Post on 30-Jul-2020
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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)