week 9

Question 1

Primary function of urinary system

Answer 1

• Excretion
• Osmoregulation
• Acid-based balance

Question 2

Secondary function of urinary system

Answer 2

• EPO secretion
• Renin
• Calcitriol
• Gluconeogenesis
• Detoxification
• BP homeostasis

Question 3

Functions of urinary system components (4)

Answer 3

Kidney - produces urine

Ureter - Transports urine towards the urine bladder

Urinary bladder - temporarily stores urine prior to elimination

Urethra - Conducts urine to exterior, in males transports semen as well

Question 4

External Anatomy

Answer 4

adrenal gland
fibrous tissue
fat layer

Question 5

Overall diagram of kidney (label)

Answer 5

Cortex
Medulla
Renal capsule
Pelvis
Hilum

Question 6

Nephron

Answer 6

• corpuscle, tubules & collecting duct
• filters blood to produce urine
• adjusts levels of nutrients & wastes by:
  
  • reabsorption
  • secretion

Question 7

Urinary cycle

Answer 7

Renal artery -> segmental arteries -> interlobar arteries -> arcuate arteries -> afferent arterioles -> glomerulus -> efferent arteriole -> peritubular capillaries -> venules -> cortical radiate veins -> arculate viens -> interlobar viens -> renal viens

Question 8

Afferent and efferent arteriole

Answer 8

Afferent arteriole ENTERS glomerulus - blood is filtered
Efferent arteriole leaves glomerulus
Peritubular capillaries delivers blood to venules

Question 9

Nerve supply

Answer 9

• Autonomic control
• Sympathetic nerve fibres
  
  • Adjust rate or urine formation
  • Stimulates renin release

Question 10

Renal nerve sympathetic activity

Answer 10

• Stimulates renin release
• Enhances renal sodium and water resorption
• Causes renal vasoconstriction

Question 11

Path of urine flow

Answer 11

Kidney pyramids 
Minor calyces
Major Calyces
Renal pelvis
Ureters
Bladder
Urethra

Question 12

Parts of urine production

Answer 12

glomerular filtration, relevant pressures, tubular reabsorption, tubular secretion

Question 13

Roles of kidneys in BP control

Answer 13

autoregulation, autonomic regulation

Question 14

3 parts to the Nephron

Answer 14

• Renal corpuscle
• Renal tubule
• Collecting duct

Question 15

Renal corpuscle

Answer 15

• afferent arteriole
• glomerulus
• bowman’s capsule/ capsular space
• efferent arteriole

Question 16

Renal tubule (3 parts)

Answer 16

• proximal convoluted tubule (PCT)
• loop of henle
• distal convoluted tubule (DCT)

Question 17

Nephron (2 substances involved)

Answer 17

Blood:
- is filtered (corpuscle) to make urine

Urine:
- which is collected in tubules and emptied into collecting ducts

Question 18

Juxtaglomerular cells

Answer 18

• receptors
• in wall of afferent arteriole
• sense change in BP
• secretes renin when BP is low

Question 19

Urine formation

Answer 19

• glomerular filtration
• tubular reasborption
• tubular secretion

Question 20

What is reabsorbed

Answer 20

• most water 99%
• most ions (sodium & potassium)
• all nutrients
• urea (50%)

Question 21

3 forces of filtration

Answer 21

• glomerular hydrostatic (forces water out of capillary into capsule)
• capsular hydrostatic (water pushes back into capillary from capsule)
• colloid osmotic (proteins inside capillary draw water back into capillary)

Question 22

Net filtration pressure (NFP)

Answer 22

• Out of blood = 50 mmHg
• Back into blood = 15+25 mmHg
• Net = 50-40 = 10mmHg out of blood

Question 23

Collecting system

Answer 23

• receive fluid from many nephron
• begins in cotrex
• descends into medulla
• carries fluid towards minor calyx

Question 24

Micturition reflex (2 parts)

Answer 24

SNS - Store

PNS - Pee

Question 25

Polyuria

Answer 25

lots of urine (>30mL/kg)

Question 26

Oliguria

Answer 26

minimal urine (0.5mL/kg)

Question 27

Anuria

Answer 27

no urine

Question 28

Storage (micturition)

Answer 28

garding reflex -> distension -> afferent impulse -> increase sympathetic outflow ->increase bladder outlet tone and decrease detrusor contraction -> promotes continent

Question 29

Voiding (micturition)

Answer 29

micturition reflex -> significant distension -> intense afferent impulse -> increase parasympathetic outflow and decrease sympathetic outflow -> decrease bladder outlet tone

Question 30

Glomerular Filtration Rate (GFR)

Answer 30

- volume of fluid filtrated per minute - normal GFR = 90-125 ml/min Afferent arterioles dilate - more blood flows in, increase GFR Afferent arterioles constrict - less blood in decrease GFR

Question 31

Regulation of GFR

Answer 31

GFR need to be constant - Low GFR = can't excrete waste - Hight GFR - less time for reabsorption

Question 32

Body water content

Answer 32

- at birth: 70-80% - adulthood: 50-65% - old age: 40-45%

Question 33

Body water intake and loss

Answer 33

INTAKE preformed: 2300ml/day metabolic: 200ml/day ``` LOSS kidneys: 1500ml/day skin: 600ml/day lungs: 300ml/day GIT: 100mml/day menstrual flow ```

Question 34

Fluid compartments

Answer 34

``` Intracellular fluid (ICF) Extracellular fluid (ECF) - plasma - interstitil fluid - other ```

Question 35

Water in the body

Answer 35

- main component of all body fluids - movement via osmosis - if fluids are balanced so are electrolytes - we aim for balance unless directed otherwise

Question 36

Dehydration

Answer 36

thirst centre in hypothalamus stimulated | adjusting water volume = ADH, aldosterone

Question 37

ADH

Answer 37

- decrease plasma volume - collecting ducts more permeable to water - more concentrated urine

Question 38

ADH secretion

Answer 38

- stimulated by anything that increases loss - inhibited by alcohol and high blood volume - dilute urine

Question 39

Electrolytes in body fluids

Answer 39

inside: potassium, protiens and phosphates outside: sodium and chloride

Question 40

Specific Gravity (SG)

Answer 40

High SG: - urine concentrated - more solutes in each ml Low SG: - urine dilute - less solutes in each ml

Question 41

Aldosterone

Answer 41

- retain more sodium, water (water always follows sodium) | - more water (increases blood volume thus GFR)