3.2 O RGANS AND O RGAN S YSTEMS

H OOK ( VIDEO )

A GENDA Hook Video on Bicycle Riding From Cells to Tissues to Organs Types of Organ systems The Digestive Organ System

N OTE : T UESDAY Q UIZ ON THE D IGESTIVE S YSTEM

F ROM C ELLS TO T ISSUES AND O RGANS Human stem cells differentiate into epithelial, muscle, nervous, and connective cells. These accumulate to become tissues. These tissues are organized to form organs, which are designed to perform a specific function. The organs are used to form organ systems which together provide everything necessary to keep the organism (human) alive.

H IERARCHY OF A NIMAL S YSTEMS Organ Systems (Circulatory, Digestive, Respiratory, etc.) Organs (Heart, Liver, Intestine, Blood Vessel, etc.) Tissues (Connective, Muscular, etc.) Specialized Cells (Blood, Heart, Bone, etc) Stem Cells

T-P-S : N AME THE O RGAN S YSTEMS

O RGAN S YSTEMS I DENTIFIED A. Muscular B. Skeletal C. Nervous System D. Endocrine E. Circulatory F. Integumentary G. Lymphatic (Immune) H. Respiratory I. Digestive J. Excretory K. Reproductive

D IGESTIVE S YSTEM The digestive system has 4 primary functions: Ingestion Digestion Absorption Egestion

I NGESTION & E GESTION Ingestion refers to the consumption of a substance (1 st step). Egestion refers to the removal of unwanted materials from the body. (Last step)

D IGESTION Digestion is the mechanical and chemical breakdown of food into smaller components. (2 nd step) It is the breakdown of large food molecules into smaller ones.

A BSORPTION (F IG. 3.16) Absorption is the process by which digested food nutrients and water are taken from the intestine and moved throughout the body. (3 rd step) Body (Through Blood Vessels)

D IGESTIVE S YSTEM L ABELLED Gallbladder Pancreas

I N C LASS W ORK /H OMEWORK Newspaper article (Due Monday) Read pages Answer Questions 1,3, 4 (page 90) Answer questions #4-8 (page 92) Read pages for the quiz on Tuesday November 15 Answer questions #1-3 (page 99) Read ahead to the circulatory system (pages )

H OOK V IDEO

L ABEL THE D IGESTIVE S YSTEM C OMPONENTS

S CENARIO : E ATING A B URGER The burger enters the oral cavity (i.e. the mouth) A bite is taken out of the burger and chewing proceeds (mechanical digestion) The salivary glands secrete amylase to breakdown the carbohydrates. (chemical digestion) Once the food has been broken down into small enough pieces, the food is swallowed.

D OWN THE O ESOPHAGUS TO THE S TOMACH The partly digested food travels through the pharynx down the oesophagus through peristaltic contractions.

D IGESTION IN THE S TOMACH The food passes through a sphincter into the stomach where gastric juices surround the food. Hydrochloric acid and the enzyme pepsin break down most of the protein. (chemical digestion) The stomach then covers the food in mucus and sends the food down to the small intestine (duodenum)

T HE S MALL I NTESTINE The pancreas, liver, and gall bladder release chemicals to help break down the food further. The small intestine contains millions of tiny folds called villi and microvilli Provides increased area for absorption Nutrients and water can be reabsorbed into the bloodstream

T HE L ARGE I NTESTINE Includes the colon, rectum, and anus Mainly absorbs water Also absorbs vitamins and various salts Undigested food leaves as feces ( E.g. Corn)

V IDEO /M ULTIMEDIA T OOL

R EVIEW S NOWBALL A CTIVITY (Q UESTIONS ) Take out a blank sheet of paper Skim through pages in the textbook. Create questions to review The Digestive System Begin the snowball activity

B REAK T IME (5-10 MIN )

E XAMINING H UMAN O RGANS AND S YSTEMS Old Method Exploratory surgery New Methods Medical imaging technologies X-ray CT or CAT scan Ultrasound MRI Scan

X-R AY Transmits electromagnetic waves that radiate through the body. Since bone is dense, the radiation is absorbed. Produces an image of bone structure

CT OR CAT S CAN Makes use of X-rays to get thin slices of a body part. Each slice is computerized and joined to form a 3D image

U LTRASOUND Makes use of high frequency sound waves. Waves are directed at a body part for a period of time in order to examine movement

MRI Magnetic Resonance Imaging Uses radio signals in a magnetic field to create images of body parts

I N C LASS W ORK / H OMEWORK Read/Review The Digestive System (pages 96-99) for the quiz on Tuesday November 15 Read ahead to the circulatory system (pages )