Nervous System Flashcards
Afferent:
Sensory info to the CNS
Efferent:
Motor commands from the CNS
Nerves:
Bundles of axons in the PNS
Tracts:
Bundles of axons in the CNS
Ganglia:
Clusters of neuronal cell bodies in the PNS
Nuclei:
Clusters of neuronal cell bodies in the CNS
White Matter:
Mostly myelinated axons; contains tracts
Grey Matter:
Cell bodies, dendrites, unmyelinated axons and glia; contains nuclei
EPSP:
Neurotransmitter binding causes cation channels to open & Na+ enters cell; less negative membrane potential
IPSP:
Neurotransmitter binding causes channels to open & either K+ to leave or Cl- to enter the cell: more negative membrane potential
Dura Mater:
Outer thick fibrous sheath → provides stability and protection
Arachnoid Mater:
The middle of three layers that make up the meninges, containing CSF
Pia Mater:
Inner membrane bound to spinal chord → provides support to blood vessels of the spinal chord
Epidural Space:
Loose connective tissue, blood vessels and adipose tissue between Dura mater and vertebrae
Subarachnoid Space:
Strands of connective tissue that looks like a spiders web, surrounded by cerebrospinal fluid, between arachnoid mater and pia mater. CSF acts as a shock absorber and diffusion medium for gasses and nutrients.
Dorsal Horn:
Cell bodies of interneurons receiving sensory info (towards the back)
Ventral Horn:
Cell bodies of somatic motor neurons (towards the front)
Lateral Horn:
Cell bodies of autonomic motor neurons (to the side)
Dorsal Root:
Sensory (afferent) axons
Ventral Root:
Motor (efferent) axons
Dorsal Root Ganglia:
Collection of sensory cell bodies
Monosynaptic:
One synapse between afferent and efferent neuron
Polysynaptic:
More than one synapse. Involves interneurons
Muscle Spindle:
Sensory receptor for stretch reflex
Reciprocal Inhibition:
Simultaneous stimulation and inhibition of antagonistic muscles
Contralateral:
Motor response on opposite side to stimulus
Ipsilateral:
Motor response on same side as stimulus
Chloroid Plexus:
A network of blood vessels in each ventricle of the brain, producing the cerebrospinal fluid.
Blood Brain Barrier:
Formed by tightly adhered capillary cells
Sensory Homunculus:
Represents the sensitivity of each body region
Motor Homunculus:
Represents the amount of motor control devoted to each body region
Autonomic Tone:
Basal rate of activity to allow increase AND decrease
Two Motor Neuron Chain:
Two motor neurons that synapse at an autonomic ganglion in the PNS
Preganglionic Neuron:
Cell bodies in the CNS
Ganglionic Neuron:
Cell bodies in autonomic ganglia
Preganglionic Fibres:
Axons in the CNS
Postganglionic Fibres:
Axons in the autonomic ganglia
Autonomic Ganglia:
Autonomic ganglia are clusters of neuron cell bodies that transmit sensory signals from the PNS to integration centres in the CNS.
Cholinergic Fibres:
Release acetylcholine
Adrenergic Fibres:
Release norepinephrine
Nicotinic Receptors:
Sodium channels on all ganglionic neurons. Binding of Ach is excitatory.
Muscarinic Receptors:
G-protein coupled receptors on all parasympathetic target organs. Binding of Ach is excitatory or inhibitory
Adrenergic Receptors:
5 types of G-protein coupled receptors, found on sympathetic target organs, that bind epinephrine and nor epinephrine with differing affinities.
Receptor Adaptation:
Most receptors adapt to constant stimulation, which means receptor potential magnitude decreases over time
Tonic Receptors:
Adapt slowly or not at all, with a constant response to stimuli
Phasic Receptors:
Adapt quickly and responds to changes in stimuli
Labelled Line:
Neural pathway from sensory receptor to cortex, specific to each type of stimuli
Receptive Field:
The area monitored by a single sensory neuron
Mechanoreceptors:
Responds to touch, pressure, vibration and position of joints and muscles
Thermoreceptors:
Two types; warm and cold. They are fast adapting phasic receptors and respond strongly to changes in temperature.
Nociceptors:
Detects pain and is associated with behavioural and emotional responses.
Chemoreceptors:
Detects chemical stimulus
