Unit 1: Levels of Organization

1. Unit 1:Levels of Organization Chapter 1: Introduction to Human Anatomy and Physiology

2. Additional Historical points to Ponder (1.1) • Primitive people were hunter-gatherers. • Killed when hungry and ate their kills • Gathered wild plants which contained and provided chemicals that naturally fought infections

3. Additional Historical points to Ponder • Introduction of Agriculture • Brought exposure to pin, hook, and tape worms in the fertilizer – animal manure • The ability to grow crops lessened the need to rely on wild plants. This decreased the ability to fight infections naturally through the chemicals in the wild plants

4. Additional Historical points to Ponder • Urbanization • Leaving the country and forming towns increased the number and severity of infectious illnesses as well as malnutrition • People became sedentary and altered their diets • Evidence documented in bones and teeth (p. 11)

5. Learning Outcome 1.1 Identify some of the early discoveries that lead to our current understanding of the human body.

6. Anatomy & Physiology (1.2) • Ana- (up) + -tomy (to cut or break) = Anatomy • The study of the structure (morphology and form) of body parts • Literally  to cut up or break apart the body into its parts • Physio- (relationship to nature) + -ology (to study) = Physiology • The study of the function of body parts • What they do and how they do it – the study of what and how each body part does naturally

7. Anatomy & Physiology • These 2 sciences are very closely related • Structure determines functions; therefore ANATOMY DETERMINES PHYSIOLOGY

8. Ultrasonagraphy

9. Magnetic Resonance Imaging (MRI)

10. CT Imaging

11. Learning Outcome 1.2 Explain how anatomy and physiology are related.

12. Levels of Structural Organization (1.3) Protons Neutrons Electrons Subatomic particles

13. Subatomic particles The smallest particle of an element Atom

14. Subatomic particles Atom A particle composed of 2 or more joined atoms Molecule

15. Subatomic particles Atom Molecule Macromolecule A large molecule composed of lots of molecules – lipids, carbohydrates, DNA

16. Subatomic particles Atom Molecule A small organ of a cell which performs a particular function Macromolecule Organelle

17. Subatomic particles Atom Molecule Macromolecule The basic unit of structure and function of living organisms Organelle Cell

18. Subatomic particles Atom Molecule Macromolecule A group of similar cells that performs a specialized function Organelle Tissue

19. Subatomic particles Atom Molecule A structure consisting of a group of tissues that performs a specialized function Macromolecule Organ Organelle Cell

20. Subatomic particles Atom Organ system Molecule Macromolecule A group of organs that act together to carry out a specialized function Organelle

21. The most complex level of organization – an individual living thing Subatomic particles Atom Organ system Molecule Macromolecule Organelle Organism Cell Tissue

23. Learning Outcome 1.3 List the levels of organization in the human body and the characteristics of each

24. 10 Characteristics of Life (1.4) • Movement- change in position of the body or body part; motion of an internal organ • Responsiveness- reaction to a change inside or outside the body • Growth- increase in size without a change in general shape • Reproduction- production of offspring • Digestion- process of breaking down food • Excretion- process of removing waste

25. 10 Characteristics of Life • Respiration – exchange of gases between the atmosphere and the body cells • Absorption – passage of substances through membranes and into body fluids • Circulation – movement of substances in body fluids • Assimilation – chemically changing absorbed substances in the body • These processes that obtain, release, and use energy are largely metabolism – all the chemical reactions in an organism that support life.

26. Learning Outcome 1.4 List and describe the major characteristics of life Give examples of metabolism

27. Maintenance of Life (1.5) • Nutrients- chemicals used for energy and cell building • Oxygen- chemical reactions that release energy from foods require oxygen – cellular respiration • Water- 60 to 80 % of the body weight – for most metabolic reactions, lubrication • Heat – needed to maintain body temperature- 98.6°F • Too low: metabolic reactions slow down until they stop • Too high: metabolic reactions speed up until proteins all break down • Atmospheric Pressure- weight of air – needed for breathing and filtering blood through the kidneys

28. Homeostasis • The body’s maintenance of a relatively stable internal environment despite external changes • This is done by keeping conditions in a homeostatic range compatible with life, near a “set point” value • Most life processes and metabolic reactions work to maintain homeostasis

29. Homeostasisinternal Environment • Anatomically – the conditions inside the body but surrounding the cells (outside) • Cells act in ways that keep the internal environment relatively constant and stable • Consists of fluid that surrounds cells (extracellular fluid) • Protects our cells from external changes that would kill isolated cells

30. Homeostasis All homeostatic mechanisms – self-regulating control systems - have three components in nature 1. Receptor – senses change in the environment 2. Control Center – regulates set point of variables 3. Effector – organ that acts in response to changes

31. Homeostasis 4. Output information sent along efferent pathway to activate 3. Input information sent along afferent pathway Control center (set point) (Change is compared to the set point.) Receptors (sensor) Effectors (muscles or glands) 2. Change detected by receptor 1. Stimulus (Change occurs in internal environment.) 5. Response – return to homeostasis (Change is corrected.)

32. Homeostasis • Most homeostatic mechanisms are regulated by negative feedback – brings conditions back toward set point - Automatic (regulates body temp, heart rate, blood pressure, breathing rate, blood levels of: oxygen, glucose, carbon dioxide, minerals) • Sometimes conditions are purposely moved away from the set point – positive feedback - RARE in human body • Control events that happen explosively • “fight-or-flight”, childbirth, blood clotting

33. Control center Thermostat detects deviation from set point and signals effectors. HomeostasisNegative Feedback Receptors Thermostat in room detects change. Effectors Heater turns off; air conditioner turns on. Stimulus Room temperature rises above set point. Response Room temperature returns toward set point. too high Thermostat set point Normal room temperature too low Stimulus Room temperature drops below set point. Response Room temperature returns toward set point. Receptors Thermostat in room detects change. Effectors Heater turns on; air conditioner turns off. Control center Thermostat detects deviation from set point and signals effectors.

34. HomeostasisPositive Feedback Control center The hypothalamus detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above set point. Response Body heat is lost to surroundings, temperature returns toward set point. too high Normal body temperature 37°C (98.6°F) too low Response Body heat is conserved, temperature returns toward set point. Stimulus Body temperature drops below set point. Effectors Skin blood vessels constrict and sweat glands remain inactive. Receptors Thermoreceptors send signals to the control center. Control center The hypothalamus detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

35. Animation: Positive and Negative Feedback Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

36. Homeostatic Imbalance • Disturbance in homeostasis occurs • As we age our body organs become less efficient and our internal conditions become less stable. • Any disease or abnormal condition in the body.

37. Learning Outcome 1.5 List and describe the major requirements of organisms Explain the importance of homeostasis to survival Describe the parts of a homeostatic mechanism and explain how they function together