Biochem Lecture 3 Autonomic Nervous System Flashcards
Central nervous system composed of
Spinal cord
Peripheral nervous system
Somatic nervous system
Autonomic nervous system
Somatic nervous system
Voluntary control of skeletal muscles
•motor control: efferent nerves/motor nerves
•sensory system: afferent nerves/sensory nerves
Autonomic nervous system
subconscious’ control
•Smooth muscle; glands; control of organ function
Sympathetic nervous system
‘Fight-or-flight’
Prepares the body for activity
Associated with:
Increased heart rate
Vasoconstriction in visceral organs
Parasympathetic nervous system
Rest-and-digest’
Promotes restorative functions
Associated with:
Slowing of the heart rate
Motility and secretion by the gastrointestinal tract
Normal conditions
balanced signalling from both systems controls activity
anatomic
The division between the somatic and autonomic nervous system The division between the somatic and autonomic nervous system
Somatic
single axon extends from neuron in CN
Autonomic:
two-neuron system
Synapse
Structure between two neurons that allows one neuron (nerve cell) to transmit a signal to a second neuron.
Neurotransmitter (main
Acetylcholine (at ganglia)
Nicotinic acetylcholine receptors:
Different types of nicotinic acetylcholine receptors
Cell-surface receptors
Typically pentameric configuration
Homo- or heteromeric
Non-selective ion channel; K+ and Na+; Ca2+ (depending on subunit type)
adrenergic receptors
At the effector organ, the receptors for noradrenaline and adrenaline are adrenergic receptors (adrenoceptors)
Adrenergic receptors:
Different genes; each sub-type is encoded by one gene
Amino acid sequence is similar, but not identical
Overall 3D structure of receptor is similar, but not identical
Different sub-types have different expression pattern
