CellsCLA-2nd Grade

Day 1: Today we will be introduced to cells – their types, and their functions.

Cells… How important are they?

Happy Cells, Happy Life

Cells A cell is the smallest part of 

your  body that carries out the activities of life. 

Cells are the basic building blocks that make up all living things.            

The tiniest organisms are only single cells.

 Multicellular organisms, on 

the other hand, have many cells, maybe trillions.

Most cells are too tiny to be seen by the eye alone. 

Cells

A single drop of blood would hold millions of red blood cells like the ones pictured on the right. 

You definitely need a microscope to see them.

Cells

Animal Cell

Let’s look at an animal or human cell and some of the parts that make it up.

Mitochondria are the cell’s power producers. Mitochondria combine oxygen and food to 

produce energy.

Vacuoles can sometimes act like a stomach, storing and breaking down material. In plants, vacuoles may store 

water

Cytoplasm is allthe material of thecell between thecell membrane andthe nucleus.

The cell membrane surrounds a cell, holding the parts of the cell together. It allows needed materials, such as sugar, water, and oxygen, to enter the cell. It 

allows certain other materials, such as carbon dioxide and other waste products, to exit.

The cell nucleus acts like the brain of the cell. It helps control eating, movement, and reproduction.

Just as footballs, basketballs, and hockey pucks all have different shapes and different purposes, so do different cells.

Your body has about 200 different kinds of cells.

A cell’s shape is often specialized to fit its job.

Cells

Plants, animals and people are made up of many cells.

Different cells do different jobs.

The three different jobs that cells have are to make 1) tissues,2) organs,3) and systems.

Day 2: Today we will explore how cells form four types of tissues.

From Cells to Organ Systems

• Cells combine to form tissues, and tissues combine to form organs.

• Tissues are a team of cells that join together to form organs that do a special job.

• Cells combine to form four primary tissues:

– 1) Epithelial tissue– 2) Connective tissue– 3) Muscle tissue – 4) Nervous tissue

1) Epithelium-Human Stomach

• Two types:

– A) membranes • form the coverings or linings of organs

– B) glands• form exocrine and endocrine glands

Epithelium

• An important structural component of organs – Consists of two types:

• Dense connective tissue • Loose connective tissue

2) Connective Tissue

• Consists of specialized cells that contract when stimulated

• The body has three types of muscle tissue:

• Cardiac (involuntary)• Skeletal (voluntary) • Smooth muscle (involuntary)

3) Muscle Tissue

4) Nervous Tissue• Contains specialized cells that

conduct impulses

• Conducting cells, called neurons, transmit impulses from one region of the body to another.

• Nonconducting cells, neuroglia, are a type of nervous system connective tissue.

Nerve Tissue

Day 3: Today we will explore how groups of tissues form organs.

Organs

• Tissues combine to form organs.

– Organs are discrete structures that have evolved to perform specific functions

A group of different kinds of tissues working together to carry out a body function is called an organ. Some kinds of organs include:

1) eyes 2) ears 3) stomach 4) heart5) lungs 6) pancreas 7) tongue 8) liver9) mouth 10) small & large intestines

Day 4: Today we will explore how groups of organs form organ systems.

Some systems we will discuss next include the digestive and excretory systems.

Other kinds of systems include circulatory, nervous, respiratory, muscular and skeletal.

We will also review cells.

Organ Systems• Tissues combine to form organs.

– Organs are discrete structures that have evolved to perform specific functions

– Most organs do not function alone, they are part of a group of cooperative organs, called an organ system.

– Organs combine to form organ systems.

– Organ systems are a group of organs that work together to do a major job that keeps an organism alive.

Types of Organ SystemsLet’s take a quick overview of some of our body’s organ systems.

Integumentary system -regulates fluid and blood loss Skeletal system -frame work for the body Muscular system - -creates movement

Immune System -portions of many different systems that fight disease Lymphatic System - -supports immune systems: houses white blood cells Cardiovascular System -transportation of nutrients and gas waste

4) Nervous tissue4) Nervous tissue

 Urinary system -get rid of nitrogenous waste out of blood

Digestive system -breaks down food into the building blocks for the body Respiratory system -portions moistens and heats air 

Nervous system -coordination of muscles Endocrine System -secrets hormones that regulate growth, metabolism and general body function. Reproductive System--production offspring ous tissue

4) Nervous tissue

Day 5: Today we will review and test on cells.

Digestive & Excretory SystemsCLA-2nd Grade

This week we will discover how the digestive and excretory systems work in our bodies.

Day 1: Today we will be starting our digestive adventure with our mouths, teeth, taste buds, and esophagus.

The Digestive System

• Esophagus• Stomach• Small Intestine• Large Intestine• Liver• Gall Bladder• Pancreas

What has happened to the food you ate today?

In the Mouth

• Digestion actually begins in the mouth.

• The teeth break the food into smaller pieces, and the tongue moves the pieces around so that saliva can be mixed with them.

• This begins the digestion.• Then swallow, and the journey

begins!

Esophagus

• About 10” long• Moves food from the

throat to the stomach.– The muscle movement is

called peristalsis.

• Heartburn is when acid from the stomach gets in here.

Day 2: Today we will find out what happens to food in the stomach, small intestine, and large intestine.

Stomach

• Stores the food you eat, breaks it down into tiny pieces.

• Mixes food with digestive juices.

• Acid in the stomach kills bacteria.

• It can stretch and shrink.

Small Intestine• Small intestines are roughly

22 feet long. “Small” refers to its diameter, not its length.

• Insides are coated with little ‘fingers’ called cilia to increase surface area.

• Nutrients from the food pass into the bloodstream through the small intestine walls.

• You can have pieces removed but it is very hard for your body to get the right nutrients.

Large Intestine

• About 5 feet long.• Accepts what small intestines

don’t absorb. • Absorbs water and minerals

from the waste matter.• You can lose a large part of

this and still survive.

Day 3: Today we will discuss the roles of the liver, gall bladder, and pancreas.

Liver

• Directly affects digestion by producing bile.– Bile helps digest fat.

• Processes nutrients in the blood, filters out toxins and waste.

• Is often called the body’s energy factory.

• You cannot live without a liver, although you can live with a part of one.

• Drinking alcohol damages the liver.

Gall Bladder

• Stores bile from the liver.• Delivers bile when food is

digested.• Fatty diets can cause

gallstones.• You can live without a

gallbladder.

Pancreas

• Produces compounds to digest fats and proteins.

• Neutralizes acids that enter small intestine.

• Regulates blood sugar by producing insulin.

• If it doesn’t work right you get diabetes.

Day 4: Today we will learn about a system our body uses to eliminate toxins and stay healthy.

Let’s also watch a video about how the digestive and excretory system work and then review.

Digestive System video

Fun Facts

• HOW LONG ARE YOUR INTESTINES? At least 25 feet in an adult. Be glad you're not a full-grown horse -- their coiled-up intestines are 89 feet long!

• Food drying up and hanging out in the large intestine can last 18 hours to 2 days!

• In your lifetime, your digestive system may handle about 50 tons of food and liquid!!

On a sheet of paper, write the name of each colored organ:

• Green:• Red:• Pink:• Brown:• Purple:• Green:• Yellow:

Did you get the answers right?

• Green: Esophagus• Red: Stomach• Pink: Small Intestine• Brown: Large Intestine• Purple: Liver• Green: Gall Bladder• Yellow: Pancreas

Great Job!

References and Links

• Your Digestive System and How It Works: http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/Your_Digestive_Sys.pdf

– Digestive system diagram comes from this site

• The Real Deal on the Digestive System

http://kidshealth.org/kid/body/digest_SW_p2.html

• Pancreas: Introduction and Index http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pancreas/index.html

• Your Gross and Cool Body – Digestive System http://yucky.discovery.com/flash/body/pg000126.html