Topik 7 Flashcards
Function of urinary system
Waste toxins, drugs
Regulate homeostasis of water balance, electrolytes, rbc production
Organs of urinary system
Kidneys
Ureters
Urinary bladder
Urethra
Location of kidneys
Against dorsal body wall
Top kidney is an adrenal gland
3 regions of kidney
Renal cortex - outer
Renal medulla- inside
Renal pelvis - inner collecting tube
Kidney structures
Medullary pyramids
Renal columns
Calyces
What is nephrons
The structural and functional units of kidneys
Responsible forming urine
2 main structures of the nephrons
Glomerulus
Renal tubule
Explain about glomerulus
A specialized capillary bed
Attached to the arterioles on both sides
*Afferent arteriole
*Efferent arteriole
Explain about renal tubule
Glomerular capsule (bowman’s)
Loop of Henle
2 types of Nephrons
Cortical nephrons - located in cortex
Juxtamedullary nephrons - located at boundary of cortex and medulla
What is peritubular capillaries
Arise from afferent arteriole
Attached to venule
Reabsorb some substances from collecting tube
3 type urin formation process
Filtration
Reabsorption
Secretion
Explain about filtration
Nonselective passive process
Water and solutes smaller than protein
Blood cells cannot pass out to capillaries
Collected at glomerular and leaves via renal tubule
Explain about reabsorption
Material; some water, glucose, amino acids, ions
Some is passive, most is active
What is material that not reabsorption
Urea,uric acid, excess water, creatinine
Explain about secretion
Some move from glomerular to renal tubule
*Hydrogen/potassium ions
*Creatinine
Some from renal tubule move to ureter
Characteristics urine use for medical
Colored yellow (pigment urochrome)
Normal pH:6
95 water 5 waste products
Explain about ureters
Slender tubes attached to the kidney
Behind peritoneum
Explain about urinary bladder
Smooth, muscular sac
Stores urine
Trigone- 3 opening
Explain about urinary bladder wall
Three layer of smooth muscle (detrusor muscle)
Wall are thick and folded
Explain about Urethra
Thin walls tibe that carry urine from bladder to outside of body by peristalsis
Release of urine controlled by 2 sphincter
- internal urethral sphincter (involuntary)
- external urethral sphincter (voluntary)
Urethra of male
Long
Length 18-20 cm
Function; urination/ejaculation of semen
Location; through prostate and penis
Urethra of female
Short
Length 3-4 cm
Function; urination
Location; along vagina
What is micturition
Micturition/urination is process of expelling urine from bladder
Also known as voiding of bladder
Regulate by nervous and muscle of bladder and urethra
Can store around 350-400 ml
2 types of micturition
Filling phase
Voiding phase
Explain filling stages
-The urine is transported from kidneys via ureters to bladder
-The opening of ureter not control by any sphincter or muscle
-Oblique nature of opening prevent urine from re-entering ureters
-The main muscle of urinary bladder, detrusor muscle is relax so its allow bladder to accommodate more urine
Explain voiding stage
-Both urinary bladder and urethra work together
-Detrusor muscle contract once bladder storage capacity is reached
- urethra controlled by 2 muscle, internal and external urethral sphincter
-Internal sphincter is smooth muscle, while external is skeletal muscle
-both sphincter contract during filling stage
Water balance
Young adult females- 50
Young adult males- 60
Babies- 75
Old age- 45
Development aspect of urinary system
Functional kidneys are develop by 3 month
Urinary system of newborn; bladder is small, urine cannot be concentrate
Control of voluntary urethral sphincter does not start until 18 month
Aging and urinary system
The bladder shrink (kendur)
Urinary retention is common in males
