Nakamura Human Anatomy Ch 24

Question 1

Kidneys

Answer 1

Maintain the chemical consistency of the blood
–Filter many liters of fluid from blood
–Send toxins, metabolic wastes, and excess water out of the body
–Main waste products
•Urea, uric acid, and creatinine

Question 2

Organs of the urinary system

Answer 2

• kidneys
• ureters
• urinary bladder
• urethra (diff in male/female)

Question 3

Location and external anatomy of kidneys

Answer 3

.Lateral to T12–L3 vertebrae (located at bottom of ribs)
•Average kidney – 12 cm tall, 6 cm wide, 3 cm thick
•Renal capsule surrounds the kidney
Not in the peritoneal cavity

Question 4

Internal gross anatomy of the kidneys

Answer 4

Frontal section through the kidney
    –Renal cortex, renal pyramids, and renal pelvis
•Nerve supply: renal plexus
   –A network of autonomic fibers
   –An offshoot of the celiac plexus

Question 5

Nephron

Answer 5

• function unit
• approximately 1 million per kidney
• no veins, only arteries
• glomerular capsule: vessel/capillary network of arterioles (afferent and efferent)

Question 6

Renal corpuscle

Answer 6

-glomerulus and glomerular capsule
–Glomerulus: tuft (a cluster) of capillaries
•Capillaries are fenestrated
-fed and drained by afferent and efferent arterioles

Question 7

Glomerular (bowman’s) capsule

Answer 7

-Parietal layer: simple squamous epithelium

–Visceral layer: consists of podocytes (covering glomerular capillary)

Question 8

Mechanisms of urine production

Answer 8

Filtration
Reabsorption
Secretion
Body ph is 7.4 
Protein has to have correct ph (it's structure depends on it)

Question 9

Filtration

Answer 9

Filtrate of blood leaves kidney capillaries (GFR (glomerular filtration rate) = 180 L/day)

Question 10

Reabsorption

Answer 10

Most nutrients, water, and essential ions reclaimed

• process of retiring filtered material to blood stream: 99% of what is filtered. Involve transport proteins
• 1% that is left forms urine (1.5 L)

Question 11

Tubular section of nephron

Answer 11

.Filtrate proceeds to renal tubules from glomerulus
   –Proximal convoluted tubule
   –Loop of Henle
       •Descending limb
       •Thin segment
       •Thick segment
    –Distal convoluted tubule

Question 12

Secretion

Answer 12

Active process of removing undesirable molecules

Question 13

Classes of nephron

Answer 13

.Cortical nephrons – 85% of nephrons

•Juxtamedullary nephrons – 15% of nephrons

Question 14

Collecting tubules (collecting ducts)

Answer 14

Receive urine from distal convoluted tubules

Question 15

Microscopic blood vessels

Answer 15

• Nephrons associated with two types of capillary beds
  - glomerulus
  - peritubular capillaries
• vasa recta
• juxtaglomerular apparatus (JGA)
• macula dense

Question 16

Peritubular capillaries

Answer 16

In the cortex, arise from efferent arterioles

• low pressure, porous capillaries
• absorb salutes

Question 17

Vasa recta

Answer 17

• in the medulla
• thin-walled looping vessels
• part of the kidney’s urine-concentrating mechanism

Question 18

Juxtaglomerular apparatus (JGA)

Answer 18

• juxtaglomerular cells, macula dense, afferent and efferent vessels and mesangial cells
• functions in the regulation of blood pressure

Question 19

Juxtaglomerular cells

Answer 19

Secrete renin

Question 20

Macula dense

Answer 20

Portion of distal convoluted tubule

• tall, closely packed epithelial cells
• act as chemoreceptors (senses NaCl)

Question 21

Ureters

Answer 21

Carry urine from the kidneys to the urinary bladder
•Histology of ureter
      –Mucosa: transitional epithelium
      –Muscularis: two layers
              •Inner longitudinal layer
              •Outer circular layer

Question 22

Urinary bladder

Answer 22

A collapsible muscular sac
      •Stores and expels urine
–Full bladder: spherical
     •Expands into the abdominal cavity
–Empty bladder: lies entirely within the pelvis

Question 23

Urethra female

Answer 23

length of 3–4 cm

Question 24

Urethra male

Answer 24

20 cm in length
three named regions
–Prostatic urethra: passes through the prostate gland
–Membranous urethra: through the urogenital diaphragm
–Spongy (penile) urethra: passes through the length of the penis

Question 25

Urethra histology

Answer 25

-Transitional epithelium: near the bladder –Stratified and pseudostratified columnar: mid urethra –Stratified squamous epithelium: near the distal end •Internal urethral sphincter: involuntary smooth muscle •External urethral sphincter: voluntarily skeletal muscle it controls urination