Urinary Flashcards
1
Q
urinary system
A
- kidneys, ureters, urinary bladder, & urethra
- urine flows from each kidney, down its ureter to the bladder and to the outside via the urethra
- filter the blood and return most of water and solutes to the bloodstream
2
Q
kidney functions
A
- regulation of blood consumption (Na+, K+, Ca2+, Cl- and phosphate ions)
- regulation of blood pH, osmolarity and glucose
- regulation of blood volume (conserving/eliminating water)
- regulation of blood pressure
- excretion of wastes and foreign substances
3
Q
external anatomy of kidney
A
- just above waist between the peritoneum and posterior wall of abdomen (retroperitoneal along with adrenal glands and ureters)
- protected by 11th and 12th ribs with right kidney lower
- has concave hilum where blood vessels, nerves, and ureters enter/exit
- renal capsule= transparent membrane, maintains organ shape
- adipose tissues help protect from trauma and for thermal insulation
- renal facia= dense, irregular connective tissue that holds It against back body wall
4
Q
internal anatomy of kidneys
A
- parenchyma of kidney (renal cortex is superficial and medulla)
- inner portion consisting of cone-shaped renal pyramids separated by renal columns (part of cortex)
- renal papilla point toward centre of kidney
5
Q
regions of the kidney
A
- outer renal cortex and inner renal medulla
- extensions of renal cortex called renal columns project into medulla and subdivide it into renal pyramids
- 8-15 renal pyramids
- wide base of renal pyramid makes contact with the cortex in a region called corticomedullary junction
- apex of renal pyramid is renal papilla
6
Q
drainage system of kidneys
A
- fills renal sinus cavity
- cup-like structure called minor calyces collect urine from papillary ducts of papilla
- minor & major calyces empty into renal pelvis which empties into ureter
7
Q
material supply to kidney
A
- blood enters kidneys by renal arteries
- within renal sinus, renal arteries branch into segmental arteries
- segmental arteries branch into interlobar arteries
- interlobar arteries branch into arcuate arteries
- arcuate arteries branch into interlobular arteries
- afferent arterioles—> glomerulus—> efferent arterioles
8
Q
vasa recta
A
- specialized vessels in the kidney that surround the Loop of Henle to supply blood to renal medulla
9
Q
the nephron
A
- functional unit of kidneys
- over 1 million is one kidney composed of a renal corpuscle & tubule
10
Q
renal corpuscle
A
- site of plasma filtration
- glomerulus is capillaries where filtration occurs
- Bowmans capsule is double-walled epithelial cup that collects filtrate, helps solidify some urine
11
Q
renal tubule
A
1) proximal convoluted tubule
2) Loop of Henle
3) distal convoluted tubule
- collecting ducts and papillary ducts drain urine to the renal pelvis and ureter
- allows u to pull water, iron, fats, etc back if you need to
12
Q
structure of renal corpuscle
A
- vascular pole vs tubular pole
- Bowmans capsule surrounds capsular space
- podocytes cover capillaries to form the capsules visceral layer
- simple squamous cells form the parietal layer of capsule
- glomerular capillaries arise from afferent arteriole and form a call before exiting via the efferent arteriole
- Bowmans space is space between bowman and glomerulus
13
Q
bowmans capsule
A
1) visceral layer: directly overlies and comes in contact with the glomerulus, comprised of specialized cells called podoocyes
2) parietal layer: formed from simple squamous epithelium
14
Q
filtration membran
A
- stops all cells and platelets, stops large plasma proteins, stops medium-sized proteins, not small ones
- kidney capillaries are fenestrated
- podocytes cover fenestrations as a gatekeeper to filter things efficiently and quickly
15
Q
podocytes
A
- have long processes called pedicles that wrap around the glomerular capillaries but don’t completely surround it
- pedicles are separated from each other by thin spaces called filtration slits
- filtration slits and fenestrated capillary wall makes up the filtration membrane, which mostly leaks indiscriminate contents from the plasma into capsule
- role of the remainder of nephron to adjust the contents of the urine
16
Q
glomerular filtration
A
- BP inside glomerulus produces ultrafiltrate
- 48 gallons (180L)/day of filtrate (1-2 qt. urine)
- kidneys absorbs and filters ultrafiltrate
- filtering capacity enhanced by thinness of membrane and large surface area of glomerular capillaries
- glomerular capillary blood pressure is high due to small lumen of efferent arteriole
17
Q
cortical nephron
A
- 80-85% of nephrons
- renal corpuscles are in outer cortex and loops of Henle lie mainly in cortex
18
Q
juxtamedullary nephron
A
- 15-20% of nephrons
- renal corpuscles close to medulla and long loops of Henle extend into deepest medulla enabling excretion of dilute or concentrated urine
- right beside medulla, not all nephrons are in the same position
19
Q
juxtaglomerular apparatus cells
A
- structure where afferent arteriole makes contact with distal convoluted tubule
1) macula densa: thickened part of DCT, monitors urine concentration
2) extraglomerular (juxtaglomerular) cells: regulate signals between macula dense and afferent arteriole
3) afferent arteriole: granular (JG) cells of smooth muscle monitor BP, secrete renin
20
Q
juxtaglomerular apparatus function
A
- acts as quality control mechanism for glomerulus
- macula dense cells respond to changes in filtrate osmolarity
- renin released from juxtaglomerular cells in response to low BP
- renin cells bind with angiotensin
- renin-angiotensin system leads to ADH and aldosterone release from anterior pituitary
- more sales and water are reabsorbed, leading to higher blood volume and BP
- can’t change urine, can monitor it so the next batch of urine is better
21
Q
nephron components
A
- distal convoluted tubule has to meet up with afferent arteriole
- glomerulus is always in cortex
- collecting ducts only collect urine, passage from point a to point b
22
Q
kidney innervation
A
- innervated by a mass of sensory and autonomic fibers collectively called the renal plexus, which enters the kidney at hilum
- pain from kidneys is usually referred to dermatomes T10-T12
23
Q
kidney stones
A
- crystal aggregates of various substances
- uric acid, calcium oxalate/phosphate, struvite, cystine
- may become stuck in kidney, bladder or any urinary tubes
- may be painful and dangerous
24
Q
anatomy of ureter
A
- extends from renal pelvis to bladder
- enters posterior wall of bladder obliquely
- urine flows through ureters results from peristalsis, gravity, and hydrostatic pressure
- ensures no matter what position you’re in urine will move in one direction
25
Q
hydrostatic pressure
A
fluid in a tube will move if the fluid behind it is moving
26
Q
histology of ureters
A
3 layers in wall
1) mucosa: transitional epithelium
2) muscular: inner longitudinal and outer circular smooth muscles, peristalsis contributes to urine flow
3) adventitia layer: loose areolar connective tissue anchors in place
27
Q
location or urinary bladder
A
- posterior to pubic symphysis
- anterior to vagina and inferior to uterus
- males anterior to rectum
28
Q
anatomy of urinary bladder
A
- hollow, distensible muscular organ with normal capacity of 350ml
- extreme 700-800ml
- trigone is smooth flat area bordered by 2 urethral openings
29
Q
wall of urinary bladder
A
- 4 tunics
1) mucosa: transitional epithelium that lines internal surface of bladder, rug allow for distension of bladder
2) submucosa: supports bladder wall
3) muscular: 3 layers of mixed smooth muscle called detrusor muscle, and internal urethral sphincter muscle at urethral opening
4) adventitia: outer layer of areolar connective tissue
30
Q
detrusor muscle function
A
makes it so bladder is completely empty after every time you pee
31
Q
transitional epithelium
A
- bladder and ureter epithelium is transitional in that it appears cuboidal when relaxed, and squamous when distended
- needed to protect the underlying tissues from toxic urine and well as being easily stretched
32
Q
urethra
A
- fibromuscular tube that originates at neck of urinary bladder and conducts urine to exterior of body
33
Q
2 sphincters of that control the release of urine from the bladder into urethra
A
1) internal urethral sphincter: smooth muscle
2) external urethral sphincter: skeletal muscle
34
Q
female urethra
A
- has single function of transporting uringe to exterior body
- belongs exclusively to urinary system
35
Q
male urethra
A
- 2 functions: urinary and reproductive, serves as transport to urine and semen
3 segments
1) prostatic urethra: in prostate gland
2) membranous urethra: muscle band, always shortest segment
3) spongy urethra: spongy tissue - ends as opening called external urethral orifice
36
Q
micturition
A
- urination
- occurs via urinary reflex, when spinal cord senses pressure in bladder walls, the trigone and both urethral sphincters relax, while detrusor muscles contract
- can be voluntary by contraction of perineal muscles and external urethral sphincters
- difficulty/inability to urinate is called urinary retention (ishuria) can be seen in spinal/neurological injury, infection, blockages, tumours, medications
- inability to hold urine is called incontinence, can be caused by obesity, pregnancy, diabetes, infection, hernia, aging
