Urinary System (Q4, P3)

Question 1

Main Functions of the Urinary System

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

Question 2

Secondary Functions of the Urinary System

Answer 2

• Regulates blood volume and blood pressure
• Regulates pH
• Eliminates urea
• Controls electrolytes and metabolites

Question 3

Organs of the Urinary System

Answer 3

• 2 Kidneys
• 2 Ureters
• 1 Urinary Bladder
• 1 Urethra

Question 4

Location of Kidneys

Answer 4

• Located retroperitoneally: behind the peritoneum
• Lateral to T12-L3 vertebrae

Question 5

Size of the Average Kidney

Answer 5

• 12 cm tall (4.7 in)
• 6 cm wide (2.4 in)
• 3 cm thick (1.2 in)

Question 6

Hilus of the Kidneys (Hilum of 1 Kidney)

Answer 6

• an indentation in the surface of a kidney where blood vessels, ducts, nerve fibers, etc. enter or leave it.
• found on the concave surface of the kidney

Question 7

Renal Capsule

Answer 7

The fibrous connective tissue that surrounds each kidney.

Question 8

Renal Cortex

Answer 8

the outer layer of the kidney

Question 9

Renal Pyramids

Answer 9

• kidney tissues that are shaped like cones
• found in the medulla

Question 10

Renal Pelvis

Answer 10

• The area at the center of the kidney.
• Urine collects here and is funneled into the ureter, the tube that connects the kidney to the bladder.

Question 11

Renal Plexus

Answer 11

complex network of nerves in the kidneys

Question 12

Nephron

Answer 12

• the functional units of the kidney.
• composed of the renal corpuscle and renal tubules
• Each kidney has millions of nephrons

Question 13

Renal Corpuscle

Answer 13

• the blood-filtering component of the nephron of the kidney.
• Composed of a Glomerulus
  and Glomerular/Bowman’s Capsule

Question 14

Glomerulus

Answer 14

• network of small capillaries known as a tuft, located at the beginning of a nephron in the kidney
• where waste products are filtered from the blood.
• Capillaries are fenestrated-little openings that increase permeability

Question 15

Bowman’s Capsule

Answer 15

• a cup-like sac at the beginning of the tubular component of a nephron in the kidney that performs the first step in the filtration of blood to form urine.
• A glomerulus is enclosed in the sac.
• Fluids from blood in the glomerulus are collected in the Bowman’s capsule.

Question 16

Renal Tubules

Answer 16

• long pipe like structure containing the tubular fluid filtered through the glomerulus.
• After passing through the renal tubule, the filtrate continues to the collecting duct system
• Composed of the proximal convoluted tubule, Loop of Henle, and the distal convoluted tubule

Question 17

Proximal Convoluted Tubule

Answer 17

• the segment of the nephron in kidneys which begins from the renal pole of the Bowman’s capsule to the beginning of loop of Henle. (in the renal cortex)
• lined by simple cuboidal epithelium with brush borders which help to increase the area of absorption
• responsible for the reabsorption and secretion of some water and some salts.

Question 18

Loop of Henle

Answer 18

• Long U-shaped portion of the renal tubule that conducts urine within each nephron of the kidney
• helps concentrate filtrate

Question 19

Distal Convoluted Tubule

Answer 19

• portion of kidney nephron between the loop of Henle and the collecting tubule.
• reabsorbs some water and some salts

Question 20

Collecting Ducts/Tubules

Answer 20

The last part of a long, twisting tube that receives urine from the distal convoluted tubules

Question 21

Mechanisms of Urine Production

Answer 21

• Filtration
• Reabsorption
• Secretion

Question 22

Filtration

Answer 22

Filtrate of blood leaves kidney capillaries

Question 23

Reabsorption

Answer 23

most nutrients, water, and essential ions are reclaimed

Question 24

Secretion

Answer 24

Active process of removing undesirable molecules

Question 25

Flow of Urine through the Renal Structures

Answer 25

Renal Corpuscle (Glomerulus and Glomerular/Bowman’s Capsule) Proximal Convoluted Tubule Loop of Henle Distal Convoluted Tubule Collecting Ducts Papillary Ducts Minor Calices Major Calices Renal Pelvis Ureters Bladder Urethra

Question 26

Ureters

Answer 26

- Carry urine from the kidneys into the urinary bladder - oblique entry into bladder prevents backflow of urine

Question 27

Urinary Bladder

Answer 27

- A collapsible muscular sac - Stores and expels urine

Question 28

Shape of the Full Bladder

Answer 28

- Spherical - Bladder expands into the abdominal cavity

Question 29

Shape of the Empty Bladder

Answer 29

Lies entirely within the pelvis

Question 30

Urethra

Answer 30

the hollow tube that lets urine leave the body - Epithelium - composed of the internal urethral sphincter and the external urethral sphincter

Question 31

Internal Urethral Sphincter

Answer 31

- Involuntary smooth muscle - regulates involuntary control of urine flow from the bladder to the urethra

Question 32

External Urethral Sphincter

Answer 32

- voluntarily inhibits urination - provides voluntary control of urine flow from the bladder to the urethra

Question 33

External Urethral Orifice

Answer 33

the external opening (or meatus) of the urethra.

Question 34

Length of Urethra in Females

Answer 34

3–4 cm

Question 35

Length of Urethra in Males

Answer 35

- 20 cm in length - Three regions: prostatic, membranous, spongy/penile

Question 36

Prostatic urethra

Answer 36

- Passes through the prostate gland - first portion of the male urethra

Question 37

Membranous Urethra

Answer 37

Through the urogenital diaphram

Question 38

Spongy/Penile Urethra

Answer 38

Passes through the length of the penis

Question 39

Renal Medulla

Answer 39

Medial layer of the kidney