Chapter 1: An Introduction to Anatomy and Physiology

anatomy

to “cut up” or dissect

study of internal or external structures

study of relationships among body parts

physiology

study of how living organisms perform the functions essential to life

key concept for anatomy and physiology

all specific functions are performed by specific structures

levels of organization

chemical

cellular

tissue

organ

organ system

organismal

chemical level

simplest level of organization

atoms combined to form molecules

cellular level

molecules work together to form structural and functional components of cells

tissue level

groups of cells working together to perform one or more specific functions

organ level

two or more tissues working together to perform one or more specific functions

organ system level

multiple organs working together

organismal level

highest and most complex level or organization

all systems working together

homeostasis

existence of a stable internal environment

homeostatic regulation

adjustment of physiological systems to preserve homeostasis

what happens when homeostasis is failed to maintain?

results in illness and/or death

what are the three components of homeostasis?

receptor, control center, effector

receptor

sensor - senses environmental change = stimulus

control center

receives and processes information from receptor - sends response or command

effector

cell or organ that responds to commands of the control center - activity opposes or enhances the stimulus

negative feedback

variations trigger a response to correct the problem - activity tends to oppose the stimulus - most common type of regulatory control

positive feedback

stimulus produces a response that increases change - activity tends to enhance the stimulus - seldom occurs because the response takes body away from homeostasis

what are the the three examples of positive feedback?

childbirth, blood clotting, and lactation