30.1 organization of the human body - home -...

Lesson OverviewLesson Overview30.1 Organization of 30.1 Organization of 30.1 Organization of 30.1 Organization of

the Human Bodythe Human Body

Lesson OverviewLesson Overview Organization of the Human BodyOrganization of the Human Body

Question #1Levels of Organization (smallest to largest)

Cells = Basic unit of structure and function in living things

� Our specialized cells are uniquely suited to perform a particular

function

Tissues = A group of cells that perform a single function

� Types include epithelial, connective, nervous, and muscle

Organs = A group of different tissues that work together to perform a

single function or several related functions

Organ Systems = A group of organs that perform closely related

functions (interact to maintain homeostasis in the body as a whole)


Question #2Types of Tissues

Epithelial Tissue

� Functions = Protection, absorption, excretion of materials

� Locations = Skin, lining of digestive system, certain glands



Connective Tissue

� Functions = Binding of epithelial tissue to structures, support, transport of substances

� Locations = Under skin, surrounding organs, blood, bones



Nervous Tissue

� Functions = Receiving and transmitting nerve impulses

� Locations = Brain, spinal cord, nerves



Muscle Tissue

� Functions = Voluntary and involuntary movements

� Locations = Skeletal muscle, muscles surrounding digestive tract and blood vessels, heart


Question #3Human Body Systems


Question #4Homeostasis

“Similar standing”

The relatively constant internal physical and chemical conditions that organisms maintain despite changes in internal and external environments

� The systems of the body work to keep internal conditions within a

certain range, never allowing them to go too far one way or the other

� This is like keeping a car in the center of a lane – you constantly move

the steering wheel to the left and the right


Question #5What is feedback inhibition?

Negative feedback

The process in which a stimulus produces a response that opposes the original stimulus


Question #6Feedback inhibition = Home heating system

When the furnace is switched on, it produces heat

This raises the air temperature in the house

This environmental change then “feeds back” to “inhibit” the operation of the furnace

The furnace is switched off


Question #7AFeedback inhibition = Maintaining body temperature

If the body temperature begins to cool, the hypothalamus in the brain signals the body cells to speed up activities, such as cellular respiration, which creates heat (sometimes your body will begin to shiver to produce heat)body will begin to shiver to produce heat)

Also, a message is sent to the skin capillaries to constrict (which means less heat is lost as radiation)

Also, a message is sent to the sweat glands to stop perspiration (less heat is lost by evaporation)


Question #7BFeedback inhibition = Maintaining body temperature

If the body temperature rises, the hypothalamus in the brain signals the body cells to slow down activities, producing less heat

Also, a message is sent to the skin capillaries to dilate (which means more heat will be lost as radiation)

Also, a message is sent to the sweat glands to produce sweat and perspiration begins (heat will be lost by evaporation)


Question #8AThe liver and homeostasis

The liver converts ammonia (which is a toxic byproduct produced when proteins are broken down for energy) to urea, which is much less toxic� The kidneys then remove urea from the blood� The kidneys then remove urea from the blood

The liver also converts other substances (drugs, etc.) into compounds that can be removed from the body safely


Question #8BThe liver and homeostasis

Also, the liver helps to regulate the level of glucose…

� When glucose levels are high the liver converts the glucose into glycogen and stores it

� When glucose levels are low the liver breaks down the glycogen and releases glucose

This is important because too little glucose can result in cells slowing down and too much glucose can damage cells of the eyes, kidneys, heart, and the immune system

30.1 organization of the human body - home -...

Documents