Homeostasis 2

• Homeostasis


  The tendency of biological systems to maintain relatively constant conditions in the internal environment while continuously interacting with and adjusting to changes originating within or outside the system
• Homeostatic mechanisms


  The control processes that maintain homeostasis
• Homeostasis


  First coined by US physiologist Walter Cannon
• Homeostasis


  From the Greek word, homoios, meaning "same," and stasis, "standing."
• Stressors


  • Changes in the internal and the external environment that affect the normal conditions of the body
• Types of adaptations


  • Structural
  • Behavioral
  • Functional
• Feedback


  When response to either a biotic or abiotic factor has an effect on the person of some kind (or animal/mammal)
• Feedback Control Loop


  A highly complex and integrated communication control system or network. Information is transmitted in these loops by nervous impulses or by specific chemical messenger called hormones which are secreted in the blood.
• Feedback Control Loop


  1. Receptor

  2. Control center

  3. Effector
• Negative feedback


  When the response diminishes the original stimulus
• Negative feedback


  • Exercise creates metabolic heat which raises the body temperature (the stimulus), Cooling mechanisms such as vasodilation (flushed skin) and sweating begin (the response). Body temperature falls (thus decreasing the original stimulus).
• Positive feedback


  When the response enhances the original stimulus
• Positive feedback


  • A baby begins to suckle her mother's nipple and a few drops of milk are released (the stimulus). This encourages the baby and releases a hormone in the mother which further stimulates the release of milk (the response). The hungry baby continues to suckle, stimulating more milk release until she stops.
• Anatomical planes


  • Frontal/Coronal plane
  • Transverse/Horizontal plane
  • Sagittal/Lateral plane
• Anatomical orientations


  • Supine
  • Prone
  • Anterior
  • Posterior
  • Ventral
  • Dorsal
  • Superior
  • Inferior
  • Superficial
  • Deep
  • Medial
  • Lateral
  • Proximal
  • Distal
• Anatomy is the scientific discipline that investigates the structure of the body
• Physiology deals with the processes or functions of living things
• Homeostatic mechanisms are controlled by negative feedback loops
• Negative feedback loops work to maintain stability within an organism's internal environment.
• The hypothalamus is the control centre of homeostasis