GEN ANA_M2 NEUROANATOMY

Neuron

conducting cells of the nervous system

Cell body

contains the nucleus and the surrounding cytoplasm

Dendrites

thread-like extensions of the cytoplasm

Axon

long, hair-like extension of a nerve cell that carries a message to another nerve cell

Multipolar neurons

dendrites branch into treelike processes

Unipolar & bipolar neurons

dendrites resemble axons

Neurotransmitters

neurons communicate with each other by sending chemical called ______

Synapse

tiny space between the axons and dendrites of adjacent neurons

Dura mater or pachymenix

most external membrane

Dura mater or pachymenix

dense connective tissue envelope

Arachnoid

located between the dura mater and pia mater

Pia mater

innermost connective tissue membrane

Pia mater

thin, translucent membrane; adherent to the surface of the brain and spinal cord

Leptomeninges

pia mater and arachnoid have a similar structured and collectively are called ______

Outer periosteal layer

Inner meningeal layer

cranial dura consists of:

Outer periosteal layer

adherent to the inner surface of the cranium, which is rich in blood vessels and nerves.

Inner meningeal layer

with flat cells

Falx cerebri

largest; extends in the midline from the crista galli to the internal occipital protuberance

Falx cerebri

divides the cerebral hemispheres

Tentorium cerebelli

horizontal projection of the dura mater which separates and covers the cerebellum from the posterior part of the cerebral hemisphere

Falx cerebelli

small midline projection of the dura mater in the posterior cranial fossa

Diaphragm sellae

small horizontal shelf of the dura mater that covers the hypophyseal fossa in the sella turcica of the sphenoid bone

Diaphragm sellae

contains an opening in the center which passes the infundibulum

Infundibulum

connects the pituitary gland with the base of the brain and accompanying blood vessels.

Middle meningeal artery

larger artery the supplies the greatest part of the dura mater

Ethmoidal arteries

anterior meningeal arteries are branches of ______

Maxillary artery

middle meningeal artery is a branch of the _______

Foramen spinosum

middle meningeal artery passes through the ______

Anterior branch of middle meningeal artery

passes in an almost vertical direction to reach the vertex of the skull, crossing the pterion during its course

Posterior branch of middle meningeal artery

passes in a posterosuperior direction, supplying this region of the middle cranial fossa

Accessory meningeal artery

small branch of the maxillary artery that enters the middle cranial fossa through the foramen ovale and supplies areas medial to this foramen

Trigeminal nerve (V1, V2, V3)

Vagus nerve

First, second, and third cervical nerves

dura mater is innervated by small meningeal branches of:

Arachnoid mater

thin, avascular membrane that lines, but it is not adherent to, the inner surface of the dura mater

Longitudinal fissure

arachnoid does not enter the grooves or fissures of the brain, except for the __________ between the two cerebral hemispheres

Pia mater

follows the contour of the brain, entering the grooves and

fissures on its surface and is closely applied to the roots of the cranial nerves at their origins

Extradural space

potential space between the dura mater and bone

Potential space

__________ between dura and bone can become a fluid filled actual space when a traumatic event results in vascular hemorrhage

Extradural hematoma

bleeding into the extradural space due to rupture of a meningeal artery or atorn dural venous sinus

Subarachnoid space

deep to the arachnoid mater is the only normally occurring fluid filled space associated with the meninges

Subarachnoid cisterns

expanded areas that contain CSF and blood vessels

Cerebrospinal fluid

clear, colorless liquid containing small amounts of protein, glucose and potassium and relatively large amounts of sodium chloride

Cerebrospinal fluid

support and cushion the CNS against trauma

Choroid plexus

secretes ~70% of the CSF

Metabolic water production

where the remaining 30% of the CSF is derived from

Choroid plexus

villous structure extending from the ventricular surface into the CSF

Arachnoid villi

CSF returns to the venous system through the _____

Arachnoid villi

project as clumps or arachnoid granulations into the superior sagittal sinus and its lateral extensions (lateral lacunae)

Lumbar Tap / Puncture

needle is inserted into the lower back to collect CSF

Hydrocephalus

abnomal dilatation of the cerebral ventricular system due to:

• obstruction to the flow of CSF

• overproduction of CSF

• failure of reabsorption of CSF

Interruption of the normal CSF absorption

the common cause of hydrocephalus in adults

Telencephalon (cerebrum)

Diencephalon

Mesencephalon (midbrain)

Metencephalon

Myelencephalon (medulla oblongata)

five continuous parts of the brain from rostral to caudal

Telencephalon

becomes the large cerebral hemispheres

Diencephalon

hidden from the view in the adult brain by the cerebral hemispheres

Diencephalon

considered as the most rostral part of the brainstem

Diencephalon

it is not considered as part of the brainstem

Mesencephalon

first part of the brainstem seen

Mesencephalon

located at the junction between and in both the middle and posterior cranial fossae

Metencephalon

gives rise to the cerebellum and the pons

Myelencephalon

caudal most part of the brainstem

Myelencephalon

Ends at the foramen magnum or the uppemost rootlets of the first cervical nerve and to which cranial nerves VI to XII are attached.

Cerebral Hemispheres

mirror image duplicates consisting of a highly convoluted gray cortex (pallium), an underlying white matter, and a collection of deep neuronal masses, known as the basal ganglia

Pallium

highly convoluted gray cortex

Basal ganglia

collection of deep neuronal masses

Cerebral Hemispheres

partially separated from each other by the longitudinal fissure

Corpus callosum

broad interhemispheric commisure

Lateral sulcus

begins inferiorly in the Sylvian fossa and extends obliquely posterior, separating the frontal and temporal lobes. Caudally this sulcus separates portions of the parietal and temporal lobes.

Central sulcus

prominent sulcus running from the superior margin of the hemisphere downward and forward toward the lateral sulcus

Frontal lobe

largest of all the lobes of the brain, comprises about one-thrid of the hemispheric surface

Frontal lobe

extends rostrally from the central sulcus to the frontal pole; its inferior boundary is the lateral sulcus.

Frontal lobe

where the primary motor area is located where all parts of the body are represented in a distorted but topographical manner also called the HOMONCULUS (little person)

Parietal lobe

its boundaries are less precise, except for its anterior border on the lateral convexity formed by the central sulcus

Parietal lobe

where the primary somesthetic area, the cortical region where tactile and kinesthetic sense from superficial and deep receptors are somatotopically represented

Temporal lobe

lies inferior to the lateral sulcus

Temporal lobe

where the primary auditory and olfactory cortex is located

Occipital lobe

rests on the tentorium cerebelli and constitutes the caudal pole of the hemisphere.

Occipital lobe

where the primary visual cortex is located.

Brodmann’s areas

regions of the cerebral cortex defined by Korbinian Brodmann in the early 20th century based on cytoarchitectonic (cellular structure) differences. These areas correspond to various functional regions of the brain.

BA 4

Primary motor cortex (precentral gyrus): Voluntary motor movement.

BA 6

Premotor cortex and supplementary motor area: Planning of movements.

BA 8

Frontal eye fields: Eye movement control.

BA 9, 10, 11, 12

Prefrontal cortex: Executive functions, decision making, personality

BA 44, 45

Broca's area (usually in left hemisphere): Speech production.

BA 1, 2, 3

Primary somatosensory cortex (postcentral gyrus): Sensory perception (touch, proprioception).

BA 5, 7

Somatosensory association cortex: Spatial attention, integration of sensory input.

BA 22

Wernicke’s area (partially overlaps, typically left hemisphere): Language comprehension.

BA 41, 42

Primary auditory cortex: Hearing.

BA 20, 21, 37

Higher-order visual and language processing.

BA 17

Primary visual cortex: Initial processing of visual information.

BA 18, 19

Visual association areas: Further interpretation of visual input (motion, color, shape).

Corpus callosun

most prominent structure on the medial surface is the massive interhemispheric commissure called ________

Corpus callosum

composed of myelinated fibers, reciprocally interconnects nearly all cortical regions of the two hemispheres

Corpus callosum

forms the floor of the longitudinal fissure, as well as the roof of the lateral ventricle

Corpus callosum

plays an important role in the interhemispheric transfer of learned discriminations, sensory experience and memory.

Dienchepalon

brain region that retains its embryologic name in adulthood

Dienchepalon

Function: Acts as a major connection between the cerebrum and the rest of the nervous system

Dienchepalon

Most brain, spinal cord, and PNS information relays to the cerebrum through the ______________

Olfactory (smell) system

connects directly to the cerebrum

Dienchepalon

positioned deep beneath the cerebrum, forming the walls of the third ventricle

Dienchepalon

Major regions: Thalamus, hypothalamus, and epithalamus.

Dienchepalon

Other structures: Includes subthalamus with the subthalamic nucleus (related to basal nuclei).