Excretory System Function a group of organs working

Excretory System • Function: a group of organs working together to maintain osmotic balance and remove nitrogenous wastes from the blood stream • Structures involved: – Kidneys – Urinary bladder – Urethra Kidney anatomy http: //anatomy. mheducation. com/html/apr. html? animal=human&session. Id=6573744145286599094324705 ccc 8 f 4044 f 49 c 13 ab 7 b 1502 e 380&existinguser=true

Excretory system

Excretion: Structures and Functions • Liver: converts ammonia (formed from metabolic wastes from organic compounds) into urea. • Kidneys: regulate the amount of water and salts contained in blood plasma and removes urea from the blood. – Made-up of 1 million bloodfiltering units called nephrons – Nephrons will filter wastes from blood, retains useful molecules and produce urine – Nephrons will filter, reabsorb, and secrete

Nephrons Role in Excretion 1. Filtration water, amino acids, glucose, salts, and urea diffuses from the blood (forms filtrate)due to osmotic pressure and size 1. » remains in the blood: all blood cells, platelets, plasma proteins, and FATS. Occurs in the bowman’s capsule 2. Re-absorption: reabsorbs useful molecules like water, amino acids, glucose, and salts back into the blood » Occurs in the tubules 3. Secretion: urine formation: made-up of water, urea and salts » Urine formation Occurs in the collecting http: //anatomy. mheducation. com/html/apr. html? animal=human&session. Id=6573744145286599094324705 ducts ccc 8 f 4044 f 49 c 13 ab 7 b 1502 e 380&existinguser=true

• diagram renal

Mouse kidney nephron Read 357 -364

Warm-up • What is the importance of filtration, reabsorption, and secretion in regards to the human excretory system? http: //anatomy. mheducation. com/html/apr. html? animal=human&session. Id=6573744145286599094324705 ccc 8 f 4044 f 49 c 13 ab 7 b 1502 e 380&existinguser=true

Diagram • Diagram

Renal pelvis Renal medulla Renal cortex http: //www. biologymad. com/resources/kidney. swf Renal pyramid

Structures and Functions • Ureter: tubes that transports the urine from the kidney to the urinary bladder • Urinary bladder: a hollow, muscular sac that stores the urine (holds. 63 quarts) • Males have a larger UB • Stretch receptor cells that detect when it’s full: attached to spinal cord and it sends impulses that will contract the muscular walls • Urethra: tube that transports urine from UB out of the body through urination • Females have a shorter urethra which leads to more urinary tract infections

Animation: Micturition Reflex https: //www. bing. com/videos/search? q=micturition+reflex+animation&view=detail&mid=06 A 594856 C 1 E 4 A 9 AE 4 A 006 A 594856 C 1 E 4 A 9 AE 4 A 0&FORM=VIRE

Kidney Dialysis • Artificial filtering of the blood – Surgically insert catheters into an artery and a vein in the forearm