Chemical and Nervous Control Flashcards
(36 cards)
_______________________ are the simplest animals with nervous systems.
Hydras, jellies, and other cnidarians are the simplest animals with nervous systems.
In most cnidarians, interconnected neurons form a __________, which controls the contraction and expansion of the gastrovascular cavity.
diffuse nerve net
In more complex animals, the axons of multiple neurons are often bundled together, forming _____________.
nerves
Animals that have elongated, bilaterally symmetrical bodies have even ____________.
more specialized nervous systems
The organization of neurons in such animals reflects _____________, an evolutionary trend toward a clustering of sensory neurons and interneurons at the anterior (front) end of the body.
cephalization
an evolutionary trend toward a clustering of sensory neurons and interneurons at the anterior (front) end of the body.
cephalization
In nonsegmented worms, such as a planarian, a ______________________constitute the simplest clearly defined CNS.
small brain and longitudinal nerve cords
Their behavior is regulated by more complicated brains and by ventral nerve cords containing _____________, segmentally arranged clusters of neurons.
ganglia
Types of Nervous System Organization (for molluscs)
Sessile, Active predatory species
Slow-moving species – have relatively simple sense organs and little or no cephalization
Sessile
have the most sophisticated nervous systems of any invertebrates, rivaling those of some vertebrates.
Active Predatory Species (mollusks)
In _______________, the brain and the spinal cord form the CNS; nerves and ganglia are the key components of the PNS.
vertebrates
Primary components of CNS
Brain and Spinal Cord
Primary components of PNS
Ganglia and Nerves
a set of neurons that carry out integration
Central Nervous System (CNS)
a set of neurons that carry information into and out of the CNS.
Peripheral Nervous System (PNS)
protects the body by providing a rapid, involuntary response to a particular stimulus.
Reflex
Corresponds to arousal and energy generation
Sympathetic ANS
causes opposite responses that promote calming and a return to self-maintenance functions
Parasympathetic ANS
It controls the function of the digestive system independently of the central nervous system. Digestive tract,
pancreas, and
gallbladder.
Enteric
Regions of a Vertebrate Brain
Forebrain, Midbrain, Hindbrain
contains the olfactory bulb and cerebrum, has activities that include processing of olfactory input (smells), regulation of sleep, learning, and any complex processing.
Forebrain
coordinates routing of sensory input, i.e. Visual and Auditory.
Midbrain
controls involuntary activities, such as blood circulation, and coordinates motor activities, such as locomotion.
Hindbrain
