Nervous Tissue Flashcards
What is the function of neurons ?
metabolism
What is the structure of a neuron?
dendrites, soma, axon, telodendron
What are glial cells?
astrocytes
oligodendrocytes
microgliocytes
ependeymal cells
What are the two branches of the nervous system?
Central and peripheral nervous system
What are the two branches of the peripheral nervous system?
autonomic and somatic
What are the two branches of the autonomic system?
sympthaic and parasympathic
What are the two branches of the CNS
brain and spinal cord
What is grey matter?
parts of the CNS rich in cell bodies but limited numbers of myelinated axons
What is white matter?
region rich in myelinated axons
What are the components of the CNS?
ectodermal origin and mesodermal origin
What is the ectodermal origin of the CNS?
neurons
astrocytes
oligodendrocytes
What is the mesodermal origin of the CNS?
microglia
vascular endothelium
What is the structure of the neuron soma?
euchromatic nucleus with prominent nucleolus
basophillic cytoplasm
lipofuscin
How do dendrites receive stimuli?
at synapses
How do axons work?
transmit signals and terminate on other neurons, skeletal muscle, smooth muscle, cardiac muscle or glands
T or F: there are both inhibitory and excitatory neurons
True
T or F: types of neurons are named according to the number of dendrites neurons are ?
True
What is pseudounipolar?
unipolar dendrite
What is bipolar dendrite?
two
What is multipolar dendrite?
many
What is contained in the cell body?
soma and perikaryon
What is Nissi substance?
Rough Endoplasmic Reticulum
What are the 3 parts of each nerve synapse?
presynaptic part=terminaton axon=Bouton terminaux
inter synaptic cleft
postsynaptic part
T or F: Acetylcholine is released by somatic neurons into synaptic cleft and stimulate muscle contraction
True
T or F: stimulatory synapse contain acetylcholine?
True
T or F: inhibitory synapse contain GABA?
True
What are naked nerve endings?
nociceptors for pain
termoreceptors for temp
What are common encapsulated nerve endings?
mechanoreceptors for touch and pressure
What are meissners corpuscle?
sense touch
What is pacinian corpuscle? Where are they found?
senses pressure
skin, pancreas of cats
bulbs of horse heels
tendons
Where is the golgi organ located?
insertion of skeletal muscle fibers into the tendons
What is a muscle spindle?
a specialized sensory receptor for muscle stretch and position sense
What are astrocytes?
CNS counterpart of the fibroblasts
What are the two types of astrocytes?
protoplasmic ( grey matter)
fibrillar ( white matter )
What is the function of astrocytes?
transport of nutrients maintenance of extracellular matrix neurotransmitter uptake antigen presentation part of blood/brain barrier
What are oligodendrocytes?
small dark nuclei
develop and maintain myelin in CNS
can be destroyed by viruses/toxins
T or F: oligodendrocytes form myelin in CNS?
True
T or F: when activated microgila during inflammation they are called Glitter cells?
True
What are microglia?
resistant macrophages of CNS
mesodermal origin
phagocytic/antigen presentation
What are ependymal cells?
- ciliated cubodal cells lining neural canal, ventricles, chrorid plexus
- line the central canal of the spinal cord
How is myelin synthesized?
oligodendrocytes and Schwann cells
T or F: oligos connect to multiple internodes, Schwann cells one?
True
What is myelin made up of?
75% lipid, 25% protein
What is the function of myelin?
conduction
speed of impulses
What is the difference between white and grey matter?
- white matter contains myelinated axons and and glial cells
- white matter is peripheral in spinal cord, central in brain
- grey contains neurons, glial cells and axons
- grey matter position is peripheral in brain, central in spinal cord
What is the hippocampus?
portion of the brain involved with laying down memory tracks
contains numerous glutamate receptors
What is the function of the cerebellum?
coordination of body movements
What are the three layers of the cerbellar cortex?
molecular layer
purkinje cell layer
granular cell layer
What does the brain stem contain?
collections of neurons known as nuclei
What are the regions of the brain stem?
medulla oblongate, pons
thalamus
hypothalamus
What is the spinal cord organization?
grey and white matter
central canal
meninges
dorsal and ventral roots
T or F: Neurons in spinal cord are present in gray matter only?
True
What are multipolar motor neurons?
in ventral horns, their long axons leave spinal cord as ventral roots
innervate skeletal muscle
What are funicular neurons?
in dorsal horns, axons go in dorsal funicles to brain
What is autonomic neurons?
small nerve cell bodies in lateral horns
What are meninges?
membranous coverings of brain and spinal cord
What is pachymeninx?
dura matter of meninges
What is leptomeninx?
pia mater of meninges
What is the subarachnoid space?
contains CSF
What is cerebrospinal fluid?
transudate, formed by capillaries and ependymal cells
nourishes CNS tissue, acts as cushion
What is the choroid plexus?
a cluster of arborizing blood vessels covered by a thin connective tissue
site of CSF production
located in ventricles
What is the somatic system?
sensory fibers bring information to CNS
motor fibers innervate skeletal muscle
What are the autonomic system?
effectors are smooth muscle, cardiac muscle, glands
What are ganglia?
collections of neuronal cell bodies and processes found outside of CNS
How is a signal sent from autonomic nervous system?
impulse begins in brain stem or spinal cord two neuron chain activates the effector first neuron is in CNS ANS neuron is ganglion targets are effectors CM, SM, Glands
What is the myenteric plexus?
between inner and outer layers of tunica muscularis
helps control movement of GI tract
