Section 2 Flashcards
(36 cards)
What inputs are the kidneys controlled by?
Endocrine and neural
What are the primary function of the kidneys?
Maintain the ECF volume, electrolyte composition and osmolarity
Describe how kidneys act in presence of excess/too little water.
In excess water or excess particular electrolyte (solute), the kidneys will increase their elimination
In times of deficit of water or a solute, the kidneys CANNOT actively correct this. However, they can further reduce their elimination.
List all the major functions of the kidneys (10)
- Maintain water balance in the body
- Maintain body fluid osmolarity
- Maintain proper plasma volume
- Help maintain acid-base balance
- Regulate ECF solutes (such as sodium, potassium, chloride, calcium, phosphate, and others)
- Excrete wastes of metabolism
- Excrete foreign compounds ingested
- Produce erythropoietin
- Produce renin
- Activate vitamin D
Where are the kidneys located?
associated with the adrenal gland (one on top of each kidney)
What is the structure of the kidney? (outer to inner part, and basic unit)
The outside is the renal cortex, and the inner part is the renal medulla.
At the inner core of each kidney is the renal pelvis, through which the urine empties and is channeled to the ureter
the nephron is the basic functional unit of the kidney
What compartments is the nephron divided into?
The vascular component, which supplies blood to the nephron
The tubular component, which carries the filtrate throughout the nephron
What is the major part of the vascular component of the nephron?
The major part is the glomerulus, which is a ball-like capillary through which water and solutes are filtered from the plasma.
How does blood enter the kidney?
Blood enters the kidney via the renal artery, which subdivides into many small afferent arterioles, each supplying a nephron.
What transports unfiltered blood from the glomerulus?
The efferent arterioles transport unfiltered blood from the glomerulus.
How are the capillaries of the nephron different from typical capillaries?
In the capillaries of the nephron, arterial blood enters and then leaves without extracting oxygen. Instead, the efferent arterioles subdivide into peritubular capillaries, which deliver oxygen to the renal tissues.
Describe the flow of blood through the vascular component of the nephron.
Blood enters the kidney via the renal artery, which subdivides into afferent arterioles supplying each nephron. Within the glomerulus, blood is filtered, and unfiltered blood exits via efferent arterioles. The efferent arterioles then divide into peritubular capillaries, delivering oxygen to renal tissues before merging into venules and eventually the renal vein for blood exit.
What is the structure that collects fluid filtered from the glomerular capillaries?
Bowman’s capsule encircles the glomerulus to collect the filtered fluid.
Where is the proximal tubule located and what is its structure?
The proximal tubule, located within the renal cortex, is highly coiled along its length.
Describe the structure and location of the loop of Henle.
The loop of Henle forms a hairpin loop that dips down into the renal medulla. The descending limb travels from the cortex to the medulla, while the ascending limb travels from the medulla back to the cortex.
What region does the ascending limb of the loop of Henle pass through?
The ascending limb passes through the fork of the afferent and efferent arteries in a region called the juxtaglomerular apparatus.
What is the structure that follows the distal tubule, and where does it ultimately drain?
The distal tubule empties into a collecting duct, which travels deep into the medulla and drains into the renal pelvis.
Describe the flow of fluid through the tubular component of the nephron.
Filtered fluid enters Bowman’s capsule, then moves into the highly coiled proximal tubule in the renal cortex. It continues through the loop of Henle, which dips into the renal medulla, and returns to the cortex via the ascending limb. Passing through the juxtaglomerular apparatus, it enters the coiled distal tubule before emptying into a collecting duct, which extends deep into the medulla and drains into the renal pelvis.
What are the two types of nephrons?
Cortical nephrons and juxtamedullary nephrons
What are cortical nephrons?
Cortical nephrons primarily serve secretory and regulatory functions.
The glomeruli of cortical nephrons lie in the outer layer of the cortex.
How deep does the loop of Henle of cortical nephrons dip into the renal medulla?
The loop of Henle of cortical nephrons only slightly dips into the renal medulla.
Peritubular capillaries from cortical nephrons wrap around the short loops of Henle.
What are juxtamedullary nephrons responsible for and where are they found?
Juxtamedullary nephrons are responsible for the concentration and dilution of urine.
Juxtamedullary nephrons are found on the inner layer of the cortex.
What structures form hairpin loops of vasculature near the long loops of Henle in juxtamedullary nephrons?
Peritubular capillaries from juxtamedullary nephrons form hairpin loops of vasculature, called the vasa recta, which are in close proximity to the long loops of Henle.
Arrange these terms in the order of which blood flows from the renal artery to the renal vein in the nephron:
- Peritubular capillaries
- Afferent arteriole
- Glomerulus
- Efferent arteriole
- Afferent arteriole
- Glomerulus
- Efferent arteriole
- Peritubular capillaries
