1. Ch. 32 Notes: Digestive and Excretory Systems

2. mouth esophagus liver gallbladder large intestine small intestine rectum/anus

3. 9A compare the structures and functions of different types of biomolecules, including carbohydrates, lipids, proteins, and nucleic acids 9C identify and investigate the role of enzymes; 10A describe the interactions that occur among systems that perform the functions of regulation, nutrient absorption, reproduction, and defense from injury or illness in animals; 10C analyze the levels of organization in biological systems and relate the levels to each other and to the whole system Objectives

4. Cells require many different nutrients, and six types of nutrients help to maintain homeostasis Water- natural solvent, aids in digestion and excretion, blood volume and body temperature Carbohydrates- main source of energy (4 cal/gram) Proteins- raw materials for growth and repair, catalyze reactions Fats- provide energy and energy storage, make up cell membranes (9 cal/gram) Minerals- repair tissues and carry out body functions Vitamins- work with enzymes to regulate cell functions, growth, and development

5. Nutrients from food Simple and Complex Carbohydrates

6. Cells require many different nutrients, and six types of nutrients help to maintain homeostasis Water - natural solvent, aids in digestion and excretion, blood volume and body temperature Carbohydrates - main source of energy Proteins - raw materials for growth and repair, catalyze reactions Fats - provide energy and energy storage, make up cell membranes Minerals - repair tissues and carry out body functions Vitamins - work with enzymes to regulate cell functions, growth, and development

7. Digestive System The digestive system breaks down food into simpler molecules Digestion - process where large complex food molecules are broken down into smaller molecules that can be used by the body Digestive system - collection of organs that breaks down food into energy

8. Digestion begins in the mouth and continues in the stomach Mechanical digestion- physically breaking down food into smaller pieces Chemical digestion- enzymes and acids chemically break down food molecules

10. Pathway Mouth - mechanical digestion, plus chemical digestion of starches Esophagus Peristalsis - rhythmic, involuntary contraction of smooth muscle, helps you swallow and move food around in your stomach/intestines Stomach - mechanical digestion and chemical digestion Small intestine - most digestion takes place here Large intestine - absorbs water Rectum - holds waste before excretion

11. Peristalsis esophagus muscles contract muscles relax food stomach

12. A – Esophagus B – Gall bladder (stores bile) C – Liver D – Stomach E – Duodenum (part of small intestine) F – Pancreas G – Small intestines H – Large intestines

13. Digestion involves lots of different enzymes that each break down specific things EX: amylase- breaks down starches EX: pepsin- breaks down proteins EX: lipase- breaks down fats

14. Nutrients are absorbed in the small intestine Use villi- small fingerlike projections that absorb nutrients Water is absorbed from the large intestine Other organs involved with digestion Liver (also filters your blood!)- makes bile - helps break down fat Pancreas - produces enzymes

15. Excretory System The excretory system removes waste and helps maintain homeostasis Organs Kidneys - filter and clean blood and producing urine (water, urea, salts, etc) Nephrons- structures in the kidneys that filter blood Ureter (2)- carries urine from the kidney to the bladder Bladder - sac like organ for urine storage Urethra - tube that releases urine outside the body

16. skin lungs kidneys ureters urinary bladder urethra

18. Kidneys help to maintain homeostasis Remove waste products from the blood Help maintain pH and electrolyte levels in the blood Use feedback loops to do this Positive feedback loop- there is a change occurring that the body wants to continue occurring. Negative feedback loop- stop what is changing and return it to normal

19. What would happen if your kidneys stopped working? ________________________________________________________________