1. Organization of the Body
Unit 2
Organization of the Body

2. Hierarchy of Human Structure
Guided Reading:
List the levels of organization, starting with molecules.
What are stem cells?

3. Hierarchy: a series of ordered groupings within a system
Alpha male & female Pups & adults Outcasts / Dispersers

4. Levels of Organization
Cells in multicellular organisms cooperate by doing specific jobs  specialization
Molecular LOO, Cellular LOO, Tissue LOO, Organ LOO, Organ System LOO, Organism, Society, Envirome
Tissue: organized assembly of cells that have a similar structure and perform a special function. Function as one unit b/c cells communicate with one another as they respond to environment & surrounding cells.
The type of tissue that makes up an organ determines the function of that organ.
Organ system: a collection of organs having related roles in an organism’s function. Has distinct tasks to maintain homeostasis in the body. Digestive breaks down & uptakes food and the circulaotry moves it around the body.
Organism: any living thing / an individual biological unit capable of reproduction
Society: organism interacts with another organism, living working together. has an impact on homeostasis of the body
Envirome: all environmental factors that affect the survival of an organism or a society of organisms

5. Stem Cells Undifferentiated cells
have the potential to develop into many different cell types during early life & growth
Can be induced to become specialized cells
brain cells, red blood cells, skin cells, etc.
Embryonic stem cells: derived from fertilized eggs
Induced pluripotent stem cells: adult specialized cells that can be “reprogrammed” to become a different kind of cell
Blastocyst (early stage of development)
stem cells differentiate into specialized cells
Adults: stem cells still exist (in organs & bone marrow) to replace old/damaged cells

6. The Human Physiological Environment
Guided Reading:
If humans live on land, why does the author say that the human physiological environment is “aqueous”?
What does it mean when people say that something acts as a “solvent”?

7. The Human Physiological Environment
All the internal conditions that allow cells to perform their functions effectively & efficiently. This positively impacts body organization
Involves internal & external cellular conditions.
Both rely on water.
Needs specific conditions to maintain homeostasis:
pH, ions, chemical reactions, transport of molecules between internal & external environments
Allows us to maintain homeostasis…

8. More on homeostasis Homeostasis ≠ balance.
Allows us to adapt to changing environments. Maintained by negative feedback loops
Maintain constant conditions inside the body when the external environment fluctuates.
“Set point”
Often utilizes chemical messengers (e.g. hormones)

9. Negative Feedback Systems

10. Negative Feedback: Maintaining Homeostasis
“System” has a set point (ideal level) and “sensors” that detect changes…
If it drops below set point, something is produced…
If it exceeds that level, production stops…
Examples:
Thermostat
Toilet

11. Body Temperature Example

12. Negative Feedback Loop

13. Generic Example: X Y Gland X releases hormone X… X
This stimulates target cells to release hormone Y.
Eventually, an excess of hormone Y exists
Gland X "senses" this… and inhibits its release of hormone X. X Y X

14. Positive Feedback

15. Defined…
“Feedback in which the system responds so as to increase the magnitude of any particular perturbation”

16. Results in amplification of the original signal instead of stabilization.
Any system where there is a net positive feedback will result in a runaway situation.
Requires a feedback loop to operate.
Examples: Fruit ripening, childbirth, breastfeeding

17. The Human Physiological Environment
The human physiological environment is aqueous.
Water is contained in the cells, the blood, body cavities, organ systems, and tissue.
Not just sloshing around under the skin!!
Water’s atomic structure provides it with all the properties that make it useful for the body.
Polarity, adhesion (latch onto other molecules), cohesion (stick together), high specific heat. Good biological solvent b/c it forms hydrogen bonds with -OH groups on carbs and attracts the electrical charges of R groups on peptides. Natural solvent for ions.

18. The universal solvent
Water is polar  can dissolve most materials needed for human survival
Solvent = dissolves other chemicals & forms a solution
Solute = a particle that is dissolved in a solvent
Water is a good bio solvent b/c it is polar (charged)
Most chemical reactions require an aqueous environment

19. Water is a natural solvent for ions, needed for cellular functions
Adhesion & cohesion  won’t evaporate quickly (so we won’t become easily dehydrated)
High specific heat  water absorbs much heat energy when it evaporates

20. Living in a balance Dehydration: tissues deprived of water
Diarrhea
Sweating
Vomiting
Indicators: extreme thirst, stop sweating, nausea & exhaustion
Water intoxication?
Body takes in more water than it loses at a given period of time.
Upsets natural balance of ions, minerals
A Fraternity Hazing Gone Wrong : NPR

21. Tissues Guided Reading:
What are the four types of tissue found in humans?
What are the major characteristics/functions of the four types of tissue? (Recommend you make a chart)

22. Stem cells again!!!! Retain ability to undergo cell division
Assist further body development and healing later in life
Stem cells from bone can produce a variety of human tissues
Brain stem cells can develop into many types of cells
See p. 107 in text

23. Embryological germ layers
Ectoderm  skin and brain
Mesoderm  Bone and muscle
Endoderm  Digestive organs
Lay down the 4 human tissue types into the hierarchy that eventually forms a human

24. Create a Concept Map (aka Mind Map) for One Type of Tissue…
How to create a concept map
Constructing a concept map
Example
For each cell type…..
Names of cells & structures
Characteristics
Locations
Functions
Examples

25. Four Types of Tissues
Connective: forms the supportive framework of the organs & body
Epithelial: covers internal & external body surfaces; forms layers of cells that line body cavities
Muscle: provides body w/ movement & support
Nervous: conducts & coordinates body info; highly specialized cells
TISSUE: An organized assembly of cells that have similar structures and perform a specific function
Epithelial Tissue – covers internal and external body surfaces
Connective Tissue – forms the supportive framework of the organs and the body
Muscle Tissue – provides the body with movement and support
Nervous Tissue – conducts and coordinates body information

26. Types of Cells/structures Characteristics of these cells
Tissue Type
Types of Cells/structures
Characteristics of these cells
Epithelial
Squamous
Cuboidal
Columnar
Flat
Cube-shaped; produce secretions
Tall, column-shaped; secretions, uptake
Simple: Single-layer
Stratified: Multi-layered; subject to wear and tear
Pseudostratified: False-stratification
Connective
Matrix
Protein: Collagen
Protein: Elastin
Protein: Reticulum
Loose
Dense
Made of gel, liquid, protein, salts
Strength
Flexibility
Support
Most abundant; attachment, stabilization, structure, support
Strength, storage, flexibility
Muscle
Smooth
Cardiac
Skeletal
Spindle-shaped; no visible fibers; weak contractions; line organs
Heart; visible striations; intercalated disks
Large cells; distinct striations; (in)voluntary
Nervous
Neurons
Neuroglia
Motor, Sensory, Interneuron
Assist Neuron functions (astrocytes, oligodendites, ependymal cells)

27. Organs, and Systems Guided Reading
What is the relationship between tissues and organs/systems?
What are the various organ systems found in humans?

28. Organs and Systems Cardiovascular  regulates blood flow
Digestive  regulates nutrition
Integumentary  provides protection
Lymphatic  regulates body fluids, helps fight disease
Muscular  provides structure and movement
Skeletal  provides support and movement
Endocrine  regulates body function and development
Reproductive  regulates sexual function
Respiratory  regulates atmospheric gasses and certain body wastes
Urinary  regulates production, storage, and removal of urine

29. Wellness and Illness over the Life Span
Guided Reading:
What does this statement mean? “Cell pathology causes hierarchy dysfunctions of the body”?
What is the purpose of a biopsy?
Make a chart describing the major types of cell pathology.
What is “molecular decay”?
What does “telomere shortening” cause for a cell?

30. Cell Pathology
The basis of understanding dysfunction of the body’s hierarchy
Dysfunction: Abnormal, impaired, or incomplete functioning of an organism, organ system, organ, tissue or cell. All gross diseases.
Cell pathology: examining cells microscopically
Biopsy: Removal of diseased cells for study

31. Types of Cell Pathology
Prefixes
Dys: bad, abnormal
A: not
Hyper: over, above, exceedingly, in excess
Meta: changed; altered
Roots
Trophy: make to thrive
Plasia: formation
Stasis: place

32. Cell Pathology Terms
Atrophy: Wasting or decrease in size of a cell, tissue or organ.
Caused by malnutrition / blood flow problems
Lack of muscle use / nerve damage  muscle atrophy
Dystrophy: “ill growth.” progressive changes in a tissue that is almost always due to long-term malnutrition, decreased blood flow.
Muscular dystrophy: general weakening of muscles
Hypertrophy: Enlargement of a tissue or organ due to an increase in cell size, NOT CELL NUMBER.

33. Cell Pathology Terms
Dysplasia: disorderly growth pattern in a tissue or organ.
Not cancerous
Has significant impact on body structure
Hyperplasia: abnormal multiplication in the number of normal cells in a tissue
Increases the risks of certain cancers
Distorts the function of the tissue/organ
Metaplasia: A change in cell and tissue function from normal to abnormal.
Can be reversible
Can produce inappropriate functioning of the tissue or organ
Cause: DNA damage, exposure to certain chemicals
Can lead to cancer or breakdown in cell communication / tissue organization

34. Cell Pathology Terms
Metastasis: Diseased cells break away from the original location and establish themselves in new areas of the body
Can carry out functions in new location
Reserved from cancerous or highly abnormal cells

35. Cell Pathology: Amyloid deposition
Amyloid: protein-like material
Disagreement: do they cause disease or are they the result of disease?
Intended to help but cause harm when build up in cytoplasm
Indicators of cell damagecell senses & corrects
Cell death is the result usually

36. Cell Pathology: Fatty Change
Accumulation of lipids in the cell in response to cellular injury.
Excessive alcohol intakeincreased fat in liver cells, disrupting cell function & thus tissue function

37. Cell Pathology: Necrosis
Localized tissue death
Blood flow decrease (bed sores!) burns, chemical damage, infections, injury
Results in diminished functioning of the tissue, organ & organ system.

38. Cellular Aging: Non-mitotic cells
Occurs because of accumulated molecular damage
Especially in cells that cannot undergo mitosis: fat cells, skeletal muscle, nervous tissue.
They can’t fix the damage
Fail at tasksaffect tissues, organs, etc.
Caused by environmental factors, stress
Cells can die early or undergo programmed death protect the nearby cells