Module 12- renal Flashcards
Most vital function of renal tubules
resorption
What is the capsule around the kidneys?
dense connective tissue
2 hormones produced by the kidneys
Renin and erythropoietin
What hormone aids regulation of systemic arterial blood pressure?
renin
What hormone stimulates production of erythrocytes in bone marrow?
erythropoeitin
What 2 parts of the kidney are shown here?
Cortex (dark red) and medulla (lighter)
What are the spaces between renal pyramids called?
renal columns, or columns of Bertin
Flow of urine through the kidneys
pyramids -> papillae -> major calyces -> minor calyces -> renal pelvis -> ureters -> bladder
what percentage of cardiac output is designated for the kidneys?
~25%
Flow of blood through the kidneys
Renal artery -> interlobar arteries -> arcuate arteries -> interlobular arteries -> afferent arterioles -> efferent arterioles
Think R-I-A-I-A-E, or Roberta is an irrepressible australian entertainer
Which vessel flows into the glomerulus, and which flows out?
afferent arteriole flows in and efferent arteriole drains out
What structure is filled by efferent arterioles and drains into arcuate veins?
Vasa recta, or recurrent capillary loops
What is the flow of blood from the cortex and medulla of the kidney?
drain into interlobular veins, which drains into the renal vein
Functional unit of the kidney
neprhon
What are the components of a nephron?
renal corpuscle (glomerulus and bowman’s capsule), proximal tubule, loop of Henle, and distal tubule
type of capillaries/endothelium in the glomerulus
fenestrated
cells within the Bowman’s capsule that embrace the glomerular capillaries
podocytes/pedicels
2 parts to the wall of the Bowman’s capsule
parietal (external) layer of simple squamous epithelium and a visceral (internal)layer of podocytes/pedicels
space between parietal and visceral layers of Bowman’s capsule
urinary space
structure located wehre afferent arteriole enters and efferent arteriole exits the renal corpuscle
vascular pole
Structure located where the proximal tubule begins
urinary pole
Filtration slits between adjacent pedicels, fused basal lamina of podocytes, and endothelial cells
filtration barrier
physical filtration barrier layer in renal corpuscle
lamina densa
Charge barrier of filtration in the renal corpuscle
Lamina Rara
Structure consisting of a secretory nephron and excretory collecting duct
uriniferous tubule
Where in the kidneys are the majority of nephrons found?
cortex
What gives the renal cortex uniform granularity?
the proximal and distal tubules
Which type/location of nephron is larger?
juxtamedullary
What structure is indicated by the arrows?
corpuscles/nephron/glomerulus
What tissue is pictured?
Renal cortex: RC is the renal corpuscles, MR medullary rays (containing proximal and distal straight tubules and collecting ducts), CL cortical labyrinth
What kind of tubules are present in the medullary rays?
straight tubules. NO convoluted tubules
Where do the nuclei of renal corpsucle endothelial cells sit?
close to the mesangium, at the base of the capillary tuft where Mesangial cells also reside
What structure is magnified here? And identify the parts
Up close of renal corpuscle: the large round object is a red blood cell, up against a fenestrated capillary. The slits between the larger blob projections are filtration slits, and the blobs are the pedicels
What kind of filtration barrier in the kidneys allows water and ions to opass into the bowman’s space but not larger molecules/cells?
tripartite renal filtration barrier
What cells provide support and phagocytic role in maintaining basement membrane components, but are NOT part of the glomerular filtration barrier?
mesangial cells
What helps contract podocytes to widen the gaps between them?
actin microfilaments
longest segment of a nephron
proximal tubules
Kidney tubule with simple cuboidal or low columnar epithelium, many mitochondria, and a prominent microvilli brush border
proximal tubules
Differences between proximal and distal tubules
Distal tubules are shorter, less convoluted, only have cuboidal cells, smaller overall diameter but wider lumen than proximal tubules, and no brush border
what kind of transport happens in proximal tubules?
active transport
What kidney tubule resorbs most water, glucose, amino acids, bicarbonate, ascorbic acid, and all protein?
proximal tubules
The macula densa and juxtaglomerular cells make up what?
the juxtaglomerular complex
modified smooth muscle cells found in the tunica media of the afferent arterioles in the kidney that secrete renin
JG cells
what hormone regulates systemic arterial blood pressure and Na+ concentration?
renin
Flow of the renin-angiotensin system
JG cells secrete renin -> renin meets angiotensinogen and breaks it down into Angiotensin I -> this meets angiotensin converting enzyme (ACE) and makes angiotensin II -> vasoconstriction, raise BP, H2O absorption, and aldosterone secretion
narrow, closely packed epithelial cells in the distal tubule with many organelles, prominent Golgi, face JG cells, and monitor sodium and ultrafiltrate volume in the distal tubule
Macula densa
Where are the loops of henle located?
in the renal medulla
Epithelium of loops of henle
simple squamous epithelium
What creates the concentration gradient in tissue fluid in the renal medulla causing countercurrent multiplication of urinary concentration?
Loops of Henle
What makes lateral cell borders in the collecting tubules and ducts more distinct than other tubules?
lack of intercellular projections and invaginations
Glycogen deposition around nuclei of lining cells in collecting tubules and ducts gives what appearance?
a halo pattern around the nuclei
2 types of cells found in collecting ducts
light (principal) cells and dark (intercalated) cells
Which cells in the collecting ducts are partly responsible for urine acidification and have numerous stubby microvilli?
Dark cells
What kind of junction connects the principal and intercalated cells of collecting ducts?
tight junctions
What hormone increases water permeability in the collecting ducts?
ADH
What gland secretes ADH?
posterior pituitary
What structure secretes aldosterone?
zona glomerulosa from the adrenal cortex
What does aldosterone regulate?
Resorption of Sodium and Chloride ions
What renal structure concentrates urine and maintains the acid-base balance?
Collecting ducts
What ions move in and out of the collecting ducts?
Protons and bicarb ions secreted, Potassium resorbed
What structure is pictured?
Collecting duct (note the single continuous layer of cuboidal epithelium, with rounded nuclei)
4 concentric layers of the ureters and urinary bladder
urothelium, underlying cellular and fibrous lamina propria, muscularis externa of smooth muscle, and adventitia (serosa)
Expandable tissue in the ureters and urinary bladder that is thick when collapsed and thin when distended
urothelium (transitional epithelium)
Is there flow of ions or water in the ureters?
no, so the concentration of urine is pretty much the same
What makes up the mucosa/mucous membrane of the ureters and bladder
urothelium and lamina propria
What structure is pictured?
Ureter
What covers the superior bladder outer surface?
serosa of the peritoneum (as opposed to adventitia everywhere else)
Structure in females analogous to prostate in males
Skene’s glands
What structure is pictured?
Skene’s gland (paraurethral gland)
What gland is pictured?
Bartholin gland
