Lab 10 Flashcards
How does placement of right and
left kidney differ?
- Right kidney is lower and
more lateral than the left - Crowded by the liver
RENAL CAPSULE
1.Peri-renal Fat
* Cushion/shock absorption
2.Fibrous Connective
Tissue Covering
* Protection
on the concave medial surface of the kidney
* Site where ureter, nerves, blood and lymphatic
vessels enter and exit the kidney
renal hilum
the two parts of the nephron
glomerulus and renal tubule
what part of the kidney houses 85% of all nephrons?
the cortex (cortical nephrons)
- Associated with following capillary beds:
o Glomerulus
o Peritubular capillaries
where are peritubular capillaries located?
in the cortex of the kidneys (cortical nephrons)
JUXTAMEDULLARY NEPHRONS
- Long loops of Henle
o Deeply invade the medulla - Important in the production of
concentrated urine - Associated with following capillary beds:
o Glomerulus
o Vasa Recta
where is the vasa recta located?
medulla of the kidneys (juxtamedullary nephrons)
filtrate
Components of blood entering the renal tubule (Urine composition: <1% of total filtrate)
GLOMERULAR FILTRATION
- Passive mechanical process
whereby molecules <5 nm are
permitted into the tubule
TUBULAR REABSORPTION
- Returns all glucose and amino
acids, 99% of water, salt, and
other components to the blood
TUBULAR SECRETION
- Selective addition of nonfiltered substances into urine
Main driving force for
filtration is ____
blood pressure
GFR
glomerulular filtration rate. * Volume of filtrate formed
per min
where does most tubular reabsorption occur?
the proximal convoluted tubule.
- Components absorbed include:
1. Organic solutes
o Nutrients (glucose, amino acids)
o Small proteins
o Phosphate
o Nitrogenous compounds (urea)
2. Inorganic solutes
o Ions (Na+, Cl-, K+, Ca2+, Mg2+,HCO3-)
3. Water
where does tubular secretion mostly occur?
- Occurs mainly at proximal convoluted tubule
o Parts of distal convoluted tubule and
collecting ducts also involved - Solutes from peritubular capillaries or tubule cells are
moved to the filtrate
o Inorganic solutes (K+, H+, NH4+)
o Organic solutes (urea, creatinine)
o Drug metabolites/toxins
what kind of epithelium line proximal and
distal convoluted tubules?
simple cuboidal
Renal corpuscles
(glomerulus with bowman’s capsule)
* Cluster of capillaries
surrounded by a
Bowman’s capsule
* Capillaries are surrounded
by podocytes (dark nuclei)
* Filtrate enters Bowman’s space
and is funneled into proximal
tubule at the urinary pole
histological features of ureter:
-star-shaped lumen
-3 layers (adventitia, muscularis, lamina propria)
-mucosa lined by transitional epithelium
what are the three layers of the ureter from superficial to deep?
adventitia, muscularis, lamina propria
histological features of the bladder:
- Mucosa lined by transitional epithelium
- Thick muscularis composed of 3 layers of smooth muscle (Detrusor muscle)
- Outer layer is a connective
tissue adventitia
epithelia of ureter lumen
transitional
epithelia of bladder lumen
transitional
epithelia of urethra lumen
transitional near bladder, then mostly pseudostratified columnar, then stratified squamous near external urethral orifice
histological features of the urethra:
- Branching lumen
- Mucosa lined by variable
epithelia:
o Transitional epithelium near bladder
o Mostly pseudostratified columnar epithelium
(both males and females)
o Stratified squamous epithelium near external
urethral orifice - Thick lamina propria
supporting the mucosa - Muscularis of smooth muscle
- Adventitia of connective
tissue
the filtration membrane of the glomerulus composition
a fenestrated
endothelium, a basement membrane and
the foot processes of enveloping
podocytes
Proximal
Convoluted
Tubule
Reabsorb 60
-70% of filtrate
* Water * Inorganic solutes/ions (Na+, K+, Mg2+, Ca2+, Cl-)
* Organic solutes * Vitamins * Urea * Amino acids * Lipid-soluble substrates
Loop of Henle
(Nephron Loop)
● Descending limb: water
● Ascending limb: inorganic solutes (mostly Na+ and Cl-)
Distal Convoluted
Tubule
Under hormonal control
* Water
* Inorganic solutes (Na+ and Ca2+)
Collecting Duct
Under hormonal control
* Water
* Inorganic solutes (mostly K+)
* Organic solutes
* H+, HCO3-
Sites of secretion:
Proximal convoluted tubule
► Distal convoluted tubule
► Collecting duct
what does presence of ketones in urine indicate?
(ketonuria) advanced diabetes
what does presence of proteins in urine indicate?
(proteinuria) hypertension
histological features of renal cortex
-presence of renal corpuscles and renal tubules
-renal tubules lines w simple cuboidal epithelium
histological features of renal corpuscle
● Outer envelope of simple squamous epithelium called Bowman’s (glomerular)capsule
○ Surrounds a Bowman’s (glomerular) space
● Cluster of varied cells suspended in Bowman’s space is the glomerulus
○ Endothelial cells of the glomerulus
are simple squamous epithelia
○ Endothelial cells are mostly
masked by darker staining oval
nuclei of mesangial cells and
podocytes
● urinary pole of the glomerulus is the
site where the capsular space of the
renal corpuscle gives rise to the
proximal tubule
histological features of the renal medulla
Collection of renal tubules in the
absence of renal corpuscles (glomeruli)
● Loops of Henle and collecting ducts
● Renal tubules lined by simple cuboidal
or simple squamous
● May appear round, oval or
elongated in shape depending on
sectional plane
histological features of the ureter
● Star-shaped lumen
● Mucosa (inner most layer) lined by
transitional epithelium ○ Epithelium sits atop a sparse and paler staining lamina propria of
areolar connective tissue
● Muscularis (middle layer) of smooth
muscle
● Adventitia (outer layer) of pale
-staining
connective tissue ○ Interspersed fat, blood vessels,
and nerves
histological features of the bladder
Mucosa lined by transitional epithelium
○ Epithelium sits atop a thick and
paler staining lamina propria of
areolar connective tissue
● Thick muscularis composed of smooth
muscle
○ Called the detrusor muscle
histological features of the urethra
● Branching lumen
● Mucosa lined by a variety of epithelia depending on the distance from the bladder:
○ Transitional epithelia close to the
bladder ( proximal urethra)
○ Pseudostratified columnar at the
midpoint
○ Stratified squamous near the urethral
orifice
● Three mucosa layers
○ Epithelia sits atop a thick, lighter
staining lamina propria of areolar
connective tissue
○ Muscularis (middle layer) of circular
and longitudinal smooth muscle
○ Adventitia (outer layer) of pale-staining connective tissue
Interspersed fat, blood vessels, and
nerves
histological features of the kidney
Bean-shaped, two variable staining
regions, pale-staining capsule
