Introduction Flashcards
- composed of specialized cells, whose function is to: receive sensory stimuli and to transmit them to effector organs, whether muscular or grandular
nervous sytem
coordinated so that the effector organs work harmoniously together for the well-being of the individual
efferent impluses
- consists of the brain and spinal cord
- brain and spinal cord are the main centers where correlation and integration of nervous information occurs
central nervous system
- consists of the cranial and spinal nerves and their associated ganglia
peripheral nervous sytem
- both the brain and spinal cord are covered with a system of membranes ___ and are suspended in ___
meninges, cerebrospinal fluid
- protected by the bones of the skull and the vertebral column
- protective covering of the spinal cord
meninges
- CNS is composed of large numbers of neurons
- excitable nerve cells
neurons
- processes of neurons are known as
axons or nerve fibers
- neurons are supported by specialized tissue called
neuroglia
- the CNS interior is organized into ___ and ___
gray matter, white matter
- gray in color
- consists of nerve cells embedded in neuroglia
gray matter
- consists of nerve fibers embedded in neuroglia and is white in color because of the presence of lipid material in nerve fiber myelin sheaths
white matter
- In the PNS, the ___ and ___ nerves conduct information to and from the CNS
- unprotected and are commonly damaged by trauma
cranial and spinal nerves
- innervates the body’s involuntary structures such as the heart, smooth muscle, and glands
- distributed throughout the CNS and PNS and is divided into two parts: sympathetic & parasympathetic
autonomic nervous system
- prepare the body for an emergency
sympathetic part of the ANS
- conserving and restoring energy
parasympathetic
- meninges is formed by
- three meninges
dura, arachnoid, and pia matter
- space between the arachnoid and pial membranes
- contains cerebrospinal fluid (CSF)
subarachnoid space
- projects into the dural venous sinuses to drain CSF from the subarachnoid space
- connect the dura mater to the pia mater
arachnoid mater
Central Nervous System
Brain Forebrain Midbrain Hindbrain Spinal cord
Central Nervous System
Forebrain
Cerebrum
Diencephalon (between brain)
Central Nervous System
Hindbrain
medulla oblongata
pons
cerebellum
Central Nervous System
Spinal cord
cervical segments thoracic segments lumbar segments sacral segments coccygeal segments
Peripheral Nervous System
cranial nerves and their ganglia spinal nerves and the ganglia 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
Peripheral Nervous System
12 pairs that exit the skull through the foramina
Cranial nerves and their ganglia
Peripheral Nervous System
31 pairs that exit the vertebral column through the intervertebral foramina
spinal nerves and their ganglia
- situated within the vertebral canal of the vertebral column and is surrounded by three meninges
- roughly cylindrical and begins superiorly at the foramen magnum in the skull where it is continuous with the medulla oblongata of the brain.
spinal cord
- protection of the spinal cord is provided by the ___ which surrounds the spinal cord in the ___
cerebrospinal fluid, subarachnoid space
- 31 pairs of spinal nerves are attached by the ___ and the ___
anterior or motor roots, posterior or sensory roots
- each posterior nerve root possesses a ___,
- the cells of which give rise to peripheral and center nerve fibers
posterior root ganglion
TRUE OR FALSE
the spinal cord is composed of an inner core of gray matter which is surrounded by an outer covering of white matter
true
- seen on cross section as an H-shaped pillar with anterior and posterior gray columns, or horns united by a thin gray commissure containing the small central canal
gray matter
- divided into anterior, lateral, and posterior white columns
white matter
- lies in the cranial cavity and is continuous with the spinal through the foramen magnum
- surrounded by the dura mater, the arachnoid mater, and the pia mater
brain
- divided into three major divisions: the hindbrain, midbrain, and forebrain in ascending order from the spinal cord
brain
- collective term of medulla oblongata, pons, and midbrain
- what remains after the cerebral hemispheres and cerebellum are removed
brain stem
- comprises the medulla oblongata, the pons, and the cerebellum
hindbrain
- conical in shape and connects the pons superiorly to the spinal cord inferiorly
medulla oblongata
- medulla oblongata contains many collections of neurons called
- serves as a conduit for ascending and descending nerve fibers
nuclei
- situated on the anterior surface of the cerebellum, inferior to the midbrain and superior to the medulla oblongata
- large number of transverse fibers on it anterior aspect connecting the two cerebellar hemispheres
pons
- contains many nuclei and ascending and descending nerve fibers
pons
- posterior cranial fossa of the skull
- posterior to the pons and the medulla oblongata
cerebellum
- cerebellum consists of two laterally placed hemispheres connected by a median portion called the
vermis
- the cerebellum is connected to the ___ by the superior cerebellar peduncles, to the ___ by the middle cerebellar peduncles, and to the ___ by the inferior cerebellar peduncles
mid- brain, pons, medulla
- composed of large bundles of nerve fibers connecting the cerebellum to the remainder of the nervous system
peduncles
- the surface layer of each cerebellar hemisphere
- composed of gray matter
cortex
- thrown into folds or folia, separated by closely set transverse fissures
cerebellar cortex
- certain masses of gray matter are found in the interior of the cerebellum, embedded in the white matter
- the largest of these is known as
denate nucleus
- the medulla oblongata, the pons, and the cerebellum surround a cavity filled with CSF, called
fourth ventricle
- fourth ventricle is connected superiorly to the third ventricle by the
- inferiorly it is continuous with the central canal of the spinal cord
cerebral aqueduct
- narrow part of the brain that connects the forebrain to the hindbrain
midbrain
- the narrow cavity of the midbrain
- connects the third and fourth ventricles
cerebral aqueduct
TRUE OR FALSE
the midbrain does not contain a lot of nuclei and bundles of ascending and descending nerve fibers
false, contains a lot
- comprises the diencephalon (between brain)
- central part of the forebrain, and the cerebrum
forebrain
- consists of a dorsal thalamus and a ventral hypothalamus
- between brain
diencephalon
- large, egg-shaped mass of gray matter that lies on either side of the third ventricle
thalamus
- anterior end of the thalamus forms the posterior boundary of the
interventricular foramen
TRUE OR FALSE
the thalamus forms the lower part of the lateral wall and floor of the third ventricle
false, hypothalamus
- largest part of the brain
- consists of two cerebral hemispheres, which are connected by a mass of white matter
cerebrum
- mass of white matter in the cerebrum
corpus callosum
- the hemispheres are separated by a deep cleft called
- into which projects the falx cerebri
longitudinal fissure
- surface layer of each hemisphere
- composed of gray matter
cortex
- the cerebral cortex is thrown into folds called
gyri
- the cerebral cortex is separated by fissures or
sulci
TRUE OR FALSE
this arrangement greatly increases the surface area of the cortex
TRUE
- a number of the large sulci are used to subdivide the surface of each hemisphere into
lobes
- within the hemisphere is a central core of white matter containing several large masses of gray matter
basal nuclei or ganglia
- fan shaped collection of nerve fibers
- passes in the white matter to and from the cerebral cortex to the brainstem
corona radiata
- the corona radiata converges on the basal nuclei and passes between them as the
internal capsule
- the tailed nucleus situated on the medial side of the internal capsule is the
caudate nucleus
- the lens shaped nucleus on the lateral side of the internal capsule is the
lentiform nucleus
- within each cerebral hemisphere is a cavity called
lateral ventricle
- communicate with the third ventricle through the
interventricular foramina
TRUE OR FALSE
during the process of development, the cerebrum becomes enormously enlarged and overhangs the diencephalon, midbrain, and hindbrain
true
- composed of an inner core of white matter, which is surrounded by an outer covering of gray matter
brain
- situated deeply within the white matter
gray matter
- grey cerebellar nuclei in the ___ and the gray thalamic, caudate, and lentiform nuclei in the ___
cerebellum, cerebrum
- made up of bundles of nerve fibers supported by connective tissue
cranial and spinal nerves
- leave the brain and pass through foramina in the skull
12 pairs of cranial nerves
- leave the spinal cord and pass through intervertebral foramina in the vertebral column
31 pairs of spinal nerves
- the spinal nerves are associated with regions of the spinal cord:
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
- 8 cervical nerves yet only _ cervical vertebrae
7
- 1 coccygeal nerve but _ coccygeal vertebrae
4
- each spinal nerve is connected to the spinal cord by two roots:
anterior root & posterior root
- consists of bundles of nerve fibers carrying nerve impulses away from the CNS - efferent fibers
- their cells of origin lie in the anterior gray horn of the spinal cord
anterior root
efferent fibers that go to skeletal muscles and cause them to contract are
motor fibers
consists of bundles of afferent fibers that carry nervous impulses to the CNS
posterior root
afferent fibers covey information about sensations of touch, pain, temperature, and vibration, they are called
sensory fibers
- the cell bodies of the afferent fibers are situated in a swelling on the posterior root called the
- sensory ganglia of spinal nerves
posterior root ganglion
the spinal nerve roots pass from the spinal cord to the level of their respective intervertebral foramina, where they unite to form a
spinal nerve
TRUE OR FALSE
because of the disproportionate growth in length of the vertebral column during development, compared with that of the spinal cord, the length of the roots increases progressively from above downward
true
- the spinal nerve roots are short and run almost horizontally, but the roots of the lumbar and sacral nerves below the level of the termination of the cord
- consists of the atlas (C1) and the axis (C2)
upper cervical region
- the upper cervical region forms a vertical leash of nerves around the
- a fibrous band that extends from the conus medullaris to the periosteum of the coccyx, and its functions are to fixate, stabilize, and buffer the distal spinal cord from normal and abnormal cephalic and caudal traction.
filum terminale
lower nerve roots of the upper cervical region
cauda equina
- after emerging from the intervertebral foramen, each spinal nerve immediately divides into a large ___ and ___
- each containing both motor and sensory fibers
anterior ramus and posterior ramus
passes posteriorly around the vertebral column to supply the muscles and skin of the back
posterior ramus
continues anteriorly to supply the muscles and skin over the anterolateral body wall and all the muscles and skin of the limbs
anterior ramus
join one another at the root of the libs to form complicated nerve plexuses
anterior rami
found at the root of the upper limbs
cervical and brachial plexuses
found at the root of the lower limbs
lumbar and sacral plexuses
divided into sensory ganglia of spinal nerves (posterior root ganglia) and cranial nerves and autonomic ganglia
ganglia
- fusiform (spindled-shaped) swellings on the posterior root of each spinal nerve just proximal to the root’s junction with a corresponding anterior root
- referred as posterior root ganglia
sensory ganglia
ganglia found along the course of cranial nerves5,6,8,9, & 10
sensory ganglia
- irregular in shape, situated along the course of efferent nerve fibers of the autonomic nervous system
- found in the paravertebral sympathetic chains around the roots of the great visceral arteries in the abdomen and close to or embedded within the walls of various viscera
autonomic ganglia
NERVOUS SYSTEM
- inner most layer
- gives rise to the gastrointestinal tract, the lungs, and liver
entoderm
NERVOUS SYSTEM
- gives rise to the muscle, connective tissues and the vascular system
mesoderm
NERVOUS SYSTEM
- third and outermost layer
- formed of columnar epithelium, gives rise to the entire nervous system
ectoderm
NERVOUS SYSTEM
during the ___ week of development, the ectoderm on the dorsal surface of the embryo between the primitive knot and the buccopharyngeal membrane thickens to form ___
third ,neural plate
NERVOUS SYSTEM
plate which is pear shaped and wider cranially, develops a longitudinal ___
neural groove
NERVOUS SYSTEM
the groove now deepens so that it is bounded on either side by ___
neural folds
NERVOUS SYSTEM
the neural folds fuse, converting the neural groove into a ___
neural tube
NERVOUS SYSTEM
the cavity of the tube remains in communication with the amniotic cavity through the
anterior and posterior neuropores
TRUE OR FALSE
fusion starts at about the midpoint along the groove and extends cranially and caudally so that the cavity remains in communication with the amniotic cavity
true
Which closes first? the anterior neuropore pr posterior neuropore?
anterior, posterior closes 2 days after
how many days does the neural tube closes normally?
28 days
sunk beneath the surface ectoderm after neural tube closure
neural tube
- the ___ will differentiate into the cells of the posterior root ganglia, sensory ganglia of the cranial nerves, autonomic ganglia, cells of the suprarenal medulla, and melanocytes
- give rise to mesenchymal cells in the head and neck
neural crest cells
the ___ at the cephalic end of the neural tube causes it to dilate and form three primary brain vesicles
proliferation of cells
the rest of the tube elongates and remains smaller in diameter; it will form the ___
spinal cord
Primary Division of the Developing Brain
- Primary Division of Forebrain vesicle
prosencephalon (forebrain)
Primary Division of the Developing Brain
- Primary Division of Midbrain vesicle
mesencephalon (midbrain)
Primary Division of the Developing Brain
- Primary Division of hindbrain vesicle
rhombencephalon (hindbrain)
Primary Division of the Developing Brain
- Subdivision of Forebrain vesicle
telencephalon & diencephalon
Primary Division of the Developing Brain
- Subdivision of midbrain vesicle
mesencephalon
Primary Division of the Developing Brain
- Subdivision of hindbrain vesicle
metencephalon & myelencephalon
Primary Division of the Developing Brain
- Adult Structures of forebrain vesicle (telencephalon)
cerebral hemisphere, basal ganglia, hippocampus
Primary Division of the Developing Brain
- Adult structures of forebrain vesicle (diencephalon)
thalamus, hypothamus, pineal body, infundibulum
Primary Division of the Developing Brain
- Adult structures of midbrain vesicle
tectum, tegmentum, crus cerebri
Primary Division of the Developing Brain
- Adult structures of hindbrain vesicle
pons, cerebellum, medulla oblongata
excessive numbers of neurons and neuroglial cells develop, and many will be programmed to die by a process known as
programmed cell death
promote the development and survival of neurons
identification of neurotrophic factors
TRUE OR FALSE
the spinal cord is longer than the vertebral column, the spinal cord segments do not correspond numerically with the vertebrae that lie at the same level
false, shorter
the degree of spinal cord injury at different vertebral levels is determined largely by
anatominal factors
Spinal cord injury
in the ___, dislocation or fracture dislocation is common
cervical region (neck area)
Spinal cord injury
- ceases if the cord is completely severed above the segmental origin of the phrenic nerves (c3-c5)
- intercostal muscles (muscles between your ribs) and the diaphragm are paralyzed resulting in death,
respiration
Relationship of spinal cord segments to vertebral numbers
Vertebrae: cervical vertebrae
Spinal segment: ?
add 1
Relationship of spinal cord segments to vertebral numbers
Vertebrae: upper thoracic vertebrae
Spinal segment: ?
add 2
Relationship of spinal cord segments to vertebral numbers
Vertebrae: lower thoracic vertebrae (7-9)
Spinal segment: ?
add 3
Relationship of spinal cord segments to vertebral numbers
Vertebrae: 10th thoracic vertebra
Spinal segment: ?
L1-L2 cord segments
Relationship of spinal cord segments to vertebral numbers
Vertebrae: 11th thoracic vertebra
Spinal segment: ?
L3-L4 cord segments
Relationship of spinal cord segments to vertebral numbers
Vertebrae: 12th thoracic vertebra
Spinal segment: ?
L5 cord segment
Relationship of spinal cord segments to vertebral numbers
Vertebrae: 1st lumbar vertebra
Spinal segment: ?
sacral and coccygeal cord segments
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: add 1
cervical vertebrae
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: add 2
upper thoracic vertebrae
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: add 3
lower thoracic vertebrae (7-9)
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: L1-L2 cord segments
10th thoracic vertebra
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: L3-L4 cord segments
11th thoracic vertebra
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: L5 cord segments
12th thoracic vertebra
Relationship of spinal cord segments to vertebral numbers
Vertebrae: ?
Spinal segment: sacral and coccygeal cord segments
1st lumbar vertebra
Spinal cord injury
- spinal cord in the adult extends down only as far as the level of the lower border of the 1st lumbar vertebra
- the large size of the vertebral foramen in this region gives the roots of the cauda equina ample room
fracture dislocations of the lumbar region
Spinal cord injury
-partial or complete loss of function at the ___ and partial or complete loss of function of afferent and efferent nerve tracts ___
level of the lesion, below the level of the lesion
Spinal nerve injurues
- transmit the spinal nerves and the small segmental arteries and veins, all of which are embedded in areolar tissue
intervertebral foramina
Spinal nerve injurues
- less comon
- 5th. 6th, and 7th cervical vertebrae
cervical disc herniations
Spinal nerve injurues
- pain if felt near the lower part of the back of the neck and shoulder and along the area in the distribution of the spinal nerve involved
cervical disc herniations
Spinal nerve injurues
- more common
- discs usually affected are those between the 5th lumbar vertebra and the sacrum
lumbar disc herniations
Spinal nerve injurues
- the roots of the cauda equina run posteriorly over a number of intervertebral discs
lumbar region
Spinal nerve injurues
- press on one or two roots and commonly involves the nerve root going to the intervertebral foramen just below
lateral herniation
Spinal nerve injurues
- pain is referred down the leg and foot in the distribution of the affected nerve
lumbar disc herniations
Spinal nerve injurues
- pain is usally felt down the back and lateral side of the leg, radiating to the sole of the foot, a condition known as
sciatica
Spinal nerve injurues
- causes muscle weakness
pressure on the anterior motor roots
performed to withdraw a sample of CSF (Cerebrospinal fluid) for microscopic or bacteriologic examination or to inject drugs to combat infection or induce anesthesia
spinal tap (lumbar puncture)
Spinal Tap
- the lower part of the vertebral canal is thus occupied by the
- interval between the arachnoid membrane and the pia mater.
subarachnoid space
Spinal Tap
- contains the lumbar and sacral nerve roots and the filum terminale
subarachnoid space
TRUE OR FALSE
a neddle inserted into the subarachnoid space in this region usually pushes the nerve roots to one side causing damage
False, without causing damage
Spinal Tap
- the needle will pass through the following anatomical structures before it enters the subarachnoid space: a,b,c,d,e,f,g, h
a - skin b- superficial fascia c - supraspinous ligament d- interspinous ligament e - ligamentum flavum f - areolar tissue containing the internal vertebral venous plexus g - dura matter h - arachnoid matter
Spinal Tap
- measured by attaching a manometer to the needle
- normal pressure is about 60 to 150 mm of water
CSF pressure
Spinal Tap
- the pressure shows oscillations corresponding to the movements of respiration and the arterial pulse
CSF pressure
Caudal Anesthesia
- anesthetic solutions may be injected into the ___ through the sacral hiatus
sacral canal
- obstetricians use this method of nerve block to relieve the pains of the first and second stages of labor because anesthetic administered by this method does not affect the infant
- used in operations in the sacral region, including anorectal surgery
caudal anesthesia
Skull fractures
- in the ___ fractures of the skull are common, but they are less common in the young child
adult
Skull fractures
- the skull bones are more resilient, and they are separated by fibrous sutural ligaments
infants
Skull fractures
- sutural ligaments begin to ossify (harden) during ___
middle age
Skull fractures
- resembles an eggshell, with limited resilience
- a severe localized blow will cause a local indentation, commonly with bone splintering
adult skull
Skull fractures
- resembles a ping-pong ball
- a localized blow produces a depression without splintering
young child’s skull
caused by displacement and distortion of the neural tissues at the moment of impact
brain injuries
brain injuries
- ___ lead to displacement of the brain
- cause severe cerebral damage, stretching and distortion of the brainstem, and stretching and even tearing of brain commissures
blows on the front or back of the head
brain injuries
- cause less cerebral displacement, and the injuries to the brain consequently tend to be less severe
blows to the side of the head
brain injuries
- tough structure and may cause considerable damage to the softer brain tissue in cases of a severe blow to the side of the head
falx cerebri
brain injuries
- the brain is forcibly thrown against the sharp edges of bone within the skull
brain lacerations
brain injuries
- result in damage to the brain at two sites: at the point of impact and at the pole of the brain opposite the point of impact, where the brain is thrown against the skull wall
contercoup injury
Intracranial Hemorrhage
- injuries to the meningeal arteries or veins
- minor blow to the side of the head, resulting in fracture of the skull in the region of the anterior-inferior portion of the parietal bone
epidural hemorrhage
Intracranial Hemorrhage
- bleeding occurs and strips the meningeal layer of dura from the internal surface of the skull
- intercranial pressure (ICP) rises, and the enlarging blood clot exerts local pressure on the underlying precentral motor (motor area)
arterial or venous injury
Intracranial Hemorrhage
- to stop the hemorrhage, the torn artery must be ___ or ___
ligated or plugged
Intracranial Hemorrhage
- tearing of the superior cerebral veins where they enter the superior sagittal sinus
- blow to the front or back of the head resulting in excessive anterposterior displacement of the brain within the skull
subdural hemorrhage
Intracranial Hemorrhage
- caused by a sudden minor blow
meningeal hemorrhage
Intracranial Hemorrhage
- nontraumatic leakage or rupture of a cogenital aneurysm on the cerebral arterial circle
subarachnoid hemorrhage
Intracranial Hemorrhage
- most common in patients with hypertension (high blood pressure)
cerebral hemorrhage, spontaneous intracerebral hemorrhage
Intracranial Hemorrhage
- a branch of the middle artery
lenticulostriate artery
the most common cause of traumatic injury death in infancy
inflicted head injury
- most cases takes place during the first year of life
- usually restricted to infants under 3 years of age
shaken baby syndrome
- the fontanelles (soft spots on an infant’s head where the bony plates that make up the skull have not yet come together) are bulging
- child may have retinal hemorrhages
shaken baby syndrome
- include tumor, hematoma, abscess
- these lesions will add to the normal bulk of the intracranial contents
space occupying or expanding lesions
- first accommodated by the expulsion of CSF from the cranial cavity
expanding lesion
- used for the detection of intracranial lesions
- quick, safe, accurate
CT (computed tomography)
- structures are distinguished from one another by their ability to absorb energy from x-rays
Computed tomography
- uses the magnetic properties of the hydrogen nucleus excited by radio frequency radiation transmitted by a coil surrounding the head
- best imaging method for detecting low-contrast lesions such as brain tumors or small multiple sclerosis plaques
MRI (magnetic resonance imaging)
- used radioactive isotopes that decay with the emission of positively charged electrons to map the biochemical. physiologic, and pharmacologic processes taking place in the brain
- successfully used in evaluation of patients with brain tumors, movement, disorders, seizures, and schizophrenia
Positron Emission Tomography (PET)
comprises the central nervous system and peripheral nervous system
nervous system
consists of the brain and the spinal cord, both of which are surrounded by the meninges and the cerebrospinal fluid
central nervous system
consists of all other nerves in the body
peripheral nervous sytem
concerned with involuntary structures and distributed throughout both CNS and PNS
autonomic nervous system
3 major divisions of the brain
hindbrain, midbrain, forebrain
subdivided into the medulla oblongata, pons, and cerebellum
hindbrain
subdivided into the diencephalon and cerebrum
forebrain
largest component of the brain and consists of two hemispheres, covered by cerebral cortex, which is made up of a series of folds and fissures called gyri and sulci
cerebrum
cylindrical structure continuous with the medulla oblongata of the brainstem
spinal cord
TRUE OR FALSE
27 pairs of spinal nerves are attached
false, 31
connect the spinal nerve to the spinal cord
motor and sensory roots
divide into anterior and posterior rami, both containing motor and sensory fibers
spinal nerves
distributed to the muscles and skin of the back
posterior rami
supply the muscles and skin of the limbs and the anterolateral body wall
anterior rami
collections of neuronal cell bodies that result in fusiform (spindle-shaped) swellings within the dorsal roots, or as irregular swellings within the ANS
ganglia
during development, the embryo differentiates into three layers:
entoderm, mesoderm, ectoderm
gives rise of the entire nervous system, initially forming the neural plate, then neural folds, and subsequently fusing into the neural tube
ectoderm
contains neural crest cells which differentiate into ganglion cells, schwann cells, melanocytes, and cells of the suprarenal medulla
leading edge of the neural folds
Spinal cord
- the neural tube is seen to dilate at the cephalic end into the:
forebrain vesicle, midbrain vesicle and hindbrain vesicle
Spinal cord
- the rest of the tube elongates and remains smaller in diameter, it will form the
spinal cord
Spinal cord
- the wall of the neural tube consists of a single layer of pseudostratified columnar epithelial cells, called
matrix cells
Spinal cord
- this thick zone of epithelium, which extends from the cavity of the tube to the exterior is referred to as
ventricular zone
TRUE OR FALSE
repeated division of the matrix cells results in an decrease in length and diameter of the neural tube
false, increased
Spinal cord
- incapable of further division
neuroblasts
Spinal cord
- these cells migrate peripherally to form the
intermediate zone
Spinal cord
- the intermediate zone will form the ___ of the spinal cord
gray matter
Spinal cord
- neuroblasts give rise to nerve fibers that grow peripherally and form a layer external to the intermediate zone called
marginal zone
Spinal cord
- nerve fibers in the marginal zone become myelinated and form
white matter
Spinal cord
- matrix cells give rise to the ___ and the ___ of the neuroglia
astrocytes and oligodenrocytes
Spinal cord
- dervied from the surrounding mesenchyme, migrate into the developing spinal cord along with blood vessels
microglial cells
Spinal cord
- formed from the matrix cells that line the neural tube
ependymal cells
Spinal cord
- intermediate zone of the lateral wall of the tube forms a large anterior thickening known as
basal plate
Spinal cord
-posterior thickening
alar plate
Spinal cord
- the neuroblasts in the basal plate will form the ___ of the anterior column (horn)
motor cells
Spinal cord
- neuroblasts in the alar plate will become ___ of the posterior column
sensory cells
Spinal cord
- the motor basal plate and the sensory alar plate are separated on each side by the
sulcus limitans
Spinal cord
- continued growth of the basal plates on each side of the midline forms a deep longitudinal groove called
anterior median fissure
Spinal cord
- walls of the posterior portion of the tube fuse forming the
posterior median septum
Spinal cord
- the lumen of the neural tube becomes the
central canal
Spinal cord
- gives rise to axons that will leave the anterior surface of the spinal cord as autonomic preganglionic fibers
lateral group of neurons
Spinal cord
- lateral group of neurons will form the ___, that is, the ___
lateral gray column (horn), sympathetic outflow
Spinal cord
- axons leaving the anterior surface of the spinal cord will form the
anterior roots of the spinal nerves
Spinal cord
- each neuroblast develops two processes:
peripheral process & central process
Spinal cord
- grow out laterally to become typical axons of sensory nerve fibers
peripheral process
Spinal cord
- also axons, grow into the posterior part of the developing spinal cord and either end in the posterior gray column or ascend through the marginal zone to one of the higher brain centers
central process
Spinal cord
- peripheral processes join the anterior root to form
spinal nerve
Spinal cord
- some of the neural crest cells form the:
- surround the unipolar nerve cell bodies in a ganglion
capsular or satellite cells
Spinal cord
- formed of the unipolar neurons and the capsular cells
posterior root ganglion
Spinal cord
- formed from the mesenchyme (sclerotome) that surrounds the neural tube
pia mater, arachnoid mater, dura mater
Spinal cord
- develops as a cavity in the mesenchyme which becomes filled with CFS
subarachnoid space
Spinal cord
- formed from areas of condensation of the mesenchyme
ligamentum denticulatum
TRUE OR FALSE
during the first 2 months of intrauterine life, the spinal cord is the same length as the vertebral column
true
Spinal cord
- at birth, the ___ of the cord lies at the level of the third lumbar vertebra
- in adult, the lower end of the spinal cord lies at the level of the lower border of the body of the first lumbar vertebra
coccygeal end
Spinal cord
- pia mater, extends down as a slender fibrous strand from the lower end of the cord to the coccyx and forms the
filum terminale
Spinal cord
- obliquely coursing anterior and posterior roots of the spinal nerves and the filum terminale, which now occupy the lower end of the vertebral canal, collectively form the
cauda equina
Spinal cord
- the spinal cord becomes swollen in the cervical and lumbar regions to form the
cervical and lumbar enlargements
Brain
- three primary vesicles
forebrain vesicle, midbrain vesicle, hindbrain vesicle
Brain
- forebrain vesicle will become
prosencephalon
Brain
- midbrain vesicle will become
mesencephalon
Brain
- hindbrain vesicle will become
rhombencephalon
Brain
- by the ___ week, the forebrain and hindbrain vesicles divide into two secondary vesciles
fifth
Brain
- secondary vesicle of the forebrain
- primitive cerebral hemisphere
telencephalon
Brain
- secondary vesicle of the forebrain
- develops optic vesicles
diencephalon
Brain
- secondary vesicle of hindbrain
- future pons and cerebellum
metencephalon
Brain
- secondary vesicle of hindbrain
- medulla oblongata
myelencephalon
Brain
- cavity in each cerebral hemisphere
lateral ventricle
Brain
- cavity of the diencephalon
third ventricle
Brain
- cavity of the midbrain vesicle becomes small and forms
cerebral aqueduct or aqueduct of sylvius
Brain
- cavity of the hindbrain vesicle forms the
- continuous with the central canal of the spinal cord
fourth ventricle
Brain
- lateral ventricles communicate with the third ventricle through the
interventricular foramina
Brain
- ___ in development, the embryo is a flat disc and neural tube is straight. later the head and tail fold, the neural tube becomes curved
early
Brain
- anterior thickenings
basal plates
Brain
- posterior thickenings
alar plates
Brain
- what separated the basal and alar plates
sulcus limitans
Primary Divisions of the Developing Brain
Primary Vesicle: ?
Primary Division: prosencephalon
Subdivision: telecephalon & diencephalon
forebrain vesicle
Primary Divisions of the Developing Brain
Primary Vesicle: ?
Primary Division: mesencephalon
Subdivision: mesencephalon
midbrain vesicle
Primary Divisions of the Developing Brain
Primary Vesicle: ?
Primary Division: rhombencephalon
Subdivision: metencephalon & myelencephalon
hindbrain
Primary Divisions of the Developing Brain
Primary Vesicle: forebrain vesicle
Primary Division: ?
Subdivision: telecephalon & diencephalon
prosencephalon
Primary Divisions of the Developing Brain
Primary Vesicle: midbrain vesicle
Primary Division: ?
Subdivision: mesencephalon
mesencephalon
Primary Divisions of the Developing Brain
Primary Vesicle: hindbrain vesicle
Primary Division: ?
Subdivision: metencephalon & myelencephalon
rhombencephalon
Primary Divisions of the Developing Brain
Adult Structure: cerebral hemisphere, basal ganglia, hippocampus
forebrain, prosencephalon, telencephalon
Primary Divisions of the Developing Brain
Adult Structure: thalamus, hypothamalus, pineal body, infundibulum
forebrain, prosencephalon, diencephalon
Primary Divisions of the Developing Brain
Adult Structure: tectum, tegmentum, crus cerebri
midbrain, mesencephalon, mesencephalon
Primary Divisions of the Developing Brain
Adult Structure: pons, cerebellum
hindbrain, rhombencephalon, metencephalon
Primary Divisions of the Developing Brain
Adult Structure: medulla oblongata
hindbrain, rhombencephalon, myelencephalon
Brain
- descending axons from the neurons in the motor ares of the cerebral cortex produce swellings called
pyramind
Brain
- arises from the anterior part of the metencephalon
- receives a cellular contribution from the alar part of the myelencephalon
pons
Brain
- formed from the posterior part of the alar plates of the metencephalon
cerebellum
Brain
- the alar plates bend medially to form
- as alar plates enlarge, the lips project caudally over the roof plate of the fourth ventricle and unite with each other in the midline to form the cerebellum
rhombic lips
Brain
- at the 12th week, a small midline portion called
vermis
Brain
- two lateral portions recognized at the 12th week of development
cerebellar hemisphere
Brain
- develops for the midbrain vesicle, the cavity of which becomes much reduced to form the cerebral aqueduct or aqeuduct of sylvius
midbrain
Brain
- separates the alar plate from the basal plate on each side, as seen in the developing spinal cord
sulcus limitans
Brain
- two alar plates and the original roof plate form
tectum
Brain
- representing the four colliculi appear on the posterior surface of the midbrain
four swellings
Brain
- associated with visual reflexes
superior colliculi
Brain
- associated with auditory reflexes
inferior colliculi
Brain
- develops from the forebrain vesicle
forebrain
Forebrain
- at an early stage, a lateral diverticulum called ___ appears on each side of the forebrain
optic vesicle
Forebrain
- the optic vesicle and stalk ultimately will form the ___ and ___
retina and optic nerve
Diencephalon Fate
- in some individuals, the two thalami may meet and fuse in the midline to form the ___ of gray matter that crosses the third ventricle
interthalamic connection
Brain
- forms the anterior end of the third ventricle which is closed by the lamina terminalis
telencephalon
Brain
- diverticulum on either side forms the
cerebral hemisphere
Brain
- arises at the beginning of the fifth week of development
- One half of the cerebrum, the part of the brain that controls muscle functions and also controls speech, thought, emotions, reading, writing, and learning.
cerebral hemisphere
Brain
- cerebral hemisphere grow and expand rapidly, first anteriorly to form the
frontal lobes
Brain
- cerebral hemisphere grow and expand rapidly, then laterally and superiorly to form the
parietal lobes
Brain
- cerebral hemisphere grow and expand rapidly, and finally posteriorly and inferiorly to produce the
occipital and temporal lobes
Brain
- cover the midbrain and hindbrain
hemisphere
Brain
- medial wall of the cerebral hemisphere remains thin and is formed by
ependymal cells
Brain
- separated from the cerebellum by mesenchyme
occipital lobe
Brain
- occipital lobe condenses to form
tentorium cerebelli
Brain
- occipital lobe condenses to form
tentorium cerebelli
Brain
- the thickening protrudes into the lateral ventricle and forms
hippocampus
Brain
- the compact bundle of ascending and descending tracts is known as
internal capsule
Brain
- consists of a few cortical projection fibers that pass lateral to the lentiform nucleus
external capsule
Brain
- cortex covering the lentiform nucleus remains as fixed area called
- a thin ribbon of gray matter tissue that lies just deep to the lateral brain surface, separating the temporal lobe from the inferior parietal cortex.
insula
Brain
- cephalic end of the neural tube, forms a bridge between the two cerebral hemispheres and enables nerve fibers to pass from one cerebral hemisphere to other
lamina terminalis
Brain
- first commissure to develop
- runs in the lamina terminalis
anterior commissure
Brain
- second commissure to develop
- connects the cortex of the hippocampus in each hemisphere
fornix
Brain
- connects the olfactory bulb and the temporal lobe of the cortex on one side with the same structures of the opposite hemisphere
anterior commissure
Brain
- largest and most important commissure
- third commissure to develop
corpus callosum
Brain
- its first fibers connect the frontal loves of both sides and later the parietal lobes
- as it increase in size because of increased numbers of fibers, it arches back over the roof of the developing third ventricle
corpus callosum
Brain
- remains of the lamina terminalis, which lie between the corpus callosum and formix, become stretched out to form a thin septum
septum pellucidum
Brain
- formed in the inferior part of the lamia terminalis
- contains fibers from the medial halves of the retinae
optic chiasma
Brain
- formed and maintained by the oligodenrocytes of the neuroglia
myelins sheath
Brain
- ___ in the ___ begins first in the cervical region, and from here, the process extends caudally
- begins within the cord at about the fourth month, and the sensory fibers are affected first, the last affected are the descending motor fibers
myelination in the spinal cord
Brain
- process by which brain oligodendrocytes produce layers of myelin that wrap around the neuronal axons and act as a layer of insulation for the transmission of electric action potentials down the neuronal axon.
myelination
Brain
- ___ in the ___ begins at about the sixth month of fetal life but is restricted to the fibers of the basal ganglia
myelination in the brain
TRUE OR FALSE
at birth, the brain still is largely unmyelinated
TRUE
Cogentinal Anomalies
- the spines and arches of one or more adjacent vertebrae fail to develop
- occurs most frequently in the lower thoracic, lumbar, and sacral regions
spina bifida
Cogentinal Anomalies
- result of failure of the mesenchyme
spina bifida
Cogentinal Anomalies
- the spines and arches of one or more vertebrae, usually in the lumbar region, are absent,
- the vertebral canal remains open posteriorly
spina bifida occulta
Cogentinal Anomalies
- spinal cord and nerve roots usually are normal
- defect is covered by the postvertebral muscles and cannot be seen from the surface
spina bifida occulta
Cogentinal Anomalies
- small tuft of hair or a fatty tumor may be present over the defect
- symptomless
spina bifida occulta
Cogentinal Anomalies
- meninges project through the defect in the vertebral arches, forming a cystic swelling beneath the skin and containing CSF which communicates with the subarachnoid space
- spinal cord and nerves usually are normal
meningocele
Cogentinal Anomalies
- spinal cord lies within the meningeal sac, which projects through the vertebral arch defect
- spinal cord or nerve roots are adherent to the inner wall of the sac
meningomyelocele
Cogentinal Anomalies
- neural tube fails to close in the region of the defect
- oval raw area is found on the surface
myelocele
Cogentinal Anomalies
- rare
- meningomyelocele is present
syringomyeolocele
Cogentinal Anomalies
- central canal of the spinal cord at the level of the bony defect is grossly dilated
syringomyeolocele
Cogentinal Anomalies
- most common defect of the spine
- require no treatment
spina bifida occulta
Cogentinal Anomalies
- the next most common defect in the spine
myelocele
Cogentinal Anomalies
- should be removed surgically
meningcele & meningomyelocele
Cogentinal Anomalies
- abnormal increase in the volume of cerebrospinal fluid within the skull
- this condition may be associated with spina bifida and meningocele
hydrocephalus
Cogentinal Anomalies
- caused by stenosis of the cerebral aqueduct or by normal single channel being represented by many inadequate minute tubules
- overgrowth of neuroglia around the aqueduct
hydrocephalus
Cogentinal Anomalies
- hydrocephalus with spina bifida
arnold chiari phenomanon
Cogentinal Anomalies
- inadequate development or failure of development of the interventricular foramen, or foramina of magendie and luschka
- may occur before birth and if it is advanced, it could obstruct labor
hydrocephalus
Cogentinal Anomalies
- greater part of the brain and the vault of the skull are absent
anencephaly
Cogentinal Anomalies
- caused by the failure of the rostal end of the neural tube to develop
- cavity remains open
anomaly
Cogentinal Anomalies
- although eyes are present, the optic nerves are absent
- commonly involves the spinal cord, and neural tube remains open in the cervical region
anencephaly
Cogentinal Anomalies
- commonly diagnosed before birth
- most infants are stillborn or die shortly after birth
anencephaly
Cogentinal Anomalies
- development and closure of the neural tube are normally completed within
28 days
Spinal cord
- in the early development, the neural tube dilates at the cephalic end to form the ___, ___, and ___. the rest of the tube elongates to form the ___
forebrain, midbrain, hindbrain vesicle; spinal cord
Spinal cord
- matrix cells in the epithelial walls of the neural tube are referred to as
ventricular zone
Spinal cord
- formed and migrate to the intermediate zone to form the gray matter of the spinal cord
neuroblasts
Spinal cord
- the cells of the intermediate zone grow fibers that extend and form a layer external to the intermediate zone called ___
- these fibers become myelinated and form the ___ of the spinal cord
marginal zone; white matter
Spinal cord
- matrix cells will also give rise to ___ and ___
astrocytes and oligodendrocytes
Spinal cord
- migrate in from the mesenchyme
microglial cells
Spinal cord
- formed from the mesenchyme that surrounds the neural tube
layers of the meninges
Brain
- once the neural tube closes
three primary vesicles complete development
Brain
- forebrain vesicle forms
- matures into the cerebral hemisphere, basal ganglia, and hippocampus
telencephalon
Brain
- becomes the thalamus, hypothalamus, pineal body, and infundibulum
diencephalon
Brain
- forms the tectum, tegmentum, and crus cerebri components of the midbrain
midbrain vesicle
Brain
- forms the metencephalon which includes the pons and cerebellum, and the myelencephalon, which includes the medulla oblongata
hindbrain vesicle
Anatomical References
- pointing towards the rat’s nose
anterior
Anatomical References
- direction pointing toward the rat’s tail
posterior
Anatomical References
- direction pointing up
dorsal
Anatomical References
- direction pointing down
ventral
Anatomical References
- the right side of the brain and spinal cord is the mirror image of the left side, this is known as
bilateral symmetry
Anatomical References
- invisible line running down the middle of the nervous system
midline
Anatomical References
- structures closer the the midline
medial
Anatomical References
- structures farther away from the midline
lateral
Anatomical References
- two structures that are on the same side are said to be ___ to each other
ipsilateral
Anatomical References
- structures are on opposite sides of the midline
contralateral
Anatomical References
- plane of the section resulting from splitting the brain into equal right and left halves
midsagittal plane
Anatomical References
- sections parallel to the midsagittal plane
sagittal plane
Anatomical References
- parallel to the ground
horizontal plane
Anatomical References
- perpendicular to the ground and to the sagittal plane
- splits the brain into anterior and posterior parts
coronal plane
Central Nervous System
- largest part of the brain
cerebrum
Central Nervous System
- split down the middle into two cerebral hemispheres, separated by the deep ___
sagittal fissure
Central Nervous System
- ___ receives sensation from, and controls movement of the left side of the body and vice versa
right ceberal hemisphere
Central Nervous System
- lying behind the cerebrum
- contains as many neurons as both cerebral hemispheres combined
cerebellum
Central Nervous System
- a movement control center that has extensive connections with the cerebrum and the spinal cord
cerebellum
Central Nervous System
- concerned with movements of the left side of the body and vice versa
left side of the cerebellum
Central Nervous System
- forms the stalk from which the cerebral hemispheres and the cerebellum sprout
- complex nexus of fibers and cells that in part serves to relay information from the cerebrum to the spinal cord and cerebellum and vice versa
brain stem
Central Nervous System
- vital functions are regulated, such as breathing, consciousness, and the control of body temperature
- most important to life and damage is usally fatal
brain stem
Central Nervous System
- encased in the bony vertebral column and is attched to the brain stem
- major conduit of information from skin, joints, and muscles of the body to the brain and vice versa
spinal cord
Central Nervous System
- does not mean the muscles cannot function, but they cannot be controlled by the brain
paralysis
Central Nervous System
- spinal cord communicates with the body via ___
- part of the peripheral nervous system
spinal nerves
Central Nervous System
- exit the spinal cord through notches between each vertebra of the vertebral column
spinal nerves
Central Nervous System
- each spinal nerve attaches to the spinal cord by means of two branches: ___ and ___
dorsal root and ventral root
Central Nervous System
- contains axons bringing information into the spinal cord
dorsal root
Central Nervous System
- contains axons carrying information away from the spinal cord
ventral root
Central Nervous System
- all spinal nerves that innervate the skin, joints, and muscles that are under voluntary control
- innervate and collect information from the skin, muscles, and joints, enter the spinal cord via the dorsal roots
somatic PNS
Central Nervous System
- consist of the neurons that innervate the internal organs, blood vessels, and glands
autonomic nervous system
Central Nervous System
- bring information about visceral function to the CNS, such as the pressure and oxygen content of the blood in the arteries
visceral sensory axons
Central Nervous System
- command the contraction and relaxation of muscles that form the walls of the intestines and the blood vessels, the rate of cardiac muscle contraction, and secretory function of various glands
visceral motor fibers
Central Nervous System
- carry to
- the somatic or visceral sensory axons bringing information into the CNS
afferent
Central Nervous System
- carry from
- axons that emerge from the CNS to innervate the muscles and glands
efferent
Central Nervous System
- each has a name and a number associated with it
- contain a complex mixture of axons that perform different functions
12 pairs of cranial nerves
Central Nervous System
- the CNS, skull and vertebral column, does not come in direct contact with the overlying bone. it is protected by three membranes collectively called
- greek for “covering”
meninges
Central Nervous System
- three membranes the covers are
dura mater, arachnoid membrane, pia mater
Central Nervous System
- “hard mother”
- leather-like consistency
dura mater
Central Nervous System
- forms a tough, inelastic bag that surrounds the brain and spinal cord
dura mater
Central Nervous System
- “spider”
- appearance and consistency resembling a spider web
arachnoid membrane
Central Nervous System
- no space between the dura and the arachnoid, if the blood vessels passing through the dura are ruptured, blood can collect here and form
- disorder is treated by drilling a hole in the skull and draining the blood
subdural hematoma
Central Nervous System
- “gentle mother”
- thin membrane that adheres closely to the surface of the brain
pia mater
Central Nervous System
- run many blood vessels that utimately dive into the substance of the underlying brain
pia mater
Central Nervous System
- pia is separated from the arachnoid by a fluid-filled space called
subarachnoid space
Central Nervous System
- the subarachnoid space is filled with salty clear liquid called
- brain floats inside the head in this thin layer
cerebrospinal fluid
Central Nervous System
- fluid-filled caverns and canals inside the brain constitute the
ventricular system
Central Nervous System
- CSF is produced by a special tissue called
choroid plexus
Central Nervous System
- CSF is absorbed by the blood vessels at special structures called
- if the normal flow of CSF is disrupted, brain damage can result
arachnoid villi
Central Nervous System
- if the flow of CSF from the choroid plexus through the ventricular system to the subarachnoid space is impaired, the fluid will back up and cause swelling of the ventricles
hydrocephalus
Central Nervous System
- allows visualization of deep structures without sectioning the brain
- soak the brain in a solution that replaces light-absorbing lipids with a water-soluble get that turns the brain transparent
clarity
Central Nervous System
- Godfrey Hounsfields and Allan Cormack
- generate and image of a slice of brain
computed tomography (CT)
Central Nervous System
- who created comupted tomography
Godfrey Hounsfields and Allan Cormack
Central Nervous System
- noninvasively revealed, for the first time, the gross organization of gray and white matter, and the position of the ventricles, in the living brain
CT scans
Central Nervous System
- yields a much more detailed map of the brain
- does not require x-irradiation and images of brain slices can be made in any plane desired
magnetic resonance imaging (MRI)
Central Nervous System
- uses information about how hydrogen atoms in the brain respond to perturbations of a strong magnetic field
- used for determining the amount of certain atoms at different locations in the body
magnetic resonance imaging
Central Nervous System
- enables visualization of large bundles of axons in the brain
diffusion tensor imaging (DTI)
Central Nervous System
- the frequency at which the protons absorb energy
resonant frequency
Central Nervous System
- ___ and ___ observe and measure changes in brain activity associated with the planning and execution of specific tasks
- both methods detect changes in regional blood flow and metabolism within the brain
positron emission tomography (PET) & functional magnetic resonance imaging (fMRI)
Central Nervous System
- developed in 1970s
- radioactive solution containing atoms that emit positrons (positively charged electrons) is introduced into the bloodstream
PET imaging
Central Nervous System
- oxyhemoglobin has a magnetic resonance different from that of deoxyhemoglobin
fMRI method
Collections of Neurons
- generic term for a collection of neural cell bodies in the CNS
- when a freshly dissected brain is cut open, neurons appear gray
gray matter
Collections of Neurons
- any collection of neurons that form a thin sheet, usually at the brain’s surface
- latin for bark
cortex
Collections of Neurons
- distinguishable mass of neurons, usually deep in the brain
- latin for nut
nucleus
Collections of Neurons
- group of related neurons deep within the brain but usually with less distinct borders than those of nuclei
substantia
Collections of Neurons
- small, well-defined group of cells
locus
Collections of Neurons
- collection of neurons in the PNS
- greek for knot
ganglion
Collections of Axons
- bundle of axons in the PNS
- only one collecton of CNS axons is called this which is the optic
nerve
Collections of Axons
- generic term for a collection of CNS axons
- when a freshly dissected brain is cut open, axons appear white
white matter
Collections of Axons
- collection of CNS axons having a common site of origin and a common destination
tract
Collections of Axons
- collection of axons that run together but do not necessarily have the same origin and destination
bundle
Collections of Axons
- collection of axons that connect the cerebrum with the brain stem
capsule
Collections of Axons
- collection of axons that connect one side of the brain with the other side
commmissure
Collections of Axons
- tract that meanders through the brain like a ribbon
lemniscus
Central Nervous System
- the embryo begins as a flat disk with three distinct layers of cells called
endoderm, mesoderm, ectoderm
Central Nervous System
- gives rise to the lining of many of the internal organs (viscera)
endoderm
Central Nervous System
- the nervous system and the skin derive entirely from
ectoderm
Central Nervous System
- part of the ectoderm that give rise to the nervous system
neural plate
Central Nervous System
- formation of a groove in the neural plate that runs rostal to caudal
neural groove
Central Nervous System
- walls of the groove are called
neural folds
Central Nervous System
- neural folds move together and fuse dorsally, forming
neural tube
Central Nervous System
- as the neural folds come together, some neural ectoderm is pinched off and comes to lie just lateral to the neural tube. this tissue is called
- develops in close association with the underlying mesoderm
neural crest
TRUE OR FALSE
the entire central nervous system develops from the walls of the neural crest
false, neural tube
TRUE OR FALSE
all neurons with cell bodies in the PNS derive from the neural crest
true
Central Nervous System
- mesoderm forms prominent bulges on either side of the neural tube called
- 33 individual vertebrae of spinal column and the related skeletal muscles will develop
somites
Central Nervous System
- nerves that innervate these skeletal muscles are called
somatic motor nerve
Central Nervous System
- neural plate becomes the neural tube called
- occurs very early in embryonic development
neurulation
Central Nervous System
- crucial event in the development of nervous system
- occurs early - only 3 weeks after conception
neural tube formation
Central Nervous System
- many neural tube defects can be traced to a deficiency of
folic acid
Central Nervous System
- structures become more complex and functionally specialized during development
differentiation
Central Nervous System
- rostal-most vesicle
- pro for before and encephalon for brain in greek
- forebrain
prosencephalon
TRUE OR FALSE
the entire brain derives from the three primary vesicles of the neural tube
true
Central Nervous System
- connects with the caudal neural tube, which gives rise to the spinal cord
rhombencephalon
Central Nervous System
- optic vesicles grow and invaginate to form the optic stalk and optic cups, which will ultimately become ___ and ___ in the adult
optic nerves and two retinas
Central Nervous System
- telecephalic vesicles together form the ___ or endbrain
- consisting of two cerebral hemispheres
telencephalon
Central Nervous System
- fluid-filled spaces within the cerebral hemisphere
lateral ventricles
Central Nervous System
- space at the center of the diencephalon
third ventricle
Central Nervous System
- nestled deep inside the forebrain
- inner chamber
thalamus
Central Nervous System
- contains all axons that run to and from the neurons in cerebral cortex
white matter
Central Nervous System
- continuous with the cortical white matter and forms an axonal bridge that links cortical neurons of the two cerebral hemisphere
corpus callosum
Central Nervous System
- links the cortex with the brain stem, particularly the thalamus
internal capsule
Central Nervous System
- seat of perceptions, conscious awareness, cognition and voluntary action
forebrain
Central Nervous System
- most important structure in the forebrain
- the brain structure that has expanded the most over the course of human evolution
cerebral cortex
Central Nervous System
- information from the eyes, ears, and skin is brought to the ___ for analysis
cerebral cortex
Central Nervous System
- referred to as the gateway to cerebral cortex
- each of sensory pathways serving vision, audition, and somatic sensation relays in the ___ en route to the cortex
thalamus
Central Nervous System
- send axons to the cortex via the internal capsule
- axons of each internal capsule carry information to the cortex about the contralateral side of the body
thalamic neurons
Central Nervous System
- send axons through the internal capsule, back to the brain stem
- important way cortex can comment voluntary movement
cortical neurons
Central Nervous System
- collection of cells in the basal telecephalon
- lie deep within the cerebrum
basal ganglia
Central Nervous System
- involved in fear and emotion
amygdala
Central Nervous System
- controls the visceral (autonomic) nervous system, which regulates bodily functions in response to the needs of the organism
- orchestrates body’s visceral flight-or-fight response
hypothalamus
Central Nervous System
- dorsal surface of the mesencephalic vesicle becomes a structure called
tectum
Central Nervous System
- floor of the midbrain becomes the
tegmentum
Central Nervous System
- CSF-filled space in between constricts into a narrow channel called
cerebral aqueduct
Central Nervous System
- serving as a conduit for information passing from the spinal cord to the forebrain and vice versa
- contains neurons that contribute to sensory systems, the control of movement, and several other functions
functions of the midbrain
Central Nervous System
- receives direct input from the eye so it is also called optic tectum
superior colliculus
Central Nervous System
- control eye movements, which it does via synaptic connections with the motor neurons that innervate the eye muscles
optic tectum
Central Nervous System
- receives sensory information but from the ear instead of the eye
- important relay station for auditory information en route to thalamus
inferior colliculus
Central Nervous System
- most colorful regions of the brain because it contains both the substantia nigra (black substance) and red nucleus
tegmentum
Central Nervous System
- the ___ and ___ develop from the rostal half of the hindbrain (metencephalon)
cerebellum and pons
Central Nervous System
- develops from the caudal half (myelencephalon)
medulla
Central Nervous System
- CSF-filled tube becomes the ___
- continuous with the cerebral aqueduct of midbrain
fourth ventricle
Central Nervous System
- tissue along the dorsal-lateral wall of tube
- grows dorsally and medially until it fuses with its twin on the other side
rhombic lip
Central Nervous System
- ventral wall of the tube differentiates and swells to form the
pons
Central Nervous System
- important conduit for information passing from the forebrain to spinal cord and vice versa
- contribute to the processing of sensory information, control of voluntary movement and regulation of the autonomic nervous system
hindbrain
Central Nervous System
- little brain
- important movement control of center
cerebellum
Central Nervous System
- receives massive axonal inputs from the spinal cord and pons
- compares these types of information and calculates the sequence of muscle contractions that are required to achieve movement goals
cerebellum
Central Nervous System
- damage to this results in uncoordinated and inaccurate movements
cerebellum
Central Nervous System
- latin word for bridge
pons
Central Nervous System
- crossing of axons from one side to the other is knowns as
decussation
Central Nervous System
- crossing of axons in the medulla explains why the cortex of one side of the brain controls movements on the opposite side of the body
pyramidal decussation
Central Nervous System
- contains neurons that perform many different sensory and motor functions
medulla
Central Nervous System
- damage to cochlear nuclei leads to
deafness
Central Nervous System
- upper part of the butterfly’s wing is the
dorsal horn
Central Nervous System
- lower part of the butterfly’s wings
ventral horn
Central Nervous System
- gray matter between the dorsal and ventral horns
intermediate zone
Central Nervous System
- bundles of axons running along the dorsal surface of the cord
dorsal columns
Central Nervous System
- bundles of axons lateral to the spinal gray matter on each side
- contains the axons of the descending corticospinal tract which also cross from one side to other in medulla
lateral columns
Central Nervous System
- bundles on the ventral surface
ventral columns
Central Nervous System
- contains axons that carry somatic sensory information up the spinal cord toward the brain
large dorsal column
Central Nervous System
- reveals the paired hemispheres of telencephalon
dorsal view
Central Nervous System
- shows the telencephalon extending rostrally from the diencephalon
midsagittal view
Central Nervous System
- grooves in the surface of the cerebrum
sulci
Central Nervous System
- bumps of the surface of the cerebrum
gyri
Central Nervous System
- thin sheet of neurons that lies under the surface of the cerebrum
cerebral cortex
Central Nervous System
- ___ and ___ result from the tremendous expansion of the surface area of the cerebral cortex during fetal development
sulci and gyri
Central Nervous System
- without ___, a person would be blind, deaf, dumb and unable to initiate voluntary movement
cerebral cortex
Central Nervous System
- the tip of the horn lies right under the temporal bone of the skull, so this portion of the brain is called
temporal lobe
Central Nervous System
- portion of the cerebrum lying just under the frontal bone of the forehead
frontal lobe
Central Nervous System
- marks the posterior border of frontal lobe
central sulcus
Central Nervous System
- caudal to the central sulcus lies the ___ under the parietal bone
parietal lobe
Central Nervous System
- at the back of the cerebrum under the occipital bone lies the
occipital lobe
Central Nervous System
- has only single cell layer
- greek for seahorse
- major role in learning and memory
hippocampus
Central Nervous System
- connected to the hippocampus ventrally and laterally is another type of cortex that has only two cell layers
olfactory cortex
Central Nervous System
- olfactory complex is separated by sulcus called
rhinal fissure
Central Nervous System
- remaining cortex of the olfactory complex
- found only in mammals
neocortex
Central Nervous System
- german neuroanatomist, Korbinian brodmann
- each area of cortex having a common cytoarchitecture is given a number
cytoarchitectural map
Central Nervous System
- cortical areas that look different perform different functions
cytoarchitectural map
Central Nervous System
- first type of neocortex
- first to receive signals from the ascending sensory pathways
primary sensory areas
Central Nervous System
- second type of neocortex
- designated because of their heavy interconnections with the primary sensory areas
secondary sensory areas
Central Nervous System
- third type of cortex
- intimately involved with the control of voluntary movement
motor areas
Central Nervous System
- more recent evolutionary development, a noteworthy characteristic of the primate brain
association cortex
