Anatomy Final

always takes two nerons to get from central nervous system to the effector: pre-ganglionic fiber and post

in the somatic nervous system it takes one

responsible for unconscious processes (fight or flight) - homeostasis

motor nervous system that controls glands, cardiac muscle, and smooth muscle (visceral motor system)

sympathetic and parasympathetic

unconscious, automatic, stereotyped responses to stimulation involving visceral receptors and effectors and somewhat slower responses

receptors - nerve endings that detect stretch, tissue damage, blood chemicals, body temperature, and other internal stimuli

afferent neurons - leading to the CNS

interneurons - carry motor signals away from the CNS

efferent neurons - carry motor signals away from the CNS (pre-ganglionic fiber: produce AcH and are myelinated)

effectors - that make adjustments (post-ganglionic fiber)

Visceral - two neurons

Somatic - one neuron

prepares body for physical activity

• -increases heart rate, BP, airflow, blood glucose levels, etc
• -reduces blood flow to the skin and digestive tract

calms the body

• -digestion and waste elimination
• -"resting and digesting" state (meditation)

• normal background rate of activity that represents the balance of the two systems according to the body's changing needs
• -parasympathetic-maintains smooth muscle tone in intestines
• -sympathetic-keeps most blood vessels partially constricted and maintains blood pressure

a motorneuron from the brainstem or spinal cord issues a myelinated axon that reaches all the way to the skeletal system

• signals must travel across two neurons to get to the target organ
• must cross a synapse where these two neurons meet in an autonomic ganglion
• presynaptic neuron - the first neuron has a soma in the brainstem or spinal cord
• synapse with a postganglionic neuron whose axon extends the rest of the way to the target cell