Module 18: The Urinary System

Question 1

Functions of the urinary system

Answer 1

removes waste from blood
excretes in form of urine
controls acid-base balance
regulates fluid balance
regulates electrolyte balance
stimulates the production of RBC
controls blood pressure

Question 2

Organs of urinary system

Answer 2

2 kidneys
2ureters
urinary bladder
urethra

Question 3

Kidney

Answer 3

Highly vascular

Retroperitoneal organ

Question 4

3 parts of kidney

Answer 4

renal cortex (outer)
Renal medulla (middle)
Renal pelvis (inner)

Question 5

surrounding each kidney are 3 layers of tissue

Answer 5

fibrous capsule (inner)
peritoneal fat capsule (middle)
Renal fascia (outer)

Question 6

Hilum

Answer 6

notch where ureter leaves the kidney and blood vessels, nerves, lymph vessels enter and leave the kidney

Question 7

Renal pyramids

Answer 7

triangular structures that look striated due to renal tubules

Question 8

Renal papillae

Answer 8

tips of pyramids

Question 9

Minor calyces

Answer 9

surround the tip of each renal pyramid
funnel shaped structures
Function is to collect urine from the ducts of pyramids

Question 10

Major calyces

Answer 10

join together to form large collecting area called renal pelvis

Question 11

Nephrons

Answer 11

microscopic units of kidney that regulate the composition and volume of blood and form urine
Nephron consists of glomerulus, bowman capsule, renal tubule

Question 12

Glomerulus

Answer 12

network of capillaries
surrounded by bowman capsule
where blood is filtered

Question 13

Bowmans capsule

Answer 13

receive filtered blood (filtrate) from glomerulus and deliver to renal tubule
contains fluid that is the raw material of urine

Question 14

Renal tubule

Answer 14

long convoluted tube
site of urine formation by reabsorption and secretion
juxtaglomerular apparatus is what regulates the rate of filtrate formation

Question 15

3 parts of renal tubule

Answer 15

Proximal convoluted tubule
loop of hence
distal convoluted tubule (then leads to collecting duct)

Question 16

3 steps of urine formation

Answer 16

glomerular filtration
tubular reabsorption
tubular secretion

Question 17

Physical properties of urine

Answer 17

clear fluid
light yellow
slight odor

Question 18

chemical properties of urine

Answer 18

95% water
5% urea, na, cl, k ,ca, mg, sulfates, phos, bicarbonates, uric acid, ammonium ions, creatinine
slightly acidic Ph 4.5-8

Question 19

Antidiuretic hormone (ADH)

Answer 19

synthesized in the hypothalamus
stores and secreted by posterior pituitary gland
High levels of ADH increase water reabsorption
Low levels of ADH decrease water reabsorption

Question 20

Aldosterone

Answer 20

hormone released by adrenal glands
helps regulate fluid balance
stimulates distal tubules to reabsorb Na+ and water, and to excrete K+

Question 21

Atrial Natriuretic Peptide (ABP)

Answer 21

inhibits the reabsorption of Na+ and water

decreasing blood volume and pressure

Question 22

Renin

Answer 22

secreted by juxtaglomerular apparatus
involved with control of blood
leads to formation of angiotensin I which converts to angiotensin II
angiotensin II raises blood pressure

Question 23

Erythropoietin (EPO)

Answer 23

secreted by kidneys in response to low oxygen in arterial blood
targets bone marrow
stimulates production of RBC

Question 24

Ureters

Answer 24

long tubes

wave like contraction of smooth muscle in walls of ureters move urine down towards the baldder

Question 25

Bladder

Answer 25

resembles inflatable balloon
3 openings (2ureter, 1 urethra) form Trigone

3 layers of smooth muscle collectively called detrusor muscle
Transitional epithelium mucous membrane

Question 26

Urethra

Answer 26

female 3-4cm
male 20cm
3 regions: prostatic, membranous, spongy(penile)

Question 27

micturition

Answer 27

aka voiding or urination

detrusor muscle contracts

Question 28

control of micturition

Answer 28

when bladder is partially full, stretch receptors transmit nerve impulses to spinal cord; initiate conscious desire to expel urine and micturition reflex (unconscious)

Exit of bladder is internal sphincter (involuntary contraction)
External sphincter is voluntary