Module 18: The Urinary System Flashcards Preview

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Flashcards in Module 18: The Urinary System Deck (28):
1

Functions of the urinary system

removes waste from blood
excretes in form of urine
controls acid-base balance
regulates fluid balance
regulates electrolyte balance
stimulates the production of RBC
controls blood pressure

2

Organs of urinary system

2 kidneys
2ureters
urinary bladder
urethra

3

Kidney

Highly vascular
Retroperitoneal organ

4

3 parts of kidney

renal cortex (outer)
Renal medulla (middle)
Renal pelvis (inner)

5

surrounding each kidney are 3 layers of tissue

fibrous capsule (inner)
peritoneal fat capsule (middle)
Renal fascia (outer)

6

Hilum

notch where ureter leaves the kidney and blood vessels, nerves, lymph vessels enter and leave the kidney

7

Renal pyramids

triangular structures that look striated due to renal tubules

8

Renal papillae

tips of pyramids

9

Minor calyces

surround the tip of each renal pyramid
funnel shaped structures
Function is to collect urine from the ducts of pyramids

10

Major calyces

join together to form large collecting area called renal pelvis

11

Nephrons

microscopic units of kidney that regulate the composition and volume of blood and form urine
Nephron consists of glomerulus, bowman capsule, renal tubule

12

Glomerulus

network of capillaries
surrounded by bowman capsule
where blood is filtered

13

Bowmans capsule

receive filtered blood (filtrate) from glomerulus and deliver to renal tubule
contains fluid that is the raw material of urine

14

Renal tubule

long convoluted tube
site of urine formation by reabsorption and secretion
juxtaglomerular apparatus is what regulates the rate of filtrate formation

15

3 parts of renal tubule

Proximal convoluted tubule
loop of hence
distal convoluted tubule (then leads to collecting duct)

16

3 steps of urine formation

glomerular filtration
tubular reabsorption
tubular secretion

17

Physical properties of urine

clear fluid
light yellow
slight odor

18

chemical properties of urine

95% water
5% urea, na, cl, k ,ca, mg, sulfates, phos, bicarbonates, uric acid, ammonium ions, creatinine
slightly acidic Ph 4.5-8

19

Antidiuretic hormone (ADH)

synthesized in the hypothalamus
stores and secreted by posterior pituitary gland
High levels of ADH increase water reabsorption
Low levels of ADH decrease water reabsorption

20

Aldosterone

hormone released by adrenal glands
helps regulate fluid balance
stimulates distal tubules to reabsorb Na+ and water, and to excrete K+

21

Atrial Natriuretic Peptide (ABP)

inhibits the reabsorption of Na+ and water
decreasing blood volume and pressure

22

Renin

secreted by juxtaglomerular apparatus
involved with control of blood
leads to formation of angiotensin I which converts to angiotensin II
angiotensin II raises blood pressure

23

Erythropoietin (EPO)

secreted by kidneys in response to low oxygen in arterial blood
targets bone marrow
stimulates production of RBC

24

Ureters

long tubes
wave like contraction of smooth muscle in walls of ureters move urine down towards the baldder

25

Bladder

resembles inflatable balloon
3 openings (2ureter, 1 urethra) form Trigone

3 layers of smooth muscle collectively called detrusor muscle
Transitional epithelium mucous membrane

26

Urethra

female 3-4cm
male 20cm
3 regions: prostatic, membranous, spongy(penile)

27

micturition

aka voiding or urination
detrusor muscle contracts

28

control of micturition

when bladder is partially full, stretch receptors transmit nerve impulses to spinal cord; initiate conscious desire to expel urine and micturition reflex (unconscious)

Exit of bladder is internal sphincter (involuntary contraction)
External sphincter is voluntary