Nervous system 1 Flashcards
Briefly describe the type of communication in the nervous system?
Rapid and specific chemical and electrical signals that usually cause immediate response.
Divisions of NS?
Central nervous system: Brain, Spinal cord
Peripheral Nervous system: Cranial Nerves, Spinal nerves, ganglia.
What are astrocytes?
CNS Star-shaped Form blood-brain barrier Metabolize neurotransmitters Regulate K+ balance Structural support
What are oligodendrocytes?
Most common glial cell CNS Large cells w/ slender extensions Extensions form myelin sheaths Allows for faster impusles in CNS Analogous to shwann cells
What are microglia?
CNS
Small, found near blood vessels
Clear dead cells
What are ependymal cells?
Form epithelial membrane lining cavities of brain and spinal cord
Produces CSF in choroid plexus
What are satellite cells?
PNS
Small, flat surrounds neuronal soma
What are shwann cells?
Encircles PNS neurons with myelin sheath
What is myelin?
Lipid-protein covering of neurons that is an electrical insulator and speeds up impulses.
White matter vs grey matter?
White matter: Myelinated axons
Grey matter: Unmyelinated axons
What is a synapse?
Region where a neurons connects to another neuron or muscle. Mainly uses chemical neurotransmitters to induce depolarization.
What are multipolar neurons?
Multiple processes extend from cell body with one axon. Most are interneurons, some are motorneurons.
What are bipolar neurons?
Two processes etend from body, one is dendrite other is axon. Mainly sensory neurons.
What are unipolar neurons?
One process from cell body. They are sensory neurons
Afferent vs efferent?
Afferent: Entering Nervous system
Efferent: Exits nervous system
Somatic vs autonomic (viscera) fibers?
Somatic: Conscious control
Autonomic: unconscious control.
Are sensory and motor neurons afferent or efferent?
Sensory: Afferent
Motor: Efferent
What is epineurium?
In nerves, thick layer of CT, encloses entire nerve
What is perineurium?
Layer of CT that wraps bundles of axons and fascicles
What is endoneurium?
Layer of areolar CT that separates and electrically insulates each axon.
Sympathetic vs parasympathetic?
Sympathetic: Fight or flight
Parasympathetic: Rest and digest.
Directional terms of brain?
Rostral: toward nose
Caudal: Toward tail
What are the cranial meninges?
Dura mater: Strongest, 2 layers-dural venous sinuses and septa.
arachnoid mater: CSF, choroid plexus, arachnoid villi.
Pia Mater: Delicate, tight, vascular.
What are the 4 cranial dural septa?
Falx cerebri: Projects longitudinal fissure and separates left and right cerebral hemispheres.
Tentorium cerebelli: Separates cerebrum and cerebellum.
Falx cerebelli: separates right and left cerebellar hemispheres.
Diaphragma selae: between pituitary and hypothalamus.
