Nervous System Flashcards
nerve nets
the simplest creatures (cnidarians) have nerve nets throughout their bodies
nerves
what more complex animals have
in which what the axons of multiple neurons are bundled together
cephalization
the clustering of sensory organs at the front end of body
in bilateral animals
simplest of cephalized animals
flatworms
they have a centralized nervous system (CNS)
small brains and nerve cords
peripheral nervous system
consists of neurons carrying info into and out of the cns
regulates movement and internal environment
PNS and its two compenents
motor system
autonomic nervous system
motor system
carries signals to skeletal muscles and can be voluntary or involuntary
autonomic nervous system
regulates smooth and cardiac muscles and is involuntary
PNS and its neurons
afferent neurons
efferent neurons
afferent neurons
transmit info to the CNS
efferent neurons
transmit info away from the CNS
autonomic nervous system has
sympathetic division
parasympathetic division
enteric nervous system
sympathetic division
regulates arousal and energy generation;
adrenaline, fight or flight
parasympathetic division
promotes calming and a return to “rest and digest” functions;
helps hearts slow down
enteric nervous system
exerts direct, partially independent, control over the digestive tract, pancreas and gallbladder
central nervous system
develops from hollow dorsal nerve cord
nerve cord cavity - gives rise to narrow central canal of spinal cord and brain ventricles
cerebrospinal fluid
supplies cns w nutrients and hormones and carries away wastes
brain and spinal cord contain what matters
gray matter
white matter
gray matter
neuron cell bodies, has unmyelinated axons
white matter
consists of bundles of myelinated axons
what does spinal cord do
conveys info to and from the brain
controls basic locomotion
reflexes independent of brain
reflex
the body’s automatic response to a stimulus
sections of the brain
forebrain
midbrain
hindbrain
forebrain
smell, sleep, learning, and complex processing
