Anatomy and physiology Essay Example | Topics and Well Written Essays - 250 words - 1

Anatomy and physiology - Essay Example From here lateral lemniscuses column (3rd order neurons) go to the inferior colliculi and superior colliculi that also receives visual impulse and acts as an integration center to carry impulse to the primary auditory cortex of the CNS in the temporal lobe at Brodmann area 41 and 42. The visual pathway was carried from the eyes to the optic nerve to the visual cortex. The afferent auditory neurons from the organ of corti (inner ear) and auditory cortex involves many synapses which are in the brain stem and medial geniculate body of thalamus. The brain stem causes the input for arousal and alertness. The thalamus sorts and relays signals upwards to generate the action in the individual (Purvez, 2012) (Janmey2007).To elicit the visual response signal transduction occurred in the rod cells to convert rhopodpsin into metarhodopsin which activated trasducin. Transducin blocked the sodium ions entry into the rods causing hyperpolarization which caused liberation of inhibitory neurotransmitter release from rods. Thus the inhibition on the bipolar cells was lifted and they got stimulated to release glutamate. Glutamate acted on the ganglion cells and stimulated them that lead to activity in the optic nerve (1st order neurons). The optic nerve is the IInd Cranial nerve a nd criss -cross at the optic chiasm and reaches the lateral geniculate nucleus from where impulse go to the primary visual cortex which is the Brodmann Area 17, 18 and 19 through the optic radiations( 2nd order neurons) Further as the individual was under stress the hypothalamic locus ceruleus system got activated to release nor epinephrine that was responsible for flight or fight response (getting into action) (Purvez, 2012) (Janmey2007). The reaction starts in the amygdala which stimulates hypothalamus, which cause release of ACTH from pituitary on one hand and stimulates