C5: Nervous System Flashcards
neuron
the functional unit of the nervous system
- synapse
- what are the 2 types of synapse?
- a junction between the axon terminus of a neuron and the dendrites, soma, or axon of a second neuron
- electrical and chemical
- electrical synapse
- what happens to action potential as a result of an electrical synapse?
- occur when the cytoplasms of two cells are joined by gap junctions
- it will spread directly from one cell to the other
- chemical synapse
- what happens to action potential as a result of an chemical synapse?
- found at the ends of axons where they meet their target cell
- it is converted to a chemical signal
what are the 8 steps required in order for a signal to be transmitted across a a chemical synapse?
- an AP reaches the end of an axon (synaptic knob)
- depolarization of the presynaptic membrane opens voltage gated calcium channels
- calcium influx into the presynaptic cell causes exocytosis of neurotransmitter stored in secretory vesicles
- neurotransmitter molecules diffuse across the narrow synaptic cleft
- neurotransmitter binds to receptor proteins in the postsynaptic membrane. these receptors are ligand gated ion channels
- the opening of these ion channels in the post synaptic cell alters the membrane polarization
- if the membrane depolarization of the postsynaptic cell reaches the threshold of voltage gated sodium channels, an AP is initiated
- neurotransmitter in the synaptic cleft is degraded and/or removed to terminate the signal
- what is a common example of a chemical synapse?
- what neurotransmitter is involved here?
- neuromuscular junction (is between neurons and skeletal muscle)
- acetylcholine (ACh) is released
what are 4 other common neurotransmitters (besides ACh)?
- gamma-aminobutyric acid (GABA)
- serotonin
- dopamine
- norepinephrine
excitatory neurotransmitter
- ex?
a neurotransmitter that opens a channel that depolarizes the postsynaptic membrane
- acetylcholine
inhibitory neurotransmitter
a neurotransmitter that induces hyperpolarization of the postsynaptic membrane
synaptic transmission
when an action potential reaches the end of an axon at a synapse, the signal is transformed into a chemical signal with the release of a neurotransmitter into the synaptic cleft
describe a neuron’s structure
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within a neuron,
what do dendrites do?
collect incoming signals
within a neuron,
the cell body/soma contains ____
organelles
within a neuron,
the axon hillock is where ____
summation occurs
summation
decides whether an action potential is fired or not
within a neuron,
a myelin sheath is made of?
schwann cells in the PNS and olgiodendrocytes in the CNS
saltatory conduction
when the myelin sheath speeds up the movement of action potentials by forcing the action potential to jump from node to node
in the sodium potassium ATPase pump,
- what ions are transported?
- active/ voltage-gated regulation?
- active/passive transport?
- function?
- 3 Na+ ions out, 2 K+ ions in
- no regulation, always active
- primary active transport
- maintains resting membrane potential
in potassium leak channels,
- what ions are transported?
- active/ voltage-gated regulation?
- active/passive transport?
- function?
- K+ ions out
-no regulation, always active - passive transport
- maintains resting membrane potential
in voltage gated sodium channels,
- what ions are transported?
- active/ voltage-gated regulation?
- active/passive transport?
- function?
- Na+ ions in
- voltage gated
- passive transport
- depolarization
in voltage gated potassium channels,
- what ions are transported?
- active/ voltage-gated regulation?
- active/passive transport?
- function?
- K+ ions out
- voltage gated
- passive transport
- repolarization
in voltage gated calcium channel,
- what ions are transported?
- active/ voltage-gated regulation?
- active/passive transport?
- function?
- Ca2+ ions in
- voltage gated
- passive transport
- synaptic transmission
describe an action potential
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describe the breakdown of the nervous system (categorized)
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within the autonomic nervous system,
describe the differences between the sympathetic and parasympathetic nervous systems:
- general functions
- heart rate
- pupils
- vision
- digestive glands
- gastric motility
- digestive sphincters
- bladder
- urethral sphincter
- bronchial smooth muscle
- S: flight, fright, fight, fuck, mobilize energy; P: rest and digest, store energy
- S: increased; P: decreased
- S: far; P: near
- S: inhibit, P: stimulate
- S: inhibit; P: stimulate
- S: contract, P: relax
- S: relax (inhibit urination); P: contract (cause urination)
- S: contract; P: relax
- S: relaxed, open airways; P: constricted, closed airways
- where is the adrenal gland located?
- how many do we have?
- what do these glands release?
- medulla
- cortex
- adrenal medulla
- above the kidney
- 2, one above each kidney
- epinephrine AKA adrenaline upon activation of the sympathetic system
- the inner portion of the adrenal gland
- the outer portion of the adrenal gland
- part of the sympathetic nervous system
central nervous system (CNS)
the brain and spinal cord
peripheral nervous system (PNS)
includes all other (besides the ones in the brain and spinal cord) axons, dendrites, and cell bodies
nuclei
bunched together neuronal cell bodies within the CNS
ganglia
bunched up somas located outside the CNS
what are the 3 subdivisions of the brain?
- hindbrain
- midbrain
- forebrain
the entire CNS floats in ____
cerebrospinal fluid
what is the function of the spinal cord?
simple reflexes
what is the function of the pons?
relay station and balance
what is the function of the cerebellum?
movement, coordination
what is the function of the hypothalamus?
homeostasis and behavior
what is the function of the limbic system?
emotion, memory, and learning
what is the function of the cerebral cortex?
perception, skeletal muscle movement, integration center
what is the function of the corpus callosum?
connection of the left and right cerebral hemispheres
what are the 5 types of sensory receptors?
- mechanoreceptors
- chemoreceptors
- nociceptors
- thermoreceptors
- electromagnetic receptors
- mechanoreceptors
- 2 examples?
- sensory receptors that respond to mechanical disturbances
- pacinian corpuscles: pressure sensors located deep in the skin
- auditory hair cell: cell found in the cochlea of the inner ear, detects vibrations cause by soundwaves
- pacinian corpuscles: pressure sensors located deep in the skin
- chemoreceptors
- 2 examples?
- respond to particular chemicals
- olfactory receptors: detect airborne chemicals, allow us to smell things
- gustatory receptors: taste buds
- olfactory receptors: detect airborne chemicals, allow us to smell things
nociceptors
pain receptors, stimulated by tissue injury
thermoreceptors
stimulated by changes in temp
- electromagnetic receptors
- ex?
- stimulated by electromagnetic waves
- photoreceptors: rod and cone cells in the retina of the eye
