Lec 18 (The Nervous System) Flashcards
1
Q
Major subdivisions of the nervous system
A
Central Nervous System(CNS)
Peripheral Nervous System(PNS)
2
Q
It’s a complex grouping of organs that are composed of nervous tissues
A
The Nervous System
3
Q
Composed of the brain and the spinal cord
A
Central Nervous System(CNS)
4
Q
Composed of the nerve trunks (cranial and spinal nerves), ganglia
and nerve endings
A
Peripheral Nervous System(PNS)
5
Q
The PNS may be divided on anatomical basis into what?
A
somatic nervous system and autonomic nervous system
6
Q
It includes nerve trunks and nerve endings that
carry impulses from external environment to the CNS and subsequently carry information back to skeletal muscles
A
somatic nervous system
7
Q
It functions in the same matter as somatic nervous system however the effectors are the internal and/or visceral organs
A
autonomic nervous system
8
Q
Group of nerve cell bodies outside the CNS
A
Ganglia
9
Q
Corresponding groups of ganglia in the CNS
A
nuclei
10
Q
Types of ganglia
A
Craniospinal Ganglia(sensory ganglia)
Autonomics Ganglia(motor ganglia)
11
Q
It includes the dorsal root ganglia of the spinal nerves and the cranial ganglia of the cranial nerves
A
Craniospinal Ganglia(sensory ganglia)
12
Q
Other term for Craniospinal Ganglia
A
sensory ganglia
13
Q
representative of the craniospinal ganglia
A
dorsal root ganglia
14
Q
predominant neuron of craniospinal ganglia
A
pseudo-unipolar type
15
Q
Components of the Peripheral Nervous System
A
Ganglia
Nerve Trunks
Afferent Nerve Endings
16
Q
Each neuron of craniospinal ganglia surrounded by what?
A
amphicytes
17
Q
The predominant neuron is the pseudo-unipolar type. Each neuron is surrounded by amphicytes. These cuboidal cells are in such intimate contact with the perikaryon that an indentation in the nerve cell body is often apparent. These cells are continuous
with the neurolemmal sheath of the nerve fibers. Nerve fibers, usually in distinct fascicles, comprise the
remainder of the ganglion.
A
Craniospinal Ganglia(sensory ganglia)
18
Q
include the parvertebral and prevertebral ganglia of the
sympathetic nervous system and the terminal ganglia of the parasympathetic nervous system
A
Autonomics Ganglia(motor ganglia)
19
Q
Other term for motor ganglia
A
Autonomics Ganglia
20
Q
What are ganglias within the walls of the organs
A
intramural ganglia
21
Q
The sympathetic ganglia and the neurons associated with them are smaller than the dorsal root ganglion. The former consists mainly of multipolar neurons. Parasympathetic ganglia away
from the visceral organs are similar to the sympathetic ganglia. The intramural ganglia, however consist of a few multipolar nerve cell bodies and fibers. In most cases, amphicytes are absent.
A
Autonomics Ganglia(motor ganglia)
22
Q
They are organized following the basic pattern described for the organization of solid organs
A
Nerve Trunks
23
Q
The nerve trunks consists mainly of __________
which are invested with connective tissue elements.
A
bundles (fascicles) or nerve fibers (axons)
24
Q
outermost covering of the peripheral nerve trunks
A
epineurium
25
When numerous fascicles from a
nerve trunk, each fascicle is invested with a delicate investment of connective tissue which is
continuous with the epineurium, and is also called the __________.
perineurium
26
investment of cells that are subjacent to the perineurium, which may vary from one to 3 layers thick
perineural cells
27
refers to the dendrites or dendritic zones of afferent neurons
Afferent Nerve Endings
28
are receptor organs for various types of sensations such as pain, touch, warmth, pressure, etc.
Afferent Nerve Endings
29
classified as free, diffuse and encapsulated nerve endings
Afferent Nerve Endings
30
are the most ubiquitous of the afferent nerve endings. Most
numerous in the epidermis but can also be found in the mucous and serous membranes, muscles, joints and the visceral connective tissue
Free and diffuse nerve endings
31
modified free nerve endings associated with deep epidermal cells. They generally occur in hairless skin. They are associated with tactile stimulation.
Merkel’s disks
32
present slightly to heavy encapsulated.
Encapsulated Receptors
33
one of the most ubiquitous encapsulated receptors. They occur in the dermal papillae of the soles and palms.
Meissner’s corpuscles
34
They appear like fir cone. They are slightly encapsulated and contain terminals of one or more nerves arranged in a helical order around a mass of cells similarly arranged.
Meissner’s corpuscles
35
They are receptors for tactile discrimination. Merkel’s disks may be rudimentary forms of this corpuscle.
Meissner’s corpuscles
36
are slightly encapsulated, onion-shaped receptors located in the skin and
associated mucous membranes (especially the conjunctiva). They are cold receptors.
Krause’s end bulbs
37
are similar to Meissner’s corpuscles but smaller and more thickly
encapsulated. They are considered pressure receptors
Golgi-Mazzoni corpuscles
38
They are found in the connective tissue of hairless skin and associated mucous membranes. They also occur in the dermis of the glans penis, the digital pads of carnivores and the connective tissue of the hoof.
Golgi-Mazzoni corpuscles
39
similar to Golgi-Mazzoni corpuscles but are larger and more thickly
encapsulated. They may be lobulated.
Genital Corpuscles
40
They are found in the clitoris and glans penis. They are considered pressure receptors.
Genital Corpuscles
41
are the largest encapsulated nerve endings of the body. They are
characterized by concentric layers of epithelial cells. Connective tissue cells, and capillaries surrounding
a single nerve which enters the corpuscle and terminates in a bulbous enlargement.
Vater- Pacinian corpuscles
42
They occur in the deep connective tissue, mesenteries and serous membranes as well as the connective tissue of visceral
organs, muscle and are associated with tendons and ligaments. They are pressure receptors.
Vater- Pacinian corpuscles
44
smaller version of Pacinian corpuscles that occur in tongues and beaks of birds. They are also pressure receptors.
Herb’s corpuscles
45
Components of the Central Nervous System
Meninges
Choroid Plexus
Cerebrospinal fluid
Spinal cord
Cerebellum
Cerebrum
46
Enumerate Encapsulated Receptors
Meissner’s corpuscles
Krause’s end bulbs
Golgi-Mazzoni corpuscles
Genital Corpuscles
Vater- Pacinian corpuscles
Herb’s corpuscles
Ruffini corpuscles
Neuromuscular spindles
Golgi tendon organs
47
are the fibrous membrane enclosing the CNS
Meninges
48
Meninges consists of 3 layers, namely:
Dura mater
Arachnoid
Pia mater
49
a tough dense white fibrous connective tissue covering the brain and the spinal cord
Dura mater
50
In the brain, it consists of two layers; the outer layer which is the fibrous periosteum of the inner surface of the cranial bones and the inner layer, a poorly vascularized layer which blends with the outer layer.
Dura mater
51
The dura is separated from
the arachnoid by a what?
subdural space
52
The dura of the spinal cord has only one layer (corresponding the
inner layer of the cranial dura) and is separated from the periosteum of the vertebrae by the ____________.
epidural space
53
used for administration of epidural anesthesia
epidural space
54
consists of a distinct membrane and numerous fibrous trabeculae on its inner surface
Arachnoid
55
This space is filled with CSF that mechanically protect the CNS.
subarachnoid space
56
is the most intimate protective membrane of the brain and spinal cord.
Pia mater
57
It extend into the
depressions and tissues of the CNS. It is composed of very fine collagenous and elastic fibers as well as small vessels. It is covered by a mesothelial-like epithelium.
Pia mater
58
What is the vascular network of the pia mater
Choroid Plexus
59
is a clear, colorless fluid which fills the ventricular system and the central canal of the spinal cord
Cerebrospinal fluid
60
are composed of an arborization of nerve fibers intercalating throughout a granular mass enclosed by a connective tissue capsule. They are considered heat receptors.
Ruffini corpuscles
61
It is produced mainly by the choroid plexuses
of the lateral, third and fourth ventricles of the brain. It is produced as an ultrafiltrate or dialysate of the
blood and by active secretion of the ependymal cells.
Cerebrospinal fluid
62
Its primary function is the hydraulic cushioning of the CNS
Cerebrospinal fluid
63
functions in the nutrition of the nervous tissue by being a transport medium of metabolites
Cerebrospinal fluid
64
Is the slender portion of the neural tube
Spinal cord
65
In cross-section it has a generally round to oval form
Spinal cord
66
The bulk of the spinal cord is divided into two distinct area namely:
Gray matter
White matter
67
arranged in an H or butterfly pattern
Gray matter (sc)
68
consists of the nerve cell bodies, unmyelinated nerve
fibers, some myelinated nerve fibers, protoplasmic astrocytes, oligodendrocytes, microgliocytes, some blood vessels and fine connective tissue fibers
gray matter (sc)
69
is composed of myelinated nerve fibers and some unmyelinated nerve fibers, neuroglial cells and blood vessels.
White matter (sc)
70
Its region between the dorsal gray columns is called the dorsal
funiculus: the portion between two adjacent dorsal and ventral columns is the lateral funiculus; and the portion between the two ventral gray columns is the ventral funiculus.
White matter (sc)
71
consists of an inner white matter and an outer gray matter
Cerebellum
72
the gray matter or cortex presents 3 distinct zones, namely:
Outer molecular layer
Middle Purkinje cell layer
Inner granular layer
73
has small neurons and numerous unmyelinated nerve fibers
Outer molecular layer
74
consists of pyramidal Purkinje cells which are not to be confused
with Purkinje fibers of the heart
Middle Purkinje cell layer
75
composed of small, tightly packed neurons
Inner granular layer
76
consists of myelinated nerve fibers. It is contiguous with the inner granular layer of the gray matter (cerebellar cortex).
White matter
77
consists of an outer gray matter (cerebral cortex) and an inner white matter (cerebral medulla).
Cerebrum
78
The cerebral cortex exhibits 6 layers, namely:
Molecular layer
outer granular layer
outer pyramidal cell layer
inner granular layer
inner pyramidal cell layer
Polymorphic cell laye
79
the most superficial layer. It contains chiefly unmyelinated nerve fibers and a few neurons
Molecular layer
80
contains many small neurons which give it a granular appearance
outer granular layer
81
contains pyramidal shaped neurons
outer pyramidal cell layer
82
contains small neurons
inner granular layer
83
contains pyramidal cells
inner pyramidal cell layer
84
In the motor area of the cortex, the
pyramidal cells are large and are called _______.
Betz cells
85
formed by the efferent or motor neurons of the central and peripheral nervous systems concerned with the regulation of visceral activities
The Autonomic Nervous System
86
four types of effector systems
a. Smooth muscle (intestines, urinary bladder, blood vessels)
b. Cardiac muscle
c. Exocrine glands (salivary, sweat, sebaceous)
d. Some endocrine glands (adrenal medulla)
87
integration center of the autonomic nervous system
hypothalamus
88
influences metabolic centers in the midbrain, pons and medulla
hypothalamus
89
Efferent fibers
originating from these centers as well as from the spinal cord carry general motor impulses to the
visceral effectors and are referred to as __________________.
general visceral efferent (GVE) nerves
90
nerves carrying generalized sensory information from the viscera to the brain and spinal cord
general visceral afferent (GVA) nerves
91
In the Sympathetic division the cell bodies of the preganglionic neurons are located in the intermediate gray column of the thoracolumbar spinal cord. For this reason the sympathetic division is
referred to as what?
thoracolumbar system
92
Divisions of the Autonomic Nervous System
1. Sympathetic Nervous System
2. Parasympathetic Nervous System
93
In the parasympathetic division, the cell bodies of the preganglionic neurons are located in the brainstem in nuclei of cranial nerves III, VII, IX, X and XI and in the sacral segments of the spinal cord.
This system is therefore called what?
craniosacral syste
94
designed to function spontaneously or independently of the conscious will
autonomic nervous system
95
In a typical autonomic reflex, the following conditions occur:
1. afferent impulses (GVA) reach the dorsal root and enter the dorsal gray column.
2. a synapse occurs with a neuron (preganglionic neuron) located in the intermediate gray column.
3. this axon courses out of the spinal cord and synapses with a second neuron (postganglionic neuron)
which is located in a ganglion.
4. these GVE impulses are transmitted over postganglionic fibers (axons) to the visceral effectors.
96
basahin niyo nalang
The myelinated axons of preganglionic neurons always synapse with a seconf neuron which is
located outside the central nervous system. The cell bodies of the neurons (postganglionic) may be located in the vertebral (paravertebral), prevertebral (collateral) or terminal (peripheral) ganglia. The
unmyelinated axons of postganglionic neurons terminate on visceral effectors.
97
The sympathetic division has short preganglionic and long postganglionic nerve fibers. The
synapse between the pre- and postganglionic neurons occurs some distance away from the effectors innervated. The pattern of distribution follows that of the arteries. In the cervical region, the
sympathetic trunk is enclosed within a common sheath with the vagus nerve, forming the
vagosympathetic trunk.
Pattern of Distribution of Pre- and postganglionic nerve fibers in the sympathetic divisions.
98
The autonomic reflex always consists of at least three neurons:
a. an afferent neuron
b. a preganglionic neuron
c. a postganglionic neuron
99
The parasympathetic division has long preganglionic and short postganglionic nerve fibers. The
synapse between the pre- and postganglionic neurons generally occur within the walls of the organs
innervated. They are referred to as intramural ganglia.
Most of the visceral organs of the body have a dual innervation, and the functional influence of
the sympathetic and parasympathetic innervation, upon these organs has been described as
antagonistic. There are exceptions however. Both divisions seem to stimulate salivary and pancreatic
secretions.
Pattern of Distribution of Pre- and Postganglionic nerve fibers in the Parasympathetic divisions.
100
unique organ that is innervated by preganglionic sympathetic nerve
adrenal medulla
101
These cells secrete
epinephrine and norepinephrine.
chromaffin cells
102
responsible for the “fight or flight” reaction
Epinephrine
103
It is a reaction that prepares the animal for stressful circumstances that threaten its physical well being and or homeostasis.
“fight or flight” reaction
104
The Degeneration and Regeneration of Peripheral nerves
First degree injuries
Second degree injuries
105
These are common and are generally caused by pressure being applied to a nerve at a particular site for a limited time.
First degree injuries
106
After pressure is released, recovery of sensation or motor
function may occur in a matter of minutes, hours or weeks, depending on the severity of the injury.
First degree injuries
107
These are generally caused by prolonged and or severe pressure being exerted on some part of the nerve enough to destroy the axon at the point where it is subjected to pressure
Second degree injuries
108
degeneration of the axon and its myelin sheath
Wallerian
degeneration
109
T or F
functional regeneration within the CNS occurs
False
Importantly, functional regeneration within the CNS probably does not occur.
110
T or F
The regeneration of nerve fibers within the CNS occurs at a much slower rate than within the
PNS.
Truuuu
111
occupies the subarachnoid space
Cerebrospinal fluid
