Human Biology

The Human Body

The Body as a Whole… Your body is busy

working 24/7 Blood is pumped

through vessels by your heart…

Air is pushed in and out of your body by your lungs…

The Body as a Whole… Your intestines are

giving off chemicals that break food down…

Nerves are sending out signals from your brain to all parts of your body

The Body as a Whole… Chemical messengers

are regulating all kinds of processes

These activities may seem quite different- and in many ways they are, but…

The Body as a Whole… They all have the same purpose: to

delicately control the body’s internal environment.

The human body’s internal environment must remain stable, or constant, even during extreme changes in its environment or activities of the body.

The Body as a Whole… Homeostasis – stable internal environment.

AKA the process by which the body’s internal environment is kept stable in spite of changes in the external environment.

Levels of Organization…Cells

Cells: the basic unit of structure and function of all living things.

Levels of Organization…Cells Each cell of your body has its own job. For example:

Absorbing cells Cells lining the small intestine absorb digested

food and transport it to the bloodstream which delivers it to all parts of the body

Levels of Organization…Cells More examples:

Assembly cells These cells are responsible for putting together

important chemical substances. For example, the pancreas contains a variety of assembly cells. Some produce enzymes and some produce hormones.

Enzyme=chemicals that help break food down into simpler substances

Hormones=chemical messengers that help to regulate certain activities of the body

Levels of Organization…Cells More examples:

Cells for movement For example, muscle cells These cells are unlike any other cells in your body They have the ability to contract, or shorten This causes movement

Levels of Organization…Tissue Tissues: a group of similar cells that

perform the same function There are 4 basic types of tissue in the human

body Muscle Connective Nerve epithelial

Levels of Organization…Tissue

Muscle tissue The only kind of

tissue in the body that has the ability to contract, or shorten

Levels of Organization…Tissue Types of muscle tissue:

One type causes your body to move by pulling on bones when it contracts

Another type lines the walls of structures inside your body and moves food from your mouth to your stomach

A third type is found only in your heart, and enables the heart to contract to pump blood

Levels of Organization…Tissue Connective tissue

Provides support for your body and connects all of its parts

Bone- provides structure and support

Blood- carries food and oxygen to all cells of the body

Levels of Organization…Tissue

And fat- keeps the body warm, cushions internal structures from the shock of sudden blows, and also stores food

Levels of Organization…Tissue Nerve tissue

Carries messages back and forth between your brain, spinal cord, and every other part of your body

Nerve messages can travel at speeds of up to 100 meters per sec

Levels of Organization…Tissue Epithelial tissue

Forms a protective surface on the outside of your body

One kind makes up your skin

Another kind lines the cavities, or hollow spaces of the mouth, throat, ears, stomach and other body parts

Levels of Organization… Organs Organs – different types of tissues combine

to form organs An organ is a group of different tissues with a

specific job For example: heart, stomach, brain, eye, skin,

tongue

Levels of Organization…Organ Systems Organ system – a group of organs that

work together to perform a specific job Each system performs a special function for

the body, yet no one system acts alone There are eleven organ systems of the human

body

Human Body Organ SystemsSystem Function

Skeletal Protects, supports, allows

movement, produces blood

cells, and stores minerals

Muscular Allows body movement and

maintains posture

Human Body Organ SystemsSystem Function

Digestive Breaks down food and

absorbs nutrients

Circulatory Transports nutrients, wastes,

and other materials and plays

a role in the immune

response

Human Body Organ SystemsSystem Function

Respiratory Exchanges oxygen and

carbon dioxide between

blood and air

Excretory Removes solid and liquid

wastes

Human Body Organ SystemsSystem Function

Nervous Detects sensation and

controls most functions

Endocrine Plays a part in the regulation

of metabolism, reproduction,

and many other functions

Human Body Organ SystemsSystem Function

Reproductive Performs reproduction and

controls male and female

functions and behaviors

Immune Controls the immune

response and fights disease

Human Body Organ SystemsSystem Function

Integumentary Protects, regulates

(skin) temperature, prevents water

loss

Human Biology Review List the levels of organization in humans. What are the four basic types of human tissue? List the organ systems of the human body. Using any type of machine as an example,

explain how each part of the machine works together with every other part so that the machine can do its job. Compare this with the way the systems of the body work together.

Levels of Organization Review The body as a whole

The process by which the body’s internal environment is kept stable in spite of changes in the external environment is called homeostasis.

Humans, like all living things, need energy to do work.

Human Biology Review Levels of Organization

The levels of organization in a multicellular living thing include cells, tissues, organs, and organ systems

Cells come in all shapes and sizes. Regardless of its job or shape, a cell works in harmony to keep the body alive

Cells are the building blocks of living things

Human Biology Review Levels of Organization, continued

A tissue is a group of similar cells that perform the same function

There are four types of tissues in the human body: muscle, connective, nerve, epithelial

Muscle tissue has the ability to contract, or shorten, allowing one type of muscle tissue to make the body move.

Human Biology Review Levels of Organization, continued

Another type of muscle tissue lines walls of internal structures of the body

A third type of muscle tissue enables the heart to contract

Connective tissue provides support for the body and connects its parts

Nerve tissue carries messages back and forth between the brain and spinal cord and every other part of the body

Human Biology Review Levels of Organization, continued

Epithelial tissue forms a protective surface on the outside of the body and lines its internal cavities

An organ is a group of tissues with a specific function

An organ system is a group of organs that work together to perform a specific job