EXAM PREP MISC Flashcards
What is the structural and what is the functional unit of the kidney?
Structural: Lobe - The medullary pyramids are found in the inner most part of the kidney with the renal cortex overlying them.
Functional: The nephron
How many nephrons are there in the kidney?
> 1million
What 5 structures does the nephron consist of?
– Renal corpuscle
– Proximal convoluted tubule
– Loop of Henle
– Distal convoluted tubule
– Collecting ducts
What 3 hormones are involved in the reabsorption process in the kidneys?
Antidiuretic hormone (ADH),
Aldosterone,
Atrial Natriuretic hormone
Antidiuretic hormone (ADH), Aldosterone & Atrial Natriuretic hormone are all involved in the reabsorption process in the kidneys.
Where are these hormones secreted and how do they contribute to the process?
Antidiuretic hormone (ADH)
– Secreted by the posterior pituitary
– Reabsorption of water in distal convoluted tubules and collecting ducts
Aldosterone
– Secreted by adrenal cortex
– Sodium reabsorption in exchange for potassium or hydrogen
Atrial Natriuretic hormone
– Hormone from the heart
– Reduces sodium and fluid reabsorption
How do autoregulation and hormones control pressure in the glomerular capillaries?
– Vasoconstriction of afferent arteriole - Decreased glomerular pressure and decreased filtrate
– Dilation of afferent arteriole - Increased pressure in glomerulus and increased filtrate
– Vasoconstriction of efferent arteriole - Increased pressure in glomerulus and increased filtrate
True or False: Vasoconstriction of afferent arteriole decreases glomerular pressure and decreased filtrate.
True
Will dilation of afferent arteriole result in increased or decreased pressure in glomerulus and filtrate?
Increased
What happens to the pressure of the glomerulus and filtrate when vasoconstriction occurs in the efferent arteriole?
Increased pressure in both the glomerulus and filtrate.
What are afferent arterioles and what are their functions?
They are small branches of the renal artery that carry blood to the glomerulus of the kidney.
Functions:
- Supply blood to the glomeruli
- Aids in filtration process by using BP to force plasma and solutes out of the blood initiating urine formation.
What are efferent arterioles and what are their functions?
After the blood has been filtered in the glomerulus, it exits through the efferent arterioles.
Functions:
- Narrower than afferent arterioles aiding in maintaining high BP within the glomerulus.
- Direct blood to the capillaries (peritubular capillaries or vasa recta).
What 3 factors control arteriolar constriction and how?
Autoregulation: Local adjustment in diameter of arterioles made in response to changes in blood flow in kidneys
Sympathetic Nervous System: Increases vasoconstriction in both arterioles.
Renin: Secreted by juxtaglomerular cells when blood flow to afferent
arteriole is reduced. Renin-angiotensin mechanism.
What are the names given to the outer and inner layers of the kidneys?
Outer: Renal cortex
- Glomeruli
- Proximal and distal convoluted tubules
Inner: Renal medulla
- Renal pyramids
- Loops of Henle
- Collecting ducts
- Blood vessels
What structures are found within the inner and outer layers of the kidneys?
Inner Layer: Renal medulla and renal pyramids.
Outer Layer: Renal cortex.
By what fluid movement mechanisms does the nephron function?
filtration, reabsorption, and secretion.
The endocrine system greatly influences the function of the
nephron. Which hormones are involved and what are they
responsible for?
Antidiuretic Hormone (ADH):
Responsible for regulating water reabsorption in the collecting ducts, thereby influencing urine concentration.
Aldosterone:
Regulates sodium and potassium reabsorption in the distal tubules and collecting ducts, impacting blood pressure and electrolyte balance.
Renin-Angiotensin-Aldosterone System (RAAS):
Regulates blood pressure and fluid balance by influencing sodium and water reabsorption.
These hormones play crucial roles in maintaining water and electrolyte balance, blood pressure, and overall homeostasis in the body by affecting the function of the nephron.
