Urinary Tract (Ch 27) Flashcards Preview

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Flashcards in Urinary Tract (Ch 27) Deck (35):
1

What is included in the urinary tract?

1. ureters
2. bladder
3. urethra
--> NOT kidneys

2

Ureter

--> how urine exits the body
-fibromuscular tubes located peritoneally
-ureters go from kidney inferiorly to bladder
-urine transported by gravity/peristaltic waves (smooth musc in ureter wall)

3

Kidney Stones

a.k.a. "renal calculus"
when minerals filtering through the kidneys accumulate = crystals
-80% in men

4

How do you identify kidney stones?

Location: kidney, ureter, bladder
Type: calcium, struvite, uric acid

5

What causes kidney stones?

-dehydration
-abnormal pH of urine
-over saturation of calcium/uric acid/oxialate
-block of urine flow
-bacterial infection

6

Urinary Bladder

muscular sac that stores/expels urine
-holds up to 1 liter of urine (stretches as it fills)
-lies on pelvic floor posterior to pubic symphysis

7

What is the mucosa of the urinary bladder composed of?

transitional epithelium + lamina propria
-has rugae ("folds") that will expand

8

what is the function of the detrusor muscle in the urinary bladder?

contracts/squeezes urine from bladder

9

Urethra

tube lined with smooth muscle + mucosa
--> drains urine from bladder
-longer in males (composed of prostatic, intermediate, and spongy urethra)

10

internal urethral sphincter

created by the thickening of the detrusor muscle
-at the bladder/urethra junction
*relaxation INVOLUNTARY

11

external urethral sphincter

surrounds urethra w/skeletal muscle sheet
--> inhibits urine
Females: close to outside of body, males: at base of penis
*potty training = learning to control
*relaxation VOLUNTARY

12

Micturition

*urination
-controlled by brain (pons) --> when bladder is distended (full) stretch receptors send signals to pons --> detrusor muscle stimulated to squeeze out urine

13

What are the functions of the urinary system?

1. eliminate nitrogenous wastes + excess ions (storage/excretion of urine)
2. maintain ion balance, acid-base balance, regulates blood volume

14

Kidney Anatomy

-bean shaped structure
-located in retroperitoneal position
-protected by floating ribs
-filters blood

15

Structures of the kidney

renal cortex
renal medulla
renal pyramid (in renal medulla)
renal pelvis
renal column
ureter
fibrous capsule
papilla of pyramid
minor/major calyx
hilium

16

Kidney Blood Supply

1. renal arteries branch
2. travel through renal columns
3. reach afferent arterioles
--> form capillary network (glomerulus)
4. once blood is filtered...exits through efferent arteriole
5. branch into peritubular capillaries surrounding nephron structures
6. drain into interlobar vessels

17

Vasa Recta

peritubular capillaries around Loop of Henle

18

peritubular capillaries

*kidney
-adapted to absorb materials not retained in filtrate (becoming urine)

19

The nephron

-smallest functional unit of kidney
-site of filtration of water from blood (filtrate --> urine)
-millions of nephrons in each renal pyramid

20

What are the two types of nephrons?

1. Cortical (85%): mostly located in cortex
2. Juxtamedullary (15%) --> very long loops, help concentrate urine

21

What are the two main parts of nephrons?

1. Renal Corpuscle
2. Renal Tubules

22

Renal Corpuscle

glomerulus + glomerular ("bowmans") capsule
-capillary bed
-afferent arterioles bring blood in
-glomerular capsule captures filtrate pushed out of capillaries

23

How do blood and filtrate enter/exit the nephron?

blood: enters via afferent arteriole, exits via effferent arteriole
filtrate: enters via afferent arteriole, leaks out glomerulus, exits via proximal convoluted tubule

24

What is filtrate?

water, waste, salt, glucose

25

Structure of Renal Tubules

filtrate --> tubules (via renal corpuscle)
Include:
-Proximal Convoluted Tubule
-Loop of Henle
-Distal Convoluted Tubule
-Collecting Duct

26

Renal Tubules: Proximal Convoluted Tubule

-made of cuboid epithelial cells
-secretory/absorptive (reabsorbs solutes/nutrients)

27

Renal Tubules: Loop of Henle

-descending limb permeable: simple squamous epithelium
-ascending limb permeable to water (reabsorb water)

28

Renal Tubules: Distal Convoluted Tubule

-made of cuboid epithelial cells
-selectively secretory/absorptive (secretes ions)
--> exits into collecting ducts

29

Three steps of urine formation

1. Glomerular Filtration
2. Tubular Reabsorption
3. Tubular Secretion

30

Glomerular Filtration

*in glomerulus
1. blood is filtered into filtrate (water and wastes)
2. exit out of renal corpuscle into PCT
--> movement of substances from the blood within the glomerulus into capsular space

31

Tubular Reabsorption

*in PCT and Loop of Henle (Nephron Loop)
-->movement of substances from the tubular fluid back into the blood, absorption of ions and water

32

Tubular Secretion

*in DCT
secretion of potassium and hydrogen
--> movement of substances from blood into tubular fluid

33

renal column

divide kidney up into portions (renal pyramids)

34

flow through kidney

renal column-->renal pyramid-->renal papilla-->minor calyx--> major calyx --> renal pelvis --> ureter

35

Hilum

indentation on kidney where renal artery, renal vein, and ureter enter/exit the kidney