1. AS103 Principles of Animal Science Homeostasis

2. Introduction to Anatomy and Physiology
Study of the structures of the body
Physiology
Study of the functions of cells, tissues, organs, organ systems, and organisms

3. Levels of Organization

4. Chemical and Cellular Organization
Chemical level
Atoms, molecules, macromolecules
Nucleic acids, Proteins, Carbohydrates, Lipids
Cellular level
Cell
The functional and structural unit of life
Basic and specialized functions
Specialized function requires differentiation

5. Tissue Level of Organization
Cells of similar shape and specialized function
Four major tissue types
Muscle
Specialized for contracting and generating tension
Nervous
Specialized in impulse production and transmission
Connective
Specialized for connecting and supporting
Epithelial
Specialized for surface lining and exchange

6. Organs and Organ Systems
Organ level
Composed of two or more tissues that perform a common function
Organ systems level
Composed of two or more organs that work to perform a common function that is essential to survival
Digestive, respiratory, cardiovascular
The human body contains 11 systems

7. The Organism
Collection of body systems working together to maintain life.
Strive to maintain an internal balance
Homeostasis

8. Homeostasis The maintenance of a stable internal environment.
37 degrees C, pH
Other factors that are regulated?
The internal environment is made up of the extra cellular fluid or ECF
Cells that are isolated from the external environment can still exchange materials with the ECF

9. Homeostatic Control Systems
Network of body components that operate to maintain a given factor in the internal environment relatively constant around an optimal level
Local (intrinsic) controls
Inherent, or built into a particular organ
Systemic (extrinsic) controls
Outside of an organ
Involves neural and endocrine regulation
Coordinates various organs and systems

10. Negative Feedback Loops
Maintain homeostasis by detecting a deviation from a set point and act to restore that set point
Four components of a negative feedback loop
Controlled variable
Sensor
Control center
Effector

11. Other Regulatory Mechanisms
Positive feedback loops
Continues increasing a change
Controlled variable moves in one direction
Uterine contractions
Feed forward mechanisms
Anticipate change and responds to that change before it happens

12. Homeostasis What is Homeostasis?
The maintenance of constant conditions in fluid surrounding cells (extracellular fluid) or internal environment by the integrated actions of various organs within the animal’s body
Failure in homeostasis results in disease or death

13. How is homeostasis achieved?
Homeostasis results from the work of different systems of organs with specific functions in the body

14. Systems and their functions
Respiratory system- carries O2 from the environment lungs blood ECF
CO2 from cells, ECF, blood, lungs, outside
Provision of O2 coupled with removal of CO2 from tissues allows for efficient cell growth and metabolism
Thus encourages maintenance of a relatively constant internal environment.

15. Systems and functions
Circulatory system – carries blood throughout the body
Importance in the establishment of homeostasis is through providing a passage and medium for transport for various factors within the body of the animal
Digestive System – allows for digestion and absorption of food
Digested food nutrients are used for cell growth and metabolism
By providing these nutrients the digestive system is therefore vital in homeostasis

16. Systems and functions
Urinary system – role in homeostasis is achieved through regulation of water balance, elimination of waste products, maintenance of electrolyte balance, and modulation of metabolic functions of the body
Kidneys play a dominant role in the regulation of homeostasis

17. Systems and their functions
Endocrine System - Involved in the regulation of all physiological processes occurring within the body of the animal which include digestion, circulation, respiration and reproduction
Nervous system – for short term, rapid adaptation for protection of the internal environment