Chapter 11: divisions of the nervous system
The anterior branches of the first four cervical nerves form the _______ _______, which like deep in the neck on either side. Fibers from these plexuses supply the muscles and skin of the neck.
Cervical plexuses
The preganglionic neurons of the sympathetic and parasympathetic divisions all secrete acetylcholine, and for this reason they are called ______.
Cholinergic
Axon that secretes acetylcholine at its terminal
Cholinergic fiber
The autonomic nervous system includes 2 divisions:
Sympathetic & parasympathetic
In the neck region, a thickening in the spinal cord called the ________ _______, supplies nerves to the upper limbs.
Cervical enlargement
_____ pairs of cranial nerves are located on the underside of the brain. Most are mixed nerves, but some associate with special senses, sight, smell, have only sensory fibers. Other cranial nerves that innervate muscles and glands are primarily composed of motor fibers.
12
The spinal cord consist of ____ segments, each of which gives rise to a pair of spinal nerves. Spinal nerves are grouped according to level of the vertebra with which they are associated. Within each group, pairs of nerves are numbered in sequence from superior to inferior. C1-C8, T1-T12, L1-L5, S1-S5. And one pair of coccygeal nerves Co. these nerves branch to various body parts and connect them with the CNS.
31
______ pairs of spinal nerves that originate from the spinal cord. The first pair are purely motor, the remaining pairs are mixed nerves that provide two way communication between spinal cord and parts of the upper and lower limbs, neck, and trunk.
31
Part of the nervous system that controls the viscera. Includes fibers that connect the CNS to viscera such as heart, stomach, intestines, and various glands. Controls subconscious actions.
Autonomic nervous system
______ nerves supply muscles and skin of the anterior, lateral and posterior regions of the arm.
Axillary nerves
The sixth pair of cranial nerves, the _______ nerves (6) are small and originate from the pons bear the medulla oblongata. They enter the orbits of the eyes and supply motor impulses to the remaining pair of the external eye muscles, the lateral Rectus muscles. This nerve is considered motor, with some proprioceptive fibers.
Abducens nerves
The 11th pair of cranial nerves, the ______ nerves (spinal accessory) originate in the medulla oblongata and the spinal cord. There's nerves have both cranial and spinal branches. Each cranial branch of an accessory nerve joins a vagus nerve and conducts impulses to muscles of he soft palate, pharynx, and larynx. The spinal branch descends into the neck and supplies motor fibers to the trapezius and sternocleidomastoid muscles. This nerve is considered motor, with some proprioceptive fibers.
Accessory nerves
Axon that secretes the neurotransmitter norepinephrine at its terminal
Adrenergic
The main portion of the nerve, the ________ branch (anterior ramus) continues forward to supply muscles and skin on the front and sides of the trunk and limbs.
Anterior branch
The _______ ______ (ventral, motor, root) of each spinal nerve consists of axons from the motor neurons whose cell bodies lie within the gray matter of the cord.
Anterior root
CSF is continuously reabsorbed into the blood. Most CSF reabsorption occurs through tiny, fingerlike structures called _______ _______ that project from the subarachnoid space into the blood-filled dural sinuses.
Arachnoid granulations
The ______ ______ is a thin, web like membrane that does not have blood vessels and is located between dura mater and pia maters. It spreads over the brain and spinal cord but generally does not dip into the grooves and depressions on their surfaces. Many thin strands extends from its undersurface and attach to the pia mater.
Arachnoid mater
The spinal tracts that conduct sensory information to the brain are called _______ tracts.
Ascending
________ areas of the cortex are neither primarily sensory nor motor. They connect with each other and with other brain structures. Occupies the anterior portions of the frontal lobes and are widespread in the lateral portions of the partietal, temporal, and occipital lobes. They analyze and interpret sensory experiences and help provide memory, reasoning, verbalizing, judgement and emotions. These areas of the frontal lobe provides higher intellectual processes, such as concentrating, planning and complex problem solving.
Association
Masses of gray matter deep within a cerebral hemisphere. Aka basal ganglia. Includes candate nucleus, the putamen, and the globus pallidus. They develop from the anterior portion of the forebrain. Produces neurotransmitter dopamine. These neurons interact with motor cortex, thalamus, and cerebellum. Facilitates voluntary movement.
Basal nuclei
The anterior branches of the lower four cervical nerves and the first thoracic nerves give rise to the ______ _____. These networks of nerve fibers are deep in the shoulders between the neck and the axillae (armpits).
Brachial plexuses
The ______ contains neural centers associated with sensory functions and is responsible for sensations and perceptions. It issues motor command to skeletal muscles and carries on higher mental functions, such as memory and reasoning. It also contains neural centers and pathways that coordinate muscular movements, and other that regulate visceral activities. Is responsible for characteristics of personality.
Brain
The ______ includes two cerebral hemispheres, the diencephalon, the brainstem, and the cerebellum.
Brain
______ waves are recordings of fluctuating electrical changes in the brain. They are classified as alpha, beta, theta, and delta waves.
Brain
The ______ connects the brain to the spinal cord. Consist of the midbrain, pons, and medulla oblongata. These structures include many tracts of nerve fibers and masses of gray matter called nuclei.
Brainstem
The cerebellum, pons, medulla oblongata together comprise the ______, which attaches the brain to the spinal cord. Midbrain
Brainstem
The ______ consist of the brain and spinal cord.
CNS
Neurons in the medulla oblongata that control heart rate.
Cardiac center
Other nuclei in the medulla oblongata control vital visceral activities:
Cardiac center, vasomotor center, respiratory center.
Each spinal nerve, except the first pair, emerges from the cord by two short branches or roots, which lie within the vertebral column. The roots arising from the superior part of the spinal cord pass outward almost horizontally, whereas those from the inferior portions of the spinal cord descend at sharp angles. The descending roots form a structure called the _____ ______.
Cauda equina
The spinal cord has two main functions:
Center for spinal reflexes, it is a conduit for impulses to and from the brain.
Tiny channel in bone tissue that contains blood vessel, Haversian canal. Also a tube in the spinal cord continuous with brain ventricles that contains cerebrospinal fluid.
Central canal
A cut into the cerebellum reveals a treelike pattern of white matter called the _______ ______, surrounded by gray matter. A number of nuclei lie deep within each cerebellar hemisphere. The largest and most important is the dentate nucleus.
Cerebellar Ortex
The cerebellum communicates with other parts of the CNS by means of three pairs of nerve tracts called _______.
Cerebellar peduncles
The _______ is a large mass of tissue inferior to the occipital lobes of the cerebrum and dorsal to the pons and medulla oblongata. Composed primarily of white matter with a thin layer of gray matter. The cerebellar cortex on its surface. This cortex doubles over on itself in a series of complex folds that have myelinated nerve fibers branching into them. It consist of two lateral hemispheres partially separated by a layer of dura mater called falx cerebelli. A structure called the vermis connects the cerebellar hemispheres at the midline.
Cerebellum
Cerebellum integrates sensory information concerning the position of the body parts and coordinates skeletal muscle activity and maintains posture. It receives sensory impulses from receptors in muscles, tendons, and joints (proprioceptors) and from special sense organs, such as eyes and ears. Damage to the cerebellum can cause a specific type of tremor (cerebellar tremor), inaccurate movements of voluntary muscles, loss of muscle tone, an uneven walk, loss of equilibrium.
Cerebellum cont...
Outer layer of the cerebrum. All lobes have this thin layer of gray matter 2-5 millimeters thick. It constitutes the outermost portion of the cerebrum. Cover the gyri, dipping into into the sulci and fissures. Contains nearly 75% of all neuron cell bodies in the nervous system.
Cerebral cortex
The cerebral cortex provides higher brain functions: interpreting impulses from dense organs, initiating voluntary muscular movements, storing information as memory, and retrieving this information in reasoning. The cerebral cortex is also part of the brain responsible for intelligence and personality.
Cerebral cortex continued..
Two prominent bundles of nerve fibers on the anterior of the midbrain comprise the cerebral peduncles. These fibers include descending tracts and are the main motor pathways between the cerebrum and lower parts of the nervous system.
Cerebral peduncles
______ is a clear, somewhat viscous liquid that differs in composition from the fluid that leaves the capillaries in the other parts of the body. It contains greater concentration of sodium and lesser concentration of glucose and potassium than do other extracellular fluids. It's function is nutritive as well as protective. Helps maintain a stable ionic concentration in the CNS and provides a pathway to the blood waste. Mostly forms in the lateral ventricles, from where it slowly circulates into the third and fourth ventricles. Small amounts enter the central canal of spinal cord, but most CSF circulates through the subarachnoid space of both the brain and the spinal cord by passing through openings in the wall of the fourth ventricle near the cerebellum.
Cerebrospinal fluid (CSF)
The _______ which develops from the anterior portion of the forebrain, is the largest part of the mature brain. It consists of two large masses, or cerebral hemispheres, which are essentially mirror images of each other. Located in upper part of cranial cavity. Provides higher mental functions.
Cerebrum
Structures called _____ ______ secretes CSF. They are tiny, reddish cauliflower-like masses of specialized capillaries from the pia mater, covered by a single layer of specialized ependymal cell. The ependymal cells are joined closely by tight junction. They project into cavities of the ventricles.
Choroid plexuses
The ____ ______ are in the abdomen, closely associated with certain large blood vessels.
Collateral ganglia
Decreased activity in the reticular formation results in sleep. If the reticular formation is injured and ceases to function, the person remains unconscious, even with strong stimulation. This is called ______ ______.
Comatose state
Just inferior to the lumbar enlargement, the spinal cord tapers to a structure called the ____ ______. From this tip, nervous tissues, including axons of both motor and sensory neurons, extends downward within the vertebral canal to become spinal nerves at the remaining lumbar and sacral levels. The resulting structure (like a horses tail) is called the cauda equina.
Conus medullaris
Two pairs of rounded knobs on the superior of the midbrain mark the location of four nuclei, known as ______ ______. The upper masses ( superior colliculi) contain centers for certain visual reflexes. The lower masses (inferior colliculi) contain auditory reflex center that operate when it is necessary to move the head to hear sounds more distinctly.
Corpora quadrigemina
A broad, flat bundle of axons called ______ ______ connects the cerebral hemispheres. Mass of white matter.
Corpus callosum
A _______ tract originated in the cerebral cortex and conducts motor impulses on so-called upper motor neurons downward through the spinal cord. These impulses control lower motor neurons at various levels of the spinal cord whose cell bodies are in the anterior horn and whose axons lead to skeletal muscles.
Corticospinal
Most of the fibers of the lateral tracts cross over in the lower medulla oblongata. Some fibers of the anterior tracts cross over at various levels of the spinal cord. Axons in the corticospinal tracts conduct motor impulses from the brain and synapse either directly or through interneurons with lower motor neurons, whose axons continue through spinal nerves to various skeletal muscles. Thus, fibers of the corticospinal tracts conduct motor commands that control voluntary movements.
Corticospinal tracts
The major descending tracts of the spinal are:
Corticospinal, reticulospinal, rubrospinal
Nerves that originate from the brain that communicate with other body parts are called _____ nerves.
Cranial
While flexor muscles on the affected side (ipsilateral side) contract, the flexor muscles of the limb on the other side (contralateral side) are inhibited. Furthermore, the extensor muscles on the contralateral side contract, helping to support the body weight shifted to that side. This is known as ______ ______ reflex, is due to interneuron pathways in the spinal cord that allow sensory impulses arriving on one side of the cord to pass across to the other side and produce an opposite effect.
Crossed extensor reflex
Each spinal nerve below C1 contains sensory fibers that reach the skin, and region innervated is called _______. Highly organized, but they vary considerably in size and shape.
Dermatome
The spinal tracts that conduct motor commands from the brain via neurons reaching muscles and glands are ______ tracts.
Descending
Part of the brain in the region of the third ventricle that includes the thalamus and hypothalamus. Develops from posterior forebrain and is located between the cerebral hemispheres and superior to the brainstem. Surrounds third ventricle and is largely composed of gray matter.
Diencephalon
In some regions, dura mater extends inward between lobes of the brain and forms supportive and protective partitions. In other areas, dura mater splits into two layers, forming channels called dural sinuses. Venous blood flows through these channels as it returns from the brain to vessels leading to the heart.
Dura mater
The ______ _____ is the outermost layer of the meninges. Composed of tough, white, sense connective tissue and contains many blood vessels and nerves. Attaches to the inside of the cranial cavity and forms the internal periosteum of the surrounding skull bones.
Dura mater
A small amount of loose connective tissue is called ________ and it surrounds individual axons.
Endoeurium
The sheath around the spinal cord is not attracted directly to the vertebrae, but is separated by an ________ ______, which lies between the dural sheath and the bony walls. This space contains blood vessels, loose connective tissue, and adipose tissue that pad the spinal cord.
Epidural space
Hormone the adrenal medulla secretes during times of stress; adrenalin
Epinephrine
A group of bundled fascicles, surrounded by an outermost layer of dense connective tissue called the _______, constitutes a nerve.
Epineurium
The abilities of the association areas are collectively known as
Executive function
The seventh pair of cranial nerves, the ______ ______, are mixed nerves that arise from the lower part of the pons and emerge on the sides of the face. Their sensory branches are associated with taste receptors in the anterior two thirds of the tongue, and some of their motor fibers conduct impulses to muscles of facial expressions. Still other motor fibers of these nerves function in the autonomic nervous system by stimulating secretions from tear glands and certain salivary glands. (Submandibular and sublingual glands).
Facial nerves
_____ ______ (partition) separates the right and left cerebellar hemispheres
Falx cerebelli
The partitions formed by the dura mater are:
Falx cerebelli, falx cerebri
A layer of dura mater called ______ ______ separates the hemispheres.
Falx cerebri
_______ ______ extends downward into the longitudinal fissure, and separates the right and left cerebral hemispheres
Falx cerebri
Axons organized in bundles are called _____. Each one is enclosed in a sleeve of loose connective tissue called perineurium.
Fascicles
These two tracts are ascending, they are tracts in the posterior funiculi of the spinal cord. Together they constitute the posterior column. Their fibers conduct sensory impulses from skin, muscles, tendons, and joints to the brain, where they are interpreted as sensations of touch, pressure, and body movement.
Fasciculus gracilis, fasciculus cuneatus
Major ascending tracts of the spinal cord are:
Fasciculus gracilis, fasciculus cuneatus, spinothalamic tract, spinocerebellar tracts.
A thin cord of connective tissue originating from the pia mater and dura mater descends to the upper surface of the coccyx. This cord is called the ______ ______, it anchors the spinal cord.
Filum terminale
A very deep groove is called a _______. Deep groove separating loves of the cerebrum.
Fissure
The portion that becomes the brain has 3 major ventricles (cavities) at one end- the ______ (prosencephalon) the ________ (mesencephalon) and the _____ (rhombencephalon).
Forebrain, midbrain, hindbrain
Many ridges or convolutions called _____, separated by grooves, mark the cerebrum's surface. Elevation on the brains surface caused by infolding.
Gyrus aka gyri
Cephal-
Head
The _______ ventricle is in the brainstem, just anterior to the cerebellum. A narrow canal, the cerebral aqueduct (aqueduct of sylvius) connects the third ventricle to the fourth ventricle and passes lengthwise through the brainstem. This ventricle is continuous with the central canal of the spinal cord and has openings in its roof that lead into the subarachnoid space of the meninges.
Fourth
The _______ lobe forms the anterior portion of each cerebral hemisphere. It is bordered posteriorly by a central sulcus (fissure of Rolando) which passes out from the longitudinal fissure at a right angle and inferiorly by lateral sulcus (fissure is Sylvius) which exits the undersurface of the brain along its sides.
Frontal
Most of the 5 lobes of the cerebral hemispheres are named after the skull bones they underlie.
Frontal, parietal, temporal, occipital, insula
______ _______ ______ fibers conduct sensory impulses inward to the brain or spinal cord from receptors in the skin and skeletal muscles.
General somatic afferent fibers
______ ______ _____ _____ fibers conduct motor impulses outward from the brain or spinal cord to skeletal muscles and stimulate them to contract.
General somatic efferent fibers
The nerve fibers in the cranial and spinal nerves can be subdivided further into four groups:
General somatic efferent fibers, general visceral fibers, general somatic afferent fibers, general visceral afferent fibers.
______ ______ _____ fibers conduct sensory impulses to the CNS from blood vessels and internal organs
General visceral afferent fibers
______ _____ ____ fibers conduct motor impulses outward from the brain or spinal cord to smooth muscle and glands associated with internal organs.
General visceral efferent fibers
The 9th pair of cranial nerves, the ________ nerves, are associated with the tongue and pharynx (the region posterior to the nasal cavity, the oral cavity and the larynx.) these nerves arise from the medulla oblongata. They are mixed nerves with predominant sensory fibers that conduct impulses from the lining of the pharynx, tonsils, and posterior third of the tongue to the brain. Fibers in the motor component of the glossopharyngeal nerves innervate certain salivary glands and a constrictor muscles in the wall of the pharynx that functions in swallowing.
Glossopharyngeal nerves
In the brain, the outer layers of the cerebral hemispheres and cerebellum are largely _____ matter.
Gray
In the spinal cord, ______ matter (the cell bodies of neurons) is found more centrally, with white matter more peripheral and consist of axons extending up to the brain or down from the brain.
Gray
______ matter in the brain, representing interconnecting axons, is found deeper with islands of gray matter located throughout.
Gray
A horizontal bar of gray matter in the middle of the spinal cord called _______ _______ connects the wings of the gray matter in the right and left sides.
Gray commissure
Most axons leaving paravertebral ganglia pass through short nerve branches called _____ ____, containing postganglionic axons returning to a spinal nerve. These branches appear gray because the postganglionic axons generally are unmyelinated, whereas nearly all of the preganglionic axons in the white rami are myelinated.
Gray ramus
The 12th pair of cranial nerves, the _________ nerves, arise from the medulla oblongata and pass into the tongue. They primarily consist of fibers that conduct impulses to muscles that move the tongue in speaking, chewing, swallowing. This nerve is considered motor, with some proprioceptive fibers.
Hypoglossal nerve
Part of the brain located below the thalamus and forming the floor of the third ventricle. Contains many nuclei. Lies inferior to the thalamic nuclei and forms the lower walls and floor of the third ventricle. Regulates: heart rate, arterial blood pressure, body temp, water and electrolyte balance, control hunger and body weight, control of movements and glandular secretions of the stomach and intestines and more.
Hypothalamus
One pair called the ______ ______, brings sensory information concerning the position of body parts such as limbs and joints to the cerebellum via the spinal cord and medulla oblongata.
Inferior peduncles
Stalk attaching the pituitary gland to th base of the brain, also the funnel shaped end of the uterine tube. (Pituitary stalk). Is a comical process behind the optic chiasma to which the pituitary gland is attached.
Infundibulum
The _______ (island of Reil) is lobe deep within the lateral sulcus of each hemisphere and is so named because it is covered by parts of the frontal, parietal, and temporal lobes. A circular sulcus separates the insula from the other lobes.
Insula
An anterior root and a posterior root unite to form a spinal nerve, extends outward from the vertebral canal through an ________ _______ (posterior root is usually absent from the first pair of spinal nerves).
Intervertebral foramen
Plex-
Interweaving
The two ________ ventricles are the largest. The first ventricle is in the left cerebral hemisphere and the second ventricle is in the right cerebral hemisphere. They extend anteriorly and posteriorly into the cerebral hemispheres.
Lateral ventricle
Connected structures in the brain that produce emotional feelings. It controls emotional experience and expression and can modify the way a person acts, producing fear, anger, pleasure, and sorrow. Creates guides behavior that may increase the chance of survival.
Limbic System
Other parts of the diencephalon includes:
Optic tracts, infundibulum, posterior pituitary gland, mammillary bodies, pineal gland.
_____ term memory can hold much more info, and lasts a lifetime.
Long
Theory pertaining to long term memory, that frequent, repeated stimulation of the same neurons in the hippocampus makes their synaptic transmission more effective.
Long term potentiation
A ________ fissure separates the right and left cerebral hemispheres.
Longitudinal
A thickening in the lower back called the _______ _____, gives off nerves to the lower limbs.
Lumbar enlargement
The ventral branches of the lumbar and first four sacral form the ________ plexuses. The lumbar portions are in the lumbar regions of the abdomen and sacral portions are in the pelvic cavity. These networks of nerve fibers give rise to a number nerves associated with the lower abdominal wall, external genitalia, buttocks, thighs, legs, and feet.
Lumbosacral
One of two small, rounded bodies posterior to the hypothalamus involved with reflexes associated with the sense of smell. Two rounded structures behind the infundibulum.
Mammillary bodies
The _______ _______ includes both motor and sensory fibers. The sensory branches conduct impulses from the scalp behind the ears, the skin of the jaw, lower teeth, and lower gum, and lower lip. The motor branches supply the muscles of mastication and certain muscles in the floor of the mouth.
Mandibular division
The fibers of the _______ ______ conduct sensory impulses from the upper teeth, upper gum, and upper lip, as well as from the mucous lining the palate and facial skin.
Maxillary division
______ nerves suppl muscles of the forearms and muscles of the skin of hands
Median nerves
Part of the brainstem between the pons and the spinal cord. It's dorsal flattens to form the floor of the fourth ventricle, and its ventral surface is marked by two longitudinal enlargements called pyramids. These contain descending tracts, most of whose fibers cross over at this level.
Medulla oblongata
Mening-
Membrane
Memories are stored in various parts of the cerebral cortex is a process called _______ _______.
Memory consolidation
Just beyond it's foramen, each spinal nerves branches. One of these parts, the small ______ branch, reenters the vertebral canal through the intervertebral foramen and supplies (innervates) the meninges and blood vessels of the cord, as well as the intervertebral ligaments and the vertebrae.
Meningeal branch
The 3 layers of membrane that cover the brain and spinal cord. Located between the bone and the soft tissues of the nervous system, protects the brain and spinal cord
Meninges
An inflammation of the meninges usually caused by bacterial or viral infection of the CSF, affects arachnoid and pia mater and sometimes the dura mater, mostly in children. Includes vision loss, hearing loss, paralysis, intellectual disability. Can be fatal. Children are vaccinated against haemophilus flu type b. Which was once the last common bacterial cause of meningitis.
Meningitis
The hindbrain partially divides into two parts: ________ and ________.
Metencephalon and myelencephalon
The ______ (mesencephalon) is a short section of the brainstem between the diencephalon and the pons. It contains bundles of the myelinated nerve fibers that join lower parts of the brainstem and spinal cord with higher parts of the brain. Includes several masses of gray matter that serve as reflex centers. Also contains cerebral aqueduct that connects the third and fourth ventricles.
Midbrain
The _______ ______ send information from the cerebral cortex about the desired position of these body parts.
Middle peduncles
Nerves that include both motor and sensory fibers are called ______ nerves.
Mixed
Also in the primary motor areas, certain regions control motor functions. A region called the _______ _____ area aka Broca's area, is in the frontal lobe, left hemisphere, anterior to the primary motor complex and superior to the lateral sulcus. It is important in generating the complex pattern processes of motor instructions for the muscular actions of the mouth, tongue, and larynx, which make speech possible.
Motor speech
Acetylcholine can combine with two types of cholinergic receptors called ______ receptors & _____ receptors.
Muscarinic & nicotinic
___ nerves supply muscles of the arms on the anterior sides and the skin of the forearms.
Musculocutaneous nerves
The major branches emerging from the brachial plexuses include:
Musculocutaneous, ulnar nerves, median nerves, radial nerves, axillary nerves.
Similarly, the collection of muscles innervated by motor nerve fibers of a particular spinal nerve is called _______.
Myotome.
_______ fiber is a term for the axon of a neuron
Nerve
The basic structure for the brain begins during embryonic development. It begins as the _______ ______ that gives rise to the central nervous system.
Neural tube
_______ sleep occurs when a person is very tired, it reflects decreasing activity of the reticular formation. It is restful, dreamless, and accompanied by reduced blood pressure and respiratory rate. May range from light to heavy and is described in 3 stages. The third stage is also known as slow wave sleep. Can last 7-90 minutes. Alternates with REM sleep
Non-REM
Neurotransmitter released from axons of some nerve fibers; a hormone from the adrenal medulla; noradrenaline
Norepinephrine
The _______ lobe forms the posterior portion of each cerebral hemisphere and is separated from the cerebellum by a shelf like extension of dura mater called the tentorium cerebelli. The occipital,parietal and temporal lobes have no distinct boundary.
Occipital
The second portion of each oculomotor nerve is part of the autonomic nervous system, supplying involuntary muscles inside the eyes. These muscles help adjust the amount of light that enters the eyes and help focus the lenses. This nerve is considered motor, with some proprioceptor fibers.
Oculomotor cont..
The third pair of cranial nerves, the_______ nerves (3) arise from the midbrain and pass into the orbits of the eyes. One component of each nerve connects to a number of voluntary muscles, including those that raise the eyelids and four of the six muscles that move the eye.
Oculomotor nerves
The first pair of cranial nerves, the _______ nerves (1) are associated with the sense of smell and include only sensory neurons. Located in the lining of the upper nasal cavity, serve as olfactory receptor cells. Axons from these receptors cells pass upward through the cribriform plates of the ethmoid bone, conducting impulses to the olfactory neurons in the olfactory bulbs, which are extensions of the cerebral cortex just beneath the frontal lobes. Sensory impulses move from the olfactory bulbs along olfactory tracts to cerebral centers where they produce the sensations of smell.
Olfactory nerves
On each side of the medulla oblongata is an oval swelling called _____, from which a large bundle of nerve fibers arises and passes to the cerebellum.
Olive
The _____ ______ of each the trigeminal nerve consists of sensory fibers that conduct impulses to the brain from the surface of the eye; the tear glands, and the skin of the anterior scalp, forehead, and upper eyelid.
Ophthalmic division
Optic tracts originate from the______ _____ (formed by some of the optic nerve fibers crossing over)
Optic chiasma
The second pair of cranial nerves, the ______ nerves (2) are sensory and lead from the eyes to the brain. Associated with vision. The cell bodies of these neurons form ganglion cell layers in the eyes, and their axons pass through the optic foramina of the orbits and continue into the visual nerve pathways of the brain.
Optic nerves
Part of the autonomic nervous sytem that arises from the brain and sacral region of the spinal cord. Most active under ordinary, restful conditions (rest and digest). Counters the effects of the sympathetic division and restores the body to a resting state following a stressful experience. The parasympathetic division decreases heart rate
Parasympathetic divisions
The _______ lobe is posterior to the frontal lobe and is separated from it by the central sulcus.
Parietal
_______ reflex is of the knee.
Patellar
Fibers from the third, fourth and fifth cervical nerves pass into the right and left _______ _____, which conduct motor impulses to the muscle fibers of the diaphragm.
Phrenic nerves
The _____ _____ is thin and contains many nerves, as well as blood vessels that nourish the underlying cells of the brain and spinal cord. It is attached to thebsurfaces if these organs and follows their irregular contours, passing over the high areas and dipping into the depressions.
Pia mater
Small, cone shaped structure in the central part of the brain that secretes the hormone melatonin, which affects certain biological rhythms. Projects from roof of diencephalon.
Pineal gland
Anterior branches of the spinal nerves form complex networks called ______ instead of continuing directly to the peripheral body parts, except in the thoracic regions T2-T12. In a plexus, the fibers of various spinal nerves are sorted and recombined in a way that enables fiber associated with a particular peripheral body part to reach it in the same peripheral nerve, even though the fibers originate from different spinal nerves.
Plexuses
The ____ occupy the full thickness of the brainstem, but it is most visible centrally as a rounded bulge where it separates the midbrain from the medulla oblongata. The central portion of the pons consists mostly of longitudinal nerve fibers, which relay information between medulla oblongata and cerebrum. It's ventral portion also contains large bundles of transverse nerve fibers that wrap around to the back and connect with the cerebellum. Conducts impulses from cerebrum to centers within cerebellum. Several nuclei of the pons relay sensory information from peripheral nerves to higher brain centers. Other nuclei may function with centers of the medulla oblongata to control breathing.
Pons
The ________ branch (posterior ramus) of each spinal nerve turns posteriorly and innervates the muscles and skin of the back.
Posterior
_____ _____ ____ hangs from the floor of the hypothalamus, attached to the infundibulum.
Posterior pituitary gland
The _____ ______ (dorsal, or sensory, root) can be identified by an enlargement called the posterior root ganglion. This ganglion contains the cell bodies of sensory neurons whose axons (peripheral processes) conduct impulses inward from peripheral body parts. The axons (central processes) of these neurons continue through the posterior root and into the spinal cord, where they form synapse with other neurons or ascend to the brain.
Posterior root
In the motor pathways of the somatic nervous system, a single neuron typically links the CNS and a skeletal muscle. In the autonomic system, pathways include two neurons. The cell body of one neuron is in the brain or spinal cord. It's axon, the _________ fiber, leaves the CNS and synapse with one or more neurons whose cell bodies are within an autonomic ganglion. The axons of such a second neuron is called a _________ fiber, and it extends to a visceral effector.
Preganglionic & postganglionic fibers
The ______ motor areas (motor cortex) of the cerebral cortex lie in the precentral gyri of the frontal lobes just in front of central sulcus and in the anterior wall of this sulcus.
Primary
Gangli-
Swelling
The nervous tissue in these regions contains many large _________ cells, named for their pyramid-shaped cell bodies. Impulses from the pyramidal cells move downward through the brainstem and into the spinal cord on descending tracts. Most of the nerve fibers in these tracts cross over from one side of the brain to the other within the brainstem. Impulses conducted on these pathways in special patterns and frequencies are responsible for movements in skeletal muscles. Upper portion-legs and thighs, middle portion- arms, forearms, lower portion-head,face, and tongue.
Pyramidal cells
_______ sleep is aka paradoxical sleep because some areas of the brain are active. Eyes can be seen rapidly moving beneath the eyelids. Sleep dream. Can last 5-15 minutes. Alternates with Non-REM
REM
_____ nerves supply muscles of the arms on the posterior sides and the skin of the forearms and hands
Radial nerves
The two types of sleep are:
Rapid eye movement (REM) and non-rapid eye movement (non-REM)
Near the center of the midbrain is a mass of gray matter called _____ ______. This nucleus communicates with the cerebellum and with centers of the spinal cord and it plays a role in reflexes that maintain posture. It appears red because it is richly supplied with blood vessels.
Red nucleus
A nerve pathway. Automatic response to stimulus.
Reflex
Components of a reflex, consisting of a sensory receptor, sensory neuron, interneuron (usually), motor neuron and effector.
Reflex arc
Maintains the basic rhythm of breathing and works with other brainstem and works with other brainstem areas to adjust the rate and depth of breathing to meet changing needs
Respiratory center
Complex network of nerve fibers and islands of gray matter in the brainstem that arouses the cerebrum. Aka reticular activating system. Extends fro the superior portion of the spinal cord into the diencephalon.
Reticular formation
The lateral ________ tracts are in the lateral funiculi, whereas the anterior and medial reticulospinal tracts are in the anterior funiculi. Some fibers in the lateral tracts cross over, whereas others remain uncrossed. Those anterior and medial tracts remain uncrossed. Motor impulses conducted on the reticulospinal tracts originate in the brain and control muscular tone and activity of sweat glands.
Reticulospinal tracts
The fibers of the ______ tracts cross over in the brain and pass through the lateral funiculi. They conduct impulses from the brain to synapses with lower motor neurons, and help to coordinate muscle actions.
Rubrospinal tracts
Skeletal muscles are usually innervated by motor neurons at more than one level of the spinal cord, although one of two levels of the spinal cord may predominate. This is called _______ _______.
Segmental innervation
_____ areas of the lobes of the cerebrum recurve and interpret impulses from sensory receptors, producing feelings or sensations.
Sensory
Funi-
Small cord or fiber
Motor pathways of the PNS that lead to skeletal muscles. Consists of nerve fibers that connect the CNS to the skin and skeletal muscles, so it plays a role in conscious activities.
Somatic nervous system
______ _____ _____ fibers conduct sensory impulses inward to the brain from the receptors of sight, hearing, and equilibrium.
Special somatic afferent fibers
_______ ______ _____ fibers conduct motor impulses outward from the brain to the muscles used in chewing, swallowing, speaking, and forming facial expressions.
Special somatic efferent fibers
3 other groups of fibers, found only in cranial nerves, are associated with more specialized structures:
Special somatic efferent fibers, special visceral afferent fibers, special somatic afferent fibers
______ ______ _____ fibers conduct sensory impulses inward to the brain from the olfactory and taste receptors
Special visceral afferent fibers
Nerves originating from the spinal cord that communicate with other body parts are called ______ nerves.
Spinal
The _____ ____ is a slender column of the nervous system that is continuous with the brain and extends downward through the vertebral canal. Originates where nervous tissue leaves the cranial cavity at the level of the foramen magnum. The cord tapers to a point and terminates bear the intervertebral disc that separates the first and second lumbar vertebrae.
Spinal cord
The posterior and anterior ________ tracts lie near the surface in the lateral funiculi of the spinal cord. Fibers in the posterior tracts remain uncrossed, whereas those in the anterior tracts cross over the medulla. Impulses conducted on their fibers originate in the muscles of the lower limbs and trunk and then travel to the cerebellum. These impulses are used by the cerebellum to coordinate muscular movements.
Spinocerebellar tracts
Tract that begins at various levels of the spinal cord and conduct sensory impulses associated with the sensations of pain and touch to the thalamus.
Spinothalamic tract
The lateral and anterior _______ tracts are in the lateral and anterior funiculi. The lateral tracts conduct impulses from various body regions to the brain and give rise to the sensations of Pain and temp. Impulses conducted in fibers of the anterior tracts are interpreted as touch and pressure. Impulses in these tracts cross over in the spinal cord.
Spinothalamic tracts
A ________ ______ between the arachnoid and pia mater contains the clear, watery cerebrospinal fluid, or CSF
Subarachnoid space
When escaping blood collects beneath the dura mater, it is called ______ _____. Can increase pressure between the rigid bones of the skull and the soft tissues of the brain. Unless removed, can cause functional loss of brain or death.
Subdural hematoma
The _____ divides each hemisphere into lobes.
Sulci
A shallow to somewhat deep groove is called ______.
Sulcus
After integrating and analyzing the information from these two sources, the cerebellum sends correcting impulses from the dentate nucleus via the ______ ______ to the thalamus and eventually to the motor cortex. These corrections are incorporated into motor impulses that travel downward through pons, medulla oblongata, and spinal cord to lower motor neurons in the appropriate patterns to move the body in the desired way.
Superior peduncles
Preganglionic fibers extend short distance, leave spinal nerves through branches called white rami (sing,ramus) and enter sympathetic ganglia. Two groups of such ganglia called ______ ______ ______ (paravertebral ganglia), form chains along the sides of the vertebral column. These ganglia, with fibers that connect them, compose the sympathetic trunks.
Sympathetic chain ganglia
That part of the autonomic nervous system that arises from the thoracic and lumbar regions of the spinal cord. Always operating without our noticing, but is most active during energy-expending, stressful or emergency situations (flight or fight). During an emergency the sympathetic divisions increases heart rate.
Sympathetic division
State of partial contraction is called
Sympathetic tone
The forebrain divides into anterior and posterior portions: ________ & _________.
Telencephalon & diencephalon
The _______ lobe lies inferior to the frontal and parietal lobes and is separated from them by the lateral sulcus.
Temporal
Dense mass called ______, bulges into third ventricle from each side. Mostly gray matter. Selective gateway for sensory impulses ascending from other parts of the nervous system to the cerebral cortex. Receives all sensory impulses (except smell).
Thalamus
The major branches of these plexuses include the following:
The obturator nerves, femoral nerves
Other nerves associated with the lumbosacral plexus that innervate various skeletal muscles include the following:
The pudendal nerves, the inferior and superior gluteal nerves
A narrow space that constitutes the _______ ventricle is in the midline of the brain beneath the corpus callosum, which is a bridge of axons that link the two cerebral hemispheres. This ventricle communicates with the lateral ventricles through openings (interventricular foramina) in its anterior end.
Third
The gray matter divides the white matter of the spinal cord into 3 regions on each side-anterior, lateral and posterior funiculi. Each funiculus consist of longitudinal bundles of myelinated nerve fibers called ______ that compose the major pathways.
Tracts
A ________ fissure separates the cerebrum from the cerebellum.
Transverse
The fifth pair of cranial nerves, the ______ nerves (5) are the largest and arise from the pons. They are mixed nerves, with more extensive sensory portions. Each sensory component includes 3 large branches, called the ophthalmic, maxillary, and mandibular divisions.
Trigeminal nerves
The fourth pair of cranial nerves, the _______ nerves (4) are the smallest. They arise from the midbrain and conduct motor impulses to a fifth pair of external eye muscles, the superior oblique muscles, which are not supplied by the oculomotor nerves. The trochlear nerve is considered motor, with some proprioceptive fibers.
Trochlear nerves
______ nerves supply muscles of the forearms and hands and the skin of the hands.
Ulnar nerves
The 10th pair of cranial nerves, the _____ nerves, originate in the medulla oblongata and extend downward through the neck into the chest and abdomen. These nerves are mixed, including both somatic and autonomic branches, with the autonomic fibers predominant.
Vagus nerve
Neurons in the brainstem that control the diameter of the arteries.
Vasomotor center
CSF is formed in four interconnected cavities called _______, that lie in the cerebral hemispheres and brainstem. Cavity.
Ventricle
The 8th pair of cranial nerves, the _______ nerves (acoustic or auditory nerves) are sensory nerves that arise from the medulla oblongata. Each of these nerves had two distinct parts-vestibular branch and a cochlear branch. The neuron cell bodies of the vestibular branch fibers are located in ganglia near the vestibule and semicircular canals of the inner ear. These structures contain receptors that sense changes in the position of the head and in response, initiate and send impulses to the cerebellum, where they are used in reflexes that manintain balance.
Vestibulocochlear nerves
The spinal nerves in the thoracic and lumbar regions have fourth branch, or _______ branch, which is the part of the autonomic nervous system. Motor fibers associated with this branch form synapse in ganglia (paravertebral ganglia) adjacent to the vertebral column.
Visceral branch
Another type of reflex, _______ reflex is when a person touches something painful.
Withdrawal
______ memory is related to short term memory, it refers to the application of short term memory to performing a specific task.
Working
3 layers of meninges
dura mater, arachnoid mater, pia mater
