Urinary System Histo Flashcards
List parts of the urinary system. What is the function(s) of each part and the urinary system overall?
- kidney
- ureter
- bladder
- urethra
function: to filter blood, dispose of nitrogenous waste, regulate the balance of water and electrolytes, acids and bases
Locate and describe the gross anatomical features of the kidney
- renal hilum: medial border renal sinus:
- renal capsule
- renal sinus
- renal cortex
- renal medulla
- renal pyramids: base faces cortex, apex is renal papilla
- renal columns between pyramids
- minor calyces
- major calyces
- renal pelvis
- renal lobe: contains pyramid, overlying renal cortex, half of each adjacent renal column
Describe the general blood flow to and drainage from the kidneys
- The glomerular capillary bed is unusual in having arterioles going both to it and away from it (afferent and efferent), instead of a vein going away as most
- It is also unusual in having two capillary beds in series (one following the other)
Define and histologically identify a nephron and its associated parts.
Structural & functional unit
Two parts
- Renal corpuscle
- Renal tubule
- where tubular reabsorption & secretion occurs
Each nephron will drain into a collecting tubule
- Nephron plus its collecting tubule form the uriniferous tubule
What are the parts of the renal corpuscle?
Where glomerular filtration occurs
Two components
- The glomerulus
- tuft of capillaries composed of 10 to 20 capillary loops.
- The glomerular capillaries are supplied by an afferent arteriole and drained by an efferent arteriole
- Bowman’s capsule (a.k.a. glomerular capsule).
What are the different parts of Bowman’s capsule?
Bowman’s capsule
- double-walled epithelial cup that surrounds the glomerulus
- Visceral layer of Bowman’s capsule
- internal layer
- Parietal layer of Bowman’s capsule
- external layer,
- simple squamous epithelium
- Visceral layer of Bowman’s capsule
What’s a podocyte, filtration slit, and filtration membrane?
Visceral Layer of Bowman’s capsule
- Podocytes: modified simple squamous epithelial cells
- Pedicels: extensions of these cells
- Filtration slit: space between two pedicels
- Slit diaphragm (filtration membrane): semipermeable membrane covering this slit
What are the parts of the renal tubule?
Consists of
- Proximal convoluted tubule (PCT)
- Loop of Henle (nephron loop)
- Distal convoluted tubule (DCT)
Where tubular reabsorption and tubular secretion occurs.
What are the two types of nephrons found in the human kidney?
- Juxtamedullary nephron
- Loop of Henle located deep in the renal medulla
- renal corpuscle is located near the medulla (but still in the cortex)
- Cortical nephron
- Loop of Henle in the renal medulla near its junction with the renal cortex
- renal corpuscle in cortex
Discuss a collecting duct, what type of epithelium lines it? What type of cells are found lining the collecting duct?
- “Collect” the urine from DCT
- Simple cuboidal epithelium
- Appears less specialized than PCT or DCT
- Cytoplasm is relatively clear and cell borders are usually distinct.
- Merge and become larger as they descend through the medulla
- Different sizes of collecting ducts may be observed at different levels in the kidney
List and briefly describe the three physiological processes of the nephron. Where do each of these processes take place relative to the nephron?
- Filtration
- Fluid is squeezed out of the glomerular capillary bed
- Resorption
- Most nutrients, water ad essential ions are returned to the blood of the peritubular capillaries
- Secretion
- Moves additional undesirable molecules into tubule from blood of peritubular capillaries
tubular reabsorption and tubular secretion occurs in the renal tubule
Define and identify histologically the juxtaglomerular apparatus
- Structure where afferent arteriole makes contact with ascending limb of loop of Henle
- Macula densa is thickened part of ascending limb
- Juxtaglomerular cells are modified muscle cells in arteriole
Macula Densa + Juxtaglomerular Cells = Juxtaglomerular Apparatus (JGA)
Trace, describe, and histologically identify the structures that urine passes through to be removed from the body
- Bowman’s Capsule
- PCT
- Loop of Henle
- DCT
- Collecting duct
- papillary duct in renal pyramid
- minor calyx
- major calyx
- renal pelvis
- ureter
- urinary bladder urethrea
How does the urethra differ anatomically and histologically between males and females?
Males
- Prostatic-urothelium
- Membranous –stratified columnar epithelium & pseudostratified columnar epithelium
- Spongy – stratified columnar epithelium & pseudostratified columnar epithelium; distally stratified squamous epithelium
Females
- Initially urothelium then stratified squamous epithelium
- occasional pseudostratified columnar epithelium
Trace a molecule of water (that is to be removed from the body) from the blood to the urethra
- aorta
- renal a
- segmental a
- lobar a
- interlobar a
- arcuate a
- lobar a
- afferent arteriole
- glomerulus
- PCT
- Loop of Henle
- DCT
- Collecting duct
- Papillary duct
- minor calyx
- major calyx
- renal pelvis
- ureter
- urinary bladder
