Intro to the Kidney Flashcards
What are the different types of human tissue?
(recap card)
Epithelia
Connective Tissue
Blood
Muscle
Nervous Tissue
What are the roles of simple squamous epithelium?
Filtration
Exchange of substances
What are the roles of simple cuboidal cells?
Absorption and production of substances
Contain mitochondria and protein producing organelles.
Larger intracellular volume= larger amount of contents
What are the functions of simple columnar cells?
Motility, absorption and processing
What are the functions of the kidney?
- Regulation of body fluid volume
- Regulation of body fluid composition
- Excretion of metabolic waste and toxins
- Endocrine functions
What are the main processes the kidney carries out?
Filtration
Reabsorption
Secretion
= forms urine
What does the uriniferous tubule consist of?
Nephron and collecting duct
What is the nephron made up of?
Renal corpuscle
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
What is the renal corpuscle made up of?
Glomerulus
Bowman’s capsule
Describe the arterial supply to the kidneys
Renal artery→Segmental arteries→Interlobar arteries→Arcuate arteries→Interlobular arteries→Afferent arterioles to the renal corpuscle→Glomerular capillaries→Efferent arterioles→Peritubular capillaries
What is the role of the glomerular capillaries?
Filtration
What is the role of the peritubular capillaries?
Reabsorption and secretion
What 2 layers make up the Bowman’s capsule?
What type of epithelium are they covered in?
What is their role?
Parietal layer:
- Outer
- Simple squamous
- Containment
Visceral layer:
- Inner
- Modified simple squamous (podocytes)
- Filtration
What cells are between the loops of the glomerular capillary for support?
Mesangial cells
Which structures form the filtration barrier?
What is its role?
- Glomerular capillary endothelium (fenestrated)
- Basement membrane (-ve charge)
- Epithelium (podocytes)
Limits the passage of substances based on their size, shape and charge.
What happens in the proximal convoluted tubule?
What is its epithelium?
Unmodified filtrate leaves the bowman’s capsule into the PCT.
- Majority of water, Na+, amino acid, glucose and Cl- reabsorption takes place here.
- Secretion of some drugs and waste products
- Simple cuboidal epithelium with microvilli (brush border- increases surface area)
What happens in the loop of Henle?
What are the different parts and their epithelia?
Thin descending limb:
- Permeable to water
- No active reabsorption or secretion of solutes
- Simple squamous epithelium
Thin ascending limb:
- Impermeable to water
- No active reabsorption of Na+ and other solutes
- Simple squamous epithelium
Thick ascending limb:
- Impermeable to water
- Active reabsorption of Na+ and other solutes
- Simple cuboidal cells
What happens in the distal convoluted tubule?
What are the different parts and their epithelia?
Early part and late parts
- Active reabsorption of Na+ and other solutes
- Secretion of K+ and H+
- Simple cuboidal cells
- Early part passes back to the vascualar pole of its own renal corpuscle to form the juxtaglomerular apparatus
What are the 3 components of the juxtaglomerular apparatus?
- Macula Densa: specialised cells that sense levels of Na+ and Cl- in the tubule
- Extraglomerular mesangial cells (Lacis cells): supporting cells
- Granular/juxtoglomerular cells: cells in afferent arterioles that alter BP and filtration.
What occurs in the collecting duct?
What is its epithelium?
- Final site for urine processing
- Water permeability is under the control of anti-diuretic hormone (ADH)
- Surrounded by medullary interstitium with a high concentration of solutes.
- Simple columnar cells
