The Urinary System15 Flashcards
Kidneys dispose of waste products like
Nitrogenous wastes
Toxins
Drugs
Excess ions
Regulatory functions of kidneys
- Make renin to maintain blood pressure
- Make erythropoietin to stimulate RBC production
- Activate vitamin D
Organs in urinary systems
Kidneys
Ureters
Urinary bladder
Urethra
Which kidney is slightly lower?
Right
It’s because the liver sits in that space
Ureters
Carry urine to bladder for storage
Kidneys are at level of which vertabrae?
T12-L3
_____ are against dorsal body wall in retroperitoneal position (behind parietal peritoneum)
Kidneys
Length and width of adult kidney
12 cm long (5 in)
6 cm wide (2.5 in)
Renal hilum
Indentation where several structures enter and leave kidneys
____ gland sits atop each kidney
Adrenal
Layers of the kidneys
- Fibrous capsule
- Perirenal fat capsule
- Renal Fascia
Fibrous capsule of kidney
Encloses each kidney
Perirenal fat capsule
Surrounds kidney, cushions against blows
Renal Fascia
Most superficial layer
Anchors kidney and adrenal gland to surrounding structures
Renal cortex
Outer region
Between capsule and medulla
Renal medulla
Deeper regions
Renal/medullary pyramids
Triangular regions of tissue in the medulla
Renal columns
Extensions of cortex-like materials that separate the pyramids
Renal pelvis
Flat, funnel-shaped tube
Medial region
Calcyces function
Collect urine
Send to renal pelvis then ureters then bladder
Form cup shaped drains that enclose renal pyramids
Calcyces
Made by calyces joining together
Renal pelvis
One quarter of total blood supply passes through kidneys each ____
Minute
Provides kidney with arterial blood supply
Renal artery
Division of renal artery
1.Renal artery
2. Segmental arteries
3. Interlobar arteries
4.arcuate arteries
5. Cortical radiate arteries
Venous blood flow
1.Cortical radiate veins
2.arcruate veins
3. Interlobar veins
4. Renal vein
There are no _____ veins in the kidneys
Segmental
Renal vein blood returns into
Inferior vena cava
Filtration happens at site of
Glomerulus (capillaries)
Structural and functional units of the kidneys
Nephron
How many nephrons in one kidney
Over 1 million
Nephron made of 2 main structures which are
Renal corpuscle
Renal tubule
Glomerulus housed in
Renal corpuscle
A knot of capillaries made of podocytes
Glomerulus
Podocytes
Make up inner (visceral) layer of glomerular capsule
Foot processes cling to
Glomerulus
____ slits make a porous membrane ideal for filtration
Filtration
Renal corpuscle parts
- Glomerulus
- Glomerular (Bowman’s) capsule
Glomerular Bowman’s capsule
Cup-shaped structure that surrounds glomerulus
First part of renal tube
Glomerular (Bowman’s) capsule
Renal tubule Extends from
glomerular capsule and ends when it empties into collecting duct
Subdivisions of renal tubule
1.Proximal convoluted tubule (PCT)
2.Nephron loop (loop of Henle)
3.distal covered tubule (DCT)
Proximal because it’s closest to the
Glomerulus
Cortical nephrons
Located entirely in cortex
Include most nephrons
Juxtamedullary nephrons found at
Found that the cortex-medulla junction
Juxtamedullary nephrons are called that because
Nephron loops dip deep into medulla
Collecting ducts collect urine from which types of nephrons?
Both cortical and juxtamedullary nephrons
Collecting ducts go through which structures
Renal pyramids
Calyces
Renal pelvis then ureters, then bladder
Two capillary beds associated with each nephron
Glomerulus
Peritubular capillary bed
Glomerulus is fed and drained by
Arterioles
Afferent arteriole
Arises from cortical radiate artery and feeds glomerulus
Efferent arteriole
Receives blood that has passed through glomerulus
How does the glomerulus work?
High pressure forces fluid and solutes out of blood and into glomerular capsule
Peritubular capillary beds arise from
Efferent arteriole of the glomerulus
Low-pressure porous capillaries
Peritubular capillary beds
Which capillary beds are adapted for absorption instead of filtration?
Peritubular capillary beds
Function of peritubular capillary beds
Cling close to renal tubule to receive solutes and water from tubule cells
Peritubular capillary beds drain into
Interlobar veins
Urine formation is a result of which 3 processes
Glomerular filtration
Tubular reabsorption
Tubular secretion
Glomerular filtration
Water and solutes forced through capillary walls and pores of glomerular capsule into renal tubule
Tubular reabsorption
Water, glucose, aminoacids and needed ions are transported into tubule cells and capillary blood
Tubular secretion
H,K, creatinine and drugs removed from peritubular blood and secreted by tubule cells into the filtrate
Is a filter
Glomerulus
Proteins and blood are too ____ to pass through the _____ membrane
Too large to pass through the filtration membrane
Once in glomerular capsule, fluid is called
Filtrate
Filtrate leaves via
Renal tubule
Filtrate will be formed as long as systemic blood pressure is
Normal
If arterial blood pressure is too low filtrate formation stops because
Glomerular pressure will be too low to form filtrate
Peritubular capillaries reabsorb useful substances from the renal tubule cells such as
Water
Glucose
Amino acids
Ions