ANP 1105 Lecture Notes - Lecture 8: Autonomic Nervous System, Postganglionic Nerve Fibers, Motor Neuron

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Joanne Savory

Document Summary

Homeostasis: is the (cid:271)od(cid:455)"s a(cid:271)ilit(cid:455) to (cid:373)ai(cid:374)tai(cid:374) relati(cid:448)el(cid:455) sta(cid:271)le i(cid:374)ter(cid:374)al (cid:272)o(cid:374)ditio(cid:374)s e(cid:448)e(cid:374) though the outside (cid:449)orld (cid:272)ha(cid:374)ges continuously. Dynamic state of equilibrium involving many systems: (i) adequate blood levels of vital nutrients, (ii) heart activity/blood pressure monitored and adjusted as needed, (iii) wastes must not accumulate, (iv) body temperature. 3 characteristic of homeostasis: receptor: senses change and sends information through the afferent pathway to control center, control center: analyzes information and determines correct response. Determines set point for variable maintenance: effector: provides means for response through the efferent pathway. Negative feedback: most homeostatic control mechanisms are negative feedback mechanisms. Its goal is to prevent sudden and severe changes. Positive feedback: set off a series of events that may be self-perpetuating and that, once initiated, have an amplifying or waterfall effect. The response enhances original stimulus; output is further stimulated. The change occurs in same direction as original response. Homeostatic imbalance: most diseases are seen as disturbance of homeostasis.