Autonomic nervous system Flashcards
What is the basic anatomy of the sympathetic and parasympathetic nervous systems?
The sympathetic nervous system covers the thoracic and the lumbar spine, and the parasympathetic covers the cervical and sacrum spine.
What are the main neurotransmitters released from the sympathetic and parasympathetic nervous systems.
Sympathetic = norepinephrine/noradrenaline
Parasympathetic = acetycholine.
Why are adrenal glands a special case?
Because they synapse with the adrenal medulla, and secrete norepinephrine and epinephrine (adrenaline and noradrenaline) into the blood vessel.
Outline the typical chemical synapse within the sympathetic nervous system.
It is a two neuron chain from the CNS to effector organs. The first neuron is a lightly myelinated axon synapsing with a non myelinated axon at the ganglion and norepinephrine is the neurotransmitter at the effector organ.
Outline the typical chemical synapse within the parasympathetic nervous system.
It is a two neuron chain from the CNS to the effector organs. The first neuron is a light myelinated axon synapsing with a non myelinated axon at the ganglion and acetylcholine is the neurotransmitter at the effector organ.
What is the differences between the effect of the somatic nervous system and the autonomic nervous system.
The somatic system enables stimulatory effects, whereas the autonomic system enables stimulatory or inhibitory, depending on the neurotransmitters and receptors of the effector organs.
What is important about the distribution of the sympathetic and parasympathetic nervous systems.
Not all tissues have both nerve supplies e.g., hair follicles only have sympathetic nerve supply.
What are generally, the antagonistic effects of the sympathetic and parasympathetic nervous systems.
Typically, they will deliver the opposite effects to one another e.g., the SNS increases heart rate whereas the PNS decreases heart rate, and SNS promotes bronchiole dilation whereas the PNS promotes bronchiole constriction in the lungs.
What are the 4 main brain stem nuclei involved in the control of cardiac output.
Solitary nucleus, depressor area, nucleus ambiguous, pressor area
What are the 3 main brain stem nuclei involved in the control of respiratory function.
Pontine nuclei, ventral respiratory group, dorsal respiratory group.
What is the role of the vagus nerve in autonomic control.
It inputs sensory information from the lungs, bladder, circulation and digestive tract.
Outline the order of autonomic control.
Cerebral cortex (frontal lobe) —> limbic system (emotional input) —> hypothalamus (overall integration of ANS) —> brain stem (regulates heart rate, blood pressure, airflow etc.) —> spinal cord (reflection for urination etc.)
