The Urinary System 3

Question 1

Low blood pressure effects on angiotensin

Answer 1

• Macula densea cells sense the low Na in the filterate duct
• JG cells detect the reduced streach in afferent arteriole
• Renin release from kidney converts angeotensinogen to angeotensin I
• Angeotensin converting enzyme converts angeotensin I to angeotensin II

Question 2

Hormonal control low pH

Answer 2

• Aldersterone travels to the DCT and the CD binding to the receptor which stimulates Na+ absorbtion to CD
• Cl- is cotransported while water follows increasing BP

Question 3

ADH secreation

Answer 3

• Released from prosterior pituitary to sensitive osmoreceptors when body fluid becomes concentrated
• Volume increases from streach receptors as there is high osmolarity and low blood pressure causing vasopressin release

Question 4

ADH function

Answer 4

• Increases permeability of duct to water therefore increasing reabsorbtion so there is only a small volume of conc urine

Question 5

Anti-Naturitic hormone

Answer 5

• Na+ secreation increased from the right atrium when blood volume increases
• Leads to loss of Na+
• Less Na+ reabsorbtion causing it to remain in the tubules
• Water moves to Na+ which increases urine volume and BP

Question 6

Ureters

Answer 6

• Carry urine from each kidney to the bladder smooth muscle

Question 7

Structure of the bladder

Answer 7

• Hollow smooth muscle organ
• Body and base

Question 8

Detrusor muscle

Answer 8

• A smooth muscle which help contract the muscle as a whole

Question 9

Trigone muscle

Answer 9

• Detects streach in the bladder

Question 10

External sphincter muscle

Answer 10

• Under somatic control voluntary part of the reflex
• Coodinate 35 reflexes coordinate activity of bladder and smooth muscle

Question 11

Filling

Answer 11

• The detrusor muscle is relaxed
• The bladder neck is closed

Question 12

Voiding

Answer 12

• The detrusor muscle contracts
• Bladder neck opens

Question 13

Miturition reflex

Answer 13

• Activated when unrinary muscle stretched (trigone)

Question 14

Control of micturition reflex

Answer 14

• CNS
• Spinal cord integrated
• Autonomic nervous syestem - pelvic and hypogastric nerves (sympathetic)
• Somatic nervous system (mainly prudential nerve) (parasympathetic)

Question 15

Storage phase

Answer 15

• Bladder fills pressures stays low
• 2 x wall tention/radius
• Bladder is full nessage detected and sent to the brain
• Volentary and local reflexes cause switch to voiding phase

Question 16

Voiding phase

Answer 16

• Volentary signal relax external sphincter
• Autonomic contraction of detrusor muscle
• Ureathra has excreatory role maintain flow until bladder empties

Question 17

Integrated sacral region

Answer 17

• Bladder fills causing sensory nerve endings to detect detrusor muscle stretch
• Message sent via dorsal spinal cord to the periqueductal gray matter at the cortext of the frontal lobe

Question 18

Switch at pons

Answer 18

• At micturition centre the message is sent via autonomic and stomatic motor nerves
• Message sent via ventral spinal cord causing detrusor muscle to contract and external sphincter relaxes

Question 19

Autonomic intervention in bladder

Parasympathetic

Answer 19

• Parasympathetic nervous system responds to aceyl choline
• Long preganglionic fibre to nicotinic receptor
• Short post ganglionic fibre to a muscarinic receptor
• Causes smooth muscles to contract when stimulated by acetyl choline

Question 20

How drug might effect bladder

Answer 20

• Drugs that antagonise and inhibit receptor causing contraction of detusor muscle and relaxation of sphincter muscle causes decrease in functionng of bladder
• Antagonist to muscarinic 2 and 3

Question 21

Automic innervation of the bladder

Sympathetic system

Answer 21

• Short preganglionic fibre first secreate acetyl choline
• Short second postganglionic fibre secreation of noradrenaline
• Noradrenaline binds to adrenoreceptors on the bladder
• Inhibition of urination

Question 22

What the sympathetic nervous system does to bladder

Answer 22

• Detrusor muscle relaxes but internal constrictor muscle are constricted
• Stopping urination

Question 23

Somatic prudendal nerve

Answer 23

• Volentary constriction of the external sphincter muscle to prevent micturition

Question 24

What happens to the bladder during infection

Answer 24

• trigone muscle also activated by irritation causes bacterial infections in urinary bladder
• Causes desire to void
• Bacteria passes up along urethra which enters and multiplies in the bladder causing inflammation
• Caused by bacteria in GI tract it WBC & RBC in urine