Lecture 1

• What is Biology?


  -Branch of science that studies living things

  -Very broad topic

  -Anatomy and physiology are subdivisions of biology
• What is Anatomy?


  The study of the structure and shape of the body and body parts and their relationships to one another.
• What is physiology?

  Science that study body functions
• Explain the interactions between Anatomy and Physiology.


  -Complementarity of structure and function: Important and unifying concept in the study of anatomy and physiology

  -Anatomica structures designed to perform specific functions (unique shape, size, form, body location, etc.)

  -Understanding interaction helps integrate isolated factual information
• How many levels of organization are there?


  6 levels (chemical-cellular-tissue-organ-organ system-organismal)
• What does the chemical level include?

  -Atoms: smallest unit of matter (carbon, hydrogen, oxygen, etc.)

  -Molecules: two or more atoms joined together (DNA, glucose, hemoglobin)
• What does the cellular level include?

  -Cells: basic structural and functional unit of an organism (of life)

  -Many diff. types of cells in the human body (100 trillion)

  -Cells contain organelles
• What does the Tissue level include?

  -Tissues: groups of cells and the material surrounding them that work together to perform a particular function.

  -4 basic types of tissue in the human body

  -Epithelial, connective, muscular, nervous tissues
• What does the Organ level include?

  -Different tissues join together

  -They have a recognizable shape and specific functions

  -brain, heart, liver, stomach
• What does the Organ System level include?

  -Group of organs that perform a specific function

  -Digestive system (11 organ systems in human)
• What does the Organismal level include?

  -All the systems of the body combined

  -Largest level of organization
• What are emergent properties?


  New properties present at one level that are not seen in the previous level
• What are the Survival Needs?

  -Nutrients

  -Chemicals for energy and cell building (carbs, fats, prots, minerals, vitamins)

  -Oxygen

  -Essential for energy release (ATP prod.)

  -Water

  -Most abundant molecule in body

  -Env. of chemical rxn

  -Fluid base fro secretions and excretions

  -Normal body temperature

  -37 degrees

  -Affects rate of chemical reactions (optimized at 37)

  -Appropriate atmospheric pressure

  -For adequate breathing and gas exchange in lungs (PV=nRT)
• What is Homeostasis?


  -Internal mechanisms ensure that the body's internal environment remains constant despite changes inside and outside the body.

  -Cells in the human body need stable conditions to function properly and aid to the survival of the body. (eg. body temp, glucose level)

  -Every body structure from cells to systems has one or more homeostatic devices that work to keep the internal environment within normal limits.
• How is homeostasis dynamic?


  It can change over a narrow range
• Under what 2 systems are homeostatic mechanisms controlled?

  -Nervous system (fast)

  -Shivering, sweating

  -Endocrine system (slow)

  -Hormones making
• What are feedback systems?


  -Involves a controlled condition in the body that is continually monitored-evaluated-changed-remonitored-reevaluated

  -Homeostasis is maintain by many feedback systems

  -A disruption that causes a change is called a stimulus

  -Disruption can be mild/temporary (body quickly restores balance) or intense (poisoning, extreme temp., infection)
• What are the 3 components of feedback system?

  -Receptor: Body structure that monitors changes in controlled condition and sends information (input) to control center.

  -Control Center:

  -Brain, sets the range of values within which controlled condition should be maintained

  -Evaluates input from receptors

  -Generated output commands (nerve or chemical signals)

  -Effector:

  -Body structure that receives output from control center

  -Produces a response that changes the controlled condition

  -Nearly all organs or tissue can be effectors
• What is a negative feedback?

  It reverses a change in a controlled condition (bring it back to normal)

  • e.g. regulation of blood pressure
• What is a positive feedback?

  • A positive feedback system strengthens a change in a controlled condition
  • It is designed to push levels out of normal ranges
  • It must be shut off by some event outside the system
  • e.g blood clotting, child birth