CH 49 Flashcards
nervous system
command and control system
-circuit of neurons and supporting cells
nerve nets
-series of interconnected nerve cells
-in Cnidarians and Echinodermata
-more complex animals have nerves
-sea stars have nerve net in each arm
nerves
bundles that consist axons of multiple nerve cells
annelids and arthropods
-have segmentally arranged clusters of neurons called ganglia
simple cephalized animals
-ex. flatworms
-have CNS
sessile molluscs
-clams and chitons
-have simple nerve systems
complex molluscs
-octopuses and squids
-more sophisticated systems
vertebrates NS
-CNS (brain and spinal cord: conveys info to/from brain, produces reflexes independently of brain)
-PNS
reflex
-bodys automatic response to stimulus
gray matter
-unmyelinated axons
-neuron bodies, dendrites
-enables movement, memory, emotions
white matter
-myelinated axons
-conducts,proccesses, and sends nerve signals up/down spinal cord
motor system
-carries signals to skeletal muscles
-voluntary
-efferent component of PNS
autonomic nervous system
-regulates smooth and cardiac muscles
-genrally involuntary
-efferent component of PNS
-3 parts: sympthatic, parasympathetic, and enteric
sympathetic division
-regulates arousal and energy generation
-fight or flight
more on sympathetic divisions
-dilates pupil
-inhibits salivary gland
-relaxes bronchi
-accelerates heart
-inhibits activity of stomach/intestines
-inhibits activity of pancreas
-stimulates glucose release form liver
-inhibits galbladder
-stimulates adrenal medulla
-inhibits emptying go bladder
-promotes ejaculation and vaginal contractions
parasympathetic divison
-throwing up after running because this system tells the digestive system to clear out to put blood where it’s needed more
-antagonistic effects on organs
-promotes calming and return to “rest and digest” functions
more on parasympathetic divison
-constricts pupil
-stimulates salivary gland
-constrictes bronchi in lungs
-slows heart
-stimulates activity of stomach and intestines
-stimulates gallbladder
-promotes emptying of bladder
-promotes erection
cerebrospinal fluid
-fills hollow parts of brain (ventricles) and central canal of spinal cord
-filtered from blood
-cushions brain and spinal cord
-provides nutrients
-removes waste
afferent neurons
-transmit info to CNS
-interal/external stimuli> sensory receptors> afferent neurons> CNS
efferent neurons
-transmit info away from CNS
-CNS> efferent neurons> EITHER autonomic nervous system or motor system
-if goes to autonomic system then >sympathetic, parasympathetic , or energetic divisions
-if goes to motor system> control of skeletal muscle
enteric divisions
-controls activity of digestive tract, pancreas and gall bladder
forebrain
-telencephalon (cerebrum)
-diencephalon( thalamus, hypothalamus, epithalamus)
midbrain
mesencephalon (midbrain)
hindbrain
metencephalon (pons, cerebellum)
myelencephalon (medulla oblongata)
reticular formation
-network of neurons at core of brainsrain
–regulates amount/type of info that reaches cerebral cortex
-affects alertness
biological clock
-molecular mechanism that directs periodic gene expression
-typically synchronized with light/dark cycles
-what mammalian circadian rhythm relies on