Chapter 24 The Urinary System

Question 1

Know Organs of the Urinary System

Answer 1

Adrenal Gland, Renal Artery, Renal Vein, Kidney, Ureter, Uterus, Urinary bladder, Urethra

Question 2

Functions of Kidney

Answer 2

• Elimination of wastes
• Chemical constancy of blood
• balance of blood (H2O/Acids vs Electrolytes/Bases)

Question 3

Location of Kidneys?

Answer 3

Superior lumbar region of the posterior abdominal wall, 12th rib is 2/3 way down kidney

Question 4

The kidneys are___. (location and attachment)

Answer 4

Retroperitoneal

Question 5

Know gross anatomy of kidney

Answer 5

renal cortex
renal medulla
major calyx
minor calyx
renal pelvis
ureter
renal pyramid
renal column
fibrous capsule

Question 6

Microscopic anatomy of kidney

Answer 6

Uriniferous tubule = Nephron + Collecting Duct

- the functional unit of the kidney

Question 7

2 parts of the nephron

Answer 7

Renal Corpuscle:

• glomerulus - tuft of capillaries
• glomerular capsule- cup shaped, hollow capsule surrounding the glomerulus (bowman’s capsule)

Tubular Section

• proximal convoluted tubule
• loop of henle
• distal convoluted tubule
• collecting duct

Question 8

Capillary beds of kidney

Answer 8

• Glomerulus- Afferent->efferent arterioles
• Peritubular capillaries- branch from efferent arteriole and cling to convoluted tubules with the function of emptying into veins
• Vasa Recta- like peritubular capillaries but for the loop of henle and runs alongside nephrons

Question 9

Juxtaglomerular Aparatus “near the glomerulus”

Answer 9

• helps regulate blood pressure
• specialized contact between ascending limb of the loop of henle and the afferent arteriole
• has Macula densa cells- modified epithelial cells of ascending loop
• Granular cells- modified smooth muscle cells of the afferent arteriole
• Mesangial cells- specialized cells between macula densa and the granular cells

Question 10

Basic processes of urine production

Answer 10

Blood: Artery-> afferent arteriole-> glomerulus-> efferent arteriole
Urine: Glomerulus-> prox conv-> loop of henle-> distal conv-> collecting duct-> ureter

There are 3 steps:
Glomerular filtration
Tubular resorption
Tubular secretion

Question 11

Ureter length?

Answer 11

10 inches long

Function: carry urine from renal pelvis to urinary bladder

Question 12

Urinary bladder

Answer 12

• Collapsible, muscular sac that stores and expels urine

- detrusor- smooth muscle of bladder wall

Question 13

Urethra

Answer 13

• Tube that drains urine from bladder
• Internal urethral sphincter- thickening of the bladder wall (detrusor) at the proximal urethra
• external urethral sphincter- skeletal muscle formed from the urogenital diaphragm

Question 14

Difference in length between male and female urethra

Answer 14

3-4cm vs 20cm

Question 15

Micturition (urination/voiding)

Answer 15

1) visceral afferent impulses from stretch receptors in bladder wall carried to spinal cord and then to pontine micturition center
2) integration in pontine micturition center initiates micturition response. Descending pathways carry impulses to motor neurons in spinal cord.
3) Parasympathetic efferents stimulate contraction of the detrusor muscle and open internal urethral sphincter.
4) sympathetic efferents to bladder are inhibited
5) somatic motor efferents to external urethral sphincter are inhibited; sphincter relaxes and urine passes