| What epithelium is in the PCT | Large simple cuboidal epithelium
Contains microvilli
Contains mitochondria to produce energy for active transport |
| What are some features of renal epithelia | Squamous --> easy diffusion and filtration
Cuboidal --> active transport
Can contain tight junctions --> different junctions have different permeability to water and solutes so some can be classified as tight leaky junctions |
| What are the 2 types of nephrons | Cortical nephron --> shorter and the glomerulus is further from the cortex
Juxtamedullary nephrons --> longer and the glomerulus is closer |
| What epithelium is in the DCT | Small simple cuboidal epithelium
No microvilli
Fewer mitochondria |
| What epithelium is in the Loop of Henle | Simple sqaumous to allow passive flux in the thin ascending and desecending
Simple cuboidal in the thick ascending and descending --> To allow active recovery of Na+/Cl- |
| What is the macula densa | This is a thickened region of ductal epithelia where the DCT passes close to the vascular pole of the glomerulus
These cells sense rise in Na+ which leads to triggers the synthesis of adenosine which then triggers Ca2+ to be released which causes smooth muscle contraction in the afferent arterioles which restricts blood flow and leads to reduced Na+ conc which shuts of the vasoconstrictive signal |
| What epithelium in the collecting duct | Small simple cuboidal epithelium
Few mitochondria
No microvilli |
| In the renal corpuscle what is the urinary and vascular pole | Vascular pole --> where the afferent and efferent arterioles leave and enter the renal corpuscle
Urinary pole --> otherwise known as the tubular pole is where the filtrate leaves the corpuscle and enters the PCT |
| What are the 3 levels of filtration | Fenestrated endothelium prevent passage of blood cells and platelets
The basement membrane to prevent passage of proteins
Filtration slit diaphragms between pedicels restricting small proteins and organic anions |
| What do the cells of the macula densa do | Basically they contain osmoreceptors that sense changes in Na+ conc
They basically stimulate contraction of the Juxtaglomerular cells which decreases blood flow hence there is less Na+ conc in the DCT which negatively feedbacks to shut off the signal |
| What hormone acts on the collecting duct | Antidiuretic hormone which stimulates type 2 aquaporins to locate in the cell membrane allowing reabsorption of water |
| Where can transitional epithelium be found | renal pelvis, ureters, bladder and the proximal parts of the urethra |
| Ureter features | Ureters are pair of muscular tubes that deliver urine from the renal pelvis to the urinary bladder
Each ureter is comprised of :
A mucosa → transitional epithelium
Circular and longitudinal layers of smooth muscle
Adventitia
Muscular contraction ( peristalsis ) of the wall conveys the movement of urine |
