Introduction/Homeostasis Flashcards
What is physiology?
The study of function
What does it mean to be an “integrative” science?
Several sciences (anatomy, chemistry, physics), are integrated together
What is the scientific method?
An accepted methodology for studying anything.
It starts with (one thing) an observation
A question is asked
A hypothesis is formed
That hypothesis is tested an data is collected
Results are analyzed
Conclusions are drawn
Results are communicated
What is the most important thing to keep in mind about variables when testing?
Only one can be changed at a time and it must be tested against a control group
What is the difference between quantitative and qualitative?
Quantitative is a number, something that can be counted or measured
Qualitative is a description, such as color or shape
What is homeostasis?
The dynamic equilibrium in which a body’s internal environment remains relatively stable despite changes in the internal and external environments
What is an example of static (as opposed to dynamic) equilibrium?
Death
What are the components of homeostatic control mechanisms?
First a VARIABLE is introduced (blood glucose)
Then a STIMULUS is introduced (level drops overnight during sleep)
RECEPTOR input (chemoreceptors sense low concentration)
CONTROL CENTER (this info is sent to the pancreas via sensory neurons)
EFFECTOR (Pancreas releases glucagon)
RESPONSE (Liver receives glucagon, breaks down glycogen and releases glucose into bloodstream)
What is negative feedback control? (Guve example)
Output or response counteracts the original stimulus, returning the variable to normal levels
Ex. Blood glucose increases, insulin is released, a decrease to normal level stops release of insulin
What is positive feedback control? (Give an example)
The output or effector is intensified or amplified – inherently self-limiting
Ex. During birth the baby’s head presses against the cervix, causing oxytocin release, which causes uterine contractions, which pushes the baby’s head against the cervix until it is born and loop stops
What is the law of minimum and maximum?
There is a minimum and maximum in a given effect where an organism can function, beyond that is death. This range is wider than the optimal range, where an organism functions most effectively
What is a feed forward control?
A reflex that starts a response loop in anticipation of of a stimulus
Ex. Mouth waters when smelling food
What are extrinsic control mechanisms?
A tissue is controlled from the outside by the nervous and/or endocrine system
Ex. Blood pressure regulation
What are intrinsic control mechanisms?
An organ or tissue controls itself.
Ex. Decreased oxygen levels in skeletal muscles causes vasodilation of blood vessels
What are neural, endocrine, and neuroendocrine reflexes?
Extrinsic Control Reflex Loops, a reflex that returns the system to homeostasis
