Final Exam LOs 4 + 5 + 6 Flashcards
Central Nervous System (CNS)
think the brain and the spinal cord, it integrates and processes sensory information to coordinate a motor response
Peripheral Nervous System
it houses the sensory receptors from sensory organs (eyes, ears, etc.), and it has many divisions under it, the main one being the afferent and efferent division (houses autonomic and somatic divisions)
Autonomic Nervous System (ANS)
controls subconscious actions (contraction of smooth muscle + cardiac muscle, and glandular secretions)
also houses the sympathetic division “fight-or-flight”
and the parasympathetic “rest-and-digest”
Somatic Nervous System (SNS)
controls VOLUNTARY an involuntary (reflexes) of skeletal muscle contractions
Neurons
cells that send and receive signals
Cell body of neuron
performs the basic functions of the nervous system
Axon
is long and carries electrical signals (action potential) to target
Dendrites
highly branched, many fine processes, receives info from other other neurons
Axon-terminals
also called synaptic terminals, plays a role in communication with other cells
Synapse
area where a neuron communicates w/another cell
Presynaptic cell
neuron that sends a signal via neurotransmitter (NT)
Postsynaptic cell
neuron that receives message from presynaptic cell
synaptic cleft
the small gap that separates the presynaptic membrane and the postsynaptic membrane
Axon hillock
this is where threshold -55 mV is met, and action potential is triggered at the axon hillock
Neuroglia cells
they are cells that support and protect neurons found in CNS and PNS
Neuroglia found in PNS
satellite and schwann cells
Satellite cells
found in the PNS, they surround neuron cell bodies, regulate oxygen and carbon dioxide, nutrient, and NT levels around ganglia.
Schwann Cells
found in the PNS, they surround axons and are responsible for their myelination
Neuroglia found in CNS
Ependymal cells, Astrocytes, Oligodendrocytes, and Microglia
Ependymal Cells
found in the CNS, they make cerebral spinal fluid (CSF)
Astrocytes
found in the CNS, they help w/the Blood Brain Barrier (BBB)
Oligodendrocytes
myelinate CNS axons, and provide structural framework
White Matter in CNS
dominated by myelinated axons
Grey Matter in CNS
areas containing neuron cell bodies, dendrites, and unmyelinated axons
Three important concepts regarding membrane potential
1) extracellular fluid (ECF) and intracellular fluid (cytosol) differ greatly in ionic composition
2) cells have selectively permeable membranes
3) membrane permeability varies by ion
Resting Membrane Potential
membrane potential of an undisturbed cell, ions move through leaky channels
Thinking about transmembrane potential…
1) inside the membrane is always more negatively charged to the outside of the membrane
2) there’s more sodium OUTside of the cell, so it’s going in, and theres more potassium INside of the cell so it’s going to leave
3) mechanisms that contribute to changes in resting membrane potential is graded potential and action potential
Graded potential
any stimulus that opens a chemically or mechanically gated channel that allows ions to move across the membrane
it can just be a bunch of signals being received, but IF stimulus is strong enough it can lead to action potential at the axon hillock (ex. NMJ and postsynaptic potentials)
Action Potentials
propagated changes in transmembrane potential, happens at the axon hillock
Chemically Gated Channel
open in presence of specific chemicals at binding site
Mechanically Gated Channel
respond to membrane distortion, found in sensory receptors (touch, vibration)