Ch. 25 Urinary System Flashcards Preview

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Flashcards in Ch. 25 Urinary System Deck (19)


- consists of two kidneys; two ureters, one urinary bladder, and one urethra
- after kidney's filter blood plasma, return most of the water and solutes to the bloodstream
- remaining water and solutes constitute urine


Kidneys Location

- retroperitoneum and posterior wall of abdomen, between the levels of the last thoracic and third lumbar vertevrae
- partially protected by 11 and 12 ribs


Kidneys Function

- regulation of blood ionic composition
- regulation of blood pH
- regulation of blood pressure
- maintenance of blood osmolarity
- production of hormones
- regulation of blood glucose level
- excretion of wastes and foreign substances


External Anatomy

- renal hilum
- 3 layers: renal capsule (deep), adipose capsule (middle), renal fascia (superficial)
- concave medial border of each kidney faces the vertebral column


3 Layers Surround each Kidney

Renal Hilum: ureter emerges from kidney along with blood vessels, lymphatic vessels, and nerves
1. Renal Capsule: deep, smooth, transparent sheet of dense irregular connective tissue that is continuous with the outer coat of the ureter
2. Adipose Capsule: middle layer and a mass of fatty tissue surrounding renal capsule that protects kidney from trauma and holds it firmly in place within abdominal cavity
3. Renal Fascia: dense regular connective tissue, anchors kidneys to surrounding structures and to abdominal wall


Internal Anatomy

2 distinct regions:
1. renal cortex-light-red region
2. Renal medullar-dark red brown region
- renal medulla consists of several renal pyramids
- renal papilla
- portions of renal cortex that extend between renal pyramids are renal columns
- parenchyma
- nephrons
- papillary ducts
- renal papillae
- minor and major calyces
- renal pelvis
- renal sinus: renal pelvis, calyces and branches of bl. vessels


Renal Lobe

- renal pyramid
- renal cortex
- renal column


Blood and Nerve Supply of Kidney

- renal arteries
- segmental arteris
- interlobar arteris
- renal lobe
- arcuate arteries
- afferent arterioles
- glomerulus
- efferent arteriole
- pertitubular capillaries
- vasa recta



2 parts:
- renal capsule (filtration of plasma)
- renal tubule (filter fluid passes)
2 components of renal corpuscle:
- glomerulus (capillary network)
- glomeruler (Bowman's) capsule
fluid (filtrate) passes through renal tubule consisting of:
- proximal convoluted tubule (PCT)
- nephron loop (loop of Henele)
- distal convoluted tubule (DCT)


Gloerular (Bowman's) Capsule

- podocytes within visceral layer
- Capsular (Bowman's) space


Renal Tubule and Collecting Duct

-principle cells: have receptors for 2 hormones that regulate function
1. antiduretic hormone (ADH)
2. Aldosterone
- intercalated cells: plays a role in homeostasis of blood pH


Functions of Nephrons

- produce urine, nephron and collecting ducts perform 3 basic processes:
- glomeruler filtration, tubular reabsorption, and tubular secretion


Glomeruler Filtration

- fluid that enters the capsular space is called glomeruler filtrate
- average daily volume of glomeruler filtrate is 150 liters in females and 180 in males
- filtratoin membrane or endothelia-capsular membrane
- filtered substances move from bloodstream through three barriers: fenestrations, basal lamina, pedicels


Filtration (endothelial-capsular) membrane

- fenestration of glomeruler endothelial cell prevents filtration of blood cells but allows all components of blood plasma to pass through
- basal lamina of glomerulus prevents filtration of larger proteins
- slit membrane between pedicels prevents filtration of medium-sized proteins


Tubular Reabsorption

- epithelial cells all along the renal tubule and duct carry out reabsorption, but proximal convoluted tubule cells make the largest contribution


Tubular Secretion

- transfer of materials from blood and tubule cells into glomeruler filtrate
- secreted substances include H+, K+, NH4+, creatine and certain drugs
- tubular secretion has 2 important outcomes:
1. secretion of H+ helps control blood pH
2. secretion of other substances helps establish them from the body


Ureter and Histology

- ureters transport urine from renal pelvis of one kidney to the urinary bladder


Urinary Bladder

- hollow, distensible muscular organ
- males: directly anterior to rectum
- females: anterior to vagina and inferior to uterus
trigone: 2 posterior corners contain two ureteral openings; internal urethral oriface lies in anterior corner
3 coats make up the wall of urinary bladder:
1. Mucosa: rugae
2. muscularis (detrusor muscle): internal and external urethral sphincter
3. adventitia: serosa



- smallest tube leading from internal urethral to external of body
females: opening of urethra is external urethral orifice; wall of urethra consists of deep mucosa and a superficial musclaris
males: urethra first passes through prostate, then through deep perineal muscles, and finally through penis
- urethra consists of deep mucosa and superficial muscularis; subdivided into 3 anatomical regions:
1. prostatic urethra
2. intermediate (membranousate) urethra
3. spongy urethra