intro to neuroanatomy Flashcards
what is the nervous system divided into
CNS,PNS
what does the CNS consist of
brain, spinal cord laying within the protection of the cranium and vertebral column
what does the peripheral nervous system consist of?
cranial and spinal nerves
Spinal nerves serving the upper or lower limbs coalesce (come together) to form the….
brachial or lumbar plexus
define ganglia
a structure containing a number of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fibre.
define somatic nervous system
neurones that detect changes in external environment or with control of movement
define autonomic nervous system
nerves which detect and control activity of the viscera (organs), non voluntary movement
what are afferent neurones
Nerve cells that carry information from peripheral receptors to the CNS
what are efferent neurones
efferent neurones carry impulses away from the CNS
what are interneurones
neurones located within the CNS
Where are the majority of neurones found?
within the CNS
True or false: the enriched areas of the brain with nerve cell bodies is the white matter
false
what is white matter?
area containing mostly nerve processes (usually axons) which are myelinated
why are axons paler in colour
myelination
in neuroanatomy, what is meant by nuclei
nerve cel bodies with similar anatomical connections and functions grouping together
true or false: parasympathetic pathway aims to increase energy
false
true or false: sympathetic pathway aims to conserve energy
false
what is the name of the deep cleft that INCOMPLETLEY separates the two cerebral hemispheres
the great longitudinal fissure
the great longnitudinal issue is occupied by the… and in depth lies the…
falx cerebri, corpus callous
what is the corpus callous
large bundle of myelinated nerve fibres that run between corresponding regions of the two hemispheres
what 3 parts is the brain conventionally divided into?
hindbrain, midbrain, forebrain
the hindbrain is further subdivided into…
medulla oblongata, pons and cerebellum
what are pons
broad horseshoe-shaped mass of transverse nerve fibres that connect the medulla with the cerebellum.
what constitutes the brain stem
medulla, pons and midbrain
what does the forebrain consist of?
forebrain consists of the diencephalon (principally the thalamus and hypothalamus) and the cerebral hemisphere.
Within the cerebral hemisphere lie several large nuclei called
the basal ganglia
what produces the ventricles containing cerebrospinal fluid (CSF)
choroid plexus
how many pairs of crinal nerves does the brain possess
12
what links the two cerebral hemispheres?
commissural fibres of the corpus callosum
The surface of the cerebral hemisphere consists of cortical grey matter, which is folded to form …. (2)
Geri and sulci ( brain wrinkles)
Beneath the surface lie the dense fibre masses of (2)
the corona radiata+ internal capsule
frontal lobe contains…
primary somatosensory cortex
Temporal lobe containing…
primary auditory cortex
Occipital lobe containing
primary visual cortex
Limbic lobe containing…
regions for memory and emotional aspects of behaviour
where does the spinal cord lie within
vertebral (spinal) canal of the vertebral column
describe the spinal cord’s position in relation to the medulla oblongata of the brain stem
it is continuous rostrally (superiorly) with the medulla oblongata of the brain stem.
how many spinal nerve pairs are within the spinal cord
31 pairs
what is dorsal
posterior
what is ventral
anterior
what is the function of the dorsal roots?
carry afferent nerves, the cell bodies of which are located in dorsal root ganglia .
what is the function of ventral roots
ventral roots carry efferent nerve fibres, the parent cell bodies of which lie within the spinal grey matter.
what is the intervertebral foramina
small apertures (pores) which spinal nerves leave the vertebral canal
what is the caudal equina
the collection of nerves at the end of the spinal cord ( looks like horse tail at the end of the foramina)
Four projections of the central grey matter extend dorsolaterally and ventrolaterally towards the lines of attachment of the dorsal and ventral roots of the spinal nerves. These projections are known as
dorsal horns and ventral horns
What does the dorsal horn do?
.site of termination of numerous afferent neurones
conveying impulses from sensory receptors throughout the body
the site of origin of ascending pathways carrying sensory impulses to the brain.
what does the ventral horn consist of/do?
contains motor neurones that innervate skeletal muscle.
where is the lateral horn located
thoracic and upper lumbar levels only
what does the lateral horn do?
contains preganglionic neurones belonging to the sympathetic division of the autonomic nervous system
what do ascending tracts of the peripheries within the spinal cord do?
carry information derived from the trunk and limbs to the brain.
what are descending tracts used for
the means by which the brain controls the activities of neurones in the spinal cord
what are the principle ascending tracts? (3)
dorsal columns, spinothalamic tracts, spinocerebrellar tracts
what is the function of the dorsal columns
carry fine touch and proprioception (awareness the body is moving/it’s position)
what is the function of spinothalamic tracts?
carry pain, temperature, coarse touch and pressure,
what is the function of spinocerebellar tracts
carry information from muscle and joint receptors to the cerebellum
what is the lateral cortiocospinal tract?
a DESCENDING tract controlling skilled voluntary movements
within grey matter, dorsal horn contains
sensory neurones
within grey matter, ventral horn contains
motor neurones
within grey matter, lateral horns contains
preganglionic sympathetic neurones.
what term describes the three concentric layers the CNS is ensheathed with
meniges
what is the dura mater
the outermost membrane of the meninges, a tough, fibrous coat that surrounds the brain and spinal cord like a loose-fitting bag
what are the two large sheets (reflections) of dura which project into the cranial cavity
falx cerebri and tentorium cerebelli
describe the location of the falx cerebri (2)
sagittal plane between the two cerebral hemispheres.
Its free border lies just above the corpus callosum
describe the location of the tentorium cerebelli
horizontally, lying BENEATH the occipital lobes of the cerebral hemispheres and ABOVE the cerebellum.
The tentorium cerebelli is continuous with the posterior part of the falx cerebri.
how many layers does the dura mater consist of
2
dura mater layers may separate to form …
dural venous sinuses (a space)
what does the dural venous sinuses do?
serve as channels for the venous drainage of the brain
where do important dural sinus’s occur? (3)
On the floor of the cranial cavity
• Along the lines of attachment of the falx cerebri and tentorium cerebelli to the interior of the skull
• Along the line of attachment of the falx cerebri and tentorium cerebelli to one another
what are the three meningeal layers
dura mater (outer), archnoid (middle) mater, pia mater (inner)
what separates the dura from arachnoid mater
a thin subdural space
what is the Pia mater
a delicate membrane of microscopic thickness that is firmly adherent to the surface of the brain and spinal cord
what is between the arachnoid and Pia layers
subarachnoid space through which CSF circulates
what supplies the brain with blood
.internal carotid
.vertebral arteries
how is the spinal cord supplied
supplied by vessels arising from the vertebral arteries, reinforced by radicular arteries derived from segmental vessels.
what mainly supplies the meninges
(inter cranial )middle meningeal artery
what vessels connect to form circlus arteriosus ( the circle of Willis)
Anterior+ posterior cerebral arteries and internal carotid arteries
why is the circlus ateriosus useful
it allows blood flow to continue if a major blood vessel is blocked on one side
what is meant by rostral
towards the nose/beak
which structure connects the third and fourth ventricle
cerebral aqueduct
name the four ventricles in the brain
lateral ventricle
interventricular foramen
third ventricle
fourth ventricle
what does the inter ventricular foramen do?
connection between the third ventricle and the lateral ventricle
what is the interthalmic adhesion?
neuroanatomical structure that forms a bridge of tissue connecting the thalamus of each hemisphere across the midline
