UNIT 2- BODY ORGANIZATION AND HOMEOSTASIS

M E L A N I E L O U L O U S I S

ANCHORING PHENOMENON- DIABETES MELLITUS

What is Diabetes mellitus

Questions:

UNIT 2.1 DRIVING QUESTION- HOW ARE LIVING THINGS ORGANIZED?

I Can Objectives:

1.State the hierarchical structural organization in an

organism

2. State that organisms are made of interacting

systems

3. Define what a system is.

4. Explain how systems in the body interact with each

other and affect each other.

LEVELS OF ORGANIZATION FOR MULTICELLULAR ORGANISMS

1.Cells-basic unit of structure and function in living things

Living things can be multicellular or

unicellular Multicellular is when the organism is

made of many cells

Unicellular is when it is made of a

single cell

• 2. Tissues -group of cells that perform a

• single function 4 basic types of tissues : epithelial,

connective, nervous, muscle

LEVELS CONTINUED

3.Organs -a group of different types of

tissues working together to perform a

single function, or several related

functions

4. Organ systems-group of organs that

perform closely related functions

Human Systems:

Nervous, integumentary,

Immune/lymphatic, muscular, circulatory,

skeletal, respiratory, digestive, excretory,

endocrine, and reproductive

5. Organism- a living individual

STEM CELLS

• Stem Cell is a cell that can develop into many different types of cells

• Different from other cells in body because they divide

repeatedly and can become more than one type of cell

• Embryonic stem cells are harvested from eggs that were fertilized the

laboratory and donated for research

• Advantages of embryonic: Can become any type of cell, easily

grown, and millions of cells can be produced from one embryo

• -Controversial to use because embryo is destroyed to use cells

• Adult stem cells are taken from adult tissue

• Use of adult stem cells: limited in types they can become,

relatively rare in the body, and currently can’t be grown to

produce large numbers of cells the lab

• Advantage: taken from patient's own body so won't be rejected when

transplanted

TISSUES

• Tissue is a group of similar cells working together to perform

a common function

• There are 4 tissue types

• Epithelial tissue covers a body surface or lines a body

cavity

• Nervous tissue makes up the nervous system its neurons

and their supporting cells

• Connective tissue connects and supports other tissues

• Muscle tissue is made of cells that contract and relax

to produce movement

TISSUE TYPES CONTINUED

• Epithelial

• -Protects the body from dehydration and

damage

• -Constantly being replaced as old cells die

• -Examples: skin, and respiratory system linings

• Nervous

• -Made of neurons which carry information to

all parts of the body

TISSUE TYPES CONTINUED

• Connective

• Functions in support, protection, connection, and

body insulation

• Includes fat, cartilage, bone, tendons, and blood

• There is two types: lose and dense connective tissue

• Muscle

• There are 3 types: skeletal, smooth, and cardiac

muscle

• Skeletal is attached to bone, smooth makes up blood

vessels and intestine walls, cardiac is found

only in the heart

SYSTEM INTERACTIONS

• While each organ system has a different set of

functions they all work together as a whole to

maintain homeostasis.

• Homeostasis - controlled, stable internal conditions

Means “similar standing”

• In the human body homeostasis is

unconsciously regulated by

instructions from the brain.

SCIENCE SYSTEMS

• A system is a set of interacting or

interdependent component parts forming a

complex/intricate whole.

• Every system is outlined by its spatial and

temporal boundaries, surrounded and

influenced by its environment, described by

its structure and purpose and expressed in

its functioning.

RESPIRATORY AND CIRCULATORY SYSTEM

• Respiratory Structures: nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs

• Function: Brings in oxygen needed for cellular

respiration and removes excess carbon dioxide from the body

• Circulatory Structures: heart, blood

vessels,blood • Function: Transports oxygen, nutrients, and

hormones to cells; fights infections; removes

cell waste; helps to regulate body temperature

THE INTERACTION

• Systems will interact in a living thing to maintain

homeostasis.

• Where do functions of the respiratory and circulatory

systems overlap? Transporting Oxygen

• The respiratory system brings in oxygen from outside the

body, once in the body the circulatory system distributes

the oxygen to all the cells through the blood. The oxygen

is necessary for a process called cellular respiration which

provides energy to cells.

HOW DO LEVELS OF ORGANIZATION AFFECT EACH OTHER?

• What would happen to the cells if the respiratory

and circulatory systems could not provide

enough oxygen for cellular respiration to occur?

• The cell would not function properly, possible die.

• Cells work to form tissues, which form organs, and

organ systems. All these levels need the prior one

working properly for the higher level to work

properly. This is called a hierarchy. Each level is

dependent upon the previous one.

QUICK LAB- MAINTAINING TEMPERATURE

You will receive a thermometer and three beakers of

water at the following temperatures: 25C, 35C, and 40C.

Develop a method to keep the temperatures of the 35C

water within one degree for a period of 5-10mins. You

may use the contents of the other two beakers.

Analyze and Conclude:

1.Was your method successful?

2.Would you do anything differently?

3.Compare this experiment to what happens in your own

body during temperature regulation.

4.Make a model that demonstrates how you maintained

temperature in the lab.

L O U L O U S I S

FEEDBACK LOOPS AND HOMEOSTASIS

2.2 WHAT IS HOMEOSTASIS AND HOW IS IT MAINTAINED IN LIVING THINGS?

1. Define homeostasis and provide examples of items

that living things need to maintain homeostasis for

2. Define feedback loop/mechanism and explain how

a feedback loop/mechanism is related to

homeostasis

3. Distinguish between and describe positive and

negative feedback with an example

WHAT IS FEEDBACK?

• Think about your grades as a student

• What would you consider normal or acceptable

range for your grades?

• What happens when you fall outside of (below) that

range?

• Work or change behavior to get grades back to

acceptable range

• Human body works in a similar fashion through the process

of homeostasis.

2.2 WHAT IS HOMEOSTASIS AND HOW IS IT MAINTAINED IN LIVING THINGS?

• Homeostasis: The body’s ability to maintain stable

(physical and chemical) internal conditions even though

the external environment changes constantly

• Living things keep their bodies’ internal conditions within

a certain range for optimal function. If outside the range

function decreases or increases to a harmful degree.

• Maintaining homeostasis is the most important function

of all body systems of living things. Examples of what is

kept at homeostasis: Temperature, Blood sugar, pH,

Nutrients, Waste

REMEMBER..

• Stimulus- something in the environment that causes a change (can be internal environment)

• Response – action of organism as a result of stimulus

• Feedback loop– processes by which the body maintains homeostasis

• Can also be called feedback mechanisms and feedback system

• Usually uses nervous and hormonal cues to conduct processes

TWO TYPES OF FEEDBACK

• Negative Feedback

• System in which a change in a

variable triggers a response which

reverses or stops the initial change

• Almost all body processes are

negative feedback loops

• Example: body temperature

NEGATIVE FEEDBACK DIAGRAM

Homeostasis

Stimulus

Receptor

Integrating

Center

(Brain)

Effector

Response

(decreases stimulus)

*System stops when

homeostasis is reached

TWO TYPES OF FEEDBACK

• Positive Feedback

• System in which a change in a variable

triggers a response that causes more of

the same change in the same direction

• Fewer body responses use positive

feedback

• Require an outside source to stop or shut

off the system

• Example: Labor and hormone of oxytocin

FEEDBACK TERMINOLOGY

• Stimulus- change in the environment

• Receptor- evaluates the stimulus and sends a

message to the integrating center

• Integrating center- is the Brain which will process

the information and send a message to the

effector

• Effector –will act on the stimulus and generate a

response, often is a hormone or gland

• Response- the reaction within the organism

FEEDBACK GRADES EXAMPLE

• Student typically receives a B on a

test. He gets a C on a the next unit

test. He is disappointed with this

grade so he decides to make flash

cards for the next test as part of his

studying. Then on the next test he

gets a B again.

FEEDBACK GRADE EXAMPLE

• What is the stimulus?

• He got a C on the test

• What is the receptor?

• He realizes he is disappointed with this

• What is the integrating center?

• His brain makes a decision to study differently

• What is the effector?

• He tells himself to make note cards

• What is the response?

• Actually making the note cards

• What ends this feedback loop?

• Student gets a B on the next test

• What type of feedback is it?

• Negative

NEGATIVE FEEDBACK EXAMPLE

• Cold environments cause body temperature to decrease, the hypothalamus senses the temperature change and signals the heating mechanisms of the body to start (like goosebumbs or shivering), then when the normal body temperature is reached the hypothalamus sends a stop signal.

NEGATIVE FEEDBACK EXAMPLE

• What is the stimulus?

• Body temperature decreases

• What is the the response?

• Goosebumbs/ shivering

• What is the integrating center? • Hypothalamus

• What is the receptor? And Effector?

• Receptor=nerve cells througout body that sense temperture chagne

• Effector=signals from the hypothalmus to start heating mechanism

• When does the feedback loop stop?

• Body temperature increases to normal

• Type of Feedback? -Negative

POSITIVE FEEDBACK DIAGRAM

Homeostasis

Stimulus

Receptor

Integrating

Center

(Brain)

Effector

Response

*System stops

when

outside factor

gets involved

POSITIVE FEEDBACK EXAMPLE

• Stimulus causes a

response that increases

the stimulus.

• During labor, a hormone

called oxytocin is released

that intensifies and speeds up

contractions. The increase in

contractions causes more

oxytocin to be released and

the cycle goes on until the

baby is born. The birth ends

the release of oxytocin and

ends the positive feedback

mechanism.

LABOR AND OXYTOCIN FEEDBACK SYSTEM

• What is the initial stimulus?

• Labor begins (water broke)

• What is the response?

• utrine contractions (Intensifies and speeds up as system

continues)

• What is the integrating center?

• Hypothalmus

• What is the receptor?

• Cells that sense labor has begun (water broke)

• What is the effector?

• Hormone oxytocin

• What ends the feedback loop?

• Birth/ no more baby (outside factor)