Chapter 49.1 Flashcards
How are the neurons that cnidarians have arranged?
in nerve nets
a series of interconnected nerve cells
nerve net
nerve net
interconnected nerve cells
what do complex animals have?
nerves
the axons of multiple neurons are bundled together
nerves
nerves
the axons of multiple neurons bundled together
What do sea stars have
a set of radial nerves connecting to a central nerve ring
what do nerves do
channel and organize information flow through the nervous sstem
what do bilaterally symmetrical animals exhibit
cephalization
when sensory organs are clustered at the front end of the body
cephalization
cephalization
when sensory organs are clustered at the front end of the body
what do flatworms have
a central nervous system (CNS)
what does the central nervous system consist of
a brain and longitudinal nerve cords
consists of neurons carrying information into and out of the CNS
peripheral nervous system (PNS)
what does the PNS consist of
neurons that cary info in and out of the CNS
What do annelids and arthropods have
ganglia
segmentally arranged clusters of neurons
ganglia
ganglia
segmentally arranged clusters of neurons
The CNS in vertebrates
composed of the brain and spinal cord
The PNS in vertebrates
is composed of nerves and ganglia
have numerous functions to nourish, support, and regulate neurons
glial cells (glia)
glial cells
have numerous functions to nourish, support, and regulate neurons
form tracks where newly formed neurons migrate
embryonic radial glia
embryonic radial glia
form tracks where newly formed neurons migrate
induce cells lining capillaries in the CNS to form tight junctions
astrocytes
results in a blood-brain barrier
astrocytes
restrict the entry of most substances into the brain
astrocytes
one of the roles of the glia
the development of the nervous system
What can act as stem cells?
radial glial cells and astrocytes
what do radial glia form in embryos
tracks where newly formed neurons migrate from the neural tube
What does the CNS develop from
the hollow nerve cord
What does the cavity of the nerve cord give rise to?
the narrow central canal of the spinal cord and the ventricles of the brain
What does the canal and ventricles fill with
cerebrospinal fluid
supplies the CNS with nutrients and hormones and carries away wastes
cerebrospinal fluid
cerebrospinal fluid
gives the CNS nutrients and hormones and carries away wastes
The brain and spinal cord contain…
gray matter and white matter
consists of neuron cell bodies, dendrites, and unmylinated axons
gray matter
what does gray matter consist of?
- neuron cell bodies
- dendrites
- unmyelinated axons
consists of bundles of myelinated axons
white matter
what does white matter consist of
bundles of myelinated axons
conveys information to and from the brain
spinal cord
generates basic patterns of locomotion
spinal cord
what does the spinal cord do
sends info to and from the brain and causes motion
produces reflexes independently of the brain
spinal cord
the body’s automatic response to a stimulus
reflex
reflex
the body’s automatic response to a stimulus
where are afferent neurons
the PNS
transmit info to the CNS
afferent neurons
what do afferent neurons do
send info to the CNS
where are efferent neurons
the PNS
what do efferent neurons do
send info away from the CNS
What are the three divisions of efferent neurons
- sympathetic
- parasympathetic
- enteric
autonomic nervous system controlling digestive tract, pancreas, and gallbladder
enteric
The two different components of the PNS
the motor system and the autonomic nervous system
carries signals to skeletal muscles and is voluntary
motor system
motor system
carries signals to skeletal muscles and is voluntary
regulates smooth and cardiac muscles and is generally involutary
autonomic nervous system
autonomic nervous system
regulates smooth and cardiac muscles and is generally involuntary
What divisions does the autonomic nervous system have
sympathetic and arasympathetic
regulates arousal and energy generation
sympathetic divison
sympathetic division
regulates arousal and energy generation
fight or flight response
sympathetic division
has antagonistic effects on target organs
parasympathetic division
promotes calming and a return to rest and digest functions
parasympathetic divison
