Chapter 30

4 Kinds of body tissues – Epithelial Tissue: Lines most body surfaces Protects other tissues from dehydration and physical damage. – Nervous Tissue: Consists of nerve cells and their supporting cells. – Connective Tissue: Support, protect, and insulate the body. – Ex. Fat, cartilage, bone, tendons, and blood. – Muscle Tissue: Enables the movement of body structures by muscle contraction. – 3 kinds of muscle tissues » Skeletal Muscle » Smooth Muscle » Cardiac Muscle

 Nutrient:  Substance needed by the body for energy growth, repair, and maintenance.  Large food molecules must be broken down  Digestion: Process of breaking down food into molecules the body can use.  The energy available in food is measured using a unit called  Calorie: Amount of heat energy required to raise the temp. of 1g of water 1 degree C.

 Carbohydrates:  Single sugar molecules called monosaccharides  Ex. Fruits, honey, onions  Proteins:  Amino acids  Ex. Eggs, fish, milk, poultry  Lipids:  Organic compounds that are insoluble in water that are used to make steroid hormones and to store energy.  Ex. Fats

 Regulate the reactions that release energy  Vitamins: Organic substances that occur in many foods in small amounts Ex. Vitamin A, B, C, D, E  Minerals: Naturally occurring inorganic substances that are used to make certain body structures and substances Ex. Calcium, Magnesium, Sodium  Water: Used by the body as a medium to transport gases, nutrients, and waste products.

 Food is broken down to its molecular components that can be absorbed and used by cells for energy.  Mechanically: The main purpose of the mouth is the physical breakdown of food into smaller pieces.  Chemically: Saliva has an enzyme called amylase Breaks down starch into smaller molecules called monosaccharides Breaks down starch into smaller molecules called monosaccharides

 Esophagus:  A muscular tube by which food or drink gets to your stomach when you swallow.  Epiglottis: The flap of skin that covers your trachea when you swallow so that food doesn’t go into your lungs.  Peristaltic Contractions:  The series of muscular contractions that pushes food down the esophagus.

 Mechanical digestion  The stomach has muscular walls that contract to mix food and digestive enzymes.  Chemical digestion  An enzyme called  An enzyme called pepsin Breaks down proteins  Hydrochloric acid provides the acidic environment that pepsin needs to work.  Mucus: Protects the stomach from the acid. Excessive acid results in an Ulcer (Hole in the wall of the stomach or small intestine)

 Small intestine:  Coiled tubular organ that functions in the digestion and absorption of nutrients.  Villi: Small projections in the lining of the small intestine.  Receives secretions from the pancreas, liver, and gallbladder  Lipase: Pancreatic enzyme that digests fats Small intestine

 All components of food that are not for energy production are considered waste  Colon: Organ that compacts waste for excretion

 Has several functions  Secretes bile Which breaks down lipids Bile is stored in the gallbladder  Hepatitis: Inflammation of the liver  Metabolism Converts extra sugar to glycogen and used when needed for energy

 The body excretes water and Metabolic wastes  Excretion: The process that rids the body of toxic chemicals, excess water, salts, and CO2  Organs of excretion  Lungs: Exhale CO2  Kidneys/skin: Excess water  Liver: Excess ammonia Urea: Less toxic nitrogen waste

 Kidneys are composed of blood- filtering units called  Nephrons: Tiny tubes that filter wastes from the blood, retain useful molecules, and produce urine.  Three different phases occur  Filtration  Re-absorption & Secretion  Urine Formation Urine: H20 and metabolic wastes left after filtering Ureters: Tube through which urine produced passes to the bladder

 Urinary Bladder:  A hollow, muscular sac that stores urine  Urethra:  Tube through which urine leaves the bladder and exits the body  Kidney damage is fixed by  Kidney dialysis  Kidney transplant