Nervous System Flashcards
Nervous system
Made up of neurons; detect external and internal stimuli (sensory perception), coordinate movement, relay and process info., maintain basic physiological processes
Nerve nets
Simplest nervous systems; tons of neurons in the soma; no central processing area; common in radially symmetrical animals; Ex: echinoderms
Ganglia
Bundles of soma/cell bodies; neurons located at the cephalon ganglia and central nerve cords; common in bilaterally symmetric animals; Ex: platyhelminthes
Cephalic ganglia
Bundles of soma located near the head region of the animal
Cephalization
Concentration of ganglia at one end of the body
Ventral nerve cords
Interconnected; forms smth like a spine of nerves
Nerves
Bundles of axons; “cable management” and organized similarly to muscles; can be very long (butt to toes)
Where is the largest concentration of neurons located?
Brain
Where do brains originate from in vertebrates?
Dorsal, hollow nerve cord; convergently evolved in arthropods and molluscs
Central vs Peripheral Nervous System
CNS: includes brain, spinal cord, optic nerve and retina, olfactory nerve; information processing and transformation
PNS: includes most cranial nerves, sensory nerves, motor nerves, autonomic nerves, and ganglia; information gathering and body maintenance
Peripheral Nervous System
Sends and revives info. using afferent and efferent neurons; splits into Somatic and Autonomic Nervous Systems
Somatic Nervous System
Voluntary movement (moving skeletal muscles); sensory perception; part of the PNS
Autonomic Nervous System
Involuntary movement (churning of the stomach); physiological regulation (glands and hormones); split into Sympathetic Nervous System and Parasympathetic Nervous System; part of the PNS
Sympathetic Nervous System
In charge of “fight or flight” response (alarm/survival mode); adrenaline
Parasympathetic Nervous System
In charge of “rest and digest”; maintenance; getting ready for “fight or flight”
