Lecture #31: Renal Histolgy II Flashcards
What type of epithelium is found in the thin segment of the loop of Henle?
Simple Squamous Epithelium
Do the cells of the thick ascending limb have a brush border?
NO
Which limb, ascending or descending, of the loop of Henle is impermeable to water?
The ascending lib is impermeable to water.
What is the descending thin limb of the loop of Henle permeable to?
Descending thin limb is permeable to water and sodium and chloride ions.
True or False:
The ascending thin limb is impermeable to water and actively pumps chloride ion out of the tubule, allowing sodium ions to follow.
True
What is the major function of the loop of Henle?
To establish the counter-current exchange system which creates the osmotic conditions necessary to pull water out of the distal convoluted tubule and collecting duct in the presence of ADH.
What kind of epithelium lines the distal convoluted tubule?
Lined with simple cuboidal epithelium with smaller cells than those of the proximal convoluted tubule.
Compare the lumen of the distal convoluted tubule and the proximal convoluted tubule.
The lumen of the distal convoluted tubule is larger than that of the proximal convoluted tubule and there is no brush border.
Is the cytoplasm of the distal convoluted tubule less eosinophilic than that of the proximal convoluted tubule?
Yes
The distal convoluted tubule is impermeable to water, except in the presence of what hormone?
ADH
Where is antidiuretic hormone derived from?
Derived from the posterior pituitary.
What does ADH function to do?
Functions to reduce water loss.
What is antidiuretic hormone also known as?
vasopressin
Look at figure 14-14
It will help show you how to determine between the PCT and DCT.
What do principal cells do?
Reabsorb sodium ions and water and secrete potassium via ATPase pump.
What do intercalated cells secrete?
Secrete either hydrogen or bicarbonate ion
True or False:
The collecting duct has a different embryological origin than that of the nephron.
True
What kind of epithelium is found in the thick segments of the loop of Henle?
Simple Low Cuboidal Epithelium
What kind of epithelium does the wall of the collecting duct consist of?
Simple Cuboidal Epithelium
What two types of specialized cell types are associated with the collecting duct?
> principal cells
> intercalated cells
What are the layers that make up the renal pelvis, ureter, and urinary bladder, starting at the mucosa and going out to the adventitia?
Mucosa
Submucosa (not clearly demarcated)
Muscularis
Adventitia (FECT external to muscularis; serosa over superior surface of bladder).
What does the mucosa of the renal pelvis, ureter, and urinary bladder consists of?
> transitional epithelium (urothelium) > basement membrane > lamina propria of FECT > some loose lymphoid tissue > a few smooth muscle cells
Does the lower or upper third of the ureter have a third external longitudinal muscle coat?
Lower Third
Other than in the lower third of the ureter, what does the muscularis layers consist of that make up the rest of the ureter?
inner longitudinal and outer circular smooth muscle coat in ureter.
What do the layers of smooth muscle in the urinary bladder form?
Detrusor Muscle
What kind of epithelium lines the mucosa of the prostatic urethra?
Transitional Epithelium
True or False:
The prostatic urethra is lightly vascularized with veins that have abundant elastic tissue in them.
False - prostatic urethra is highly vascularized with veins that have abundant elastic tissue in them.
What type of epithelium lines the membranous urethra?
Tall pseudostratified columnar cells (but variable)
True or False:
The membranous urethra extends through the urogenital diaphragm and receives striated muscle cells forming the external sphincter of the bladder.
True
What type of epithelium lines the cavernous urethra?
Lined with pseudostratified epithelium with patches of stratified squamous epithelium.
What are the two types of glands that are found in the male urethra?
> Lucanae of Morgagni are invaginations of mucous membrane containing single or groups of intraepithelial mucous cells.
> Glands of Littre are branched tubulara glands opening into the lacunae of Morgagni
What type of epithelium is the mucosa of the female urethra primarily lined with?
Stratified or pseudostratified columnar epithelium with intraepithelial nests of mucous glands.
True or False:
The lamina propria of the female urethra is highly vascularized with veins with an abundance of elastic tissue.
True
True or False:
The submucosa and adventitia of the female urethra is not discernible on micrograph.
True
Which layers of the female urethra muscularis layer are longitudinal and which one is circular?
Inner longitudinal and an outer circular layer of smooth muscle cells, but they’re not well defined.
List the functions of angiotensin II.
> Stimulates secretion of aldosterone from adrenal cortex
> Aldosterone acts on the principal cells of the collecting ducts and the thick ascending limbs of Henle
> Increases reabsorption of sodium ion and water which increases blood pressure
> Stimulates release of ADH
Where is ACE (angiotensin-converting factor from?
Pulmonary and Renal Endothelium
Where is angiotensinogen from, and where is it found?
Circulating blood protein from the liver.
Where is angiotensin I primarily produced?
Lungs
What converts angiotensionogen to angiotensin I?
Renin
What converts angiotensin I to angiotensin II?
ACE
What factors stimulate the tubuloglomerular feedback system to trigger the renin-angiotensin-aldosterone system?
1) a depletion of the extracellular fluid compartment
2) a decrease in renal blood pressure (hypotension)
3) a decrease in [Na] (sodium) at the macula densa
What does angiotensin II stimulate?
1) aldosterone secretion by adrenal cortex
2) arteriolar vasoconstriction (increases bp)
3) ADH secretion and thirst
4) reabsorption of NaCl by the proximal convoluted tubule
What does aldosterone do?
Secreted by the adrenal cortex -> it reduces the excretion of NaCl by stimulating its reabsorption by the thick ascending limb of the loop of Henle, the distal convoluted tubule, and the collecting tubule.
What does the afferent arteriole behave as?
Pressure Receptor
**when blood pressure is reduced, the secretion of renin is stimulated.
