1 - Intro Flashcards
Provide an overview of the course and its deliverables. Describe the levels of organization in the body. Describe how the internal environment interfaces with the external environment. Objectives Explain the importance of basic life processes. Describe how homeostasis is maintained within the body.
what are the life processes
Metabolism Responsiveness Movement Growth Differentiation Reproduction
Metabolism
Process of energy generation and use
Catabolism a nd anabolism
Catabolism
Breakdown of large complex molecules into
smaller ones
Anabolism
Uses energy to build body’s structural and functional components
Responsiveness
Ability to detect and respond to changes in the environment
Movement
Movement within a cell
Movement of cells
Movement of organs / organ systems Movement of whole body
Growth
Increase in size, number of cells, size of cells, extracellular space
Differentiation
Embryonic development
Stem cells
Reproduction
Replacement of cells for growth, repair Production of a new individual
Example: digestive system
- Nutrients within the lumen of the digestive tract
- Cells specialized to take those nutrients up and transfer them to the plasma
- Transport through the systems to supply energy for entire organism
Example: respiratory system
Interface with O2 in the alveoli of the lung
Gas exchage: O2 in, Co2 out
Internal environment of the body
Intracellular (=within a cell) Extracellular (=outside of a cell)
- Plasma (fluid portion of blood)
- Interstitial fluid
How do organ systems influence homeostasis?
- Nervous and endocrine systems regulate all systems
- Respiratory system regulates gas exchange and pH
- Urinary system regulates fluid balance, electrolytes, pH, removes waste, water and excess electrolytes
Explain how organs, cells, and homeostasis impact each other?
Body systems maintain homeostasis, which is necessary for cells, which are the building blocks for organ systems.
Negative Feedback
Change in controlled variable
Sensor / Receptor
Integrator / Control System
Effector
Response
Controlled variable restored to normal
Negative feedback shuts off system responsible for response
Negative Feedback Example
Change in blood pressure
Blood pressure back to normal
Baroreceptors
Brain centres
Heart, blood vessels
Change in function
Blood pressure is back to normal, homeostasis is restoredPositive Feedback
Change in controlled variable
Sensor / Receptor
Integrator / Control System
Effector
Amplification of change
Positive feedback enhances a changePositive Feedback Example
Contractions force baby’s head to push onto the cervix Stretching of the cervix
Stretch sensitive receptors
Brain interprets stimulus and releases oxytocin
Uterus contracts more, baby’s head stretches the cervix more
Birth of baby decreases stretching of the cervix, breaking the positive feedback cycle
Increased stretching of the cervix leads to more release of oxytocin, which results
in more contractions, and more stretching of
the cervix.
Feedforward Mechanism
Anticipated change in controlled variable
Sensor / Receptor
Integrator / Control System
Effector
Response
Preparation for change
Feedforward mechanisms help to prepare for an imminent change
Feedforward Mechanism Example
Seeing food
Visual system
Association areas of CNS
Salivary glands
Increased salivation
Ready for digestion
