Lecture 10 Flashcards
What is the central nervous system?
brain and spinal cord
What is the peripheral nervous system?
ganglion and nerve; anything leaving the brain or spinal cord
What does CNS stand for?
central nervous system
What does PNS stand for?
peripheral nervous system
What is afferent information?
special senses, somatic senses, visceral senses
Where does afferent information go?
sent to the CNS
What are the special senses?
vision, hearing, taste, smell, balance/equilibrium
What are the somatic senses?
information from skin, joints, and skeletal muscles
What are the visceral senses?
information from internal organs and blood vessels
What is efferent information?
CNS tells muscles or glands what to do
Where does efferent information go?
away from the CNS
What is the somatic nervous system?
voluntary, innervates skeletal muscle
What is the autonomic nervous system?
involuntary, innervates cardiac muscle, smooth muscle, and glands
What are neurons?
excitable cells that transmit nerve impulses
What are glial cells?
non-excitable cells that support and protect the neurons
What are dendrites?
stick out from the cell body
What do dendrites do?
carry signal toward cell body
What is the axon hillock?
where the plasma membrane comes together to create the axon
What is the axon?
long end of the cell
What does the axon do?
carry signals away from the cell body
What is the myelin sheath?
covers the axon
What does the myelin sheath do?
helps speed up the signal between cells
What are axon terminals?
where the axon connects to another cell
What is a node of ranvier?
space between myelin where it’s just the axon
What are the neuron classifications?
unipolar, bipolar, multipolar
What is a unipolar neuron?
only one process coming from the cell body
What is a bipolar neuron?
has two processes coming from the cell body
What is a multipolar neuron?
more than two processes coming from the cell body
What is a unipolar neuron used for?
afferent info, sensory neurons
What is a bipolar neuron used for?
afferent info, special senses
What is the least abundant neuron classification?
bipolar
What is the most abundant neuron classification?
multipolar
What is a multipolar neuron used for?
efferent info, most CNS neurons, motor neurons
What are synapses?
sites where neurons communicate with other neurons, muscle, or glands
What way does communication go in neurons?
one direction
How many different glial cells are in the CNS?
four
What are the four glial cells of the CNS?
astrocytes, oligodendrocytes, microglial cells, ependymal cells
What are astrocytes?
look like a star, in the CNS
What do astrocytes do?
control ionic environment, induce formation of the blood-brain barrier
What do oligodendrocytes do?
form myelin sheaths in CNS
What are oligodendrocytes?
connect to the axon by producing the myelin sheath
What are microglial cells?
small cells in between neurons
What do microglial cells do?
clean up debris and fight infection
What are ependymal cells?
line brain internal cavities (ventricles)
How many glial cells are part of the PNS?
two
What are the glial cells of the PNS?
Schwann cells and satellite cells
What are Schwann cells?
wraps around the axon and produces myelin in a spiral
What are satellite cells?
surround the cell body
What do satellite cells do?
protect and regulate nutrients for neuron cell bodies in ganglia
What is the structure of myelin?
white, fatty citing around axons
What is the function of myelin?
supports and protects and insulates axon, increases conduction speed of electrical signals in axons
What does gray matter contain?
neuron cell bodies and dendrites, doesn’t have myelin
What does white matter contain?
neuron axons and myelin sheaths
What side are sensory neurons on?
posterior
What side are motor neurons on?
anterior
What are nerves?
cable-like bundles of axons in the PNS
What is the endoneurium?
wraps individual axons
What is the perineurium?
wraps axon fascicles
What is the epineurium?
wraps entire nerves
What is the primary afferent neuron?
senses the stimuli and sends it to a secondary afferent neuron in the spinal cord
What is the secondary afferent neuron?
in the spinal cord, gets info from a primary afferent neuron and sends it to the tertiary afferent neuron in the brain
What is the tertiary afferent neuron?
in the brain, gets info from a secondary afferent neuron and sends it to a neuron in the sensory cortex
What is an interneuron?
get info from an afferent neuron and sends it to an efferent neuron
What is multiple sclerosis?
patches of myelin in the brain and spinal cord are destroyed, body attacks oligodendrocytes
What are the symptoms of multiple sclerosis?
blindness, weakness (efferent), numbness (afferent)
What is Alzheimer’s disease?
progressive degenerative disease of the brain
What are the symptoms of Alzheimer’s disease?
memory loss, depression, disorientation
What disease is associated with abnormal protein aggregates?
alzheimer’s disease
What does Alzheimer’s disease do?
disrupts signaling in CNS
