UNIT 2- BODY ORGANIZATION AND HOMEOSTASIS M E L A N I E L O U L O U S I S

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.

FEEDBACK LOOPS AND HOMEOSTASIS L O U L O U S I S

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 *System stops when homeostasis is reached Response (decreases stimulus) Receptor Integrating Center (Brain) Effector

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 Receptor Stimulus *System stops when outside factor gets involved Response Integrating Center (Brain) Effector

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)