Guyton Chapter 61 - Autonomic Nervous System

Proportions of secretions from the adrenal medulla are:

80% epinephrine and 20% norepinephrine

Transformation of norepinephrine to epinephrine occurs in:

Adrenal medulla

Cardioacceleration and myocardial strength stimulated by ___ receptors:

Beta 1

Parasympathetic nerve fibres leave CNS through:

CN III, VII, IX, X and 2,3 (+/- 1,4) sacral spinal nerves.

The effect of circulating adrenal medulla secretions is longer/shorter than that of direct sympathetic stimulation?

Longer - 5-10x

Sympathetic fibres originate in spinal cord between ___ & ___, passing first into:

T1 and L2, sympathetic chain

Choline acetyltransferase is necessary for what reaction?

acetyl-coA + choline to acetylcholine

muscarinic and nicotinic receptors are activated by:

acetylcholine

Acetyl choline is broken into acetate ion and choline by:

acetylcholinesterase

Most of postganglionic fibres of sympathetic neurons are:

adrenergic

Intestinal relaxation and sphincter contraction stimulated by ___ receptors:

alpha

Norepinephrine excites mainly:

alpha adrenergic receptors (and some beta)

Adrenergic receptors are called:

alpha and beta

Norepinephrine is formed in:

axoplasm of terminal nerve endings and secretory vesicles

Vasodilation and bronchodilation stimulated by ____ receptors:

beta 2

Epinephrine excites:

both alpha and beta receptors equally

All preganglionic fibres are:

cholinergic

All/most of post ganglionic neurons of parasympathetic system are:

cholinergic

Fibres that secrete acetycholine called:

cholinergic

A greater metabolic effect is caused by epinephrine/norepinephrine?

epinephrine - 5-10x

Greater effect on stimulation of cardiac system by:

epinephrine - as more Beta receptor stimulation

After loss of sympathetic or parasympathetic tone after denervation, normal function is returned by?

intrinsic tone

Synpases between pre and post ganglionic fibres contain _______ receptors:

nicotinic

monoamine oxidase and catechol-O-methly transferase destroy:

norepi + epinephrine

Adrenergic fibres secrete:

norepinephrine

Total peripheral resistance is increased more by epi/norepi?

norepinephrine - due to constriction of muscle blood vessels

The postganglionic neurons for parasympathetic system are located in:

organ wall

Sympathetic nerve endings in adrenal medulla special as:

pass through symp chain without synapsing, all the way to neuronal cells in medullae that secrete epinephrine and norepinephrine

Sacral parasympathetic fibres in the:

pelvic nerves

sympathetic nerves differ from motor nerves in what way:

pre and postganglionic neuron rather than single neuron.

The autonomic nervous system is activated by centers in:

spinal cord, brainstem, hypothalamus

Cholinergic postganglionic sympathetic fibres supply the:

sweat glands, blood vessels.

Efferent autonomic signals transmitted to organs through two subdivisions:

sympathetic and parasympathetic nervous system

Once entering the sympathetic chain from ventral root, fibres can go 3 ways:

synapse postganglionic neurons in ganglia they enter, pass up or down chain and synapse other ganglia, pass through chain and through sympathetic nerve to peripheral symp. ganglion.

denervation supersensitivity is:

the increased sensitivity to norepinephrine or acetylcholine due to up-regulation of receptors following denervation

Sympathetic nervous system made up of:

two paravertebral chains of ganglia, prevertebral ganglia and nerves from ganglia to different organs

Majority of parasympathetic nerve fibres are in the:

vagus nerve

Transmitter vesicles of neurotransmitters are stored in:

vasicosities - bulbous enlargements of nerve fibres

preganglionic neurons in intermediolateral horn send fibre through:

ventral root of cord into spinal nerve