1. EXCRETORY SYSTEM
ANATOMY & PHYSIOLOGY

2. Functions Filter & excrete fluid from blood
toxins/metabolic waste/excess ions/urea/hormones
Maintain acid/base & Water balance

3. Parts of kidney Medulla - (inner; contain pyramids)
Cortex - (contain nephrons - functional unit)

4. Nephron- filter unit (1 million/kidney)
Glomerulus: capillaries; start filtration
Renal tube: in glomerulus; reabsorb salt/food
Bowman’s capsule: separate clean blood from filtrate
Loop of Henle: filters water and salts
Renal artery: blood goes in
Renal vein: blood goes away

6. Tracing blood through kidney
Flows through at a high rate
A person’s entire blood volume passes through kidneys 20x per hour
Filtration-->reabsorption,-->secretion
From aorta blood enters kidney through renal artery

7. Tracing blood through kidney
Renal artery divides into segmental arteries
Lobar arteries-->interlobar arteries (go between pyramids) -->arcuate arteries (travel between pyramids)-->arculate arteries (travel between corex and medulla)
Go into nephron
Filter and take blood back to circulation

9. Excretory system organs
Ureters: tubes that take urine from kidney to bladder
Bladder: sack to store urine
Urethra : tube that leads urine out of body
Sphincter : outer end of urethra; muscle; controls release of urine

10. Properties of urine Fresh is clean w/ no bacteria
Clear, pale yellow to deep yellow
Transparent
Slightly acidic
Slightly aromatic (oxygen makes it smell w/ bacteria)
95% water, 5% solutes