Chpt 2 Study Questions Flashcards
Define the term homeostasis. How does it differ from the term steady state?
-Homeostasis: maintenance of “normal” environment
-Steady state: maintenance of constant internal environment, but not necessarily “normal”
Cite an example of a biological homeostatic control system.
-Regulation of body temperature and blood glucose
Briefly explain the role of the receptor, the integrating center, and the effector organ in a biological control system.
-Receptor: detects changes in variables
-Integrating center: assesses input and initiates response
-Effector organ: changes internal environment back to normal
Explain the terms negative feedback. Give a biological example of negative feedback.
-Negative feedback: reverses initial stimulus; decreases original stimulus
Example: Maintaining body temp. or blood pressure
Discuss the concept of gain associated with a biological control system.
Gain: the capacity of a system to maintain homeostasis
Large gain: system has high capacity to correct a disturbance and to maintain homeostasis; ie. cardiac output
Define cell signaling and outline the five types of cell signaling mechanisms that participate in the regulation of homeostasis and cellular adaptation.
Cell signaling: Communication between cells using chemical messengers
-Intracrine signaling: messenger inside cell triggers response
-Juxtacrine signaling: messenger passed b/w 2 connected cells
-Autocrine signaling: messenger acts on that same cell
-Paracrine signaling: messenger acts on a nearby cell
-Endocrine signaling: messengers released into the blood; affects cells w/ specific receptor
List the steps that lead to exercise-induced increases in protein synthesis in skeletal muscles.
1.Exercise activates cell signaling pathways
2.Activates transcriptional activator molecule
3.Transcriptional activator binds to gene promoter region
4.DNA transcribed to mRNA
5.mRNA leaves nucleus and binds to ribosome
6.mRNA is translated into protein
