1. Organization of the Body and Homeostasis Notes

2. There are eleven organ systems in the human body
The levels of organization in a multicellular organism include:
Cells (basic units of life)
Tissues (made of the same type of cells)
Organs (made of different types of tissue)
Organ systems (group of organs that work together to maintain homeostasis & keep the organism stable & healthy)
There are eleven organ systems in the human body

3. Big Concept Idea
Why do we have so many specialized systems? What advantage does this serve?
The human body has many specialized systems because it allows for multiple points of control which work together to keep you alive & healthy
If problems exist in one system another system can “troubleshoot” or try to fix the problem
Think of a computer- very complex piece of technology. Many points of control allow for errors to be readily corrected.
Your body corrects errors all the time without you even noticing it!

4. Organization of the Body
Cells
Cells are the basic unit of structure and function in living things
Individual cells in multicellular organisms are specialized.
Specialized cells are able to do specific functions or jobs for the organism (e.g. skin, eye, liver, heart, etc.)

5. Organization of the Body
Multicellular = made of many cells e.g. plants & animals, humans
Unicellular = made of one cell only
e.g. bacteria, algae, amoeba, etc.

7. Organization of the Body
Tissues
A group of the same type of cells that work together to do a single function (job) is called a tissue.
There are four basic types of tissue in the human body: epithelial, connective, nervous, & muscle tissue

8. Organization of the Body
Epithelial tissue includes glands and tissues that cover interior and exterior body & organ surfaces. (e.g. skin, sweat glands, blood vessel & organ linings, etc.)

9. Organization of the Body
Connective tissue supports the body and connects its parts. (e.g. blood, bone & fat cells)

10. Organization of the Body
Nervous tissue transmits nerve impulses (signals) through the body & connect structures to the brain &/or spinal cord

11. Organization of the Body
Muscle tissue, along with bones, enables the body to move. Three types: Skeletal, Heart & Smooth Muscle

12. Organs and Organ Systems
An Organ is a group of different types of tissues that work together to do a single function (e.g. muscle, nervous, connective & epithelial tissue all make up the heart)
Organ System: A group of organs that work together to do closely related jobs e.g. mouth, stomach & intestines work together to break food down into small pieces so the body can absorb & use it
There are eleven organ systems in the body.

15. Homeostasis = processes organisms use to keep internal body conditions relatively constant despite changes to its environment
e.g. steady body temperature even if its hot or cold outside; level & regular blood sugar levels no matter when or what you eat, etc.
e.g. its cold outside but Homer can make his muscles vibrate back & forth (shiver) so his inside temperature can stay at normal levels (not too hot, not too cold)
e.g. its hot outside but Homer can put water onto his skin (sweat) so his inside body temperature stays at normal levels (not too hot, not too cold)

16. Homeostasis Its all about balance…
Body systems work together to maintain (keep) homeostasis by constantly checking internal conditions & taking corrective actions as needed e.g. body low on oxygen so yawn happens to bring in more, low water levels-you feel thirsty & then take a drink, body senses low blood sugar levels-you feel hungry so you’ll eat to correct that, to much waste building up in your body-use the bathroom to remove them (go potty) etc.

17. Feedback loops
If conditions change, the body uses Feedback loops to help maintain homeostasis in 3 steps: Information is gathered (stimulus gathered by nerve receptors & carried to control center)
2. Info is processed (by the brain or other control organ) Directions are given to correct the imbalance (nerves carry directions to effector organ, tissue, muscle, etc.) that then take steps to return body to normal homeostatic conditions

18. This hurts… increase blood flow to area to promote healing
Stimulus: the thing or event that causes a reaction
ex: throwing a ball at someone. The ball is the stimulus.
Receptor(usually nerves) detects change; send info to…
Control Center: processes information and sends to effector (ex: our brain!)
Effector: the organ or tissue that causes the response to return to homeostatic conditions
This hurts… increase blood flow to area to promote healing
inflammation

19. Two types of feedback loops:
1. Negative feedback (or Feedback inhibition): receptors send information (stimulus) to the control center (brain) which then starts a response that creates the opposite effect; Negative feedback is most common
e.g. body temperature regulation
Receptors sense the body’s too hot & sends information to the control organ (brain)
Brain gets the message, sends out orders to effector (sweat glands & blood vessels in skin)
Effectors do their job to cool down the skin & body (sweat)

20. A non-biological example of Feedback Inhibition
House thermostat senses temperature increase and turns off heating system
Room temperature increases
Room temperature decreases
Thermostat senses temperature decrease and turns on heating system

21. BODY TEMP EXAMPLE- DRAW

22. e.g. Blood Glucose levels: internally regulated by negative feedback loops

23. Glucose and Insulin Negative Feedback Loop
Two primary Hormones
Insulin
Glucagon
Lowers Blood Glucose Levels
Raises Blood Glucose
Levels

24. Two types of feedback loops:
2. Positive feedback acts to increase the original stimulus instead of opposing it
e.g. ripening fruit, increasing contraction signals during childbirth, increase body temp (fever) when you’re sick
Positive feedback can feel not so positive!

25. Negative Feedback Positive Feedback
e.g. body is too hot, signal sent to reverse this, body sweats to cool down
Negative Feedback
Positive Feedback
e.g. body is too hot, signal sent to increase this so body can fight off an infection & body gets hotter: fever

26. Homeostasis Videos- WATCH VIDEO… may be tested on it…

27. Positive vs. Negative Feedback

28. Human Body Organ Systems

29. Nervous System
Structures: Brain, spinal cord, peripheral nerves
Function: Recognizes and coordinates the body’s response to changes in its internal and external environments; Basically, it’s a communication system

30. Integumentary System
Structures: Skin, hair, nails, sweat and oil glands
Function: Serves as a barrier against infection and injury; helps to regulate body temperature; provides protection against ultraviolet radiation from the sun

31. Skeletal System
Structures: Bones, cartilage, ligaments, tendons
Function: Supports the body; protects internal organs; allows movement; stores mineral reserves; provides a site for blood cell formation

32. Muscular System
Structures: Skeletal muscle, smooth muscle, cardiac muscle
Function: Works with skeletal system to produce voluntary movement; involuntary movement helps to circulate blood and move food through the digestive system

33. Circulatory System
Structures: Heart, blood vessels, blood
Function: Brings oxygen, nutrients, and hormones to cells; fights infection; removes cell wastes; helps to regulate body temperature

34. Respiratory System
Structures: Nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs
Function: Provides oxygen needed for cellular respiration and removes excess carbon dioxide from the body

35. Digestive System
Structures: Mouth, pharynx, esophagus, stomach, small and large intestines, rectum
Function: Converts food into simpler molecules that can be used by the cells of the body; absorbs food; eliminates wastes

36. Excretory System
Structures: Skin, lungs, kidneys, ureters, urinary bladder, urethra
Function: Eliminates waste products from the body in ways that maintain homeostasis

37. Endocrine System
Structures: Hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries (in females), testes (in males)
Function: Controls growth, development and metabolism; maintains homeostasis

38. Reproductive System
Structures: Testes, epididymis, vas deferens, urethra, and penis (in males), ovaries, Fallopian tubes, uterus, vagina (in females)
Function: Produces reproductive cells; in females, nurtures and protects developing embryo

39. Lymphatic/Immune Systems
Structures: White blood cells, thymus, spleen, lymph nodes, lymph vessels
Functions:
Immune System: Helps protect the body from disease;
Lymphatic System: collects fluid lost from blood vessels and returns the fluid to the circulatory system

40. Elephantitis: Lymphatic return system not working: because a parasite’s body blocks the lymph vessels, keeping excess fluid trapped below the parasite’s body

41. When playing basketball or break dancing, which systems are you using?
Endocrine
Respiratory
Circulatory
Muscular
Skeletal
Nervous
Integumentary

42. Big Concept Idea Why do we have so many specialized systems?
What advantage does this serve?
Discuss with your table
Conclusion?
The human body has many specialized systems because it allows for multiple points of control which is advantageous since the systems work together to keep you alive
If problems exist in one system another system can “troubleshoot” or try to fix the problem
Think of a computer- very complex piece of technology. Many points of control allow for errors to be readily corrected.
Your body corrects errors all the time without you even noticing it!

43. Reflex Arc Sensory neuron Motor neuron Spinal cord Interneuron
Effector (responding muscle)
Sensory receptors