1. David Sadava H. Craig Heller Gordon H. Orians William K. Purves David M. Hillis Biologia.blu C – Il corpo umano Human Body Organization

2. Why must humans regulate their internal environments? Abnormal tissue: what is cancer? How do humans alter their heat exchange with the environment? Human Body Organization - Physiology, homeostasis, and temperature regulation

3. Physiological systems are made up of organs that serve specific functions. Organs are made up of tissues, which are then made up of cells. Four types of tissue: Epithelial Connective Muscle Nervous Human Body Organization - Why must humans regulate their internal environments?

4. Epithelial tissues are sheets of tightly connected epithelial cells. The tissues form skin and line hollow organs. Some epithelial cells can: secrete substances, like hormones; move substances with cilia; act as chemical receptors; create boundaries; control filtration and transport. Human Body Organization - Why must humans regulate their internal environments?

5. Epithelial tissues

6. Muscle tissues consist of elongated cells that generate force and cause movement. Three types of muscle tissues: skeletal - responsible for locomotion and other body movements; cardiac - makes up the heart and is responsible for the heartbeat and blood flow; smooth - involved in movement and generation of forces in internal organs. Human Body Organization - Why must humans regulate their internal environments?

7. Filaments in skeletal muscle cells

8. Connective tissues are dispersed cells in an extracellular matrix that they secrete. The matrix contains protein fibers: collagen - strong and resistant to stretch, supports skin and connections between muscles and bones; elastin - can be stretched and then recoils; found in tissues that stretch (e.g., lungs, arteries). Human Body Organization - Why must humans regulate their internal environments?

9. Connective tissues: cartilage provides structural support and is flexible, it has chondrocytes - cells that secrete the extracellular matrix; bone provides support and is hardened by calcium phosphate deposition in the matrix. Human Body Organization - Why must humans regulate their internal environments?

10. More connective tissues: adipose tissue includes adipose cells that form and store lipids; blood consists of cells in a very liquid extracellular matrix, the blood plasma. Human Body Organization - Why must humans regulate their internal environments?

11. Cartilage

12. Nervous tissues contain two basic cell types: neurons and glia. Neurons encode information as electrical impulses that travel over axons to their targets. Chemical signals from the neuron stimulate a response in the target cell, via receptors. Glia provide support for neurons. Human Body Organization - Why must humans regulate their internal environments?

13. Nervous tissue includes neurons and glia

14. Organs consist of multiple tissues. An organ system is a group of organs that function together. Fore example, the stomach wall is arranged in layers: epithelial cells connective tissue smooth muscle neurons connective tissue Human Body Organization - Why must humans regulate their internal environments?

15. Fig 40.7 whole figure except stomach Human Body Organization - Why must humans regulate their internal environments? Tissues form organs

16. A stable internal environment of extracellular fluid makes complex multicellular humans possible. Cells are specialized for maintaining parts of the internal environment. External functions: transport of nutrients and waste and maintenance of ion concentrations. Internal functions: circulation, energy storage, movement, and information processing. Human Body Organization - Why must humans regulate their internal environments?

17. Homeostasis is the maintenance of stable conditions in an internal environment. Physiological systems are controlled by the nervous and endocrine systems. Regulation of the internal environment requires information. Human Body Organization - Why must humans regulate their internal environments?

18. Changes in the control of cell division lie at the heart of cancer. In the human genome, some genes act to stimulate cell division—oncogenes; others act to suppress cell division— tumor suppressor genes. Human Body Organization - Abnormal tissue: what is cancer?

19. Oncogenes are normally turned off. Products of oncogenes are involved in pathways by which growth factors stimulate division. Some control apoptosis. Activation of these genes by mutation prevents apoptosis. Human Body Organization - Abnormal tissue: what is cancer?

20. Oncogene proteins enhance cell division

21. About 10 percent of cancers are inherited. Noninherited cancers are usually a form that occur later in life—sporadic form. Inherited cancers show up earlier in life, and as multiple tumors. A tumor suppressor gene that normally acts as a brake must be inactivated. Human Body Organization - Abnormal tissue: what is cancer?

22. Full inactivation requires two mutations— both alleles must be turned off. People with inherited cancer are born with one mutant allele, and need only one more mutational event for inactivation of the tumor suppressor gene. Human Body Organization - Abnormal tissue: what is cancer?

23. Oncosuppressor-gene proteins inhibit cell division

24. Human Body Organization - Abnormal tissue: what is cancer? Two hit model for cancer development

25. Human Body Organization - Why must humans regulate their internal environments? Maintaining internal stability

26. Types of information necessary for physiological systems: set point - a reference point; feedback information - what is happening in the system; error signal - any difference between the set point and feedback information. Human Body Organization - Why must humans regulate their internal environments?

27. Effectors of systems effect changes in the internal environment. Effectors are controlled systems because they are controlled by regulatory systems. Human Body Organization - Why must humans regulate their internal environments?

28. Regulatory systems: obtain, integrate, and process information; tissue commands to controlled systems; contain sensors to provide feedback information that is compared to the set point. Human Body Organization - Why must humans regulate their internal environments?

29. uman Body Organization - Why must humans regulate their internal environments? Control, regulation, and feedback

30. Sensory information in regulatory systems includes: negative feedback positive feedback feedforward information Human Body Organization - Why must humans regulate their internal environments?

31. Negative feedback causes effectors to reverse the influence that creates an error signal; and returns a variable to its set point. Positive feedback amplifies a response; and increases deviation from a set point. Feedforward information anticipates internal changes; and changes the set point. Human Body Organization - Why must humans regulate their internal environments?

32. Human Body Organization – How do humans alter their heat exchange with the environments? Animals exchange heat with the environment

33. Radiation: heat transfer via infrared radiation. Conduction: heat transfer by direct contact. Convection: heat transfer through a surrounding medium. Evaporation: heat transfer through evaporation of water from a surface. Human Body Organization – How do humans alter their heat exchange with the environments?