Urinary System

Question 1

Diffusion

Answer 1

• Spreading of any particles in a solution.
• Moves from a high concentration to a low concentration on a concen. gradient

Question 2

Osmosis

Answer 2

Movement of water through a semipermeable membrane down a concentration gradient.
- Dilute solution to concentrated solution.

Question 3

Why is osmosis important?

Answer 3

Important for homeostasis to control water balance

Question 4

Why is diffusion important?

Answer 4

Important for homeostasis for movement of substances
Ex: O2 into the blood and CO2 out

Question 5

Active transport

Answer 5

-Uses energy to move substances against a concentration gradient across a semipermeable membrane.
- Transport in cells pick up particles and move them across the membrane

Question 6

Why is active transport important?

Answer 6

Important in homeostasis in order to move substances into cells and moving glucose and sodium ions inside the kidneys

Question 7

What are the functions of the kidneys? (4)

Answer 7

1. Filtration: reabsorption, secretion
2. Fluid balance: regulation
3. Acid-base: balance regulation
4. Hormone: production

Question 8

List the upper urinary system

Answer 8

Two kidneys
Two ureters

Question 9

List the lower urinary system

Answer 9

Urinary bladder
Urethra

Question 10

Which kidney is more cranial?

Answer 10

The right kidney!

Question 11

Glomerulus (“ball of yard” in Latin)

Answer 11

-“tuft” of capillaries
Function: Glom. capillaries filter some of the plasma out of the blood and put it in the capsular space of bowman’s capsule

Question 12

Bowman’s capsule

Answer 12

Surrounds glomerulus

Question 13

Urea

Answer 13

Nitrogen containing compound

Question 14

polydipsia

Answer 14

Excessive thirst

Question 15

Polyurea

Answer 15

Frequent urination

Question 16

Urolithiasis

Answer 16

Stones in the urinary tract

Question 17

Uremia

Answer 17

Excessive urea/nitrogen in the blood

Question 18

Nephron

Answer 18

• Functional unit of the kidney
• Main goal is to processes waste from the blood to create urine

Question 19

Proximal Convoluted Tubule (PCT)

Answer 19

Tubule NEAREST to the globulus

Question 20

Production of urine:

Answer 20

Nephrons take wastes and toxins from the blood stream and turn it into urine to be expelled from the body.

Question 21

Important substances for homeostasis

Answer 21

Sodium, potassium, calcium, magnesium, glucose, amino acids, chloride, bicarbonate, and water

Question 22

What determines urine volume regulation?

Answer 22

Volume of water contained in the tubular filtrate when reaching the pelvis

Question 23

What two hormones are responsible for the majority of urine vol regulation?

Answer 23

Two hormones:
1. Antidiuretic (released from posterior pituitary gland)
2. Aldosterone (secreted by adrenal cortex)

Question 24

What is antidiuretic (ADH) role in urine vol regulation?
Hint: without it, there would be polyuria

Answer 24

Acts on the DCT/collecting ducts to promote water reabsorption and prevent water loss from the body.

Question 25

Distal Convoluted Tubule (DCT)

Answer 25

- Continuation of the ascending loop of Henle - Empties into the collecting ducts

Question 26

Loop of Henle: Location and function

Answer 26

- Location: Descends from PCT into medulla, turns, heads upward into the cortex - Function: At the bottom loop, epithelial cells flatten to simple squamous cells and lose their brush border

Question 27

Renal corpuscle's location and function

Answer 27

- Location: Renal cortex - Function: Filters blood in the first stage of urine production

Question 28

Peritubular capillaries

Answer 28

Converge to form venules, then larger veins, and finally the renal vein

Question 29

Renal vein

Answer 29

Leaves the kidney at the hilus

Question 30

List the main blood vessels associated with the kidneys (4)

Answer 30

1. Right renal vein 2. Right renal artery 3. Left renal vein 4. Left renal artery

Question 31

Urinary bladder structure and function

Answer 31

- Structure: Lined with transitional epithelium that stretches as the bladder becomes filled with urine. Walls contain smooth muscle bundles. Neck of bladder extends caudally from the sac into the pelvic canal & joins the urethra. Neck of urinary are circular muscles of skeletal muscle fibers - Function: Controls urination

Question 32

Ureters structure and function

Answer 32

- Structure: Leave kidneys at hilus. Outer fibrous layer, middle smooth muscle, and inner layer lined with transitional epithelium. - Function: Smooth muscle propels urine through ureter by peristaltic contractions

Question 33

Micturition (simplified)

Answer 33

Expulsion of urine from the urinary bladder into the urethra

Question 34

The control of urine (micturition process)

Answer 34

1. Urine accumulates until pressure of the filling bladder activates stretch receptors in bladder wall 2. Spinal reflex returns a motor impulse to bladder muscles causing them to contract - Contraction gives the sensation to urinate 3. Voluntary control of the muscle sphincter around the neck of the bladder results in temp control of urination

Question 35

Urethra structure and function

Answer 35

- Structure: Continuation of the neck of the urinary bladder. Lined with transitional epithelium which allows it to expand. - Function: Carries the urine from the bladder to the external environment.

Question 36

Male vs female urethras

Answer 36

- Male: Urethra runs down the center of the penis and functions in the reproductive system. - Female: Urethra (shorter than the male's) opens on the ventral portion of the vestibule of the vulva

Question 37

Production of urination

Answer 37

1. Blood is forced into the glomerulus, then into the bowman capsule (filtrate). 2. PCT: Salt, glucose, Ka+, bicarbon, and water are reabsorbed. 3. H+ & ammonium are secreted into prox tube. 4. Descending loop: water will move to the hypertonic interstitial fluid. 5. Ascending loop: NaCl can diffuse out in thin, then use active transport in the thick portion. 6. DCT: H+ ammonium, Ka+ secreted back in. NaCl, water, bicarb reabsorbed. 7. Collecting duct: Hormones will control the amount of fluids reabsorbed and the rest will be urine!

Question 38

What is commonly in filtrate? (blood after it passes the Bowmans capsule)

Answer 38

1. Salt 2. Water 3. Glucose 4. Amino Acids 5. Bicarbonate ions 6. H+ 7. UREA! 8. (sometimes) Medications