BIO 201 Test 1 (chapters 1-4) solved & updated.

Anatomy studies structure of body parts and how they relate to one another Gross Anatomy study of large structures surface anatomy studies structures as they relate to the surface cytology study of cells histology study of tissues embryology studies developmental changes that occur before birth chemical level atoms form to combine molecules tissues groups of similar cells that have a common function cellular level cells are made up of molecules organ level organs are made up of different types of tissues homeostasis point of dynamic (changing) equilibrium; body's ability to maintain a relatively stable internal environment despite ever changing conditions set point level/range of "normal" for whatever variable is being considered ex: blood glucose levels receptor sensor that monitors environment and responds to changes by sending information to the control center control center determines set point; analyzes input and determines appropriate response effector provides means for control center's response to the stimulus What is the correct order of the components of the loops for homeostasis? stimulus, receptor, afferent pathway, control center, efferent pathway, effector, response Negative feedback once stimulus occurs, and the control center and effector return the body to the normal position, stimuli stop as to not over-fix the problem ex: blood glucose-once glucose levels return to normal, the stimulus for either raising blood glucose or lowering it ends Negative feedback is the most common occurrance of homeostatic balancing Positive feedback happens in infrequent events that don't need continual adjustment ex: giving birth-oxytocin is released which causes contractions to intensify, causing more oxytocin to be released, causing baby to eventually be expelled. Once baby is born, the stimulus for oxytocin to be released is shut off neural (nervous system control) quick, short lived, electrical signals ex: allows you to get out of the way of danger quickly hormonal (endocrine control) chemicals sent out in blood stream; slower process that takes multiple steps; effects are more widespread and longer lasting because as long as the hormones are in the bloodstream, they affect the body ex: growth, reproductive capability axial makes up main axis of body, includes head, neck, and trunk