Renal Anatomy Flashcards
What is the kidneys most important function?
Regulation of salt and water balance
List the 7 major kidney functions
- Regulation of ECF volume and BP
- Regulation of Osmolarity
- Maintain ion balance
- Maintenance of body pH
- Excretion of wastes
- Production of hormones
- GLuconeogenesis
How do the kidneys regulate ECF volume and BP?
If kidneys filter a lot of water back into the body, that increases EFC volume and blood pressure
-perfect urine has to be the right volume
How do the kidneys regulate osmolarity?
When you consume food, the ions that you eat are in the blood plasma and are filtered out or maintained depending on the [ion]
How do the kidneys maintain ion balance?
Through specific [ion] maintenance
How do the kidneys maintain boy pH?
Keeping the right [ion] allows for the pH to be ~7.2 which is ideal for proteins to keep their shape
-Lungs are main pH maintenance but kidneys help too
How do the kidneys excrete waste?
Through creation of urea, ammonia, creatinine
-not good for the body and are easy to filter out because they are water soluble)
How do kidneys produce hormones?
Erythroprotein Vitamin D ( activated within kidneys, they don't actually make it)
How is gluconeogenesis done in kidneys?
Can produce glucose from non-carb items such as fat (this is not something you want your kidneys doing all the time because it takes a while and a lot of energy)
Where are the kidneys located?
Posteriorly to the abdomen on each side of the spine
-level of the 11th/12th rib
What membranes are the kidneys in between?
Membranes that line the abdomen and the bones and muscles of the back
-retroperitoneal
Are the kidneys in the abdominal cavity?
Yes
What are the Major Calyces?
Large funnel shaped structures within the medulla that collect the processed fluid from the minor calyces
What is the Renal Pelvis?
Hallow area at the base of the Medulla where the urine collects from major and minor calyces
How does blood enter the kidney?
Through the renal artery
How does stuff leave the kidney?
Through the renal vein
What is the ureter?
Brings the urine stored in the renal pelvis to the bladder
What are nephrons?
The functional filtering unit of the kidneys and are located in the cortex and medulla
How many nephrons does each kidney have?
~1 000 000
What 2 structures make up the nephron?
Renal Corpuscle and Tubule
What is inside the renal corpuscle?
Bowmans Space and The glomerulus
How is the Tubule divided?
Based on functional and structural differences
What is the tubule made of?
A single layer of epithelial cells
Why does the tubule have functional differences?
Gives the nephron the ability to carefully select which items to excrete as urine
What are the 4 functionally different parts of the tubule?
- Proximal tubule
- Loop of Henle
- Distal Convoluted Tubule
- Collecting Duct
What is the purpose of the collecting duct?
Does something to the filtrate to make it perfect
What are the 2 different types of nephrons?
Juxtamedullary and Cortical
Since the amount of each nephron varies between species, what happens when you have more juxtamedullary?
You are able to conserve more water. Having more concentrated urine
What are the main differences between the 2 types of nephrons?
- Location within the cortex
- Loop Length
- How blood vessels are interwoven around them
Why is the medulla striated?
Due to the nephron loops and the collecting ducts
Why is the cortex spotted?
Due to all the renal corpuscles being in that area
In Humans, what is the ration between the 2 nephrons?
80% cortical
20% juxamedullary
What part of the nephron filters the blood?
Renal corpuscle to produce the ultrafiltrate
How does Bowmans capsule and the glomerulus physically contact?
Podocytes
What is the Juxtaglomular Apparatus (JGA)?
When part to the ascending loop of Henle pass between the afferent and efferent arterioles
What are Macula Densa Cells?
Specialized cells in the late cascading limb of the loop if Henle
-detects the filtrate composition, specifically Na and Cl
What are podocytes?
Wrap around the capillaries within Bowmans space to restrict items from being filtered
What are the Juxtamedular cells?
AKA Granular cells, Located beside the macula dense cells are responsible for producing and releasing the enzyme renin
What are fenestrations and where are they located?
Pores between the glomerulus endothelial cells, making it leaky to basically everything except for blood
How are the podocytes fused to the endothelial cells of the glomerulus?
Adhere together with with a sticky extracellular matrix called the basal lamina
-made of collagens and negatively charged glycoproteins
What does the basal lamina mostly trap from filtering?
Plasma proteins
What are slit spaces?
The slits between the podocytes to allow filtration
-can get bigger or smaller
What are the 3 barriers to filtration?
- Pore size of the glomerulus
- Basal Lamina
- Size of slits between podocytes
How much blood do kidneys receive?
20% of total Cardiac output
Why do kidneys receive a high amount of blood?
functions to help as maintenance of blood volume and ion balance in which it can be completed more efficiently
What are the major components of blood?
- Plasma
2. Red and white blood cells
What is plasma composed of
H2O Dissolved: - Proteins -Glucose -Hormones -CO2 -O2 -Na -K -Cl -Ca -H -HCO3 (bicarbonate)
What is the order of blood flow in the kidney?
Renal Artery > Afferent Arteriol > Glomerulus (capillary) > Effernt Arteriol > Peritubular Capillaries > Venule > Renal Vein
What is the peritubular capillaries?
Takes things from the tubule and puts it back in to the body
How much plasma is filtered/day?
180L
-excrete only 1 1/2L or urine/day
What are the 3 processes that affect how much fluid is excreted?
Filtration
Secretion
Reabsorption
What is filtration?
Movement of plasma components from the blood to the glomerulus into Bowmans space
What is secretion?
From the surrounding capillaries into the filtrate in the tubule
What is reabsorption?
From the filtrate in the tubule to the surrounding capillaries
What is the equation of hoe much urine is excreted?
Amount filtered - Amount reabsorbed + Amount secreted= Amount of solute excreted
