CNS Exam 1 Flashcards
The nervous system plays the dominant role in ____,____, and ____ of body responses to internal and external demand.
coordination, association, and integration
Of all body systems, the ___ reigns supreme
CNS
Mature nervous tissue has ___ capacity to store ___ or ____(glucose) and it maintains little ____ capacity.
little capacity to store oxygen or sugar and it maintains little mitotic capacity
Every cell or tissue of our body is indirectly/directly “wired” into the nervous system
Directly
modern term for studies of the nervous system
neuroscience
study of structure
neuroanatomy
The nervous system is divided by structure or anatomically divided into 2 divisions. What are those divisions?
CNS and PNS
The CNS/PNS is entirely surrounded by bone
CNS
The CNS consists of
Brain (encephalon) Spinal cord (medulla spinalis)
The PNS consists of
12 cranial nerve pairs
31 spinal nerve pairs
totaling 86 nerve trunks
ganglia- groups of neuron cell bodies clustered together in the PNS
groups of neuron cell bodies clustered together in the PNS
ganglia
The Nervous system is divided by function. This is divided into what subdivisions?
Autonomic and Somatic
Part of the nervous system that innervates the skeletal musculature
Somatic N.S.
“voluntary component” is a frequently used synonym
Somatic N.S.
Includes both efferent (motor/outgoing) and afferent (incoming/sensory) nerve fibers, even though the efferent or motor oriented fibers receive the most emphasis
Somatic N.S.
Involves both the CNS and PNS
Somatic N.S. and Autonomic N.S.
This chemical is released in the Somatic N.S. and appears to be excitatory
acetylcholine (cholinergic)
The Autonomic (visceral) component of the N.S. has three subdivisions. Those divisions are?
Parasympathetic, sympathetic, and enteric systems
This is part of the N.S. that innervates the glandular epithelium, smooth, and cardiac musculature
Autonomic N.S.
No conscious control over which system
autonomic or involuntary N.S.
The efferent (motor) nerve fibers receive emphasis and are the only ones subdivide into parasympathetic and sympathetic subdivisions. This Schema will contain two efferent nerves.
Autonomic N.S.
subdivision of the visceral component of the N.S. (rest and digest
Parasympathetic
Neurons that are part of the parasympathetic subdivision are located in____.
both the CNS and PNS
The nerves(PNS) that carry efferent parasympathetic fibers are limited to:
cranial nerves III, VII,IX,X
Sacral Nerves 2,3,4
known as a Craniosacral subdivision
___ efferent neurons are utilized to reach the gland cell or muscle cell involved. The __(first) neuron is long and the ___ (second) neuron is short
2
preganglionic
postganglionic
Preganglionic and Post Ganglionic Parasympathetic Neurons release
Acetylcholine (said to be a cholinergic system)
subdivision of the visceral component of the N.S. (fight or flight)
sympathetic
Neurons that are part of the sympathetic subdivision are located in ___. But the nerves(PNS) that carry sympathetic efferent fibers are spinal nerves ___ through and including___.
CNS and PNS
T1-L2 and L3 (thoracolumbar)
__ neurons are utilized in reaching the gland cells or muscle cells involved. Generally the __ is short and the __ is longer
2
preganglionic neuron
postganglionic neuron
Preganglionic neurons release __ while postganlionic sympathetic neurons release __.
ACH
norepinephrine
The Sympathetic N.S. is said to be __. Exceptions where __ is released at the target are known: ___, and ___)
Adrenergic system
ACH
Sweat Glands and Arrector Pili Muscles
Parasympathetic __ heart rate/__ peristalsis,__ the pupil/ __ the respiratory tree. Pre-Post ganglionic neurons :
slows/speeds/constricts/constricts 1:2
Sympathetic __heart rate/___peristalsis,__ the pupil/__respiratory tree. Pre-Post ganglionic neurons_:_
speeds/decreases/dilates/dilates 1:17
___ response(pre-post ganglionic ratio) is limited but generally more precise
parasympathetic
In general, the ___ are more comprehensible. This is primarily due to their __ and, in many cases, exclusive influence on the body’s blood vessels
sympathetics
extensive
There is ___ N.S.
one
subdivision of the autonomic nervous system supplies the gut
enteric
runs along the gut wall from esophagus to anal verges. Best known of its actions are on ___ reflexes. At least a couple dozen neuromodulators and transmitters are involved
Enteric
Peristaltic
A fertilized egg
zygote
Half the number of chromosomes
Haploid
2 sets of chromosomes
Diploid
Week 1 (pre-embryonic stage) consists of
Morula, blastocyst, inner and outer cell mass
The nervous system is derived from which germ layer
ectoderm
Bilaminar disk is composed of
Ectoderm and endoderm
Week 2 of the embryology of the CNS consist of
bilaminar disc, primitive streak (node, pit, groove), mesoderm formation
The Neural Tube will form what in the CNS
spinal cord
Week 3 of the embryology of the CNS consists of
Notochord formation, induction of the nervous system, neural plate, neural crest and tube
the Neural crest and neural tube give rise to the 3 primary brain vesicles which are
prosencephalon (forebrain)
Mesencephalon ( midbrain)
Rhombencephalon (hindbrain)
two flexures(cervical and cephalic)
The Prosencephalon gives rise to what
Telencephalon and Diencephalon
(Ti De is a pro)
Week 4
The Mesencephalon gives rise to what
Mescencephalon
Week 4
The Rhombencephalon gives rise to what
metencephalon and myelencephalon
week 4
(pontine flexure)
The telencephalon gives rise to what
Cerebral cortex basal ganglia lateral ventricles (snoop dogs tells he's from L.B.C.) Week 5-6
The Diencephalon gives rise to what
Thalamus hypothalamus pineal gland 3rd ventricle Week 5-6
The mesencephalon gives rise to what
corpora quadrigemina cerebral peduncles cerebral aqueduct (of sylvius) (mes stays mes 3 c's) Weeks 5-6
The Metencephalon gives rise to what
cerebellum
pons
4th ventricle
weeks 5-6
the myelencephalon gives rise to what
medulla oblongata
4th ventricle
(continuous with the spinal cord)
Weeks 5-6
brain at birth is __% of body weight (300-400g)
uses __% of oxygen
10
60
Brain in adult is __% body weight (1100-1700g avg1400)
uses _% oxygen
2-2.5
20
from birth to one year old the brain will more than __ in size. (2-1/2 to 3 fold increase). Outer cranial circumference will change from an average of __cm to __cm. Neurons particularly in the __, are still being produced during this critical period.
double
34 to 46
cerebellum
by this week the embryo can respond to cutaneous stimuli
8th week
by this week the fetus is spontaneously active
10th week
by this week the fetus can grasp (this is a reflex)
12th week
Neural tube cells give rise to what
CNS structures
Neuroepithealial cells (primitive-multipotentials) give rise to what
neuroblasts–> neurons
Ependymal cells
Glioblasts (spongioblasts) –> astrocytes and oliogodendrocytes
“nerve glue”
Glioblast cells
still fairly undifferentiated cells. Can undergo mitosis (probably little division beyond 5 years of life). Give rise to astrocytes and oligodendrocytes.
Glioblast cells
are the functional connective tissue of the CNS. Some of these cells help guide neurons to their proper positions during early embryonic, fetal, and neonatal development.
Glioblasts and its derivatives
It is estimated that in total there are _ to __ as many glioblast derivatives as neurons in the adult human brain
five to ten times (astrocytes and oligodendrocytes)
Stellate Shape
Astrocytes
the most numerous cell of the adult CNS
Astrocytes
two types of Astrocytes
protoplasmic astrocytes and fibrous astrocytes
type of astrocyte that is found in the grey matter and is unmyelinated
protoplasmic astrocyte
type of astrocyte that is found in the white matter and is myelinated
fibrous astrocyte
Are rather ubiquitous structural support cells (a connective tissue-like function). Found sandwhiched between blood Bessel capillaries and neuron cell bodies. Said to be apart of the BBB. Suspected to store what little excess glucose can be held by the CNS tissue. Play a dominant role in forming “scar-like” tissue following CNS injury. Neurotransmitters (Glutamate, dopamine, serotonin) may be directly influenced at these synaptic gaps. Even ions such as K+ may be altered.
Astrocytes
Fewer in number than astrocytes but still quite numerous
oligodendrocytes
Two types of oligodendrocytes
Perineuronal satellites
Interfascicular
type of oligodendrocyte that has a nutrient role in the CNS and is found in the grey matter
Perineuronal satellites
type of oligodendrocyte that forms myelin around axons in the CNS and is found in the white matter
interfascicular
Main function is to form myelin sheaths around most CNS neuron axons
interfascicular
Main function are unclear but may serve a type of nutrient role in the CNS
Perineuronal