Tissue 2 - kidney, bone

overall morphology of the kidney (large lagnification)

• capsule

• cortex - outer shell

• medulla

• papilla

• calyx

• pelvis

• hilus (the point of entry and exit of blood vessels and nerves)

smallest unit in kidney

nephron = renal corpuscle + renal tubule

• bowmans space - urinary space

  • simple squamous epithelium

• bowmans capsule/glomerulus

  • fenestrated capillaries - fenestratins are pores that allow larger molecules to pass through the capillary wall

  • endothelial cells - 1st stage of filtration of blood to primary urine

  • besement membrane - 2nd

  • podocytes - 3rd stage

  • mesangial cells - provide structural support (dark irregular nuclei, surrounded by deep pink material)

• vascular pole

  • affarent and effeent arteriole

  • juxtaglomerular apparatus 

    • macula densa - regulate blood pressure and filtration rate

    • juxtaglomerular cells - secrete enzymes renin

• urinary pole - proximal tubuli

• proximal tubuli (simple columnar epithelium) - remove small proteins from the primary urine, major site of reabsorption

• distal tubuli (simple cuboidal epithelium) - reabsorbs Ca, sodium, Cl, regulates pH in the urine

• loop of henley/collectin ducts (simple cuboidal epithelium) - reabsoprtion of water and ions

• blood vessels around - Vasa Recta

Describe the way blood and urine is transported thrpugh kidney + video

black staining in nephrons

PASM - methenamine

• silver/black - basement membrane

• primary region of ossification (deeper in the bone)

• secondary region of ossification (outer) - helps to not disturb the joint with growth

• cortical/compact bone - dense, important for bone strength

• trabecular bone - harbour precursor bone cells, haemopoietic cells (red marrow) and fat cells (yellow marow)

• growth plate - longitudinal growth (cartilage then bone)

• endosteum - inside or cortical bone

• peristeum - outside or cortical bone

osteocyte - sense mechanical forces, orchestrate bone remodelling, maintain bone respnse

osteoblasts - bone formation, can embed themselves in bone matrix and differentiate into osteocytes

osteoclast - bone resorption (in cavities, multinuclei)

chondrocytes - secrete cartilage matrix

megacaryocytes - production of blood thrombocytes - for blood clotting

TRAP - stain for osteclasts

calcified matrix - black, newly formed collagen 1 - red