Nervous System Histology Flashcards
CNS vs PNS
CNS:
-comprised of the brain and spinal cord as well as the olfactory and optic nerves
PNS:
-includes all parts of the nervous system that are outside of the CNS
functions of CNS vs PNS
CNS:
-receives and processes sensory info
-responds to sensory input with motor output instructions
PNS:
-sends sensory info to the CNS
-transmits motor output instructions from the brain to designated muscles and glands
autonomic nervous system
-involuntary
-comprised of the parasympathetic and sympathetic divisions
somatic nervous system
-voluntary skeletal muscles
-sensory and motor
two types of cell groups in the nervous system
neurons and glial cells
neurons
-conduct APs
-process signals
-contain dendrites, somas and axons
glial cells
-do not generate electrical impulses
-support and protect axons —> form myelin sheath around axon, remove cellular debris, and provide structural support
different types of neurons
-motor (efferent)- control effector organs and are primarily located in the CNS
-sensory (afferent)- receive sensory info and cell body is located in CNS or ganglia
-projection- connect different regions far away and are located in the CNS
-interneurons- create circuits by connecting neurons and are in the CNS or ganglia
types of supporting cells
astrocytes and satellite cells
astrocytes
-supporting cells of the CNS
-star-shaped
-end feet contact capillaries (they interact with blood vessels)
-provide structural support
satellite cells
-supporting cells of the PNS
-surround cell bodies in ganglia
-support and protect neurons
two types of myelinating cells
oligodendrocytes and schwann cells
oligodendrocytes
-located in the CNS
-form and maintain myelin that wrap around axons
-interact with several neurons
schwann cells
-located in the PNS
-wrap myelin around axons
-only surround one neuron
microglia
-guard and protect the CNS
-respond to sites of damage or injury
-phagocytose dying cells or debri
-immune surveillance
-only located in the CNS
ependymal cells
-cuboidal or columnar epithelial cells
-form a simple layer that line ventricles and central canal of spinal cord
-produce CSF
-cilia help circulate CSF
cerebrum
-largest part of the brain
-comprised of white and gray matter
-consists of lobes
-divided into two halves
common cell types of cerebrum
-neurons
-neuroglial cells- astrocytes, oligodendrocytes, and microglia
what neurons make up the gray matter?
-pyramidal cells
-fusiform cells
-cells of martinotti
-horizontal cells of cajal
-stellate cells
cerebellum
-cerebellar cortex (gray matter) with a white matter core
-divided into two halves
-cortex contains 3 layers: molecular layer (outer), purkinje cell layer, and granular layer (inner)
function of cerebellum
-maintain balance and equilibrium
-little brain
-controls posture changes
-coordinates voluntary muscle movements- fine and smooth movements
-cognitive functions like attention, language, and memory
what are the common cell types of cerebellum?
-neurons in the cortex
-neuroglial cells- astrocytes, oligodendrocytes, and microglia in the cortex and white matter
where are unipolar brush cells found?
primarily in flocculonodular lobe and vermis
what types of cells are inhibitory neurons?
-stellate cells
-basket cells
-purkinje cells
-golgi cells