Nervous System Exam Flashcards
injury to T:1 - L1 causes?
Paraplegic paralysis
Graded potential
a change in the membrane potential that is localized to one area of the plasma membrane; can result from 1) chemical signals binding to their receptors, 2) changes in the voltage across the plasma membrane 3) mechanical stimulation 4) temperature changes 5) spontaneous changes in membrane permeability
Refractory period
once an action potential is produced at a given point on the plasma membrane, the sensitivity of that area to further stimulation decreases for a time
Absolute refractory period
the first part of the refractory period during which complete insensitivity exists to another stimulus
Action potential
electrical impulses carried along the length of the axons; always the same regardless of stimulus; the underlying functional feature of the nervous system
Astrocytes
astrocytes first of the supporting cells;branched glial cells;
they cling to neurons and their synaptic endings, and cover capillaries; anchor neurons to their nutrient supplies, guide migration of young neurons, control the chemical environment, looks like a spider web
CNS
brain and spinal cord
integration and command center
Diencephalon
central core of the forebrain; deepest part of the brain; consists of three paired structures - thalamus,; hypothalamus, and epithalamus; encloses the third ventricle
Gyri
Ridges of cerebral hemispheres
Nodes of Ranvier
gaps in the myelin sheath between adjacent schwann cells; they are the sites where axon collaterals can emerge
Pons
conducting bridge between the midbrain and the medulla oblongata; helps out with regulation of respirations, touch, pain, and temperature
SNS
conscious control of skeletal muscles
Nerve
bundle of axons and their sheaths; connects to the CNS to sensory receptors, muscles, and glands
Synapse
junction that mediates information transfer from one neuron
Somatic vs autonomic
somatic (conscious control of skeletal muscles)
autonomic (regulates smooth muscle, cardiac muscle, and glands)
Blood brain barrier
protective mechanism that allows you to maintain a stable internal environment
selectively lets things in an out of the brain
if it can be diffused through the capillaries, it can be diffused to the brain
Broca’s area
a motor speech area that directs muscles of the tongue
Mature neurons are:
Amniotic
Where are sensory receptors
Peripheral nervous system
CSF
watery solution that contains less protein and different ion concentrations than plasma; forms a liquid cushion that gives buoyancy to the CNS organs
Cerebral white matter
consists of deep myelinated fibers and their tracts
it is responsible for communication between:
the cerebral cortex and lower CNS center, and areas of the cerebrum
Dendrite
conduct the impulses into the soma or cell body
Synaptic cleft
fluid-filled space separating the presynaptic and postsynaptic neurons; prevents nerve impulses from directly passing from one neuron to the next
Axon
Carries information away from soma
