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Neuroglial cells
Glial cells, sometimes called neuroglia or simply glia, are
non-neuronal cells that maintain homeostasis, form myelin,
and provide support and protection for neurons in the brain
and peripheral nervous system.
TERM 2
Neuron
DEFINITION 2
Cells of the nerves that are structurally composed of a cell
body, dendrites, and an axon. They not only initiate nerve
impulses but they also conduct them
TERM 3
White matter
DEFINITION 3
Myelinated axons in the CNS
TERM 4
Gray matter
DEFINITION 4
The part of the CNS made up of neuron cell bodies
TERM 5
Myelin Sheath
DEFINITION 5
Cell membrane of glial cells (oligodendrocytes, Schwann
cells) wrapped around an axon; increases speed of impulse
conduction along the axon.
Oligodendrocytes
Glial cells in the brain and spinal cord whose cellular
membrane forms the myelin sheath for axons in the CNS
TERM 7
Schwann Cells
DEFINITION 7
Glial cells associated with the peripheral nerves whose
cellular membrane forms the myelin sheath for axons in the
PNS
TERM 8
Nodes of Ranvier
DEFINITION 8
Unmyelinated areas of the axon between two adjacent
Schwann cells that are involved in rapid conduction of nerve
impulses along the axon
TERM 9
Central Nervous System
DEFINITION 9
The central nervous system is the part of the nervous system
consisting of the brain and spinal cord.
TERM 10
Peripheral Nervous System
DEFINITION 10
Nerves outside of the CNS
Corpus Callosum
White fibers that connect and provide communication
pathways between the two cerebral hemispheres
TERM 17
Gyri
DEFINITION 17
The folds that provide the wrinkled appearance of the surface
of the cerebral hemisphere
TERM 18
Sulci
DEFINITION 18
Groove, especially shallow grooves in the cerebral cortex.
TERM 19
Longitudinal fissure
DEFINITION 19
Prominent groove that divides the cerebrum into right and
left cerbral hemspheres
TERM 20
Cerebral hemispheres
DEFINITION 20
The two halves of the cereburm
Cerebellum
Second largest component of the brain; allows the body to
have coordinated movement, balance, posture, and complex
reflexes.
TERM 22
Diencephalon
DEFINITION 22
Serves as a nervous system passageway between the
primitive brain stem and the cerebrum; three major
structures of the diencephalon include the thalamus, the
hypothalamus, and the pituitary.
TERM 23
Thalamus
DEFINITION 23
Part of the diencephalon that acts as a relay station for
regulating sensory impulses to the cerebrum.
TERM 24
Hypothalamus
DEFINITION 24
A portion of the diencephalon that has extensive links to the
brain and to the pituitary gland. It functions as an important
bridge between the nervous and endocrine systems.
TERM 25
Pituitary gland
DEFINITION 25
The master endocrine gland. A pea-sized endocrine gland
located at the base of the brain; made up of the anterior
pituitary gland, which produces seven known hormones, and
the posterior pituitary gland which stores and releases two
hormones from the hypothalamus also called the hypophysis.
Dura mater
The outermost layer of the meninges that covers the brain
and spinal cord; it is considered to be the toughest layer.
TERM 32
Pia mater
DEFINITION 32
Pia mater often referred to as simply the pia, is the delicate
innermost layer of the meninges, the membranes
surrounding the brain and spinal cord.
TERM 33
Arachnoid
DEFINITION 33
The arachnoid mater is the delicate web-like layer of the
three meninges between the dura mater and the pia mater,
the protective membranes that cover the brain and spinal
cord.
TERM 34
Cerebrospinal fluid
DEFINITION 34
Fluid that bathes and protects the brain and spinal cord from
the hard inner surface of the skull and spinal vertebrae.
TERM 35
Blood brain barrier
DEFINITION 35
The functional barrier between the capillaries in the brain
and the nervous tissue; anatomically composed of capillary
walls without the openings found in other capillaries and glial
cells.
12 Cranial Nerves
Cranial nerves, are nerves that emerge directly from the brain and
the brainstem, in contrast to spinal nerves (which emerge from
various segments of the spinal cord).Olfactory I Facial VII Optic II
Auditory (vestibulocochlear) VIIIOculomotor III Glossopharyngeal
IXTrochlear IV Vagus XTrigeminal V Spinal Accessory XIAbducens
VI Hypoglossal XII
TERM 37
Ganglion
DEFINITION 37
Cluster of neuron cell bodies outside of the CNS
TERM 38
Somatic reflexes
DEFINITION 38
A reflex resulting in the stimulation or inhibition of skeletal
muscle contraction
TERM 39
Autonomic reflexes
DEFINITION 39
A reflex that results in stimulation or inhibition of smooth or
cardiac muscle or endocrine gland function; mechanisms of
homeostasis are autonomic reflexes.
TERM 40
Stretch reflex
DEFINITION 40
The stretch reflex is a muscle contraction in response to
stretching within the muscle.
Pupillary Light Reflex
The pupillary light reflex is a reflex that controls the diameter
of the pupil, in response to the intensity (luminance) of light
that falls on the retina of the pupil and the eye, thereby
assisting in adaptation to various levels of
lightness/darkness.
TERM 47
Corneal reflex
DEFINITION 47
The corneal reflex, also known as the blink reflex, is an
involuntary blinking of the eyelids elicited by stimulation of
the cornea, or bright light, though could result from any
peripheral stimulus.
TERM 48
How are the functions of neurons and
neuroglia different from each other?
DEFINITION 48
Neurons are the basic functional units of the nervous system. That is,
they are the smallest pieces of the system that show basic nervous
system functions such as responding to stimuli and conducting impulses
from one part of the cell to another. The neuroglia, or glial cells (from the
Greek glia, meaning "glue"), structurally and functionally support and
protect the neurons. They outnumber neurons about 10 to 1, but they
are not directly involved in the transmission of information or impulses
through the nervous system. Rather, they are important parts of the
infrastructure necessary for the neurons to do their jobs.
TERM 49
Name the parts of a typical neuron.
DEFINITION 49
Dendrite, axon, and cell body
TERM 50
How are the dendrites and axons different in
structure and function?
DEFINITION 50
Dendrites receive stimuli, or impulses, from other neurons and conduct this stimulation to the cell body. Dendrites also may be modified into sensory receptors that receive, or sense, stimuli such as heat, cold, touch, pressure, stretch, or other physical changes from inside or outside the body. Dendrites tend to be short, numerous, multibranched projections extending from the cell body. The axon conducts nerve impulses away from the cell body toward another neuron or an effector cell (a cell that does something when stimulated, such as a muscle or gland cell). In contrast to the short, numerous, branched dendrites, the axon is a single structure that can be very long. For example, a single axon in the horse may extend several feet from the spinal cord all the way to the lower leg. Axons are often covered by a fatty substance called myelin.
What is the difference between gray matter
and white matter?
White matter refers to nervous tissue containing many
myelinated axons. Conversely, nervous tissue that is made
up largely of neuron cell bodies, which are not myelinated,
appears darker and is called gray matter.
TERM 52
What is the relationship between the myelin
sheath and the nodes of Ranvier?
DEFINITION 52
Nodes of Ranvier are small gaps in the myelin sheaths. The
nodesof Ranvier and the myelin work together to enhance
the conduction ofstimuli.
TERM 53
What are the anatomic differences between
the CNS and the PNS?
DEFINITION 53
The central nervous system (CNS) is anatomically composed of the
brain and spinal cord, which are found associated within the
central axis of the animals body. Peripheral means to the side or
away from the center; therefore the peripheral nervous system
(PNS) is made up of those components of the nervous system that
extend away from the central axis outward toward the periphery
of the body.
TERM 54
Which are afferent nerves: motor nerves or
sensory nerves? Which are efferent?
DEFINITION 54
Motor nerves are efferent and sensory nerves are afferent.
TERM 55
Identify each of the following as being
controlled by the autonomic or the somatic
nervous system and as being either sensory
or motor:
DEFINITION 55
Conscious movement of the forelimb: somatic, motor Slowing of
the heart rate in response to an increased blood pressure:
autonomic; sensory for sensing the increased blood pressure and
motor for slowing the heart rate Constriction of blood vessels in
the skin in response to cold temperatures: autonomic; sensory for
sensing the cold temperatures and motor for constricting the
vessels Perception of pain from an injection of antibiotics: somatic,
sensory Perception of the amount of acidity present in the
duodenum: autonomic, sensory
What role do the synaptic cleft, presynaptic
neuron, neurotransmitter, and postsynaptic
neuron play in the continuation of a
depolarization wave from one nerve to
another?
The synapse is the junction between two neurons or a neuron and
a target cell. The synapse consists of a physical gap between the
two cells called the synaptic cleft. The neuron bringing the
depolarization wave to the synapse and releasing the chemical to
stimulate the next cell is called the presynaptic neuron. The
chemical released by the presynaptic neuron is called the
neurotransmitter, and the neuron that contains the receptors that
receive the neurotransmitter is the postsynaptic neuron. In this
way, depolarization continues from one cell to the next.
TERM 62
What is the functional relationship between a
neurotransmitter and a receptor? Will any
neurotransmitter stimulate any receptor?
DEFINITION 62
The neurotransmitter molecules released by the synaptic knob
bind with receptors and trigger a change in the postsynaptic cell.
However, the postsynaptic membrane receptors are very specific
about which neurotransmitters they will bind. If the
neurotransmitter and receptorare not matched, they will not bind
to each other, and no change will be triggered in the postsynaptic
cell. Thus synaptic transmission is only effective if receptors to the
neurotransmitter exist on the postsynaptic cell's membrane.
TERM 63
What is the difference between an excitatory
and an inhibitory neurotransmitter?
DEFINITION 63
Excitatory neurotransmitters have an excitatory effect on the postsynapticmembrane when they combine with their specific receptors. Specifically,excitatory neurotransmitters usually cause an influx of sodium so that thepostsynaptic membrane moves toward threshold. If the postsynapticmembrane is stimulated sufficiently by enough excitatory neurotransmitters,then threshold will be attained and depolarization of the postsynapticmembrane will occur.In contrast, inhibitory neurotransmitters tend to hyperpolarize thepostsynaptic membrane, making the inside of the cell more negative instead ofpositive and moving the charge within the postsynaptic cell farther away fromthreshold. When inhibitory neurotransmitters combine with their specificreceptors on the postsynaptic side, they may cause chloride channels orpotassium channels to open up on the postsynaptic membrane. This allowsthe negatively charged chloride ions (Cl-) to enter the postsynaptic cell andpotassium (K) ions to leave the cell, making the inside of the cell morenegatively charged (a change in charge that is opposite from that needed toreach threshold). TERM 64
How is acetylcholine different from
acetylcholinesterase?
DEFINITION 64
Acetylcholine is a neurotransmitter broken down quickly by
an enzyme called acetylcholinesterase found on the
postsynaptic membrane. The broken down components of
acetylcholine are reabsorbed by the synaptic knob,
reassembled into new acetylcholine molecules, and
repackaged into vesicles for release with the next wave of
depolarization.
TERM 65
What are
catecholamines?
DEFINITION 65
Catecholamines are the neurotransmitters norepinephrine,
epinephrine, and dopamine.
What are GABA and glycine?
Gamma-aminobutyric acid (GABA) and glycine are inhibitory
neurotransmitters. GABA is found in the brain, and glycine is
found in the spinal cord.
TERM 67
What part of the brain is responsible for
conscious thought and perception of
sensations?
DEFINITION 67
Cerebrum
TERM 68
What are the correct names for the bumps
and fissures that make the cerebral cortex
appear wrinkled?
DEFINITION 68
The folds, called gyri (plural of gyrus), are separated by deep
grooves called fissures and more shallow grooves called sulci
(plural of sulcus). The most prominent groove is the
longitudinal fissure, which divides the cerebrum into right
and left cerebral hemispheres.
TERM 69
What part of the brain is critical for
coordination, posture, and fine motor control?
How does this part of the brain accomplish
these responsibilities?
DEFINITION 69
Cerebellum. The cerebellum compares the movement the
body intends to do with the actual position of muscles and
joints to determine if the intentions of the cerebral cortex are
actually being carried out. If the movements are not being
carried out accurately, the cerebellum will stimulate or inhibit
muscles to fine-tune the movements.
TERM 70
What part of the brain serves as a relay
station for impulses going to and from the
cerebrum?
DEFINITION 70
Diencephalon
Which part of the autonomic nervous system
is responsible for "fight or flight" and which is
responsible for "rest and restore?"
The sympathetic nervous system is responsible for the fight
or flight system and the parasympathetic nervous system is
responsible for the rest and restore system.
TERM 77
Compare and contrast the sympathetic and
parasympathetic nervous systems as far as
their preganglionic neurons; their
postganglionic neurons; where the
preganglionic neurons emerge from the CNS;
their neurotransmitters; and their impact on
the heart, GI tract, blood vessels, bronchiole
diameters, and size of the pupil.
DEFINITION 77
The sympathetic nervous system emerges from the thoracolumbar area. The parasympathetic system emerges from the brain and the sacral vertebral regions and therefore is called the cranial-sacral system. Outside the thoracolumbar area of the spinal column are a series of autonomic ganglia (many ganglion) that form a chain called the sympathetic ganglion chain. The sympathetic preganglionic neuron extends out from the spinal cord and either synapses with a neuron within the ganglion chain or passes through the ganglionic chain and synapses with a neuron located beyond the sympathetic chain. Each sympathetic preganglionic neuron usually synapses with many postganglionic neurons in a wide variety of locations in the sympathetic chain or in ganglions outside the sympathetic chain. The sympathetic postganglionic neuron extends the remaining distance to the target organ. The parasympathetic preganglionic neuron travels directly from the CNS to its target organ, where it synapses with a short postganglionic neuron in the target organ. Thus the parasympathetic preganglionic neuron is relatively long compared with the very short postganglionic neuron. The sympathetic nervous system primarily uses norepinephrine as its key neurotransmitter. The neurons associated with the parasympathetic nervous system secrete acetylcholine as their neurotransmitter.Heart rate: increased by sympathetic and decreased by parasympathetic systemForce of heart contraction: increased by sympathetic, no significant effect from the parasympathetic systemDiameter of bronchioles: increased (dilated) by sympathetic and decreased (constricted) by parasympathetic systemDiameter of pupil: increased (dilated) by sympathetic and decreased (constricted) by parasympathetic systemGastrointestinal motility, secretions, and blood flow: decreased by sympathetic and increased by parasympathetic systemDiameter of skin blood vessels: decreased by sympathetic, no significant effect from parasympathetic systemDiameter of muscle blood vessels: Increased by sympathethic, no significant effect from parasympathetic systemDiameter of blood vessels to kidney: Decreased by sympathetic, no significant effect from parasympathetic system
TERM 78
With which branch of the autonomic nervous
system are the alpha1-, beta1-, and beta2-
receptors associated? What happens to the
body when these particular receptors are
stimulated?
DEFINITION 78
Sympathetic nervous system. Alpha1- adrenergic receptors
typically are found on blood vessels and cause the
vasoconstriction of the skin, GI tract, and kidney associated with
sympathetic stimulation. The increase in heart rate and force of
contraction are the result of stimulation of beta1-adrenergic
receptors by catecholamines, and the bronchodilation associated
with sympathetic stimulation results from beta2-adrenergic
receptor stimulation.
TERM 79
With which branch of the autonomic nervous
system are muscarinic and nicotinic receptors
associated?
DEFINITION 79
Nicotinic acetylcholine receptors are found primarily on the
postganglionic neurons of both the sympathetic and
parasympathetic nervous systems. Muscarinic cholinergic
receptors are found on the target organs and tissues
supplied by the postganglionic neuron of the
parasympathetic nervous system.
TERM 80
What are the differences between an
autonomic reflex and a somatic reflex?
DEFINITION 80
Somatic reflexes involve contraction of skeletal muscles.
Autonomic reflexes regulate smooth muscle, cardiac muscle,
and endocrine glands.
What role do the sensory receptor, sensory
neuron, interneuron, and motor neuron play
in the reflex arc?
A sensory receptor detects a change either in the external environment
or within the body itself. Once stimulated to threshold, the sensory
receptor sends an action potential (nerve impulse) along the sensory
neuron to the gray matter of the spinal cord or brain stem. In the CNS
gray matter, the sensory neuron synapses with other interneurons, which
serve to integrate the incoming sensory impulse with other impulses
from other sensory neurons. Finally, the integrated response of the reflex
is sent out from the spinal cord or brain stem by the motor neuron, which
ends at the target organ (muscle or endocrine gland).
TERM 82
What is the sensory receptor in the stretch
reflex? What results from the stretch reflex
arc stimulation? Is this an ipsilateral or
contralateral reflex?
DEFINITION 82
A specialized structure within the muscle called the muscle
spindle. Muscle contraction results. Ipsilateral.
TERM 83
What happens in a withdrawal reflex? Is this
reflex more or less complex than the stretch
reflex?
DEFINITION 83
A strong stimulus to a receptor causes the sensory somatic neuron
to send impulses to the spinal cord. This reflex involves synapsing
with several interneurons. Some of these interneurons will
synapse with motor neurons that will cause contraction of a
specific set of muscles responsible for pulling the limb away from
the painful stimulus. Other interneurons will inhibit those opposing
muscle groups so that the withdrawal of the limb is rapid and
complete. This reflex is more complex than a stretch reflex.
TERM 84
How is the crossed extensor reflex tied in with
the withdrawal reflex? Is the crossed extensor
reflex an ipsilateral or contralateral reflex?
DEFINITION 84
When the withdrawal reflex arc is stimulated, the afferent somatic
sensory neuron also synapses with another set of interneurons,
causing extensor muscles in the opposite leg to contract and thus
support the weight of your body when the other leg flexes. Thus
the withdrawal and crossed extensor reflexes are related. The
crossed extensor reflex is a contralateral reflex.
TERM 85
What is the role of the upper CNS on the
reflex arc? If the CNS influence is removed or
blocked, do reflexes become hyporeflexive or
hyperreflexive?
DEFINITION 85
The upper CNS normally produces a dampening or inhibitory
effect on the reflex arc. If it is removed, the reflex becomes
hyperreflexive.
Which of the following is an indication for an
abdominal exploratory surgery? a. routine
ovariohysterectomy b. splenic tumor c.
ruptured bladder d. all of the above e. both b
& c
Both b & c
TERM 92
Which of the following retractors is commonly
used in abdominal exploratory surgeries? a.
Gelpi b. Senn c. Weitlaner d. Balfour e. none
of the above
DEFINITION 92
d. Balfour
TERM 93
Which of the following procedures involves
making an incision into the stomach? a.
abdominal exploratory b. gastrotomy c.
enterotomy d. splenectomy e. laparotomy
DEFINITION 93
b. Gastrotomy
TERM 94
Which intestinal surgey involves removing a
piece of the intestine and suturing the ends of
the remaining intestines back together?
DEFINITION 94
Resection and anastomosis
TERM 95
True or False: Sterile saline can be injected
into the surgical site to check for any leakage
after the anastomosis site has been closed.
DEFINITION 95
True
Which procedure involves surgically attaching
the stomach to the body wall?
Gastropexy
TERM 97
True or False: A gastropexy procedure
prevents future bloat occurrences.
DEFINITION 97
False, a gastropexy only prevents the stomach from twisting
on itself, but the stomach can still bloat.
TERM 98
True or False: A patient that needs to have an
abdominal exploratory for internal
hemorrhage resulting after having been hit by
a car (HBC), should have his/her bladder
expressed before being moved into sx.
DEFINITION 98
False
TERM 99
What are the signs and symptoms of
peritonitis?
DEFINITION 99
Abdominal pain, manifesting as a reluctance to move
due to inflammation of the parietal peritoneum.
Depression, anorexia and lethargy and non-specific
signs of infection or systemic disease.
Vomiting and diarrhoea may occur due to alterations in
intestinal motility and functional ileus.
Hypotension and (septic) shock due to effusion of fluid
into the peritoneum and systemic vasodilation.
Hypothermia or hyperthermia.
TERM 100
What are the signs and symptoms of
intestinal ischemia?
DEFINITION 100
Therefore, decreased blood supply to these organs cause
symptoms related to eating or after-meal digestion,
including:
Abdominal pain after meals.
Weight loss.
Fear of eating or change in eating habits due to post-
meal pain.
Nausea and/or vomiting.
Constipation or diarrhea.
