26-Urinary System

Question 0

Functions of urinary system - 4

Answer 0

Regulation of blood volume and composition
Production of waste urine
Transport of urine to bladder
Discharge of urine from body

Question 1

Components of urinary system - 4

Answer 1

Kidneys
Ureters
Urinary bladder
Urethra

Question 2

Kidney functions - 6

Answer 2

Regulation of blood ionic composition - Na, K, Ca2, HPO4
Regulation of blood pH
Regulation of blood volume
Regulation of blood pressure
Regulation of blood osmolarity
Production of calcitriol and erythropoietin

Question 3

External kidney anatomy, 3 layers, 1 indentation

Answer 3

Hilum is indentation
Superficial - renal fascia
Middle - adipose capsule
Deep - renal capsule

Question 4

Internal kidney anatomy - 5

Answer 4

Parenchyma includes these 3: Renal cortex
Renal medulla
Pyramids - wide base to cortex, narrow apex is renal papilla
Papilla feed minor calyces, which feed 2-3 major calyces
Renal sinus contains renal pelvis, calyces, blood vessels, nerves

Question 5

Kidneys use how much oxygen

Answer 5

25%

Question 6

Kidney blood supply - 3

Answer 6

Glomerulus ball of capillaries, separates blood and filtrate
Surrounded by glomerular/Bowman’s capsule
Efferent arteriole takes blood away, smaller than afferent

Question 7

Nephron - 2 parts, 2+3 subparts

Answer 7

Renal Corpuscle - glomerulus and glomerular capsule

Renal Tubules - proximal convoluted tubules, distal convoluted tubules (PCT/DCT), loop of Henle

Question 8

Types of Nephrons - 2

Answer 8

Cortical - 80%, short loops of Henle mostly in cortex
Juxtamedullary - 20%, long loops of Henle mostly in medulla, loops near vasa recta arterioles, loops have thick and thin parts

Question 9

Nephron histology - 6

Answer 9

Fenestrated capillaries
Glomerular capsule has visceral, parietal layers
Parietal forms outer wall of capsule, into tubule
Visceral modified simple squamous podocytes, foot like projections form slits between for filtration
Bowman’s space between, gets filtrate

Question 10

Juxtaglomerular apparatus - 3

Answer 10

End of ascending Henle forms macula densa against afferent arteriole
Afferent arteriole at macula has modified smooth muscle, JuxtaGlomerular (JG) cells
JG apparatus regulates blood pressure in kidney, secretes renin

Question 11

Filtering is 3 step process

Answer 11

Glomerular filtration
Tubular reabsorption
Tubular secretion

Question 12

Filtration fraction

Answer 12

Fraction of blood plasma that becomes glomerular filtrate. About 1/4.

Question 13

Glomerular Membrane filtration barriers - 3

Answer 13

Epithelial cells - large fenestrations
Basal lamina - negative charge
Pedicels - filtration slits
Allows water, glucose, vitamins, minerals, amino acids, very small proteins, ammonia, urea, ions. NOT Albumin.

Question 14

Glomerular Filtration Rate (GFR) - Too high, too low, controls - 2

Answer 14

Too High - Some needed substances not reabsorbed, lost in urine
Too Low - Reabsorb some waste, drugs
Intrinsic, Extrinsic

Question 15

Intrinsic GFR - 2

Answer 15

Myogenic stretch reflex - too high causes arterioles to constrict
Tubuloglomerular feedback - juxtaglomerular cells use chemicals (ATP, NO) to vasoconstrict or vasodilate

Question 16

Extrinsic GFR - 3

Answer 16

Neural Regulation - sympathetic
Hormonal - Renin Angiotensin Aldosterone
Angiotensin II - Potent vasoconstrictor, reducing GFR, also released by kidneys

Question 17

Reabsorption/Secretion PCT - 4

Answer 17

Largest amount of solute & water reabsorbed in PCT - 100% glucose
Uses aquaporin-1
Solute reabsorption in PCT involves Na+
Secrete Urea and Ammonia PCT to tubular fluid

Question 18

Reabsorption/Secretion Loop of Henle - 2

Answer 18

Thin descending has low permeability to ions and urea, high to water
Thin ascending impermeable to water, permeable to ions including Na & Cl

Question 19

Reabsorption/Secretion late DCT and Collecting duct -

Answer 19

Na/Cl reabsorption via Na symporters
Principle Cells reabsorb Na, secrete K; Aldosterone increases Na/K pumps in these areas
Intercalated cells reabsorb K+ & bicarbonate, secrete H+
Solute reabsorption/secretion, water reabsorption varies based on body needs

Question 20

Distal Nephron - 2 cell types, what they do

Answer 20

Principle Cells - vast majority, receptors for ADH, aldosterone
Intercalated cells - role in regulating pH

Question 21

Amount of kidney function loss before symptoms

Answer 21

75% loss because kidneys can take on large loads

Question 22

ADH in the Distal Tubule, how it works, % change

Answer 22

ADH causes Insert of aquaporin-2 into tubule membrane,
Less ADH, aquaporin-2 removed
1% change in plasma water concentration can cause ADH to be released by posterior pituitary

Question 23

Concentrated Urine and countercurrent exchange/multiplication

Answer 23

Ions concentration highest in lowest part of LoH. Also in medulla surrounding LoH
Vasa Recta multiplies by looping ions around
If aquaporin-2 present in collecting duct in that area, concentration will pull water out of duct (osmosis)
This is how ADH causes more concentrated urine, conserves water in the body.

Question 24

RAA Initial Pathway - 6

Answer 24

Decreased Na, dehydration, hemorrhage -> Lower blood volume/press
JG cells of kidneys make increased renin
Renin cleaves angiotensinogen from liver to angiotensin I
Angiotensin I to lungs Angiotensin Converting Enzyme ACE -> Angiotensin II

Question 25

RAA Pathway second short

Answer 25

Angiotensin II vasoconstricts arterioles, raises blood pressure

Question 26

RAA Pathway third through adrenal cortex

Answer 26

Angiotensin II OR increased K+ extracellular -> Adrenal cortex -> increased aldosterone
Aldosterone in kidneys causes increased absorption of Na+, water -> increased blood volume -> increased blood pressure

Question 27

Ureter tissue layers 3 plus opening into bladder

Answer 27

Deep - mucosa transitional epithelium
Middle - Muscularis
Superficial - Adventitia
Oblique entry into bladder to prevent backflow

Question 28

Trigone

Answer 28

triangle in bladder of two ureter openings, urethral opening

Question 29

Muscles of bladder - 3

Answer 29

Detrusor - muscularis around bladder
Internal sphincter - involuntary smooth muscle
External sphincter - skeletal muscle, perineum

Question 30

Layers of tissue for urinary bladder, plus word for urination

Answer 30

Mucosal - transitional epithelium
Muscularis - detrusor muscle
Adventitia - holds in place
Urination = micturition

Question 31

Urethra - lengths, and 3 sections

Answer 31

Female - 4cm
Male - 20cm
        - Prostatic
        - Membranous
        - Spongy