5: Histology Flashcards
The kidneys maintain homeostasis of what?
Water and electrolytes
What do the kidneys excrete?
Toxic metabolites
e.g urea and creatitine
The kidneys are (exocrine/endocrine) glands.
What do they secrete?
endocrine glands
renin, erythropoietin
Are the kidneys intraperitoneal or retroperitoneal?
retroperitoneal
Which structures anchor the renal cortex to the pyramids of the renal medulla?
Renal columns
What structures does the urine drain through to reach the minor calyces?
Renal papillae
What is the renal capsule made up of?
Collagen
What are the functional units of the kidneys?
Nephrons
What are the two broad areas of a nephron?
Renal corpuscule
Renal tubule all the way up to collecting ducts
Where does the renal corpuscle start and end?
Glomerulus
Where do the renal tubules start and end?
After glomerulus
Before collecting duct
What cup of squamous epithelium do capillaries invaginate in the glomerulus?
Bowman’s capsule
What brings and drains blood from the glomerulus?
Afferent and efferent arterioles
What is the specialised epithelium which lines glomerular capillaries?
Podocytes
What is the connective tissue of the kidney called?
Mesangium
How thick is the basal lamina of glomerular capillaries compared to normal cells?
Very thick
What is the purpose of the mesangium?
Supports the glomerulus and clears debris
What is the purpose of the proximal tubules of the kidney?
Reabsorbs water, protein, AAs, carbohydrates and glucose
What is a feature of proximal tubular cells which allows them to absorb loads of stuff?
Big brush border, loads of microvilli
How are
a) sodium
b) glucose and amino acids
absorbed by PCT cells?
a) Active transport and diffusion
b) Co-transport (SGLT2)
Which organelles generate the ATP that PCT cells require to work?
Mitochondria
What is the purpose of the loop of Henle?
Creation of a hyperosmotic environment
What are the loopy blood vessels which supply the interstitium of the renal medulla and cortex?
Vasa recta
What is the function of the distal convuluted tubules?
Acid-base and water balance
Which hormone controls water reabsorption by the kidneys?
”” Na””?
ADH
Aldosterone
Which hormone controls sodium reabsorption by the distal tubules?
Aldosterone
Which hormone controls water absorption from the collecting ducts?
ADH
What is the juxtaglomerular apparatus?
Distal convoluted tubule loops back and runs by glomerulus
What are the three types of cells which make up the juxtaglomerular apparatus?
Macula densa cells (sense ion concentrations and send impulses to renin-producing cells and arterioles, adjusting filtration rate of glomerulus)
Juxtaglomerular cells (secrete renin into afferent arterioles > capillaries and out again)
Mesangial cells (connective tissue, join distal convuluted tubule to glomerulus)
Where is urine produced?
Renal papilla
What kind of epithelium lines the conducting pathway for urine (i.e renal papilla to urethra)?
Transitional epithelium / urothelium
What shape are the luminal cells of the urine conducting pathway i.e the cells which face the urine?
Umbrella cells
What is found below the urothelium?
Lamina propria (connective tissue)
Smooth muscle
What smooth muscle lines the bladder?
Detrusor muscle
Which type of autonomic nerve supplies the detrusor muscle?
Parasympathetic
What are the changes in epithelium for the urothelium of the prostatic urethra to the
a) membranous urethra
b) penile urethra?
a) Stratified columnar
b) Stratified squamous (mucosa)
