2.D Flashcards
Describe the division of the nervous system.
nervous system is divided into CNS and PNS
CNS is divided into brain and spinal cord
PNS is divided into sensory and motor
motor is divided into autonomic and somatic
autonomic is divided into sympathetic and parasympathetic
Define the following: neuron, nerve, ganglia, plexus, synapse
neuron: the major cell type of the nervous system, excitable cell that processes and transmits information via chemical and/or electrical signals
nerve: bundle of neuronal axons
ganglia: structure containing multiple cell bodies linked by synapses
plexus: branched network of interconnecting nerves
synapse: meeting point of two neurons
What is the role of the autonomic nervous system?
regulates autonomic functions of the body that occur without conscious control
Describe the characteristics of the autonomic nervous system.
distributed throughout the body
innervates the heart, blood vessels, glands, viscera, smooth muscle in some tissues
made up of nerves, ganglia, and plexuses
sub-divided into sympathetic and parasympathetic
What are a few things that the autonomic nervous system controls?
changes in stomach secretions
changing heart rate
redistributing blood
effecting body temperature
What are the rations of pre-ganglionic neurons to ganglionic neurons for the parasympathetic and sympathetic nervous system?
parasympathetic is 1:1
sympathetic is 1:20
What are the rations of pre-ganglionic neurons to ganglionic neurons for the parasympathetic and sympathetic nervous system?
parasympathetic is 1:1
sympathetic is 1:20
True or false: parasympathetic fibers ramify and its terminals contact large numbers of post-ganglionic neurons
false
this is describing sympathetic fibers
What are the phrases used to describe the sympathetic and parasympathetic nervous system?
sympathetic: fight or flight
parasympathetic: rest and digest
Describe the anatomy of the sympathetic nervous system.
thoracolumbar system
ganglia are located near the spinal column
pre-ganglionic axons are short
post-ganglionic axons are long
rapid coordination of multiple organ systems
What happens to the sympathetic nervous system during a moment of stress?
- signal is propagated along efferent nerves of the brain and pre-ganglionic neuron to the ganglion
- at the ganglion the pre-ganglionic neurons release ACh into synapses
- stimulates action potentials in the post-ganglionic neurons
- signal is propagated along post-ganglionic neuron to effector organ
- at the effector organ the post-ganglionic neurons release NE
Which neurotransmitters are released by the pre-ganglionic and post-ganglionic neurons of the sympathetic nervous system?
pre: acetylcholine
post: norepinephrine
What happens on a system level when the sympathetic nervous system is activated?
pupils dilate
salivary glands are inhibited
heart rate increases
breath rate increases
blood flow is directed to the heart, lungs, and skeletal muscle
blood flow is directed away from the stomach, intestines, and sex organs
piloerection
Describe the anatomy of the parasympathetic nervous system.
craniosacral system
pre-ganglionic axons are long
post-ganglionic axons are short
distributed regulation of specific organ systems
True or false: the parasympathetic nervous system is activated by the presence of relaxation
false
activated by absence of stress
What happens to the parasympathetic nervous system during the absence of stress?
- signal is propagated along efferent nerves of the brain and pre-ganglionic neuron to the ganglion
- at the ganglion the pre-ganglionic neurons release ACh into the synapse
- stimulates action potentials in the post-ganglionic neurons
- signal is propagated along post-ganglionic neuron to effector organ
- at the effector organ the post-ganglionic neurons release ACh
What happens on a system level when the parasympathetic nervous system is activated?
pupils constrict
salivary glands are activated
heart rate decreases
breath rate decreases
digestion and peristalsis increases
blood flow to the sex organs increases
Which receptors does norepinephrine act on? Describe these receptors.
alpha receptors:
-smooth muscle cells of organs & blood vessels around organs
-NE binds to alpha receptors=constrict=less blood flow
beta receptors:
-heart & blood vessels around lungs & muscle
-NE binds to beta receptors=relax=more blood flow
What is happening when ACh is released onto the adrenal glands?
the adrenal medulla releases NE and epinephrine into the bloodstream so now these molecules are hormones and they boost the sympathetic response but in a MUCH SLOWER manner
What is the difference between a hormone and neurotransmitter?
neurotransmitter: compound released into synapse
hormone: compound released into blood stream
True or false: a compound can be a neurotransmitter and hormone but it depends on the job it is completing
true
What are the key receptors of the sympathetic nervous system?
alpha and beta
What are the key receptors of the parasympathetic nervous system?
muscarinic M1-M5
nicotinic Nn-Nm
What are the key receptors of the parasympathetic nervous system?
muscarinic M1-M5
nicotinic Nn-Nm
Describe the receptors of the parasympathetic nervous system.
muscarinic receptors:
-M1-M5
-metabotropic G protein coupled receptors (GPCRs)
-work by altering Ca and K flux and altering secondary messengers like cAMP
nicotinic receptors
-Nn(neuron)-Nm(muscle)
-ionotropic ligand-gated ion channels
-increase Na, K, and Ca permeability into the cell
True or false: most PNS nerves pass through the spinal cord
false
cranial nerves go from the brain almost to the effector organ
Describe all 12 cranial nerves.
- olfactory: scents from nose to the brain (sensory)
- optic: vision from eye to brain (sensory)
- oculomotor: moves 4/6 eye muscles (motor)
- trochlear: moves eyes down (motor)
- trigeminal: face and jaw (both)
- abducens: moves eyes side to side (motor)
- facial: muscles for facial expression (both)
- auditory: info from cochlea to brain (sensory)
- glossopharyngeal: tongue and pharynx (both)
- vagus: heart, digestive tract (both)
- spinoaccessory: head and shoulder movement (motor)
- hypoglossal: swallowing reflex and speech (motor)
Where do the trigeminal, facial, glossopharyngeal, and vagus nerve relay sensory information to?
solitrary tract nucleus