histology - kidney, etc Flashcards
how do systems extrinsic to the kidneys affect the kidneys? if sense BP too low <80~~
sympathetic NS -
SNS - what can it do?
carotid sinus - glossopharyngeal, CN 9
aortic sinus - vagus CN 10
message to brain, 2 messages can be sent -
1 - alpha 1 adrenergic receptors on afferent arterioles to CONTRACT
2 - to JG cells - to stim renin - this on beta 1 adrenergic - increases calcium in JG which stim renin production
What does renin do? What is it? Renin is enzyme
aldosterone (glomerulus cortex adrenal0
Angiotensin II, binds to many receptors in the body to affect several systems. It can increase blood pressure by constricting the blood vessels. It can also trigger thirst or the desire for salt. Angiotensin is responsible for the release of the pituitary gland’s anti-diuretic hormone.
liver producing angiotensinogen (protein) -
w/ Renin becomes angiotensin 1
from lungs ACE
becomes angiotensin II
effects adrenal to make ALDOSTERONE
(which creates absorption of sodium - hence BP up) in distal convoluted tubule
in kidney - vasoconstrictor
hence BP up
prox convulated tubes - brush border
microvilli
tons of mitocondria - REABSORPTION -
pinocytic vessels
Osmosis
exocytosis
microvilli - increases surface area, lateral folding and basal invaginations ALL facilitate reaborption and secretion of substances
microvilla - longer than distal, cuboidal, acidophilic PINK
interdigitations
tight junctions - major reabsorption
folds in lateral surface - plicae and
BASAL BORDER invagations and tons of mitrochondria - active transport - ATP
reabsorption function -
all glucose
amino acids
85% NaCL and Hx0, Po4, Ca++
protein
secretions - creatinine (from muscles)
pinocytosis - active ion trasnport NA+/K ATPase
glomerulus
really capillaries - special kind - blood runs thru, and some goes out and becomes urine or starts to become urine
Aquaporin 1
aquaporin-2 (AQP2), located in collecting ducts (
in proximal convulated tubules - 70% water, bulk of solutes
Aquaporin-1 (AQP1), located in proximal tubules (PT) and descending thin limbs of Henle (DTL), and aquaporin-2 (AQP2), located in collecting ducts (CD), are channels involved in water transport across renal tubule epithelia
cortical portion of collecting tubules?
in inner and outer medulla
disorders of Prox conv tubules? PCT
can’t reabsorb - missing ATP
Fanconi syndrome is a rare disorder of kidney tubule function that results in excess amounts of glucose, bicarbonate, phosphates (phosphorus salts), uric acid, potassium, and certain amino acids being excreted in the urine.
fanconi syndrome - hereditary or acquired - fail to reabsorb because decrease in ATP - can’t use the sodium pump
cystinosis - most common cause in kids
cystinosis?
most common in kids???
when reaborbed thru walls - where go?
blood
loop of henle?
thick descending limb - simple cuboidal epith - structural similar to PCT
thick or thin descending lined w?
simple squamous epith
thick ascending -
simple cuboidal - more like distal convulated tubules DCT
four types of epithelial cells
type 1
not much going on
type 1 -
SHORT LOOP nephon
thin descending and ascending thin, simple epith - almost no interdigitations
few / no organelles
type 2
LONG NEPHRON - lots of organelles
Juxtamedullary nephon for types 2,3 and 4
thin descending LONG LOOP many small, blunt microvilli - organelles,
lateral interdig varies on species
cortical labyrinth, taller epithelium -
type 3
inner MEDULLA
thin descending INNER MEDULA, thinner epith, fewer microvilli,
lateral interdigitations absent
type 4
at bend of Loop
and entire thin ascending - flattened epith w/o microvilli, few organelles
type 4
at bend of Loop and up to THICK
and entire thin ascending - flattened epith w/o microvilli, few organelles
function loop henle?
reabsorb !! 15% of filtered water and 25% filters NACl, K+, Ca2+, HCO3-
where urine formed - hypertonic urine, water retention
thin descending p permeable to water
ascending - impermeable to water, but permeable to NA+, K+, CL-
distal convoluted Tubule CVT
Vascular pole
location - continuation of thick ascending, goes back into CORTEX - vascular pole of renal corpuscle - juxtaglmerular region
-
here find?
Macula Densa
DCT?
no brush border
Do have tons of mitochondria
simple cuboidal, smaller thatn PCT, lack brush border, few Microvilli, basal infolding are present with mitochondria
function of DCT
Aldosterone affects here - to reabsorb sodium and water
influence of aldosterone
absorb NA and Hx0
secrete K+
reabsorb bicarb ion and secretion of H+
converts ammonia to amonium
Addison disease? SALTY URINE
aldosterone deficiency - excessive loss of sodium in urine
PCTS vs DCTS
both reabsorb
adjacent to renal corpuscles
PCTs lysosomes - stain dark
DCTS - lightly stained?? which is pink?
apical domail of PCT has brush border and vesicles - DCT fewer of both
both TONS of mitrochondria
tight junctions
collecting tubules and ducts - empty into minor calyx
in cortex - seem tubules and ducts
tubules to duct
cuboidal to columnar - varies from squamous to columnar
weakly staining
few organelle
no basal striations
clear intercellular borders,
empty in to minor calyx at renal papilla
medullary collecting ducts - no tubules in medulla
(lower down) cuboidal cells and change to columnar
COLLECTING DUCTS -
two types of cells?
antidiuretic hormone (Light cells) - ONE CILIUM - reabsorb sodium and water and release Potassium - they have antidiuretic (antipee) hormone ADH - Aquaporin 2
antidiuretic is VASOPRESSIN
light vs dark cells
DARK - intercalated -
principal or light
dark or intercalated
principal single cilium, few short microvilli - small mitochondria - contain antidiuertic hormone ADH water channels AQUAPORIN 2 water channel
dark cells - small, many mito - microvilla on apilca - no basal ifolding - decrease as duct approach papilla
dark cells vs light
fewer mito in light cells
Aquaporin-1 (AQP1), located in proximal tubules (PT) and descending thin limbs of Henle (DTL), and aquaporin-2 (AQP2), located in collecting ducts (CD), are channels involved in water transport across renal tubule epithelia.
secrete H+ and reabosrob K_
light cells - reabosorb NA and water and secrte K_ - primary cilium
aldosterone -
secreted from adrenal gland cortex
angiotensin 2
stim aldosterone secretion - stim epith distal convulated tubules - to reabsorb sodium -
hypothalmus involved to??
??
water channels in ?
principal or light cells
disorders -
polycystic kidney disease
polycystin 1 - membrane receptor -
cell to cell adhesion molecules
extensive cystic enlargement of both kidneys cysts from dilation of collecting tubules - hypertension, renal failure
mutation PKD1 and 2 - predominantly in cilium lining collecting tubules
PKD1 gene account for 85-90% of cases
polycystin 1 is calcium permeable channel
complete loss (need to finish notes)
once form cysts - block
blood flow, hypertension, renal failure
kidney enlarges, tons of cysts - can’t function normally
fuction of tubules and ducts
ADH vasopressin -
causes epithelium to be permeable to H2o
reabsorb H20 and aldosterone
medullary rays?
where see tubules, collecitng ducts in medulla - heading toward renal papilla, minor major calyxes, renal pelvis
diuretics -
promotes the increased production of urine.
stopping reaborb sodium, water
drugs increase output of urine - act
osmotic diuretics
inhibit reabsorb of water and solutes in PCT
thiazide diuretcs
inhibi reaborb NAcl in DCT
carbonic anhydrase
block CA on luminal membrane in PCT
loop diuretics - furosemide, etc
inhibits na_/K+/2cl cotransportor on luminal membrane of thick ascending limb of loop of Henle
carbonic anhydrase
in PCT
decrease hydrogen formation in lumen - hence less sodium reaborbed, but becomes urine
block CA on luminal membrane in PCT
Thiazides - distal tubules - inhibit NAcl cotrasnporter
increase urine w/ na_ and CL
potatssium sparing various
aldosterone receptor antagonist
AMILORIDE and TRIAMTERENE - direct block of sodium Na_ channel blockers
Interstitial cells?
what fills in space - between all ducts -
maintenance of renal architecture and production of
erythropoetic EPOS
in renal cortex and medullary fibroblasts
EPO - producing fibroblasts - stimulator to make RBCs major growth factor for RBCs
blood oscygen down? RBCS made EPO fires it up
renal medullary fibroblast - like cells
contain actin - may secrete prostaglandins and may regulate papillary blood flow
participate in interstitial pephritis - tubulo ?? disease
excretory pathway
UROTHELIUM
minor, major calyces, renal peliv ureters, urinary bladder, urethra
mucosa - trasntional epith - and called
ureter
mucosa, foldeed, start shape - trasntional epithelium, lamina propriate (dense fibro CT)
muscularis - inner longitudinal, outer circulat
in terminal portion of ureter - thcih outer longitudinal muscle is present
adventitia
urinary bladder
mucosa - lined with transitional eptih, lamina propria
muscularis DETRUSOR - fibers in all directions, innter and out long middle circular, forms INTERNAL URETHRAL SPHINCter near opening of urethra
adventitiaaioa - mesothelium
transitional epith
can expand without losing coitinuity -
dome shaped cells
thicker when ?
male urethra
three parts - prostatic
ejac ducts and ducts of proetrate gland penetrate wall - trans. epith
membraneous
strat columnar or speudostratified
penile
- corpus spongiosum, cavernous tissue
pseudo stratified to stratified squamous
ducts of bulbourethral glands - cowpers
secrete mucous
female urethra
shorter - longitudinal folds
trans epith change to strati squa at mid portion
urethal glands, pair or parurethral glands into lomen
lamina propria highly vasculariezes
distally striated muscle form external urethral sphinchter
adventitia - outer covering of fibroelastic CT
3 layers of testis?
tunica vaginalis - single layer on basal laminal - simple squamous
t. abugenia - thick dense fibroelastic CT, coll fibers, fibroblasts, mast cells, smmoth mus, nerve, Messner nerve endings
t. vasculosa - blood vessels in loose CT
testis capsule
can contract periodically
maintains correct pressure
regulated fluids in and out
massages duct system- aid moving sperm
tunica albuginea - posterior surface divides and forms?
mediastinum testis - 250 pyramidal compartments - TEST. LOBULES
incomplete - and can communicate betw lobules
what do testic. lobules have?
1 - 4 seminiferous tubuules - in loose CT rich with blood, lymph, nerve, and LEYDIG “interstitial” cells
mesothelial cells?
tunica vaginalis cells
Mesothelial cells form a monolayer of specialised pavement-like cells that line the body’s serous cavities and internal organs. The primary function of this layer, termed the mesothelium, is to provide a slippery, non-adhesive and protective surface.
Leydig cells, also known as interstitial cells of Leydig,
are found adjacent to the seminiferous tubules in the testicle. They produce testosterone in the presence of luteinizing hormone (LH)
What do Leydig cells do?
produce testosterone in the presense of LH
Where does LH come from?
anterior pituitary
where does FSH come from?
anterior pituitary
Gonadotropic cells
are endocrine cells in the anterior pituitary that produce the gonadotropins, such as the follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Release of FSH and LH by gonadotropes is regulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus.
What cells in hypothalmus release GnRH?
preoptic nucleus - oxytocin?
arcuate nucleus
Androgen?
The predominant and most active androgen is testosterone, which is produced by the male testes. The other androgens, which support the functions of testosterone, are produced mainly by the adrenal cortex—the outer portion of the adrenal glands—and only in relatively small quantities.
what secretes androgens
Testicular androgen secretion is controlled by luteinizing hormone (LH) and follicle stimulating hormone (FSH), which influence the Leydig cell response to the LH. … Inhibin production of the Sertoli cell is stimulated by androgens.
Inhibin secreted by Sertoli
tells hypothalmus and pituitary there is enough SPERM - negative feedback loop
what do Sertoli cells do?
blood testis barrier
nourish sperm
create inhibin
1st year only
The supporting cells (Sertoli) are located within the seminiferous tubules. Their task is the creation of a hemato-testicular barrier and the nourishment of the spermatozoa. They can only proliferate in the first year of life (their equivalent in the woman are the follicular cells).
What types of hormones does the adrenal cortex secrete?
Secreted Steroids
Five classes of steroid hormones are produced in the adrenal cortex: glucocorticoids, mineralocorticoids, progestins, androgens, and estrogens.
What stimulates Sertoli cells?
FSH - which creates Androgen binding protein ADP- which combines with testosterone to keep testosterone fluid and around
In addition to stimulating spermatogenesis, FSH also causes the Sertoli cells to produce an androgen binding protein (ABP). This protein binds testosterone and helps maintain a high concentration of testosterone within the testes; this is essential for spermatogenesis to occur.
Is testosterone a testicular androgen?
yes -
rete testis?
A network of small tubes in the testicle that helps move sperm cells from the testicle to the epididymis. The epididymis is where the sperm mature and are stored.
seminiferous tubules?
highly convoluted, but at apex of lobule becomes a STRAIGHT tubule
layer of fibro connective tissue (tunica propria) - 3 - 5 layers of fibroblasts, and one layer of muscle - flattened myoid cells
complex of germinal or seminiferous epithelium - two types
SERTOLI cells
Sperm germ cells (spermatogenic lineage cells
in the interstitial spaces are the LEYDIG cells
spermatogenic lineage cells
stacked in 4 - 8 layers that occupy space betw basal lamina and lumen
spermatogenesis - how many phases?
3 -
mitosis - A cell is daughter cells - doesn’t leave Basal compartment
meoisis 1 and meoisis 2
spermatogonia divide to create primary spermatocytes, 2dary spermatocytes, spermatids , spermatozoa
division of seminiferous tubules?
basal compartment, adlumen compartment, lumen -
blood testis barrier between basal and adlumen - via tight junctions between sertoli cells
what’s a spermatogonium?
primitive germ cells in basal compartment - will divide via mitosis two create 2 identical cells - one cell will remain in basal compartment and renew the cycle -
each contains a diploid number of chromosomes
What happens at male puberty?
spermatogenesis begins -
spermatogium types
A dark, A pale, B?
A dark, A pale, B
A dark - renew themselves and create some A pale - ovoid nucleus - stain dark
A PALE - ovoid nucleus - divide mitotically to create more A Pale and some B
B - spherical nucleus, dense stain, divide via mitosis to create PRIMARY spermatacytes
Primary spermatocytes
largest germ cell in tubule -
start in basal compartment - but after division migrate to middle zone -
spherical or ovid, nucleus in some stage of karyokinesis (division of a cell nucleus during mitosis.)
soon after - become secondary spermatocytes
Quick change - what cells are hard to see?
secondary spermatocytes - they divide quickly into spermatids
spermatids -
small size - nuclei w/ condesnesed chromatin, juxtaluminal location with tubule
spermatid - complex process
- form acrosome
- condense, elongate nucleus
- develop flagellum
- loss of much of cytoplasm (becomes sleek and excited to move!)
When mature released into lumen of seminif tubule
4 phases of spermiogenesis
- GOLGI phase,
- cap phase
- Acrosome phase
- Maturation Phase
- golgi phase - PAS positive proacrosomal granules accumulate in Golgi - fuse to form single granule in a membrane ACROSOMAL Vesicle
CENTRIOLES migrate near surface and opposite to forming acrosome
- cap phase - ACROSOMAL reaction when find an ova
vesicle and granule cover anterior half of condensiing nucleus - “cap”
within has several hydrolytic enzymes - hyaluronidase, neuraminidase, acid phosphatase, acrosin - wthich dissociate cells of corona radiata and digest zonna pellucida
when spermatozoa encounter ova - the outer membrane of acrosome fueses with plasma membrane at multiple sites known as ACROSOMAL reaction
- acrosome phase
anterior pole of cell (w/ acrosome) orients toward base of seminiferous tubule
nucleus elongates - microtubules may help (the manchettes)
mitocondria aggregate around proximal part of flagellum MIDDLE PIECE
- maturation phase
residual cytoplams is she and phagocytized by Sertoli cells - spermatozoa released into lumne
(during division of spermatonia - resulting cells do not separate completely but remian attache d by cytoplamic bridges
spermatazoa ?
head, middle piece (w/ mitrochondrial sheath) responsible for movement fof tail
tail - covered by thin layer of cytoplas except at tip
Immotile cilia syndrome
infertility - due to lack of dynein or other proteins required for ciliary motility
sertoli cells
on basement membrane - few in number - at intervals between spermatogonia
columnar - extends from basal lamina to lumen - along the side of each cell - a stream of proliferating and differentiating germ cells move slowly toward the lumen
Sertoli cells connected to one another via?
via gap junctions and multiple tight junctions -
tight junctions are near base of cell - separating early vs later developoing sperm - early ones need to have access to hormones from blood
blood testis barrier
all the spermatocyctes, spermatids and spermatozoa are near the lumen - with the thigh junctions creating a blood testis barrier - to protect the spermatogenic cells from noxious substances
the barrier disappears and reappears letting the primary spermatocytes out - and keeping the germ cells (spermatogonia) in the basal compartment
Sertoli functions?
- help and nourish sperm
- phagocytose residual bodies from spermatids,
- secrete fluid into lumen for sperm movement - - including ADP, activin, inhibin, plasminogen activator, transferrin, growth factors, ions
- small quantities of estrogen - (conversion of testosterone to estradiol)
- maybe in embryo - non-sterioidal Mullerian Inhibitory Factor
- prepubertal state - substance suppressing meiotic division of gamets
- Sertoli cells do not divide during reproductive period - extememtly resistant to adverse conditions such as infection, malnutrition or X ray
Interstitial tissue - between tubules?
loose CT, nerves, blood and lymph
fibroblasts, undifferentiated connective cells, mast cells, macrophases
LEYDIG
Leydig?
crystals of REINKE
during puberty - LEYDIG become apparent - cental nucleus - have characteristics of steroid secreting cells - (smoother ER), and crystals of REINKE
leydig produce?
testosterone
leydig stim by?
ICSH (like LH) and Prolactin
ICSH - same as LH in females = from anterior pituitary -
PROLACTIN also aid in production of teststerone
puberty vs. fetal life and testosterone?
lots of Leydig during puberty
fetus - Chorionic gonadotropin from placenta stims interstitial cells of testis to produce testosterone - developing males genitalia
testosterone responsible for?
and male libido
many things - growth, devel, maintenance of accessory male sex organs, prostate, seminal vesicles, bulbourethral glands, penis
and secondary sec changth - hair - larynx enlargment, musculoskeletal growth
crystals of reinke?
Reinke crystals are rod-like cytoplasmic inclusions which can be found in Leydig cells of the testes. Occurring only in adult humans and wild bush rats, their function is unknown.
protein inclusions in cytoplams of leydig
StAR protein regs?
synthesis of steriods by transporting cholesterol across outer mitochondrial membrane - mutation of this is seen in people with defective synthesis of adrenal and gonadal steriods
steroid producing cells?
lipid droplets containing esterfied cholesterol, smooth ER, mitochondria with tubular critae
prolactin?
induces expression of LH receptor
FSH, LH, Prolactin
FSH, and LH by basophils in adenohypophysis of pituitary
PROlactin- by acidophils
fsh bind to?
sertoli which produce ABP, which binds to testosterone - and complex is transported to epididymis
Prolactin stims leydig to express LH receptors = LH binds triggering testosertone production
testosterone - 3 secretory routes?
blood circulation
lymphatic channels surroudning seminif tubules
sertoli cells where binds to androgen receptor
feeback loops - 2 regulating spermatogeneiss?
FSH and LH
GnRH in hypothalamus modulated FSH inhibi-activin loop
LH - testosterone loop
1 sertoli = inhibit if too many sperm
ACTIVIN when want more (up-regulate FSH secretion)
2LH - testosterone loop