Mod6 (NS) Flashcards
Neurons
cells that conduct nerve impulses; consist of cell body (Soma), dendrites and axons
Soma (cell body)
receives messages from dendrites, combines and processes then sends to axons; contains the nucleus, mitochondria, ER, golgi
Dendrite
multiple dendrites emerge from soma; these are specialized receiving units that collect messages from neighbouring neurons and sends them to cell body
Axons
extends from one side of cell; single axon conducts electrical impulses away from cell body to other neurons, muscles, glands. Branches at ends to form terminals
Synapse
site where two neurons or neuron and effector cell communicate
Axon Hillock
site where axons join cell body
Axon Collaterals
side branches of axon
Synaptic End Bulbs
end of synaptic terminal; contain synaptic vesicles (which contains NTs)
Neurotransmitters
means of communication btw neurons or neuron-effector; chemical messenger
Schwann Cells
type of neuroglia; generate myelin sheath in the PNS; spaced along the axon; wraps around each axon
Oligdendrocytes
neuroglia; generate myelin sheath in CNS
Myelin Sheath
protective layer of membrane around axon; increases the speed of nerve conduction along axon
Nodes of Ranvier
gaps between schwann cells that are NOT myelinated
Nerve
bundle of 100-1000’s of axons (sometimes dendrites) plus associated connective tissue and blood vessels; these lie OUTSIDE the brain and spinal cord
Spinal nerves
ext and enter spinal cord (where spinal cord contains about 100 million neurons
ganglia
small masses of nervous tissue consisting of neuron cell bodies; located OUTSIDE the brain and spinal cord
Enteric Plexuses
extensive network of neurons located in walls of organs of GI; helps to regulate digestive system
Sensory receptors in skin
monitors changes in external/internal environment (touch receptors, photoreceptors, olfactory receptors)
Astrocytes
neuroglia, support, protect neurons and help to maintain proper chemical environment for generation of AP
Microglia
protect CNS cells from disease; engulf invading microbes, clear debris
Membrane potential
difference of electrical charge btw inside and outside of plasma membrane; cell with membrane potential is POLARIZED (negative inside)
Synapse
neuron-neuro interaction site
Junction
site of interaction btw neuron and non-neuron
Synaptic Cleft
at end of synaptic end bulb; separates end bulbs from next neuron
Dorsal root ganglion
location of cell bodies of sensory neurons
Dorsal Root
entrance point for axons of sensory neurons; flows into dorsal horn of gray matter
Ventral Horn
location of cell bodies of motor neurons
ventral root
part of spinal nerve; exit point of motor axons
Reflex
fast, involuntary series of actions that occur in response to a stimulus
Somatic reflex
termed somatic reflex is the effector is skeletal muscle (ie. patellar reflex)
autonomic (visceral) reflex
termed as this reflex if effector is smooth muscle, cardiac muscle or gland
Brainstem
1/4 major regions of brain; continuous with spinal cord, consists of medulla, pons, and midbrain
Cerebellum
1/4 major regions of brain; posterior to brainstem
Diencephalon
1/4 major regions of brain; above the brainstem; consists of thalamus, hypothalamus, and pineal gland
Cerebrum
1/4 major regions of the brain; supported on the diencephalon and brainstem; forms bulk of brain; surface composed of thin gray matter (cerebral cortex) beneath this is white matter
Superior Sagittal Sinus
collects CSF and blood from brain
gyri
folded area in hemisphere of cerebrum
sulci
grooves within hemispheres of cerebrum
Cerebral Cortex
outer layer of gray matter of cerebrum
Basal Ganglia
three pairs of nuclei in cerebrum
