Unit 9 CHAPTER 35 DIGESTIVE SYSTEM NUTRITION SYSTEM ENDOCRINE SYSTEM

Which gas is needed by all cells? A. SULFUR C. CARBON DIOXIDE B. HYDROGEN D. OXYGEN

Digestive System Function – breaks down food so nutrients can be absorbed by the body

Digestive System Function – breaks down food so nutrients can be absorbed by the body Ingests food, breaks down food, and eliminates what cannot be digested

Digestion Mechanical Chemical

Digestion Mechanical – chewing food to break down, smooth muscles churn food in stomach and small intestine. Chemical

Digestion Mechanical – chewing food to break down, smooth muscles churn food in stomach and small intestine. Chemical – enzymes break down large molecules into smaller molecules that can be absorbed

Digestive System

Peristalsis Food moves through the digestive system in a process where smooth muscles contract rhythmically Starts in the Esophagus and follows all the way through stomach, small intestine and large intestine

Pancreas Function Produce enzymes that digest carbohydrates, proteins and fats Produce hormones

Liver The largest internal organ of the body Function – produces bile, which helps to break down fats 1 L every day Excess is stored in the gallbladder

Stomach Three overlapping layers of smooth muscle Break down food Mix it with secretions of the glands Acidic pH 2 Pepsin enzyme digests proteins Material resembles tomato soup

Small Intestine 7 meters long and 2.5cm in diameter Most absorption occurs Dependent on accessory organs (pancreas, liver, gallbladder) Villi absorption structure Chyme, material cannot be digested

Large Intestine 1.5 Meters long Colon, rectum, appendix Bacteria that produce vitamin K and B Absorb water from the chyme

Time for Digestion Digestive Structure Primary Function Time Food in Structure Mouth Mechanical, Chemical Digestion 5 – 30 seconds Esophagus Transport (swallowing) 10 seconds Stomach 2 – 24 hours Small Intestine 3 – 4 hours Large Intestine Water Absorption 18 hours – 2 days

Nutrition Chapter 35.2

Nutrition Certain nutrients are essential for the proper function of the body

Nutrition Certain nutrients are essential for the proper function of the body The process by which person takes in and uses food

Calorie Unit used to measure the energy content of food Equals 1 kilocalorie Heat needed to raise the temperature of 1 mL of water by 1o

Carbohydrates Cereal, pasta, potatoes, strawberries, rice Sugars (glucose, fructose and sucrose are simple carbohydrates found in fruits, soda and candy Complex carbohydrates are broken down into simple sugars provide energy for cells Excess sugar is stored in the liver in the form of glycogen

Fiber Complex carbohydrate Doesn’t digest Helps keep food moving and with elimination of wastes

Fats Most concentrated energy source Building blocks Protect some vital organs Transport vitamins Digested in the small intestine to fatty acids and clycerol

Proteins Basic structural components of all cells Amino acids build proteins Enzymes, hormones, neurotransmitters, membrane receptors Broken down to amino acids Human body requires 20 (12 synthesized in bodies)

Food Pyramid

Vitamins organic Needed for metabolic activities Help enzymes function well

Minerals In-organic compound Building material, involved with metabolic functions Calcium component of bones and involved with muscle and nerve functions

Nutrition Labels Provide information useful for monitoring fat and sodium intake Based on a 2000 Calorie diet

Summary Energy content of food is measured in Calories Carbohydrates, fats and proteins are three major groups Carbohydrates are major source of energy Fats and proteins provide energy and building blocks Vitamins and minerals are essential for proper metabolic functioning

Endocrine System CHAPTER 35.3

Opener Which one of the kidney functions conserves water in the body? A. Absorption B. Filtration C. Reabsorption D. Breathing

Homework #1 Which hormones are released from nerve cells rather than endocrine glands? A. Antidiuretic hormone and oxytocin B. Growth hormone and thyroxine C. Insulin and glucagon D. Norepinephrine and epinephrine

Homework #2 Which person is likely to have high levels of epinephrine?

The Endocrine System Chapter 35.3 Works like email

The Endocrine System Communication system Made up of glands Produce hormones

Hormone A substance causes a response

Endocrine System Thyroid Kidneys Adrenal glands Testis/ovary

Action of the Hormones Glands produce Acts as a communication system

Endocrine Glands Produce hormones Released into blood stream Distributed

Hormones Steroid hormones Estrogen, testosterone Target cells to initiate protein synthesis Soluble in lipids Diffuse across membrane Attach to DNA Activates specific gene Amino acid hormones Insulin , growth Amino acid Bind to plasma membrane Sends signals

Negative Feedback Thermostat

Negative Feedback Thermostat – works the same Once a level has been reached it stops the production of hormones or ends communication

Endocrine Glands To secrete hormones

Pituitary Gland Base of brain Most important – regulate body and other glands Human growth hormone (hGH) muscle & bone

Thyroid Thyroid – thyroxine causes cells of the body to have a higher rate of metabolism Thyroid – Calcitonin Regulates calcium in the body needed for bone formation blood clotting and nerve function

Parathyroid Parathyroid hormone Increases blood calcium levels by stimulating the bones to release calcium

Pancreas Digestive enzymes that digest carbohydrates, proteins and fats Insulin signals body cells to accelerate the conversion of glucose to glycogen Glucagon sends signals to convert glycogen to glucose

Pancreas

Normal Levels of Sugar

Adrenal Glands Outside cortex Aldosterone signals kidneys to reabsorb salt Cortisol – raises blood glucose levels and reduces inflammation Inside Adrenaline Norepinephrine - both increase heart rate, blood pressure, breathing rate, sugar levels

Link to the Nervous System Regulating activities of the body Maintain homeostasis

Working outside on a hot day Brain – hypothalamus – regulating body

Working outside on a hot day Brain – hypothalamus – regulating body Oxytocin and antidiuretic (ADH) – hormones

Working outside on a hot day Brain – hypothalamus – regulating body Oxytocin and antidiuretic (ADH) - hormones Stored in axon endings in pituitary gland

Working outside on a hot day Brain – hypothalamus – regulating body Oxytocin and antidiuretic (ADH) - hormones Stored in axon endings in pituitary gland When it’s hot you sweat, hypothalamus will detect you are dehydrated releases ADH

Working outside on a hot day Brain – hypothalamus – regulating body Oxytocin and antidiuretic (ADH) - hormones Stored in axon endings in pituitary gland When it’s hot you sweat, hypothalamus will detect you are dehydrated releases ADH ADH travels to kidneys signal to reabsorb H2O