries, and then exported through the urinary pole > part of RC that is connected to PCT
○ On the other side: instead of urinary pole > ____ > where the two arterioles enter/exit the RC
conn tissue
simple squamous
basement
glomerular capillaries
epithelial
basement
visceral and parietal
plasma
PCT
empty space
vascular pole
The Renal Corpuscle: Glomerulus
• Components:
Glomerular capillaries:
____ endothelium (____ epithelium with ____ basal lamina).
____ basal lamina: endothelial cells + ____ (in the visceral layer of the capsule).
• Mesangium:
• Mesangial ____.
• Mesangial ____.
• Capillaries ○ Fenestrated endothelium § In combo with podocytes in visceral layer > deposit dual BL > establish the filtration barrier bt capillaries and urinary space • Mesangium
fenestrated discontinuous continuous dual podocytes cells matrix
The Renal Corpuscle
• Parietal layer ○ \_\_\_\_ epi, that separates the RC from the rest of the kidney (containing CT, ducts, tubules) • Visceral layer ○ Formed by \_\_\_\_ - more difficult to follow • Between two layers - \_\_\_\_ ○ Cannot see the urinary pole here ○ But can see the vascular pole • Glomerular capillaries can be seen because full of \_\_\_\_
simple squamous
podocytes
urinary space
RBC
The Renal Corpuscle
• Visceral layer of RC • The cells seen are all podocytes ○ The body of the cells protude into the \_\_\_\_, and cover the glomeurlus ○ The capillaries are inside ○ They extend the \_\_\_\_ that branch again until they form pedicels
urinary space
cytoplasmic bodies
The Renal Corpuscle: Podocytes
• Pedicels ○ Formation of filtration barrier takes place • Section of capillary inside glomerulus ○ Epi: \_\_\_\_ epithelium § In tissues with excahgne of substances • The podocyte wraps around the capillary, and extends cytoplasmic processes (primary) that split into secondary/tertiary processes > at the end > \_\_\_\_ (not pedicles!) • Cell body of podocytes - contains \_\_\_\_ and most of \_\_\_\_ ○ Extends cytoplasmic processes (primary, then secondary, and then \_\_\_\_ > filtration slits) • Middle panel: ○ One side have the podocyte extending the pedicels ○ Other side have the endothelial cells
fenestrated pedicels nucleus organelles tertiary
The Renal Corpuscle: The Filtration Barrier
- Fenestrated endothelium of glomerular capillaries:
• Permeable to ____, small molecules.
• Low permeability of large ____. - Basal laminae:
• ____ basal lamina produced by endothelial cells and podocytes.
• ECM (e.g. ____) and adhesive (e.g. ____) proteins.
• ____ down filtration of anionic proteins. - Podocytes*:
• Interdigitating processes (pedicels) attach to the ____.
• Filtration slit: ____ between pedicels.
• Diaphragm: formed by the protein ____ joining the pedicels.• Contact bt podocytes and capillaries
• At capillary level
○ Fenestrated epi that allows filtration of water easily, but because of the elctrical cahrge of PM of endothelial > prevents the exit/filatration of large molecules that are charged negatively > prevent leaking through barrier
• Then a dual BL
○ Complex BL produced by products secreted/assembled by podocytes, and endothelial cells on the other
○ BL is a specialized type of ECM that is rich in laminin and fibronectin (adhesive protein)
• Podocyte side
○ Ultimate cyto processes: pedicels > interdigitating
§ Attached BL through ____ receptor in the podocyte binding to BL components (laminin)
○ Between two pedicels > empty space/slit > filtration takes place here
§ Nephrin - high MW protine that binds to pedicels
□ This configurarion of pedicel and barrier protein > makes this epithelium ofrmed by the podocytes as a ____ epithelium with diaphragm
□ ____ - select what goes through capillary into urinary sapce; preventig uncontroleld leak of substances into the bloodstream
water anionic proteins dual laminin fibronectin slows
basal lamina
space
nephrin
integrin
fenestrated
biological sieve
The Renal Corpuscle: The Filtration Barrier
• Below we have a capillary, lined by fenestrated endothelium ○ \_\_\_\_ goes form BS into the urinary space • Up top - podocyte • In between - the pedicels that form the filtration slits ○ In the arrow - can see the diaphragn formed by \_\_\_\_ binding to two different pedicels
ultrafiltrate
nephrin
The Renal Corpuscle: The Mesangium
• Made of mesangial cells that secrete/assemble an ECM that maintains the \_\_\_\_ of the glomerular capillaries ○ The ECM prevents \_\_\_\_ of capillary network § At this level they're very \_\_\_\_ § In addition to binding dual BL, have to be reinfocrced by these \_\_\_\_ cells
physical structure
collapse
fragile
mesangial
The Renal Corpuscle: The Mesangium
• ____ structure between the glomerular capillaries.
• Components:
• ____ cells:
• Specialized ____.
• Characteristics of smooth muscle:
• ____: Regulation of blood flow.
• Synthesis of mesangial ECM: ____ support for the glomerular capillaries.
• Synthesis of active substances: ____ and ____ (regulate local capillary
constriction).
- Characteristics of macrophage:
- ____: Control of turnover of glomerular basal laminae
- Also present outside the glomerulus: ____ mesangial cells (slide 33).• Have a dual phenotype
○ Specialized pericytes
§ (BS III) - cells that associate to capillariesm and have chracteristics of smooth muscle cells - capablae of ____ > the mesangial cells can repsond to stimuli and regualte floow of blood through each ____
§ Being similar to SM cells > synthesize a ECM
□ Mechanical support for capilaries
§ PG/endothelins - ____
□ Act locally inside glomerulus to contract capillaries that regualting bloow flow in and out of RC
○ Phagocytic cell
§ Can behave like a macrophage
§ Renovate the mesangial ECM (can both synthesize, and can remove aging matrix also)
intraglomerular mesangial pericytes contractile mechanical prostaglandins endothelins phagocytic extraglomerular contraction glomerulus vasoconstrictors
The Renal Corpuscle
• The matrix is highlighted here • Some fo the mesangial cells themselves ○ Can see some nuclei in pkaces ○ Deep pink - ECM produced by \_\_\_\_ cell • Cluster of meangial cells that are outside of glomerulus ○ EG mesangial cells
mesangial
- Renal tubule:
- ____
- ____
- ____
- Tubule from RC and is formed by PCT, the LH and the DCT all the way to the junction of the CT
- The epithelia are all ____ in each area
proximal convulated tubule
loop of henle
distal convoluted tubule
different
The Renal Tubule: Proximal Convoluted Tubule (PCT)
- Reabsorption epithelium.
- ____ epithelial cells:
- Apical domain with ____.
- Lateral domain with ____.
- Basal domain with infoldings and ____.
- Apical lysosomes.
- ____-located mitochondria: provide energy for the Na+/K+ ATPase pump (review BS-IV lectures).• Starting at urinary pole - the first segemnt of the RT is the ____ (small diameter, that’s in close prox to the renal corpuscle that is convulated and folded onto itself)
• Reabsorption epithelium
○ The nephron first makes ultrafiltrate (primary urine) - that’s not the urine that reaches the urinary bladder >
• A lot of transport of ions and water in and out of the tubules is going to take place
• This is where the modification of primary urine/ultra filtrate starts taking place
• Thus, this is a reabsorption epithelium
• Lined by cuboidal epithelium
○ Have a brush border - the apical domain forms extensions called microvilli
§ Tissue of cells are involved in absorption
□ Increase ____
§ Require high amounts of energy > cells are rich in mitochondria
□ Located in the basal domain > that attach the cells strongly to the ____
□ In order to trun he Na/K ATPase
§ Rich in lysosomes
□ Contain ____ - used to degrade peptides that get reabsorbed > converted into AA and recycled as part of normal metabolism of the body
cuboidal brush border (microvilli) tight junctions interdigitations basally
PCT
SA
BL
hydrolases
• Capillaries full of RBC
• PCT
○ Stain ____
○ Tubule has ____ lumen
stain
narrow
The Renal Tubule: The Loop of Henle
• Reabsorption epithelium.
• Segments: • Descending limb: Thick segment: Continuation of \_\_\_\_. \_\_\_\_ epithelium. Thin segment: \_\_\_\_ epithelium.
• Ascending limb:
Thin segment: ____ epithelium.
Thick segment: ____ epithelium.
• Not as \_\_\_\_ as the PCT • Divided into two main segments ○ Descending limb (thick) § Goes from PCT to the end of the handle § Based on diagram - the diameter of the tubule is different in two sectons § Thick segment □ Cuboidal epithleium § Thin segment □ Squamous, flat □ Continues into the AL until reach the thick segment of AL > goes back to cuboidal ○ Ascending limb
PCT
cuboidal
squamous
squamous
cuboidal
active
The Loop of Henle
• Cross section of medulla ○ Only expect ot find two limbs of LH of many nephrons, and some CT ○ Can see different between thick limbs (cuboidal cells), and the thin limbs (squamous cells) § NO \_\_\_\_ HERE § NO \_\_\_\_ IN THIS CROSS SECTION
renal corpuscles
CT
The Renal Tubule: The Loop of Henle
• LONGITUDINAL SECTION - find more \_\_\_\_ • Thin limbs of LH ○ Formed by squamous epithelium • Collecting tubules ○ The central region • The capillaries saw before > belong to \_\_\_\_ ○ Irrigation network of the kidney ○ Some RBC in the center • Interstitial cells > \_\_\_\_ (CT) that produce an ECM that maintains the overall structure of the medulla ○ \_\_\_\_in middle of tissues is common ○ Ducts/tubules wouldn't sustain themselves without the presence of \_\_\_\_ § Located between them
structures vasa recta fibroblasts CT CT
The Renal Tubule: The Loop of Henle
* Apposition of thin segments of several LH, and in close proximity to \_\_\_\_ * Capillaries also seen with RBC inside them
CD
The Renal Tubule: Distal Convoluted Tubule (DCT)
• Reabsorption epithelium: • Impermeable to \_\_\_\_ transport. • \_\_\_\_ epithelium: • \_\_\_\_ than those in the PCT. • Lack a prominent \_\_\_\_. • Basal domain with infoldings and interdigitations. • \_\_\_\_-located mitochondria: provide energy for the Na+/K+ ATPase pump.
• DCT is downstream of LH ○ In proxmity of renal corpuscle ○ Going back to the renal corpuscle to the filtration part of the nephron • Reabsorption epithelium • Cells lining the DCT are similar to cells that were lining the \_\_\_\_ ○ Cuboidal cells with basally located mitochondria § Not \_\_\_\_ located! ○ Potent Na/K ATPase activity ○ Missing \_\_\_\_ in apical domain ○ Do not have a prominent brush border § To differentiate between cells and the ducts
water cuboidal shorter brush border basally
PCT
apically
lysosomes
• DCT stain more pale than the ____
○ The dark stain of PCT
§ High abundance of ____ and lysosomes
• DCT has a much ____ brush border > the lumen of the tubule is ____
PCT
mito
shorter
wider
The Juxtaglomerular Apparatus
Small endocrine structure of the ____, in close proximity to the glomerulus.
Components and functions:
- ____.
- ____ cells.
- ____ cells.
- ____ fibers• DCT gets back to the RC; together with arterioles that irrigate the RC > form the ____
○ Apparatus close to the glomerulus
• Eptiehlium of the ____ in this section
• Endocrine structure
○ Porducres ____
DCT macula densa extraglomerular mesangial juxtaglomerular sympathetic nerve JG DCT hormones
- The DCT is in proximity of both afferent and efferent arterioles near ____ of the glomeurlus/RC
- Some EGC
- Specialized ____ in the DCT
vascular pole
epithelia
The Juxtaglomerular Apparatus: Macula Densa
Small endocrine structure of the DCT, in close proximity to the glomerulus.
Components and functions:
1. Macula densa:
Epithelial cells with apical ____ at the ____ portion of the DCT.
Osmoreceptor: Sensitive to changes in [NaCl]:
• Low [NaCl] → ____ release by ____ cells.
2. Extraglomerular mesangial cells.
3. Juxtaglomerular cells.
4. Sympathetic nerve fibers.
• Colelciton of epi cells that are in the DCT in proximity of the vascualr pole • Have a different morphology of nuclei ○ More \_\_\_\_ than the rest of the DCT cells ○ \_\_\_\_ differently • Cell shave receptors > for changes in osmotic pressure ○ When cxn of NaCl in DCT in filtrate in priamry urine is low > the cells will respond by sending amessage tot the JGC to produce renin
nucleus initial renin JG apical stain
The Juxtaglomerular Apparatus: Macula Densa
• Dark red - \_\_\_\_ • Up top > empty space > DCT • Where there is a pop of cells with bigger \_\_\_\_ and \_\_\_\_ > macula densa ○ Very close to vascular pole
mesangial matrix
nuclei
apical
The JG apparatus: EG mesangial cells
Extraglomerular mesangial cells (a.k.a. lacis cells):
____: mechanoreceptors.
Secretion of ____?, renin?.
• Mesangial cells outside of glomerulus • Pericytes > dual identity of \_\_\_\_ SM like cells and \_\_\_\_ • Unclear of other functions > may also produce renin and EPO ○ Definitely act as mechanoreceptors - measure \_\_\_\_ in the arterioles that come and go from the renal corpuscle
pericytes erythropoietin contractile phagocytes BP
The Juxtaglomerular Apparatus: Juxtaglomerular Cells
- JG cells
Located at the afferent arteriole wall.
____: mechanoreceptors. ____-producing cells.- Located only in the wall of the ____ artioles
- Produce the renin in response to changes in osmotic pressure detected by ____
pericytes
renin
afferent
macula densa
The Juxtaglomerular Apparatus: Juxtaglomerular Cells
• Most of what is seen is the RC ○ \_\_\_\_ cells ○ \_\_\_\_ cells § Squamous epithleium • In center > \_\_\_\_ arteriole ○ JG in close proximity to afferent arteriole, located at the wall
mesangial
parietal
afferent
The Juxtaglomerular Apparatus: Innervation
- Sympathetic nerve fibers:
____ innervation of juxtaglomerular cells.
Induce ____• Nerve fiber - belong to sympathetic symptom
○ Adrenergic innervation of JGC > when cells are activated by inmpulses from symp nerve > contraction of ____ Arteriole
adrenergic
vasoconstriction
afferent
How to distinguish between proximal & distal convoluted tubules
• TRICKY ONES • CORTEX ○ \_\_\_\_ only present in cortex ○ \_\_\_\_ tubules § Dark: \_\_\_\_ tubules
renal corpuscles
proximal and distal convulated
proximal
How to distinguish between PCTs and DCTs
- Both are adjacent to ____.
- PCTs contain cells with abundant ____: stain dark.
- The apical domain of PCTs has prominent
____ and vesicles. - The apical domain of DCTs has ____
microvilli and scarce ____. - Cells in both PCTs and DCTs contain
abundant basally located ____.• Both of tubules are next to RC
• PCT
○ Cells contain high abundance of lysosomes
§ Encocytic vesicles - stain darkly
○ In addition of basal mitochondria
○ Apical domain of PCT epithelial domain has a prominent brush border > the lumen is narrower than DCT
• DCT
○ Cells have brush border composed of short microvilli > difficult to see at LM level
○ Cells have lots of basal mitochondria
renal corpuscles lysosomes brush border (microvilli) short vesicles mitochondria
How to distinguish bt PCTs and DCTs
• Darkness of proxoimla cells ○ Contain \_\_\_\_ ○ Larger brush border - but here cannot see the lumen because it's a \_\_\_\_ section of two ducts • Difference with DCT cells ○ All lines at basal domain of each cell is \_\_\_\_ § Still very rich ○ But no lysosomes > stain \_\_\_\_
lysosomes
longitudinal
mitochondria
pale
• Differences in brush border
○ PCT has a lot ____
○ DCT is ____
more
minimal
- Collecting tubule/duct:
- ____
- ____
- ____
cortical segment
outer medullary segment
inner medullary segment
The Collecting Tubule/Duct
- Transport of the filtered urine from the nephron to the ____ for drainage into the ____.
- Cortical segment: ____ epithelium.
- Medullary segment: ____ epithelium.
- Continuous with the ____• Filter urine from nephron to reanl pelvis > ureter
• Epithleium
○ Difference bt cortical and medullary
§ Cortical: cuboidal
§ Medullary: columnar
• The types of cells in both are similar, but morphology is different
renal pelvis ureter cuboidal columnar papillary ducts of Bellini
Collecting Ducts and Papillary Ducts
• Transition into a \_\_\_\_ epi
columnar
The Collecting Tubule/Duct
Cuboidal epithelium that transitions to ____ at the medullary segments:
Principal cells:
Reabsorb ____ and ____, and secrete ____.
Intercalated cells:
Abundant ____ (appear ____ in light microscopy).
Basal domain with infoldings and ____.
Regulate acid-base balance: secrete ____ or ____.
• Two types of cells in CT no matter of what the \_\_\_\_ looks like ○ Principal cells § Involved in ion trafficking of Na and K ○ Intercalated cells § Responsible for acid-base balance ○ Different funciton reflected in \_\_\_\_
columnar
Na+
water
K+
mitochondria darker interdigitations H+ HCO3-
epithelium
morphology
The Collecting Tubule/Duct
We have Principle cells and intercalated cells
• Principle cells are usually more ____ stained than the intercalated cells
• Intercalated cells stain darker b.c they have very abundant ____
◦ These intercalated cells are similar to cells that we saw in the ____ b.c the basal domain
has infoldings and interdigitations
Again, the functions of the principle cells and intercalated cells are slightly ____.
pale
mitochondria
proximal tubules
different
Interconversion of principal and intercalated cells.
• IC and PC can actually interconvert > belong to same \_\_\_\_ • Depending on activation of cell signaling cascade mediated by \_\_\_\_, the cells will either > differentiate in IC or PC ○ In chronic kidney disease > activating of notch signal is \_\_\_\_ > the IC in repsonse to hig levels of notch > will convert into \_\_\_\_ > in chronic kidney disasee > problem in manitnaing homestasis of \_\_\_\_ (low numbers of \_\_\_\_) § Didn't \_\_\_\_ - converted!
lineage notch high PC acid-base balance IC die
The Excretory Passages of Urine: The Urothelium
- ____ epithelium with ____-dependent ____ to ____ morphologies.
- Present in renal ____, renal pelvises, ____ and urinary bladder.
• Components: • Basal cells: \_\_\_\_. • Superficial cells: • Present \_\_\_\_: thickened apical domain capable of adjusting to changes in \_\_\_\_.
• After urine leaves kidney > enters the urinary tract ○ Most imporatnt characteristic downstream of kidney: organs (ureters, bladder, upper part of urethra) are lined by sapecialed epithelium > \_\_\_\_ epithelium (urothelium) § This epi changes morphologyc dpeneding on the \_\_\_\_ that it's subject ot □ Low: more like \_\_\_\_ epi □ High: \_\_\_\_ epi § Two stypes of epi cells □ Basal ® \_\_\_\_, proliferative □ Superficial ® \_\_\_\_ ® Most of the cells are these ® Their apical domain is covered by \_\_\_\_ ◊ Deposit \_\_\_\_ > forms these plaques > therefore, these cells show \_\_\_\_ apical domain, and they allow the cells to adjust to changes in surface area induced by changes in pressure
transitional pressure squamous cuboidal calyces ureter proliferative apical plaques surface area
transitional pressure pseudostrat columnar squamous stem cell mature plaques uroplaqin thickened
The Excretory Passages of Urine: The Urothelium
• When tissue is realxed (U-R) ○ When the bladder is empty • When tissue is distended > tissue will \_\_\_\_ and extend ○ Compare depth of tissue (brackets) > see from tissue from relax to extended > the pseudostrat goes to a \_\_\_\_ flat epithleium • Ability to go from one to another > allows the organ (bladder) to expand without making any \_\_\_\_ to wall/undelrying tissue ○ Why apical domains are protected by plaques > in contact with \_\_\_\_ enviornemnt due to storage of urine
flatten
sqaumous
damage
corrosive
The Excretory Passages of Urine: Ureters
• Urinary passage with folded walls (\_\_\_\_), which \_\_\_\_ as the ureter fills with urine: \_\_\_\_ increase in intravessel pressure. • Layers: 1. Mucosa: \_\_\_\_ epithelium (urothelium). 2. Submucosa: \_\_\_\_ extending into the folds 3. Muscularis: inner \_\_\_\_l and outer \_\_\_\_ layers of SM. Induces \_\_\_\_ to propel urine. 4. Adventitia: Connective tissue. \_\_\_\_ tissue.
• The lumen folds into rugae > will flatten when hydrostatic pressure icnreases • The eptiehlium is urothelium • The wall of the bladder > the muscualr layer > formed by bundles of SM that are organized into: ○ Inner layer of longitudinal ○ Mdidle rlayer of circular ○ Outer layer of longitudinal bundles • Ureters have two layers ○ One longituindal, one circualr
rugae flatten minimal transitional CT longitudinal circular peristalsis adipose
The Excretory Passages of Urine: Female Urethra
• Lined by ____ as it leaves the bladder.
• Transitions to ____ epithelium
then to ____
epithelium near the urethral orifice.
• Muscularis:
• Inner ____ and outer ____ layers of smooth muscle.
• Part of the internal urethral sphincter that keeps the urethra ____ except during urination.
• When urethra leaves bladder > linede dby urothelium; farther go away towards the orifice > the epithelium first goes pseudostrat columnar, that then transitions into non-keratinized stratified squamous epithelium
urothelium pseudostratified columnar non-keratinized stratified squamous longitudinal circular closed
The Excretory Passages of Urine: Male Urethra
• Three segments: Prostatic urethra:
____ epithelium.
Crosses the ____ gland.
Membranous urethra:
____ epithelium.
Penile urethra (figure):
Pseudostratified columnar epithelium transitions to ____ epithelium near the urethral orifice [E].
Surrounded by a rich venous plexus: ____, erectile tissue.
Outside this layer of blood vessels is a dense CT layer called the ____
* Up to prostate > transitonal * Membranous part > the epi has transitioned into pseudostart columnar epi * At penis: the epi is now non-keratinized stratified squamous has taken place
transitional
prostate
pseudostratified columnar
non-keratinized stratified squamous
corpus spongiosum
tunica albuginea
