Please enable JavaScript.
Coggle requires JavaScript to display documents.
Excretion in humans - Coggle Diagram
Excretion in humans
carried out by
-
-
Kidney
excrete urine (urea, excess water and mineral salts)
Ultrafiltration
- AA wider lumen than EA → builds up high pressure
- partially permeable BM → wraps arnd G → has v small pores
- high hydrostatic pressure → forces small molecules through BM (glucose, amino acid, mineral salts, water, nitrogenous waste)
- large molecules remain within G (rbc, proteins)
Selective reabsorption
- PCT reabsorbs all g, aa via diffusion, active transport
- LoH & DCT reabsorb most w via osmosis & ms via diffusion
-
- metabolic waste products, excess water, excess mineral salts are pass out of CD → into RP as urine
Osmoregulation
hypothalamus in brain → pituitary glands in brain → ADH → permeability of cells on walls of CD → reabsorption of water → conc. of urine
Skin
excrete sweat (urea, excess water and mineral salts)
-
definition
the process by which metabolic waste products & toxic substances are removed from internal to external environment
need
accumulation of waste in body (from production of waste products in metabolic reactions in cells) is harmful & needs to be excreted from body
