Function & Structure of the Kidney Flashcards
What are the 7 main kidney functions?
- H20 &electrolyte balance
- Waste product excretion
- Bioactive substanc excretion
- Arterial BP regualtion
- RBC production (erythroipoitin)
- Vitamin D regulation
- *Metabolism
What are metabolic waste products?
something you metabolize/ make in your own body and it gets removed once you no longer need it
What are bioactive substances?
referring to drugs and hormones
What 2 types of waste products do we have in the body?
- Metabolic
2. bioactive
Where is erythropoietin made?
by the kidney
What does balance mean?
Input= Output (What enters the body, must exit the body)
What are the 5 main metabolic waste products that can be harmful at high concentrations?
- Urea
- Uric acid
- Creatinine
- Hemoglobin waste products
- Hormone metabolites
Where do the breakdown of the 5 main metabolic waste products comes from ?
- Urea- from breakdown of proteins
- Uric acid- from breakdown of nucleic acids
- Creatinine- from the breakdown of muscle creatinine
- Hemoglobin waste products- from the break down of Hb
- Hormones metabolites- from endocrine system
What two ways are bioactive substances excreted from the body?
- Actively
2. Passively
What 2 main ways do the kidneys use to regulate BP?
- Control of blood volume
2. Release of vasoactive substances (active regulation of smooth muscle in peripheral vasculature)
High or Low blood volume = ?
High BP/ Low BP, respectively
What does Vitamin D tell the gut/GI tract to do ?
Increase Calcium absorption
What is the role of Vitamin D?
Huge role in Calcium level regulation
Explain the multistep process of Vitamin D. First and Last step?
- UV rays (sunlight) through the skin
- Liver also has a role
Last. Kidney converts it to vitamin D. Without a functioning kidney– there is no Vitamin D!
In Metabolism, CNS uses what form of fuel?
ONLY Glucose
What happens where there is a drop in glucose levels? What 2 organs play a role?
Gluconeogenesis (where AA–> glucose)
Mainly Liver, but kidney also has a role.
What is renal ammonioagenesis? Why is this important?
- Process by which the kidney makes ammonia (wast product) to release the acidity in the body
- It maintains acid-base homeostasis
Where are the kidneys located?
Retroperitoneally
What happens in the renal cortex?
- ALL the filtration
2. A majority of reabsorption
What parts of the cortex extend in to parts of the medulla to separate it?
The renal columns (of the renal cortex)
Which part of the kidney contains more surface area?
The cortex - has more surface area than the medulla
What happens in the renal medulla?
- Some reabsorption
- Majority of collecting purposes
- Final determinant of concentration or dilution of urine
What happens after the renal medulla?
Creation of finalized urine
What are the roles of the calyx, pelvis, etc of the kidney?
Drainage purposes
What is the functional unit of the kidney?
The nephron
What happens in the nephron?
- Filtration
- Reabsorption
- determination of H20 & electrolyte balance
Where are the majority of the nephrons found?
Cortex- with a small portion found in the medulla
How many nephrons does each kidney have?
1 million
Where does filtration occur?
Glomerulus
What gets filtered?
The plasma from the blood gets filtered through the glomerulus
Is there regulation of what enters the glomerulus?
NO
How much fluid is filtered in the glomerulus per day?
180 L(plasma)/day
How much fluid is actually excreted/Urine output?
2L (urine)/ day
How much fluid is reabsorbed/ day?
Almost all of it
What makes up the renal corpuscle?
- Glomerulus (capillary)
2. Bowman’s capsule (balloon-like hollow capsule around the capillary)
What does the Bowman’s capsule do?
Picks up the plasma that is filtered out of the glomerulus