The Excretory System a general overview Excretory Organs











- Slides: 11

The Excretory System …a general overview

Excretory Organs Inferior vena cava Kidney Dorsal aorta Ureter Urinary bladder * Renal arteries carry blood TOWARDS each kidney & renal veins carry blood low in oxygen AWAY from each kidney

A Closer Look Inside the Kidney Renal cortex region Glomeruli (location of microscopic NEPHRONS) Medulla region Renal vein Renal artery Renal pelvis Ureter

Organs of Excretion SKIN - sweat glands excrete perspiration (H 2 O, salt, some urea) - cools body - more urea excreted through skin if kidneys fail Ø LIVER - produces “urochrome” (yellow pigment in urine; from breakdown of heme) - deposited in blood excreted by kidneys Ø

…more organs… - remove CO 2 - removes some H 2 O Ø INTESTINES - iron & calcium excreted into intestinal cavity - salt leaves body in feces; Na+ & K+ through skin Ø KIDNEYS - excrete urine containing end products of metabolism Ø LUNGS

What are some of our wastes? ? Ø Ammonia (NH 3) from amino acid breakdown Ø Urea (from breakdown of ammonia) 2 NH 3 + CO 2 NH 2 – C – NH 2 + H 2 O O * Some ammonia eliminated as uric acid

Ø Creatinine by-product of muscle contraction Ø Bile pigments Ø CO 2 Ø Ions Ca+2 & Fe+2 (in blood) Na+ & K+ (from nerves) Ø H 2 O

Reabsorbing things at the Kidneys - high blood pressure if too much water retained - dehydration if too much water released Ø Glucose - low energy (ATP) production - cell metabolism Ø Amino Acids - protein synthesis disrupted - body can’t produce structural parts * Results if these substances AREN’T reabsorbed back into the blood at the kidneys Ø H 2 O

A close up look at a NEPHRON (where removal of materials & reabsorption occurs in the kidneys)

Kidneys: Supplemental Questions (Answers) Regulatory Function 1. Posterior pituitary gland 2. Blood volume increases (H 2 O reabsorbed from kidneys into blood) 3. More urine 4. Inhibits secretion of ADH 5. Buffering in urine (NH 3 + H+ NH 4+); H+ ions are excreted into urine

Kidney Disorders 1. (a) urethra (b) bladder (c) nephron 2. Waste substances & urea build up in blood (imbalance of ions, high [NH 3]) 3. Immunosuppressive drug (prevents body from rejecting new organ) 4. Artificial kidney machine blood pumped through dialysis tubing & exposed to dialysis solution (wastes move into dialysis solution)
Major functions of the excretory system
Urinary structure
The excretory organ
Excretory organs in mammals
Echinoderms cephalization
Excretory organ of annelids
General overview
Sensory system organs
Function of mouth in digestive system
Accessory organs of the digestive system
Accessory organs of the digestive system
Lymphatic system organs and functions