Semester 2: L19 - Kidneys and Urinary System 1 (slid 28+) Flashcards
where are the kidneys located?
lie retro-peritoneally in the back abdominal wall
where does the uterus do?
conducts urine from the kidneys to the bladder.
what is the bladder?
expandable organ that stores urine until it is expelled from the body
what does the urethra do?
excrete urine from bladder to outside of body (micturition)
what is excretion?
removal of metabolic waste products from body fluids
what is elimination?
discharge of waste products out of the body
what is Homeostatic regulation?
regulation of the volume and solute concentration of blood
for Homeostatic regulation what needs to be controlled?
- Regulation of blood volume and pressure
- Regulation of plasma concentration of sodium, potassium, chloride and other ions
- Stabilising blood pH
- Conserving valuable nutrients
what is the renal capsule and where is it located?
connective tissue that surrounds the kidney
Na etch three regions of the kidney?
Renal cortex, Renal medulla , Renal pelvis
what is the renal cortex?
an outer granulated layer
what is the structure of the renal medulla?
divided in cone-shaped tissue masses called renal pyramids
what does the Renal pelvis contain?
contains the major renal blood vessels
what originates from the renal pelvis?
the ureter
what does the nephron do?
Filters blood and produces urine
what are the two types of nephrons?
Cortical nephrons
Juxtamedullary nephrons
what are the two parts of a nephron?
Renal Corpuscle
Tubules
cortisol nephrons have a short what?
A short loop of Henle
in Juxtamedullary nephrons
what odes the loop of Henle do?
Long loop of Henle extends into medulla
what is the Juxtamedullary responsible for?
Responsible for the medullary osmotic gradient
what do nephrons produce?
urine
what does the renal corpuscle involve?
glomerulus and the Bowman’s capsule
what happens at the renal corpuscle?
- blood flows via afferent arterioles into clusters of capillaries (glomerulus),
- 20% leaks into bowman space
- the rest exit via efferent arterioles
whats the Glomerulus?
Tangled capillary network
wha are the two layers of the Bowman’s capsule?
Parietal layer (outer) Visceral layer (inner)
what shape is the Bowman’s capsule?
Invaginated sphere
what does the renal corpuscle do?
its a filtration unit
what does the Glomerular filtration barrier contain?
- Fenestrated endothelium
- Glomerular Basement Membrane
- Visceral epithelial cells (podocytes)
what do Fenestrated endothelium form?
fenestrae (pores) of 70-100nm
what are Glomerular Basement Membrane ?
mesh of extracellular proteins
what do Visceral epithelial cells form?
the filtration slit diaphragm
Proximal tubule consists of?
Proximal convoluted tubule
Proximal straight tubule
the loop of hence ha a ______ limb a ____ ascending limb and a ______ ascending limb.
Descending
Thin
Thick
what does the Proximal convoluted tubule
have?
- Cuboidal epithelial cells
- Covered with microvilli
- Brush border that allow reabsorption of filtrate components
70% of water and sodium, 100% glucose - Rich in mitochondria
- Tight junctions allow paracellular transport
what Iines Both thin ascending and descending loop of Henle ?
simple squamous epithelium
what lines The thick ascending limb ?
cuboidal epithelium
what does Distal Convoluted Tubule have?
Simple cuboidal epithelium
No brush border
High proportion of mitochondria (fewer than PCT)
Tight junctions
what happens to collecting ducts as they descend through the medulla?
Collecting ducts merge and become larger as they descend through the medulla
the collecting duct contains?
Simple cuboidal epithelium
what does the juxtaglomerular apparatus do?
Regulates blood pressure and the filtration rate of the glomerulus
whats the Macula densa?
Densely packed group of modified epithelial cells in the DCT
what do Macula densa do?
Detect sodium concentration
what happens when theres an increase of sodium in the macula dense?
contraction of the afferent arteriole, reducing flow of blood to the glomerulus and the glomerular filtration rate (GFR).
Juxtaglomerular cells
are also known as?
granular cells
Juxtaglomerular cells derive from where?
Derived from the smooth muscle cells of the afferent arteriole
what happens when blood pressure decreases in the arterioles?
JG cells secrete renin causing blood pressure to increase via the renin-angiotensin-aldosterone system
How much of the total cardiac output do kidneys recieve?
20-25%
how does the kidney receive blood?
through a renal artery
How do Renal arteries enter the kidney?
Renal arteries enter kidney at hilus direct from aorta
Renal ____ also exit at ____ and connect the kidney with the ____ ___ ____.
veins
hilus
inferior vena cava
Renal ____ branches into
five ____ ______ which branch into
smaller _____ arteries.
artery
segmental arteries
interlobar
interlobar arteries supply blood to the what in the kidney?
arcuate arteries
where are arcuate arteries found?
arch in the border between the medulla and the cortex
arcuate arteries branch into what?
interlobular arteries.
From each interlobular artery branch numerous ______ arterioles.
afferent
The afferent arteriole divides into the ____ _______, which will reunite to form the ___ ____
glomerular capillarie
efferent arteriole.
The efferent arterioles will lead to the ____ capillaries around the renal tubules and to the vasa recta (straight vessels) around the loop of Henle.
peritubular
How does blood supply to the kidney go?
renal artery segmental arteries interloper arteries affterent arteries glomerular capillaries efferent arterioles particular capilaries interlobular veins arcuate veins interlobal veins renal veins
what are the three processes which form urine?
- Glomerular Filtration
- Tubular Reabsorption
- Tubular Secretion
