Grade 10 AP Biology - Organ Systems

What is the hierarchy of structure in animals?

Cell -> Tissue -> Organ -> Organ System -> Organism

What is a cell?

The simplest unit of life.

What is a tissue?

Similar cells grouped together to perform a specific function.

What is a organ?

Tissues grouped together to perform a complex body function.

What is an organ system?

One or more organs and structures that work together to perform a major body function.

What are the four main type of tissues?

Epithelial tissue

Connective tissue

Muscle tissue

Nerve tissue

What is the function of epithelail tissue?

Protection

Thin sheets of tightly packed cells that covers external surfaces and lines internal structures.

What is the function of connective tissue?

Support and insulation.

Most abundant and diverse tissue type in the body.

What is the function of muscle tissue?

Movement.

Cells can contract and turn chemical energy into mechanical energy.

What is the function of nerve tissue?

Communication within the body.

Why is it important that multicellular organisms are organized according to a hierarchy of structure?

Multicellular organisms are organized according to a hierarchy of structure to enable greater complexity, efficiency, and size. The organized hierarchy—from cells to tissues, organs, and organ systems—allows for a "division of labor," where specialized groups of cells perform distinct functions that a single, unspecialized cell could not.

Why is there no hierarchy of structure within single-celled organisms?

There is no hierarchy of structure because for their to be a hierarchy you need multiple cells to make tissue, then multiple tissues to make an organ, then multiple organs to make an organ system. But if their is only one cell you can't even make tissues, therefore there is no need to have a hierarchy.

What is the purpose of the digestive system?

To convert food into energy to be used by the body's cells.

What are the two parts of the digestive system?

Gastrointestinal tract

Accessory organs

What is the gastrointestinal tract?

It is the tube that forms the digestive system from the mouth to the anus. It is the part that the food passes through. Includes the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.

What are accessory organs?

They are organs that produce secretions that assist digestion and food does not pass through these organs. Includes the salivary glands, liver, pancreas, and gall bladder.

How many steps are there in the digestive process?

3

What are the steps in the digestive process?

1. Digestion

2. Absorption

3. Excretion

What happens during each step of the digestive process?

Digestion - process of breaking foods into smaller pieces.

Absorption - process of nutrients entering the circulatory system to be moved around the body.

Excretion - process of getting rid of solid waste.

What happens during the digestion stage of the digestive process?

Foods are broken into smaller pieces.

What happens during the absorption stage of the digestive process?

Nutrients enters the circulatory system to be moved around the body.

What happens during the excretion stage of the digestive process?

When solid waste is removed from the body.

What organs are involved in the digestion stage of the digestive process?

Mouth, Epiglottis, Esophagus, Liver, Stomach, etc.

What organs are involved in the absorption stage of the digestive process?

Small intestine, Colon, etc.

What organs are involved in the excretion stage of the digestive process?

Rectum, Anus,, etc.

What are the 2 types of digestion?

Mechanical digestion

Chemical digestion

How does mechanical digestion work?

Physical breaking down of food, their is no chemical change. An example would be the chewing in the mouth, and churning in the stomach.

How does chemical digestion work?

Breaking down of food into molecules that are small enough to be absorbed into the circulatory system and cells. Involves enzymes and digestive juices.

What are the roles of epithelial tissue in the digestive system?

Secretion and absorption.

In stomach - epithelial tissue cells, called goblet cells, produce mucous that protects the stomach from stomach acid and digestive enzymes.

In small intestine - epithelial cells are organized into villi to increase surface area for absorption.

What are villi?

Villi are finger like protections form the side of organs that increase surface area to increase the productivity and efficiency of that organ.

What are the roles of muscle tissue in the digestive system?

Made up of smooth muscle cells.

Found in:

esophagus, stomach, small intestine, and large intestine.

Used for:

movement of food and mechanical digestion.

What are the roles of nerve tissue in the digestive system?

• stimulates muscular contraction that moves food.

• stimulates contraction of the stomach for mechanical digestion.

• Signals acid secretion in the stomach.

• Signals when stomach is full.

What are the roles of connective tissue in the digestive system?

Digestive glands - produce, store, or secrete digestive juices and enzymes.

Blood cells - absorption.