Urinary System Flashcards
Non-hormonal function of the urinary tract
Production, storage and voiding of urine
Function of the kidneys and urinary tract
Maintaining water and electrolyte balance, body fluid osmolarity, acid-base balance, excrete toxic metabolic waste products and produce renin and erythropoetion
Where is the kidney
In the retroperitoneal area
What covers the kidney
Thin but strong capsule
What is the capsule composed of
Dense collagen fibres
What enters/exits at the hilum of the kidney
Renal artery - enters
Renal vein and ureter - exit
Structures of the kidney
Renal pelvis, major calyces and minor calyces
Two main areas of the kidney
Medulla and cortex
What is the medulla divided into
Medullary pyramids
Where do the apices of the medullary pyramids point to
The hilum of the kidney
What are the apices of the medullary pyramids called
Papillae
What is each medullary pyramid and associated tissue known as
A lobe of the kidney
What is the capsule of the kidney continuos with
The connective tissue that lines the renal sinuses
What are medullary rays
Collections of collecting ducts and the straight segments of the proximal and distal convoluted tubules
Where are the medullary rays found
In the cortex
What provides the vascular supply to the kidney
Anterior and posterior branches of the renal artery, interlobar, interlobular and arcuate arteries and afferent arterioles
What is the basic functional unit of the kidneys
The nephron
What is the nephron composed of
Renal corpuscle and renal tubules
What is the principle role of the renal corpsucle
Production and collection of glomerular filtrate
What is the renal corpuscle formed of
A tuft of capillaries and a cup of simple squamous epithelium
What is the tuft of capillaries known as
The glomerulus
What is the cup of simple squamous epithelium known as
The bowman’s capsule
What is the glomerulus supplied by
An afferent arteriole
What is the glomerulus drained by
An efferent arteriole
What are the two cell layers that separate the blood from the glomerular filtrate
Capillary endothelium and podocytes
What are podocytes
Epithelial cells that are part of the specialised epithelium that lies on top of the glomerular filtrate
What type of epithelium do the podocytes make
Fenestrated epithelium with pores
What do the interdigitating cell process of the podocytes make
Filtration slits
What is between the podocytes and enodthelium of capillaries
A thicker than usual basal lamina made up of GAGs
What do scattered mesangial cells produce
Connective tissue core called a mesangium
Function of mesangium
Support and removal of debris
What is the glomerular filtrate
An ultrafiltrate of plasma
What are the three components of the glomerular filtrate
Fenestrated endothelium of the capillaries, thick basement membrane and filtration slits between podocytes
What is the principle role of the proximal convoluted tubule
Reabsorption of water, proteins, amino acids, carbohydrates and glucose
The proximal convoluted tubule leads to
The proximal straight tubule
How to sodium reabsorbed
Active transport
How is water reabsorbed
Diffusion
How is glucose and carbohydrates reabsorbed
Cotransport
Proximal vs distal convoluted tubules
P are larger and have a well defined margin due to the presence of a brush border
Principle role of loop of Henle
Creation of hypertonic environment in the medulla
What are the loops of blood vessels in the medulla called
The vasa recta
What are the structures found in the outer medulla
Collecting ducts, blood vessels of the vasa recta, thin limb of the loop of Henle and the proximal and distal straight tubules
Principle role of distal convoluted tubule
Controlling acid-base and water balance
Border of distal convoluted tubules
Sparse microvilli
What controls reabsorption of Na+ in the distal convoluted tubule
Aldosterone
What secretes aldosterone
The adrenal cortex
What controls aldosterone secretion
The renin-angiotensin system
Are the collecting ducts part of the nephron
No
What do the collecting ducts and tubules do
Participate in controlled reabsorption of water under the control of ADH
What increases the collecting ducts permeability to water
Vasopressin
What secretes vasopressin
Posterior pituitary
What is the juxtaglomerular apparatus
A specialised site where the distal convoluted tubule passes adjacent to the vascular pole of the same renal corspuscle
What are the three components of the juxtaglomerular apparatus
Macula densa, juxtaglomerular cells and extraglomerular mesangial cells/lacis cells
Cells of the distal convoluted tubule
Tall, crowed together and the nuclei stain intensly
Function of macula densa
Sensing sodium content
What are the juxtaglomerular cells
Modified smooth muscle cells
What do the juxtaglomerular cells contain
Renin
What are the lacis cells
Modified mesangial cells extending outside the renal corpuscle
Function of lacis cells
Signalling that alters glomerular filtration
Urine produced in the renal papillae is collected in
The minor calyx
What lines the urinary tract
Specialised epithelium = transitional epithelium/urothelium
Characteristics of urothelium
Stratified and in 3-6 cell layers
Characteristics of cells facing the lumen in urothelium
Specialised, thickened and inflexible membrane
What lines the lumen of the ureter
Transitional epithelium
Smooth muscle layers near the bladder
Inner longitudinal, outer circular and outer longitudinal
What do the smooth muscle layers form within the bladder
Detrusor muscle
Function of detrusor muscle
Micturition
What innervates the bladder
Parasympathetic ganglia
Lining of female urethra
Transitional epithelium and then stratified squamous near surface of body
