|Parasympathetic Division||•Preganglionicneurons in –brain stem–S2-S4–Cranial nerves III, VII, IX, X
•Preganglionicneurons synapse on terminal ganglia located near target organ.
•Preganglionicfibers –long and myelinated.
•Postganglionic fibers –short and unmyelinated.
|AUTONOMIC NEUROTRANSMITTERS||•Transmission is primarily cholinergic, but also adrenergic and peptidergic.
•All preganglionicfibers release ACh(i.e. parasymp. & sympathetic).
•Parasympathetic postganglionic fibers release also release ACh
•Sympathetic postganglionic fibers releas
|SYMPATHETIC DIVISION||•Prega neurons in T1 -L2 in the lat horns.
•Prega neurons send fibers out the ventral root to the symp trunk.•Postgan fibers leave symp trunk and pass through spinal nerve again before going to target organ
|Divisions of the Autonomic Nervous System||•Sympathetic division–Prepares the body for action
•Parasympathetic division–Settles the body down
•Enteric division–Control of function of digestive organs
|Characteristics of ANS||•two-neuron pathway
•Sensory signals from viscera and skin send signals to autonomic neurons in brain and spinal cord.•A prega cell body within the CNS
•Prega synapse w/ postg in the PNS
•The postg terminates on the effector organ
|Differences between Somatic Motors System and ANS||•Somatic motor neurons project directly to skeletal muscles (monosynaptic)
•Autonomic pathway is dysynaptic. Preganglionicneurons project to postganglionic neurons, which project to the target organs.
|Hypothalamic Functions||•Neuroendocrine:Hypothalamic pituitary portal system: Releasing and inhibiting hormones that target pituitary
•Limbic: Hypothalamus is critical for making the connections between the expression of affect and the motor response
|Hormones of the Hypothalamus||•Provided to the anterior pituitary
–TRH, GnRH, GHRH, CRH, somatostatin–Dopamine
•Providedto the posterior pituitary
|Zones of the Hypothalamus||•Medial:VMH (satiety/agression control), Dorsomedial n.(feeding behavior/insulin control) •Lateral: LHA (appetite stimulation) •Paraventricular: Paraven&supraopn.(oxytocin/AHD), Preopticn(reprod& autonomic functions), anthyp(Parasymp),suprachi(circ r)|
|Hypothalamus Characteristics and Functions||-Phylogenetically old
-Influences nearly all bodily functions
-hormonally (via pituitary stimulation)