5 Organization of the Nervous System Flashcards
-it is one of the major coordinating systems of the body and concepts regarding this system are important for understanding other systems of the body.
-maintains homeostasis, the body must receives information from the external and internal environment and must respond to that information
The nervous system
It is the central processing unit of the entire nervous system. The brain and spinal cord are part of this
Central Nervous System
-made up of the right and left cerebral hemispheres.
-Each hemisphere is composed of a covering of gray matter and white matter
cerebrum
-It is the covering of gray matter
-arranged as a layer of cells and possesses several areas with specific functions such as the neocortex, white matter fibers, a motor area, and a sensory area.
the cerebral cortex,
only found in mammals is associated with higher brain functions such as conscious behavior.
neocortex
The cortex can be designated into three areas:
- Motor areas
- Sensory areas
- Association areas
*Cortex areas
responsible for the control of voluntary functions,
Motor areas
*Cortex areas
responsible for the perception of various sensations,
Sensory areas
*Cortex areas
areas that integrate the motor and sensory signals.
Association areas
The motor and sensory areas can also be grouped into three projection areas, namely:
Projection areas
Rhinencephalon areas (olfactory and limbic)
Association areas (receive and process information, develop a response, and predict the consequences.)
The white matter fibers of the cortex:
a. Association fibers
b. Projection fibers
c. Commissural fibers
*white matter fibers of the cortex
-allow complex problem-solving and creative thinking.
-also connect different parts of the cortex.
Association fibers.
The parietal and occipital lobe association areas are involved in ____ functions.
cognitive
____ areas are involved with general alertness, intelligence, and temperament,
Frontal association
____ area is involved with learning and memory.
temporal association
*white matter fibers of the cortex
These fibers connect the cortex with subcortical structures and the remainder of the nervous system.
Projection fibers.
*white matter fibers of the cortex
Impulses from these areas in one hemisphere cause muscle movements on the opposite (contralateral) side of the body. Thus, fibers of the cerebral hemispheres cross between hemispheres as?
Commissural fibers.
-the cerebral white matter also includes some deep subcortical nuclei called the
-composed of pools of neurons organized for the control of semi-voluntary movements such as walking and running.
-generally includes the caudate nucleus, putamen, globus pallidus, substantia nigra (consisting of the pars reticulata and pars compacts), and subthalamic nucleus.
basal nuclei (previously known as ganglia)
in what animal is the cortex poorly developed but the basal nuclei are highly developed.
Birds
limbic system located in the
cerebral white matter
-consists of a group of structures found in the medial region of each cerebral hemisphere.
-Structures include the cingulate gyrus, dentate gyrus, parahippocampal gyrus, fornix, anterior nucleus thalamus, and amygdaloid body.
-is involved in emotional and behavioral patterns.
limbic system
functions of the limbic system
(1) establishment of emotional states;
(2) linking of conscious functions with the unconscious, autonomic functions;
(3) long-term memory storage and retrieval.
The rabies virus generally attacks the ____ and results in emotional changes including bouts of terror and rage.
hippocampus
-enables the body to make automatic adjustments to prevent the distortion of inertia and momentum.
-serves as the collecting house for all information regarding the instantaneous physical status of the body.
Cerebellum
The effect of the cerebrum is exerted on the ____ while the cerebellum exerts its effect on the ____.
opposite side (contralateral)
same side (ipsilateral)
composed of the interbrain, midbrain, pons, and medulla oblongata.
Brain Stem
composed of the hypothalamus, thalamus, and epithalamus.
interbrain
organ that is associated with complex sensing and neurosecretory function and assumes a major role in the integration of functions carried out by the autonomic nervous system.
Hypothalamus
contains many nuclei and serves as a relay center. Impulses from all areas of the body are transmitted in this organ for transfer to the cerebral cortex.
thalamus
contains the olfactory correlation center and the pineal gland.
epithalamus
gland that regulates gonadal hormones and affects daily rhythms.
pineal gland
contains auditory and visual reflex centers, the nuclei of two cranial nerves, and several descending tracts.
midbrain
contain many ascending and descending pathways, the sensory and motor nuclei for all of the cranial nerves originating in the brain stem (except the two located in the midbrain), and a large part of the central mechanism of the postural reflexes (e.g., hopping, righting, placing).
medulla oblongata and pons
-is the caudal continuation of the medulla oblongata.
-It receives sensory afferent fibers via dorsal roots of the spinal nerves and gives off efferent motor fibers to the ventral roots of the spinal nerves.
Spinal Cord
is a bundle of nerve fibers having a common origin, termination, and function; and connects the brain stem and higher centers with the spinal nerves.
tract
The ____ (centrally-located) consists of nerve cell bodies and processes while the ____ (peripherally arranged) is composed of distinct tracts.
gray matter
white matter
The cells of origin for sensory impulses to the brain or other parts of the spinal cord are located in the ____ of the gray matter, and the cells of origin of motor impulses to the spinal nerves are located in the ____ of the gray matter.
dorsal horns
ventral horns
-includes that part of the nervous system outside the brain and spinal cord.
-responsible for collecting most of the sensory information that is relayed to the central nervous system (CNS).
-also responsible for carrying motor signals to the skeletal and smooth muscles.
-consists of the spinal nerves and the cranial nerves.
Peripheral Nervous System
-a collection of axons from many neurons and is found in the peripheral nervous system.
-vary in size and are surrounded by a series of connective tissue layers.
-consists not only of axons, but its bulk is composed of other tissues, including blood vessels, glial cells, and connective tissue.
Nerves
____ nerves carry impulses toward the CNS, whereas ____ nerves carry impulses away from the CNS.
Sensory or afferent
motor or efferent
Nerves that carry impulses in both directions are called
mixed nerves.
are collections of neuron cell bodies located in the peripheral nervous system.
Ganglia
nerves that can function within the autonomic (visceral) nervous system or somatic nervous system. Therefore, they can be further classified as visceral afferent, visceral efferent, somatic afferent, or somatic efferent.
Peripheral nerves
-associated with the voluntary control of muscles. They arise from the spinal cord and emerge from the vertebrae.
-composed of a dorsal and ventral root and its branches.
-generally supply sensory and motor fibers to the region of the body in the area where they emerge from the spinal cord.
Spinal Nerves
In ____, there is a pair of spinal nerves that merges behind the vertebrae of the same serial number and name with exception of the cervical and caudal nerves.
dogs
There are __ pairs of cranial nerves, with a right and left nerve making up each pair.
12
-supply innervation to structures in the head and neck except for the vagus nerve.
-In addition to its sensory and motor supply to the pharynx and larynx, it also supplies parasympathetic fibers to visceral structures in the thorax and abdomen.
-have no dorsal or ventral roots and emerge through foramina in the skull.
-Some are strictly sensory (afferent), some are strictly motor (efferent), and some are mixed (both sensory and motor).
Cranial Nerves
-also called the involuntary or visceral nervous system, is essential in the maintenance of normal function, adapting to the environment, and responding to stress.
-has sympathetic (stress response), parasympathetic (homeostatic response in the absence of stress), and enteric nervous system (digestive regulation).
Autonomic Nervous System
follows the fight, fright, or flight concept
sympathetic system
follows the eat-or-sleep concept.
parasympathetic system
The processing of impulses in ANS is divided into
central components
peripheral components.
The cells of origin for the sympathetic nerves are located in the ____ part while the cells of origin of the parasympathetic nerves are located ____ part.
thoracolumbar
craniosacral
