TOPIC 15 - URINARY SYSTEM Flashcards
What are the functions of the kidney?
- Regulation of blood ionic composition
Na+, K+, Ca+2, Cl- and phosphate ions - Regulation of blood pH, osmolarity & glucose
- Regulation of blood volume
conserving or eliminating water - Regulation of blood pressure
- secreting the enzyme renin
- adjusting renal resistance - Release of erythropoietin & calcitrol
- Excretion of wastes & foreign substances
The parenchyma is organized into what structures ?
Cortex and medulla
What are the structures present in parenchyma of kidney ?
- nephrons
- collecting ducts
- blood vessels
- lymphatics
- nerves
Functional unit of the kidney
Nephron
Tubules of kidney in which urine is formed
Nephron
Nephron is consists of 5 parts. What are these?
- Renal corpuscle
- Proximal convoluted tubule
- Medullary loop (loop of Henle)
- Distal convoluted tubule
- Collecting duct
Renal corpuscles produce what fluid vital in urination?
Glomerular ultrafiltrate
This is the cluster of blood vessels present in renal corpuscle.
Glomerulus
The double-walled envelope of renal corpuscle
Bowman’s capsule
Afferent arterioles enter while the efferent arterioles leave the glomerulus at ____ ____ while ultrafiltrate leave corpuscle at ____ ____.
vascular pole, renal pole
What is the type of capillary present in renal corpuscle ?
Fenestrated capillary
Bowman’s capsule comprise of inner ____ and outer ____ layers and ____ space in between the layers.
visceral, outer, Bowman’s
Parietal layer of bowman’s capsule is formed by ____ ____ cells. (Hint: type of epithelium)
simple squamous
Visceral layer of bowman’s capsule is formed by ____ whose foot processes contact glomerular blood capillaries.
Podocytes
What is the term for foot processes of podocytes ?
Pedicels
The connective tissue stroma of the glomerulus is constituted by ____ cells, which support the glomerular capillaries.
Mesangial
Part of nephron that is responsible for reabsorption of water, nutrients, and solids
Proximal convoluted tubule
Proximal convoluted tubule is lined by what epithelium ?
Simple cuboidal epithelium
Tubule cells of proximal convoluted tubules have microvilli on their luminal surfaces. True or False?
True
Tubule cells appear striated due to ?
Numerous basal infoldings & plenty of mitochondria
Part of nephron that functions as a counter-current multiplier system.
Medullary loop/Loop of Henle
What is the function of counter-current multiplier system?
To determine the osmolarity of urine
Blood flow in the medullary loop is similar to that in medullary vasa recta. True or False?
False, not similar but rather “counter”
Loop of Henle extends from what structures ?
Corticomedullary junction to medulla
Medullary loop is consists of three parts. What are these ?
- Descending limb
- Thin segment
- Ascending limb
The thin part of medullary loop is lined by what epithelium ?
Simple squamous
This part of nephron is responsible for reabsorption which is regulated by ADH and aldosterone.
Distal convoluted tubule
Distal convoluted tubule extends from what structure to what structure ?
Medullary loop and extends to collecting tubule within cortex
DCT is lined by what epithelium?
Low simple cuboidal epithelium
Same as the tubule cells of PCT, tubule cells of DCT has microvilli. True or False?
False, DCT has no microvilli
The epithelial cells of DCT stain less osmophilic compared to those of PCT. True or False?
True
Formed where the ascending loop of Henle/DCT contacts the afferent arteriole of renal corpuscle.
Juxtaglomerular apparatus
What are the three cells that constitute juxtaglomerular apparatus ?
- Macula densa/dense cells of DCT
- Juxtaglomerular cells of afferent arteriole
- Extraglomerular mesangial cells
Among the 3 types of cell constituting glomerular apparatus, which are the cells that become columnar and closely packed ?
Macula densa/dense cells of DCT
Among the 3 types of cell constituting glomerular apparatus, which are smooth muscle cells of tunica media that become spherical and contain renin granules ?
Juxtaglomerular cells of afferent arteriole
The juxtaglomerular apparatus produce what enzyme ?
Renin
Renin is responsible for ?
Converting angiotensinogen to angiotensin
A vasoconstrictor which raises blood pressure thus flow of ultrafiltrate
Angiotensin
Part of nephron that drain urine from nephron to renal pelvis
Collecting tubule/duct
Collecting tubule lies on ?
Medullary ray within cortex
Collecting tubule progressively increase in diameter towards cortex. True or False?
False, medulla.
In inner medulla, collecting ducts from different renal lobes unite to form ____ ____ ____, which open into renal pelvis.
large papillary ducts
Collecting duct are lined by epithelium that has 2 cell types. What are these ?
- collecting duct cells
- intercalated /dark cells
Collecting duct cells is in what form if residing in cortical part ?
Cuboidal
Collecting duct cells is in what form if residing in medullary ?
Columnar
Cells of collecting duct that resemble those of DCT but bulge into lumen of collecting duct.
Intercalated/dark cells
Permeability of collecting duct to water and ions is regulated by ?
ADH
Between the 3 parts of Loop of Henle, which is mainly responsible for formation of Juxtaglomerular apparatus ?
Ascending limb
Proximal convoluted tubule is lined with what epithelium ?
Simple cuboidal with brush border of microvilli
The descending limb of Loop of Henle is lined by what epithelium ?
Simple squamous epithelium
The ascending limb of Loop of Henle is lined by what epithelium ?
Simple cuboidal to low columnar epithelium
The distal convoluted tubule and collecting ducts are lined by what epithelium ?
Simple cuboidal composed of principal & intercalated cells which have microvilli
The renal physiology constitutes three functions. What are those ?
- Glomerular filtration of plasma
- Tubular reabsorption
- Tubular secretion
What is the net filtration pressure (NFP) or the total pressure that promotes filtration in the nephron?
10 mm Hg
A microscopic structure in the kidney that regulates functions of the nephron.
Juxtaglomerular apparatus
These are modified smooth muscle cells of the afferent arterioles of nephron which contains renin and sympathetically innervated granulated cells.
Juxtaglomerular cells
These are cells in juxtaglomerular apparatus which function as mechanoreceptors to changes in blood pressure.
Juxtaglomerular cells
These are Na+ sensor cells located at DCT that function as chemoreceptors that sense changes in solute concentration and flow of filtrate.
Macula densa cells
These are cells in juxtaglomerular apparatus that forms connections via actin and microtubules for selective vasoconstriction and vasodilation of the afferent and efferent arterioles.
Extraglomerular mesangial cells
Other term for extraglomerular mesangial cells
Lacis cells
What are the functions of juxtraglomerular apparatus?
- Tubuloglomerular Feedback (TGF) Mechanism
- Increased renal arterial pressure
- Return of osmolality and filtrate flow rate to normal
- Decreased renal arterial pressure
What are the processes include in renin-angiotensin-aldosterone system ?
- Release of renin
- Angiotensinogen to Angiotensin I (and II)
- Release of aldosterone
- Release of ADH
What converts angiontensin I to II?
Angiotensin-converting enzyme (ACE) (in the lungs)
Hormone that counteracts RAAS (renin-angiotensin-aldosterone system)
Atrial Natriuretic Peptide (ANP)
What are the 3 tissue layers of ureter? (innermost to outermost)
- Tunica mucosa
- Tunica muscularis
- Tunica serosa/adventitia
Tunica mucosa of ureter is lined by how many layers of transitional epithelium?
5-6 cell layers
Tunica muscularis of ureter has inner and outer longitudinal and middle layer of smooth muscles. True or False?
True
What are the 4 layers of urinary bladder? (innermost to outermost)
- Tunica mucosa
- T. submucosa
- T. muscularis
- T. serosa/adventitia
Tunica mucosa of urinary bladder is lined by how many layers of transitional epithelium?
14 cell layers
T. submucosa of urinary bladder contains small amount of vessels and is rich in hyaline fibers. True or False?
False, highly vascular and elastic fibers
The tunica muscularis of ureter and urinary bladder both contains inner and outer longitudinal and middle layer. True or False?
True
In T. serosa of urinary bladder, in which junction can you find a sphincter that prevents backflow of urine and at neck of bladder to regulate urine emptying?
Ureterovesicular junction
What are the 4 tissue layers of urethra?
- T. mucosa
- T. submucosa
- T. muscularis
- T. serosa/adventitia
Tunica mucosa of urethra has transitional epithelium that changes to stratified squamous at ____ ____ ____.
external urethral orifice
These are tissue spaces present in T. submucosa of urethra.
Cavernous tissue spaces
T. muscularis of ureter, urinary bladder, and urethra contain inner and outer longitudinal layer and middle layer. True or False?
True
In T. muscularis of urethra, this is the additional external layer of skeletal muscle.
Striated urethralis muscle
What makes the T. muscularis of urethra different from ureter and urinary bladder?
It is directed towards external urethral orifice