Chapter 3 Flashcards
CNS
central nervous system-located in skull (brain) and spine (spinal cord)
PNS
peripheral nervous system-located OUTSIDE skull and spine, aka NOT the CNS2 parts-Somatic nervous system, Autonomic nervous system
SNS
somatic nervous system-part of the PNS, interacts with the external environment-composed of AFFERENT NERVES and EFFERENT NERVES
SNS afferent and efferent nerves
afferent-carry sensory signals from skin, skeletal muscles, joints, eyes, ears, etc. to the CNSefferent-carries motor signals from CNS to skeletal musclesAfferent, go TOWARD the CNS, begins with A, like advance, approach, arriveEfferent, goes AWAY from CNS, begins withE, like exit, embark, escape
ANS
autonomic nervous system-part of the PNS, regulates the body’s internal environment-afferent nerves & efferent nerves
ANS afferent and efferent nerves
afferent-carry sensory signals from internal organs to CNSefferent-carries motor signals from CNS to internal organsAfferent, go TOWARD the CNS, begins with A, like advance, approach, arriveEfferent, goes AWAY from CNS, begins withE, like exit, embark, escape
two types of efferent nerves
sympathetic and parasympathetic
sympathetic nerves
Thoracic & lumbar“Fight or flight”Second stage neurons far from target organ
parasympathetic nerves
Cranial & sacral“Rest & restore”Second stage neurons near target organ
All sympathetic and parasympathetic nerves are ___-___ ______ paths
two-stage neural paths-The sympathetic and parasympathetic neuronsproject from the CNS and go only part of the way to the target organs before they synapse on other neurons (second-stage neurons) that carry the signals the rest of the way. -sympathetic neurons that project from the CNS synapse on second-stage neurons at a substantialdistance from their target organs-parasympathetic neurons that project from the CNS synapse near their target organs on very short secondstage neurons
MEMORIZE division of NS picture in third slide notes
DO EET
Meninges
CNS encased in boneThree meninges (protective membranes)Dura mater.Tough outer membraneArachnoid membrane.Web-like.beneath arachnoid Subarachnoid space Pia mater.Delicate.Adheres to surface of CNS
CSF
CSF (cerebrospinal fluid) produced by choroid plexusesSubarachnoid space, ventricles, central canalExcess absorbed from subarachnoid space into dural sinuses, drains into jugular veins of neck
Hydrocephalus
?
Protection of the Brain
Physical.Skull.Meninges.CSFChemical.Blood-brain barrier..Tightly-packed cells of blood vessel walls prevent entry of many molecules (proteins & other large molecules, w/ some exceptions like glucose) (much tighter packed than in rest of body)
Choroid Plexuses
networks of capillaries (small blood vessels) that protrude into the ventricles from the pia mater.continuously produce CSF
neurons
cells that are specialized for the reception, conduction, and transmission of electrochemical signals
cell body
aka SOMAThe metabolic center of the neuron;
cell membrane
The semipermeable membrane that encloses the neuron
dendrites
The short processes emanating from the cell body, which receive most of the synaptic contacts from other neurons
Axon hillock
The cone-shapedregion at the junction between theaxon and the cell body
axon
The long, narrow processthat projects from the cell body
