What is physiology Flashcards
what are the different levels of physiological organization
Molecules, cells, tissue, organs, organ systems
what are the four major cell/tissue types
neurons/nervous tissue, muscle cells/tissue, epithelial cells/tissue, connective tissue/cells
what do neurons/nervous tissue do?
specialized for sending and receiving information
what do muscle cells/muscle tissue do
specialized for contraction
where are epithelial cells/tissue found?
found on organs, glands, and lining body cavities
what are Endocrine glands
secrete molecules (usually hormones) directly into the bloodstream (ex: pancreatic and thymus glands)
what are exocrine glands
utilize a duct and secrete molecules into a body cavity or to the exterior of the body (ex: stomach, salivary, sweat glands)
what qualifies as a connective tissue cell
bone cells, body cells, fat cells, etc
how are connective tissue cells characterized
by very few and lots of extracellular materials
define homeostasis
the ability to maintain a relatively stable internal environment despite fluctuations in the external environment
why is homeostasis so important
it is essential for survival and function of all cells
if there is a deviation from homeostasis, what does this indicate
disease
how is homeostasis accomplished (most often)
negative feedback
what does negative feedback involve
returning internal conditions to a “set point”
what does a negative feedback loop help do
it helps return internal conditions to a set point when they deviate too far outside of an acceptable range
what is an example of negative feedback
shivering when you get cold
what happens after your body sense a change
once the change is detected, information is sent to the integrating center in which the integrating center assesses change around a set point. then, the integrating center then sends instructions to an effector which makes the appropriate adjustments
why do people often shiver when they have a fever
fever is physiological response
it involves changing the body temp set point (hypothalamus)
the elevated set point causes heat retaining/producing physiological responses such as vasoconstriction and shivering
So, shivering helps the fever happen
Individuals with fever feel cold because the set point has changed
what is an example of an antagonistic reaction
when you are hot, you sweat; when you are cold, you shiver
what is positive feedback
moves conditions future away from a set point. they input and the output in a positive feedback loop are the same
what is an example of positive feedback
uterine contractions during childbirth
Further explanation: releases of oxytocin causes the uterus to contract. This pushes the baby’s head against the cervix, activating stretch receptors that signal to the hypothalamus. this results in more oxytocin release which results in stronger contractions
