Exam 2 Flashcards
What are some functions of the nervous system?
Communication and control of all body activities
Monitor of internal and external environment
What are the 3 componenets of the nervous system?
Brain
Spinal cord
Nerves
What are the 2 main divisions of the nervous system? What is a minor third section?
Central nervous system (CNS)
Peripheral nervous system (PNS)
Enteric nervous system (ENS)
What composes the CNS?
Brain and spinal cord
What composes the PNS? What is it’s function?
All nerves of the body
Carries information between CNS and other parts of the body
What is the ENS in charge of? What is the ENS controlled by?
Digestive activities
Controlled by autonomic nervous system
What are the two divisions of the PNS? What direction does the nervous signal go for each?
Afferent - sensors to CNS
Efferent - CNS to effector organs (muscles, glands, other organs)
What are the 3 nervous systems that fall under the efferent classification? What environments do they interact with?
Somatic - outside world
Autonomic - internal
Includes enteric - digestive
What do the somatic nervous system signal to?
Fibers of motor neurons that supply skeletal muscles
Voluntary organs
What do the autonomic nervous system signal to?
Smooth muscle, cardiac muscle, glands, other motor organs
Involuntary organs
What are the 2 divisions of the autonomic nervous system? What “catch phrase” summarizes their function?
Sympathetic - fight or flight (stimulation)
Parasympathetic - feed and breed (relaxation)
What are the primary cells that encompass nervous tissue?
Neurons - make up brain, spinal cord, and nerves
What are some characteristics of neurons?
High maintenance:
High requirement for O2
Cannot reproduce
Need support cells called glial cells
What are the 3 structures in a neuron?
Central cell body
Dendrites
Axon
Describe the central cell body of a neuron -
resembles the typical cell
Describe dendrites in a neuron -
process and increase surface area
Describe the axon in a neuron -
outgoing information
<1 micrometer to >1 meter in length
What are the neuron cell types in the CNS called? Where are they found?
Interneurons
In the CNS between afferent and efferent neurons
What are some things interneurons are responsible for?
planning, memory, creativity, intellect, motivation, and other complex actions
more interneurons = more complex action
What are the neuron cell types in the PS called? Where are they found?
Afferent neuron - cell body in PNS and axon terminals in CNS
Efferent neuron - cell body in CNS with axon terminals in PNS
What are the support cells for neurons called? How many per neuron?
glial cells
10 glial cells per 1 neuron
connective tissue of the CNS
What are the 6 types of glial cells in the CNS?
astrocytes
oligodendrocytes
ependymal
microglia
schwan cells
satellite cells
Describe astrocytes
glial cell
star shaped
most abundant
“glue” of the CNS - BBB, brain injury repair, nutrient transport from blood to neurons
Describe oligodendrocytes
glial cell
insulator
form myelin sheath
multilayered
white
phospholipid
segmented covering