The HUMAN BODY

Chapter 30

Digestive and Excretory Systems

Chapter 30.1 Organization

• Objectives– Describe how the human

body is organized.– Explain homeostasis.

ORGANIZATION

• Cells• Tissues• Organs• Organ Systems• Organisms

Tissue Types• Muscle Tissue- can contract

and shorten for movement• Connective Tissue- provides

support and connects all parts of the body

• Nerve Tissue- carries messages back and forth from body to brain and spinal cord

• Epithelial Tissue- forms a protective surface inside and outside of the body (glands, too)

Organ Systems• Organs made of tissue make up

the organ systems:• These systems are interconnected

– Skeletal– Muscular– Integumentary– Digestive– Circulatory– Respiratory– Excretory– Immune– Endocrine– Nervous– Reproductive

Homeostasis

• Process by which organisms keep internal conditions relatively constant (balance)– Ex. Shiver when

cold to heat up

Check-inWhat tissue type:

– Carries messages between brain and body• Nervous tissue

– Provides support and connects parts of body• Connective tissue

– Contracts and shortens for movement• Muscle tissue

– Forms protective surface• Epithelial tissue

Chapter 30.2 Food Nutrition

• Objectives– Identify essential nutrients

needed by your body and explain how each is important

Nutrition

• Food supplies us with the following:– Energy– Materials for body

processes• Growth

• Repair

• Maintenance

Nutrients

• Water

• Carbohydrates

• Fats (Lipids)

• Proteins

• Vitamins

• Minerals

Check-in• What two things does food supply us with?

– Energy and raw materials for body processes

• What is the most important nutrient?– Water

• Organic molecule that regulates body processes– Vitamins

• Main source of energy– Carbohydrates

Chapter 30.3 Digestive System

• Objectives– Describe the organs of the

digestive system and their functions.

– Explain what happens during digestion.

– Describe how nutrients are absorbed and wastes are eliminated.

Digestive System

• Function: To break down and absorb nutrients from food to provide the body with energy

Types of Digestion

• Mechanical Digestion:– Food is physically

broken into smaller pieces

– Ex. Teeth

• Chemical Digestion:– Food is changed at the

molecular level

– Ex. Gastric Juices

Path of Digestion

• Mouth– Mechanical: use teeth and

tongue to mechanically break down food

– Chemical: saliva breaks starchessugars

• Esophagus– Passage from mouth to stomach

– Adds mucous to ball of food

Path of Digestion

• Stomach– Chemical: Gastric juices

(Pepsin and Hydrochloric Acid) to break down proteins

– Mechanical: Stomach churns food into a soupy substance: chyme

Path of Digestion

• Small Intestine– Food is broken down with various juices

and then the nutrients are absorbed *lined with villi- finger-like projections that

increase surface area for absorption

– Mechanical: Bile from the liver/gall bladder emulsifies fats (breaks into globs)

– Chemical: Intestinal and Pancreatic juices break down fats, carbohydrates, and proteins

Path of Digestion

• Large Intestine– Absorbs water and

vitamins from undigested waste

• Rectum– Storage area for waste

• Anus– Place where waste

exits the body

Accessory Organs of Digestion• Salivary Glands

– Produce salivary amylase to break down carbohydrates

• Liver– Produces bile to emulsify fats

• Gall Bladder– Stores the bile made by the liver

• Pancreas– Produces pancreatic juices to

break down fats (Lipase), carbs (Amylase), and proteins (Trypsin)

Digestion Video

http://www.youtube.com/watch?v=XxvRbxhqoZk&feature=related

Check-in • Type of digestion in which food is

physically broken into smaller pieces– Mechanical digestion

• Trace the path food takes on its trip through the digestive system– Mouth esophogusstomachsmall

intestinelarge intestinerectumanus

Check-in • Where are proteins digested (and by what)?

– Stomach (gastric juice – pepsin/HCl), Sm. Intestine (pancreatic juice – trypsin)

• Where are carbs digested (and by what)?– Mouth (amylase),

Sm. Intestine (pancreatic and intestinal juice)

• Where are fats digested (and by what)?– Sm. Intestine (pancreatic juice)

Check-in • Where is bile made / stored?

– Made in liver and stored in gall bladder

• Where are nutrients absorbed?– Small intestine (major of nutrients) and

large intestine (water and vitamins)

• Describe the mechanical digestion in each organ of digestive system.– Mouth (chewing), stomach (churning by

muscles), Sm. Intestine (bile emulsifies fat)

Chapter 30.4 Excretory System

• Objectives– Describe the organs of the

excretory system and their functions.

– Describe how the kidneys maintain homeostasis.

EXCRETORY SYSTEM

• Function– Removes various wastes

from the body to maintain homeostasis

– Ex. Urine, Sweat, Breath

Video clip

Main Excretory Organ

• Kidneys- – filter waste (urine) from

blood • enters through renal artery

• exits through renal vein

*Nephrons- individual filtering units of kidney

– maintain blood pH– regulate blood volume

Other Excretory Organs

• Liver- filter wastes from blood, detoxifies

• Skin- excretes sweat, oil

• Lungs- remove H2O and Carbon Dioxide

Check-in

• What are the functions of the kidney?– Filter wastes from blood, regulate blood pH,

regulate blood volume

• What organ excretes carbon dioxide and water?– Lungs

• What organ detoxifies the blood?– Liver