Urinary

Question 1

urinary system

Answer 1

• 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

Question 2

kidney functions

Answer 2

• 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

Question 3

external anatomy of kidney

Answer 3

• 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

Question 4

internal anatomy of kidneys

Answer 4

• 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

Question 5

regions of the kidney

Answer 5

• 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

Question 6

drainage system of kidneys

Answer 6

• 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

Question 7

material supply to kidney

Answer 7

• 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

Question 8

vasa recta

Answer 8

• specialized vessels in the kidney that surround the Loop of Henle to supply blood to renal medulla

Question 9

the nephron

Answer 9

• functional unit of kidneys

- over 1 million is one kidney composed of a renal corpuscle & tubule

Question 10

renal corpuscle

Answer 10

• site of plasma filtration
• glomerulus is capillaries where filtration occurs
• Bowmans capsule is double-walled epithelial cup that collects filtrate, helps solidify some urine

Question 11

renal tubule

Answer 11

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

Question 12

structure of renal corpuscle

Answer 12

• 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

Question 13

bowmans capsule

Answer 13

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

Question 14

filtration membran

Answer 14

• 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

Question 15

podocytes

Answer 15

• 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

Question 16

glomerular filtration

Answer 16

• 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

Question 17

cortical nephron

Answer 17

• 80-85% of nephrons

- renal corpuscles are in outer cortex and loops of Henle lie mainly in cortex

Question 18

juxtamedullary nephron

Answer 18

• 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

Question 19

juxtaglomerular apparatus cells

Answer 19

• 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

Question 20

juxtaglomerular apparatus function

Answer 20

• 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

Question 21

nephron components

Answer 21

• 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

Question 22

kidney innervation

Answer 22

• 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

Question 23

kidney stones

Answer 23

• 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

Question 24

anatomy of ureter

Answer 24

• 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

Question 25

hydrostatic pressure

Answer 25

fluid in a tube will move if the fluid behind it is moving

Question 26

histology of ureters

Answer 26

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

Question 27

location or urinary bladder

Answer 27

• posterior to pubic symphysis
• anterior to vagina and inferior to uterus
• males anterior to rectum

Question 28

anatomy of urinary bladder

Answer 28

• hollow, distensible muscular organ with normal capacity of 350ml
• extreme 700-800ml
• trigone is smooth flat area bordered by 2 urethral openings

Question 29

wall of urinary bladder

Answer 29

• 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

Question 30

detrusor muscle function

Answer 30

makes it so bladder is completely empty after every time you pee

Question 31

transitional epithelium

Answer 31

• 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

Question 32

urethra

Answer 32

• fibromuscular tube that originates at neck of urinary bladder and conducts urine to exterior of body

Question 33

2 sphincters of that control the release of urine from the bladder into urethra

Answer 33

1) internal urethral sphincter: smooth muscle

2) external urethral sphincter: skeletal muscle

Question 34

female urethra

Answer 34

• has single function of transporting uringe to exterior body
• belongs exclusively to urinary system

Question 35

male urethra

Answer 35

• 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

Question 36

micturition

Answer 36

• 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