Homeostasis and Bioenergetics Flashcards
(72 cards)
what is bioenergetics
when cell’s chemical pathways convert foodstuffs into a biologically usable form of energy
define homeostasis
maintenance of a constant and normal internal environement
what is considered a steady state
- physiological variable is unchanging, but not necessarily normal
- balance between demands placed on body and the body’s responses to those demeands
what are some examples of homeostasis in the body
body temperature regulation and arterial blood pressure
what are the intracellular control systems
- protein breakdown and synthesis
- energy production
- maintenance of stored nutrients
examples of organ systems that are part of the control system within the body
pulmonary and circulatory systems
define a biological control system
series of interconnected components that maintain a physical or chemical parameter at a near constant value
what are some components of the biological control system
- Sensor or Receptor: detects changes in variable
- control center: assesses input and initiates response
- effector: changes internal environment back to normal
negative feedback
response reverses the initial disturbance in homeostasis
positive feedback
response increases the original stimulus
what is “gain of a control system”
degree to which control system maintains homeostasis
-system with large gain is more capable of maintaining homeostasis than system with low gain (pulmonary and cardiovascular systems have LARGE gain)
what does the failure of the biological control system result in
disease, such as type 1 diabetes
exercise with regards to homeostasis
exercise actually disrupts homeostasis by causing changes in:
- pH
- oxygen and CO2 levels
- temperature
control systems are capable of maintaining steady state during submaximal exercise in a cool environemtn
Adaptation
Acclimatization
Cell Signaling
Adaptation: change in structure or function of cell or organ system, results in improved ability to maintain homeostasis
Acclimatization: adaptation to environmental stresses
Cell Signaling: communication between cells using chemical messengers, important for maintaining homeostasis
what areas of the brain maintains and regulates respiration
pons and medulla
at what levels are you considered to be hypoglycemic
below 70 mg/dL
what what levels are you considered to be hyperglycemic
above 99 mg/dL
list the 5 cell signaling mechanisms
- intracrine signaling: chemical messenger inside cell triggers response
- Juxtacrine signaling: chemical messenger passed between 2 connected cells
- autocrine signaling: chemical messenger acts on that same cell
- paracrine signaling: chemical messengers act on nearby cells
- endocrine signaling: chemical messengers released into blood, only affect cells with specific receptror
what do cells create when the body is under stress such as high temp or abnormal pH
cells synthesize stress proteins when homeostasis is disrupted
what are the 3 forms of biologic work
- mechanical work of muscle contraction
- chemical work for synthesizing cellular molecules
- transport work that concentrates diverse substances in body fluids
oxidation
a substance loses electrons
reduction
a substance gains electrons
what do redox reactions power
the body’s energy transfer processes
what is the main energy “currency”
ATP
