PSL300H1 Study Guide - Midterm Guide: Pupillary Light Reflex, Reticular Formation, Pretectal Area
Document Summary
June-04-13 2:01 pm retinal ganglion cells melanopsin pupillary light reflex olivary pretectal nucleus pretectal area of midbrain circular muscles radial muscles amygdala periaqueductal gray reticular activating systems histaminergic. Nts retina superchiasmatic nucleus cadiovascualr center homeostatis paraventricula nucleus arcuate nucleus ventromedial nucleus ghrelin orexigenic hormone. Reflexes autonomic retinal ganglion cells contain absorbing pigment called melanopsin (light absorbing pigment, depolarizes with light detecting general light levels) also important for sychronizing circadian rhythms w/ day-night cycle. **pupillary light reflex: on final. does not begin in same area as parasympathetic. Autonomic centers in brain brainstem autonomic centers: sympathetic modulatory tracts from raph nuclei and locus coeruleus. cardiovascular center, and respiratory pattern generator in lateral medulla/pons periaqueductal gray: midbrain promoter center, for autonomic behavioural programs. Histaminergic system: origins = posterior hypothalamus, tbn (tuberomamillary nucleus) specifically. projects through forebrain and to other activating systems in brainstem. -> ascending and descending. important for sleep/wake cycle. systems turns off when you fall asleep. histamine lvl decreases.
