Urinary System

Question 1

what does the urinary system consist of?

Answer 1

• two kidneys
• two ureters
• one urinary bladder
• one urethra

Question 2

what are the kidneys main role?

Answer 2

• filter blood to produce urine
• maintain homeostasis by:
  -> regulation of ion levels in the blood
  -> regulation of blood volume and pressure
  -> regulation of blood pH
  -> production of hormones

Question 3

what do kidneys consist of internally?

Answer 3

• renal cortex
• renal medulla
• renal pyramids
• renal columns
• major and minor calyces
• renal pelvis

Question 4

what is the structure of the kidneys nephrons?

Answer 4

renal corpuscle:
- glomerulus & glomerular (bowman’s) capsule
renal tubule:
- proximal convoluted tube (PCT); nephron loop (of Henle); distal convoluted tubule (DCT)

Question 5

what are the three basic processes involved in the production of urine?

Answer 5

• glomerular filtration
• tubular reabsorption
• tubular secretion

Question 6

what occurs in glomerular filtration?

Answer 6

• blood plasma and dissolved substances get filtered into the glomerular capsule

Question 7

what occurs in tubular reabsorption?

Answer 7

• water, ions, and other substances get reabsorbed from the renal tubule lumen into the peritubular capillaries and ultimately into the blood.

Question 8

what occurs in tubular secretion?

Answer 8

• substances such as wastes, drugs and excess ions get secreted from the peritubular capillaries into the renal tubule.
• this forms urine.

Question 9

what membranes are involved in glomerular filtration?

Answer 9

• endothelium of glomerulus
• podocytes of glomerular capsule

Question 10

what is the path of urine drainage?

Answer 10

• collecting duct
• papillary duct
• minor calyx
• major calyx
• renal pelvis
• ureter
• urinary bladder

Question 11

ureters function

Answer 11

• transports urine from the kidneys to the bladder
• as bladder fills, it expands and compresses the ureters preventing back flow.

Question 12

detrusor muscle function

Answer 12

• stretches when the ladder fills and contracts to push out urine

Question 13

urethra function

Answer 13

• small tube leading from the bladder to the outside

Question 14

rugae function

Answer 14

• rugae and the lining transitional epithelium allow the urinary bladder to expand as it fills

Question 15

peritoneum function

Answer 15

• helps hold the bladder in place

Question 16

internal urethral sphincter function

Answer 16

• involuntary smooth muscle that opens and closes the urethra

Question 17

external urethral sphincter function

Answer 17

• voluntary skeletal muscle that opens and closes the urethra

Question 18

external urethral orifice function

Answer 18

• the opening of the urethra to the outside

Question 19

what occurs during a micturition reflex?

Answer 19

• when vol of urine in bladder is over 200-400ml the pressure increases
• stretch receptors in trigone detect this
• impulses travel to micturition centre in spinal cord and trigger micturition reflex
• bladder filling causes sensation of fullness and conscious desire to urinate before micturition reflex occurs.

Question 20

impulses during the micturition reflex

Answer 20

• contraction of the detrusor muscle in bladder wall (parasympathetic)
• relaxation of the internal urethral sphincter muscle (parasympathetic)
• inhibition of somatic motor nerves to cause relaxation f skeletal muscle in external urethral sphincter

Question 21

what are the common problems related to aging and urination?

Answer 21

• UTI’s
• increased frequency of urination
• urinary retention or incontinence
• acute and chronic kidney inflammations
• renal calculi (kidney stones)

Question 22

summary of abnormal constituents in urine: albumin

Answer 22

• very small amounts of blood plasma appear in urine as it is too large to be filtered
• presence of excessive albumin indicates an increase in the permeability of filtering membranes due to injury or disease, increased blood pressure or damage to kidney cells.

(ALBUMINURIA)

Question 23

SOACIN: glucose

Answer 23

the presence of glucose in the urine usually indicates diabetes mellitus

(GLUCOSURIA)

Question 24

SOACIN: red blood cells (erythrocytes)

Answer 24

• can occur with acute inflammation of urinary organs as a result of disease or irritation from kidney stones, tumours, trauma and kidney disease

(HEMATURIA)

Question 25

SOACIN: white blood cells (leukocytes)

Answer 25

• presence of WBC and other components of pus in the urine indicate infection in the kidneys and other urinary organs

(PYURIA)

Question 26

SOACIN: ketone bodies

Answer 26

• high levels may indicate diabetes mellitus, anorexia, starvation or too little carbohydrate in the diet

(KETONURIA)

Question 27

SOACIN: bilirubin

Answer 27

• when RBC are destroyed by macrophages, the globin portion of hemoglobin is split off and the heme is converted to biliverdin
• most of the biliverdin is converted to bilirubin
• an above normal level of bilirubin is called BILIRUBINURIA

Question 28

SOACIN: urobilinogen

Answer 28

• trace amounts are normal
• elevated levels may be due to haemolytic or pernicious anemia, infectious hepatitis, obstruction of bile ducts, jaundice, cirrhosis, congestive heart failure, or infectious mononucleosis

Question 29

SOACIN: casts

Answer 29

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